JP2017060312A - Inverter control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of detecting abnormality in a control system ranging from an inverter control device to an inverter main circuit without using any high rotational speed sensor which may break down with high possibility.SOLUTION: A frequency calculator 116 of a motor control CPU 11 of an inverter control device 10 receives a current detection value of output current of an inverter main circuit 20 from a current detector 42, calculates the frequency of the current based on the current detection value and outputs the frequency of the current to an abnormality determining processor 114. The abnormality determining processor 114 calculates an actual torque estimation value from the frequency of the current, outputs, to a safety output processor 115, an abnormality determination signal which represents abnormality when the absolute value of the difference between the calculated actual torque estimation value and a torque instruction value given from a host controller 30 via an instruction input processor 110 is not less than a threshold value. The safety output processor 115 makes a blocking switch 22 to cut off supply of a gate signal to the inverter main circuit 20 according to the abnormality determination signal representing abnormality.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an inverter control device, and more particularly to an inverter control device mounted on an electric vehicle.

  An inverter device that drives and controls a motor that is a power source of an electric vehicle (hereinafter referred to as a vehicle) generally includes an inverter main circuit that supplies current to the motor and an inverter control device that controls the operation of the inverter main circuit. It is out.

JP 2012-178904 A

  If an abnormality occurs in the control system extending from the inverter control device to the inverter main circuit, the motor may perform an abnormal operation, and the vehicle may perform an abrupt operation (for example, rapid acceleration) that is not intended by the driver. Since it is very dangerous if the vehicle performs such an operation, various techniques for detecting an abnormality of the inverter control device or the like have been proposed. As an example, there is a technique in which the rotation speed of a motor is detected by a rotation speed sensor and an abnormality is detected using the speed detection result. However, the rotation speed sensor often includes a rotation mechanism for detecting the rotation speed of the motor, and there is a concern that a mechanical failure may occur.

  The present invention has been made in view of the problems described above, and is a technique capable of detecting an abnormality in a control system from an inverter control device to an inverter main circuit without using a rotation speed sensor that has a high possibility of failure. The purpose is to provide.

  In order to solve the above problems, an inverter control device of the present invention is a device that performs operation control of an inverter main circuit that drives a motor under the control of a host controller. The inverter control device of the present invention includes a frequency calculation means for calculating a current frequency based on a current detection value of an output current of the inverter main circuit, a current frequency calculated by the frequency calculation means, and a torque applied from a host controller. Abnormality determining means for determining presence / absence of abnormality based on the command value.

  The frequency of the current corresponds to the rotational speed of the motor. For this reason, in the inverter control apparatus of this invention, the rotational speed sensor of a motor is not required for abnormality detection.

  According to the inverter control device of the present invention, it is possible to detect an abnormality in the control system extending from the inverter control device to the inverter main circuit without using a rotational speed sensor that has a high possibility of failure.

  In the technique disclosed in Patent Document 1, an estimated current value to be supplied to a motor is calculated from a torque command value, and an abnormality is determined by comparing the estimated current value with a detected current value of a current detector. On the other hand, in the present embodiment, the abnormality is determined based on the torque command value and the current frequency. As described above, since the frequency of the current supplied to the motor corresponds to the rotational speed of the motor, an abnormality can be determined in the state of the actually rotating motor. For this reason, it is possible to determine a sudden change in acceleration of the vehicle. Therefore, the inverter control device of the present invention is different from the technique of Patent Document 1.

1 is a block diagram illustrating an example in which a motor drive system 1 according to a first embodiment of the present invention is mounted on a vehicle. It is a block diagram which shows the structure of the motor drive system 1 containing the inverter control apparatus 10 of 1st Embodiment. It is a figure explaining the method of calculating the frequency of an electric current from the period of an electric current. It is a figure explaining the method of calculating the frequency of an electric current from an electric current vector. FIG. 3 is a block diagram illustrating a configuration of an abnormality determination processing unit 114 of a motor control CPU 11 of the inverter control device 10 of the motor drive system 1. It is a block diagram which shows the structure of the actual torque estimation part 50 of the abnormality judgment process part 114. FIG. It is a figure explaining an example of the process in the comparison part 60 of the abnormality determination process part. It is a figure explaining another example of the process in the comparison part. It is a block diagram which shows the structure of 114 A of abnormality determination process parts of the inverter control apparatus by 2nd Embodiment of this invention. It is a block diagram which shows the structure of the moving average calculation part 70 of 114 A of abnormality determination process parts. It is a block diagram which shows the structure of the motor drive system 1B containing the inverter control apparatus 10B by 3rd Embodiment of this invention. It is a block diagram which shows the structure of the abnormality determination process part 114B of the motor control CPU11 of the inverter control apparatus 10B. It is a block diagram which shows the structure of the actual torque estimation part 50B of the abnormality determination process part 114B. It is a block diagram which shows the structure of 1 C of motor drive systems containing 10 C of inverter control apparatuses by 4th Embodiment of this invention. It is a block diagram which shows the structure of 114 C of abnormality determination process parts of motor control CPU11 of 10 C of inverter control apparatuses. It is a block diagram which shows the structure of motor drive system 1D containing inverter control apparatus 10D by 5th Embodiment of this invention. It is a block diagram which shows the structure of the abnormality determination process part 114E of the inverter control apparatus by 6th Embodiment of this invention. It is a figure explaining the process in the comparison part 60E of the abnormality determination process part 114E. It is a block diagram which shows the structure of the abnormality determination process part 114F of the inverter control apparatus by 7th Embodiment of this invention. It is a block diagram which shows the structure of the abnormality determination process part 114G of the inverter control apparatus by 8th Embodiment of this invention. It is a block diagram which shows the structure of the motor drive system 1H containing the inverter control apparatus 10H by 9th Embodiment of this invention. It is a time chart which shows the process of the comparison part of the inverter control apparatus by 10th Embodiment of this invention. It is a time chart which shows the process of the comparison part of the inverter control apparatus by 10th Embodiment of this invention. It is a block diagram which shows the structure of the abnormality determination process part 114J of the inverter control apparatus by 11th Embodiment of this invention. In 11th Embodiment, it is a time chart which shows the acceleration calculation value and torque command value when abnormality generate | occur | produces in an inverter control apparatus and a vehicle accelerates rapidly irrespective of a driver | operator's intent. In 11th Embodiment, it is a time chart which shows the acceleration calculation value and torque command value when abnormality generate | occur | produces in an inverter control apparatus and a vehicle accelerates rapidly irrespective of a driver | operator's intent. In 11th Embodiment, it is a time chart which shows the acceleration calculation value and torque command value when abnormality generate | occur | produces in an inverter control apparatus and a vehicle decelerates suddenly irrespective of a driver | operator's intent. In 11th Embodiment, it is a figure which shows the relationship between the speed of a vehicle, FTTI, a driver | operator's average reaction time, and abnormality determination timing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing an example in which the motor drive system 1 according to the first embodiment of the present invention is mounted on a vehicle. The inverter device 5 of the motor drive system 1 performs drive control of the motor 40 under the control of the host controller 30. The host controller 30 is, for example, a microcomputer such as a VCU (Vehicle Control Unit). The main shaft of the motor 40 to be controlled by the inverter device 5 is connected to the transmission 46 through a power transmission device 45 such as a clutch. The transmission 46 is connected to a drive wheel 48 of the vehicle via a differential 47. Thus, in the present embodiment, the motor 40 is a power source of the vehicle.

  FIG. 2 is a block diagram showing the configuration of the motor drive system 1. The motor drive system 1 includes a current detector 42 and a rotation speed sensor 44 in addition to the inverter device 5 and the host controller 30. The inverter device 5 includes an inverter control device 10, an inverter main circuit 20, and a blocking switch 22.

  The inverter main circuit 20 includes a switching element such as an IGBT (Insulated Gate Bipolar Transistor). This switching element is turned on / off according to the gate signal. The inverter main circuit 20 outputs a current according to ON / OFF of the switching element to the motor 40. The motor 40 operates according to the current supplied from the inverter main circuit 20.

  The inverter control device 10 includes a motor control CPU (Central Processing Unit) 11. The motor control CPU 11 is a control center that controls each unit of the inverter control device 10 by executing a program stored in a storage unit (not shown). The motor control CPU 11 controls the operation of the inverter main circuit 20 by supplying a gate signal to the switching element of the inverter main circuit 20 under the control of the host controller 30. Specifically, the motor control CPU 11 outputs to the inverter main circuit 20 a gate signal that has been subjected to pulse width modulation (PWM) based on the torque command value given from the host controller 30.

  A blocking switch 22 is provided in the supply path of the gate signal supplied from the motor control CPU 11 to the inverter main circuit 20. When the blocking switch on signal is applied, the blocking switch 22 is turned on and passes the gate signal to supply it to the inverter main circuit 20. On the other hand, when the blocking switch off signal is applied, the blocking switch 22 is turned off to block the passage of the gate signal and block the supply to the inverter main circuit 20. When the supply of the gate signal to the inverter main circuit 20 is interrupted, the motor 40 enters a free-run state (a state that rotates due to inertia). A specific example of the blocking switch 22 is a photocoupler. When a photocoupler is used as the blocking switch 22, the photocoupler may be turned off in response to the blocking switch off signal.

  A current detector 42 is provided in the supply path of the current supplied from the inverter main circuit 20 to the motor 40. The current detector 42 is a device that detects the output current of the inverter main circuit 20. The current detector 42 delivers a current detection value as a detection result to the motor control CPU 11.

  The rotation speed sensor 44 is a device that detects the rotation speed of the motor 40. The rotation speed sensor 44 delivers a speed detection value as a detection result to the motor control CPU 11.

  The motor control CPU 11 includes a command input processing unit 110, a control command input processing unit 111, a motor control processing unit 112, a control output processing unit 113, an abnormality determination processing unit 114, a safety output processing unit 115, and a frequency calculation unit 116. . Each of these units is a functional unit realized by the motor control CPU 11 executing a program.

  The command input processing unit 110 is in charge of communication with the host controller 30. The command input processing unit 110 is given a control command from the host controller 30. The control command includes various commands such as a torque command, and the torque command includes a torque command value. The command input processing unit 110 delivers the given control command to the control command input processing unit 111. The command input processing unit 110 also delivers the torque command value in the given control command to the abnormality determination processing unit 114. In addition, the command input processing unit 110 transmits and receives various data such as transmission ratio data of the transmission 46, state data indicating the state of the inverter device 5, and failure data indicating failure of each part of the vehicle to and from the host controller 30. Also do.

  The control command input processing unit 111 delivers the control command received from the command input processing unit 110 to the motor control processing unit 112. Further, the control command input processing unit 111 transmits the state data to the host controller 30 via the command input processing unit 110.

  The motor control processing unit 112 receives a control command from the control command input processing unit 111. Further, the motor control processing unit 112 receives a current detection value from the current detector 42 and receives a speed detection value from the rotation speed sensor 44. The motor control processing unit 112 performs motor control calculation from the torque command value, current detection value, speed detection value, and the like, and outputs the voltage command value to the control output processing unit 113.

  The control output processing unit 113 performs pulse width modulation (PWM) on the carrier signal in accordance with the voltage command value received from the motor control processing unit 112, and uses the signal after the pulse width modulation as a gate signal via the blocking switch 22 to inverter main circuit 20 output.

  The abnormality determination processing unit 114 performs an abnormality determination process for determining whether there is an abnormality in the control system extending from the inverter control device 10 to the inverter main circuit 20. Details of the abnormality determination processing in the abnormality determination processing unit 114 will be described later. The abnormality determination processing unit 114 outputs an abnormality determination signal indicating the abnormality determination processing result to the safety output processing unit 115.

  The safety output processing unit 115 outputs a safety output for shifting the vehicle on which the motor drive system 1 is mounted to a safe state when the content of the abnormality determination signal given from the abnormality determination processing unit 114 represents an abnormality. Do. Specifically, when the content of the abnormality determination signal indicates safety, the safety output processing unit 115 outputs a blocking switch-on signal to the blocking switch 22 and supplies the gate signal to the inverter main circuit 20. To give permission. On the other hand, when the content of the abnormality determination signal indicates abnormality, the safety output processing unit 115 outputs a blocking switch off signal to the blocking switch 22 and causes the blocking switch 22 to block the gate signal. The safety output processing unit 115 may output a signal for shutting off the power source of the inverter main circuit 20 when the content of the abnormality determination signal indicates abnormality, or power transmission in the power transmission device 45 may be performed. It is possible to output a signal for preventing the malfunction, or to notify the host controller 30 of an abnormality and operate the safety brake under the control of the host controller 30.

  The frequency calculation unit 116 calculates the current frequency based on the current detection value of the current detector 42, and delivers frequency data (hereinafter simply referred to as current frequency) of the calculation result to the abnormality determination processing unit 114. The frequency calculation unit 116 may obtain the current frequency from the current cycle in which the instantaneous value is represented by the current detection value, or may obtain the current frequency from the current vector of the current.

  FIG. 3 is a diagram for explaining a method of calculating the current frequency from the current cycle. Since the current detector 42 detects the three-phase (UVW) alternating current output from the inverter main circuit 20 for each phase, the frequency calculation unit 116 receives the U-phase current detection value and the V-phase current detection from the current detector 42. Value and W-phase current detection value are given. FIG. 3 shows a U-phase current waveform drawn by the U-phase current detection value given to the frequency calculation unit 116 and a V-phase current waveform drawn by the V-phase current detection value. As shown in FIG. 3, the frequency calculation unit 116 calculates the U-phase current detection value from the U-phase current detection value to one cycle in the U-phase current waveform (for example, the time when the U-phase current detection value changes from negative to positive Detect time from negative to positive). The frequency calculation unit 116 calculates the reciprocal of one cycle in the detected U-phase current waveform. The frequency calculation unit 116 outputs the reciprocal of the calculated current cycle as the current frequency. Not only the U phase but also the reciprocal of the current cycle in the V phase and the W phase may be used as the current frequency. A value obtained by averaging the reciprocal of the current cycle in each phase may be used as the current frequency.

FIG. 4 is a diagram for explaining a method of calculating the current frequency from the current vector. The frequency calculation unit 116 captures the current detection values of the current detector 42 (specifically, the U-phase current detection value iu, the V-phase current detection value iv, and the W-phase current detection value iw) at the sampling period Ts. The frequency calculation unit 116 converts the captured U-phase current detection value iu, V-phase current detection value iv, and W-phase current detection value iw into α-phase current i _1α and β-phase current i _1β in the αβ orthogonal coordinate system in three phases / 2. Phase change. A current obtained by combining the α-phase current i _1α and the β-phase current i _1β is a current vector. Next, the frequency calculation unit 116 calculates the phase angle θ _I of the current vector (specifically, the arctangent of the β-phase current i _{1β with} respect to the α-phase current i _1α) for each sampling period Ts. Next, the frequency calculation unit 116 calculates the difference between the phase angle of the current vector by subtracting the phase angle θ _I _n-1 of the current vector previously calculated from the phase angle theta _I _n the current vector calculated this time, calculates The difference between the phase angles of the current vectors is divided by the sampling period Ts. The sampling period Ts is, for example, 100 μs to 1 ms. The frequency calculation unit 116 outputs the division result calculated in this way as the current frequency.

Next, the abnormality determination process in the abnormality determination processing unit 114 will be described. FIG. 5 is a block diagram illustrating a configuration of the abnormality determination processing unit 114. The abnormality determination processing unit 114 includes an actual torque estimation unit 50 and a comparison unit 60. Actual torque estimating unit 50 calculates the actual torque estimate tau ^# from the frequency of the current supplied from the frequency calculation unit 116. Further, the abnormality detection processing unit 114 is not given a speed detection value by the rotation speed sensor 44.

FIG. 6 is a block diagram showing the configuration of the actual torque estimation unit 50. The actual torque estimating unit 50 first calculates the acceleration calculation value α ^# by differentiating the current frequency with respect to time.

Here, assuming that the number of poles of the magnetic pole of the motor 40 is P and the frequency of the current supplied to the motor 40 is f, the synchronous speed (rotational speed of the rotating magnetic field) Ns of the motor 40 is expressed by the following equation (1). Can be calculated.
Ns = 120 f / P [rpm] (1)
If the motor 40 is a synchronous motor, the synchronous speed Ns of the motor 40 is the rotational speed of the motor 40. Further, if the motor 40 is an induction motor, the rotational speed of the motor 40 can be calculated by correcting the synchronous speed Ns of the motor 40 in consideration of slip. That is, the frequency of the current supplied from the frequency calculation unit 116 corresponds to the rotation speed of the motor 40. Therefore, an acceleration calculation value α ^# indicating the rotational acceleration of the motor 40 is obtained by differentiating the frequency of the current corresponding to the rotational speed of the motor 40 with respect to time.

After calculating the acceleration calculation value α ^# , the actual torque estimation unit 50 calculates the actual torque estimation value τ ^# by multiplying the acceleration calculation value α ^# by the conversion coefficient. The conversion factor, as shown in the following equation (2), is intended to include the values of vehicle weight m, the gear ratio of the motor shaft and the axle K _R and the wheel diameter D _w.
τ ^# = m ((D _w / 2) / K _R ) α ^# (2)
In this operation, the speed ratio data supplied from the host controller 30 is used as the speed ratio K _R. Also, each data of the vehicle body weight m and the wheel diameter D _w is to the inverter control device 10 may be stored in advance, it may be given from the host controller 30.

As shown in FIG. 5, the actual torque estimation unit 50 delivers the calculated actual torque estimated value τ ^# to the comparison unit 60. The comparison unit 60 compares the torque command value given from the command input processing unit 110 with the actual torque estimation value τ ^# received from the actual torque estimation unit 50, and outputs an abnormality determination signal indicating the comparison result.

FIG. 7 is a diagram for explaining an example of processing in the comparison unit 60. As shown in FIG. 7, the comparison unit 60 calculates the absolute value of the difference between the actual torque estimated value τ ^# and the torque command value, and determines whether the calculation result (absolute value of the difference) is equal to or greater than the threshold value. To do. When the absolute value of the difference is equal to or greater than the threshold value, the comparison unit 60 outputs an abnormality determination signal indicating that the abnormality has been detected. When the absolute value of the difference is less than the threshold value, the comparison unit 60 indicates that the abnormality is safe. A judgment signal is output.

  The inverter control device 10 normally controls the operation of the inverter main circuit 20 so that the actual torque value of the motor 40 approaches the given torque command value. When the actual torque estimated value obtained by estimating the actual torque value of the motor 40 is different from the torque command value beyond the allowable range, the inverter control device 10 is highly likely not performing normal operation control. For this reason, the inverter control device 10 of the present embodiment is configured so that the output result (specifically, the estimated actual torque value) with respect to a given command value (specifically, the torque command value) differs beyond the allowable range. The control system extending from the inverter control device 10 to the inverter main circuit 20 is determined to be abnormal.

  FIG. 8 is a diagram for explaining another example of processing in the comparison unit 60. In the example illustrated in FIG. 8, the comparison unit 60 outputs an abnormality determination signal indicating an abnormality when the magnitude of the actual torque estimation value is equal to or greater than a threshold value determined according to the torque command value. As described above, the comparison unit 60 is not limited to the mode illustrated in FIG. 7, and may perform the comparison process of the mode illustrated in FIG. 8. However, the aspect in which abnormality is determined from the difference between the actual torque estimated value and the torque command value illustrated in FIG. 7 is more preferable than the aspect in which abnormality is determined from the magnitude of the actual torque estimated value illustrated in FIG. This is because there is a time lag between the time when the torque command value is given and the calculation time of the actual torque estimated value obtained as a result of the operation control of the inverter main circuit 20 according to the torque command value. is there.

  As described above, the inverter control device 10 according to the present embodiment is abnormal based on the current frequency calculated based on the detected current value of the output current of the inverter main circuit 20 and the torque command value given from the host controller 30. Determine the presence or absence. The frequency of the current corresponds to the rotational speed of the motor. For this reason, in the inverter control device of the present invention, the rotation speed sensor 44 is not required for determining whether there is an abnormality. Therefore, according to the inverter control device 10, it is possible to detect an abnormality in the control system extending from the inverter control device 10 to the inverter main circuit 20 without using the rotational speed sensor 44 that has a high possibility of failure.

  Further, since the torque command value and the actual torque estimated value are compared using the current frequency corresponding to the rotation speed of the motor, it is possible to determine abnormality in the state of the actually rotating motor. For this reason, it is possible to detect a sudden change in acceleration unintended by the driver, such as sudden acceleration or sudden deceleration of a vehicle on which the inverter control device 10 is mounted.

  Further, in the inverter control device 10, since the speed detection value of the rotation speed sensor 44 is not used to determine whether there is an abnormality, the rotation speed sensor 44 can be omitted if the rotation speed sensor 44 has no other use. Costs for constructing the motor drive system 1 including the control device 10 can be reduced.

(Second Embodiment)
The inverter control device of the second embodiment of the present invention is different from the inverter control device 10 of the first embodiment in that an abnormality determination processing unit 114A is provided instead of the abnormality determination processing unit 114. FIG. 9 is a block diagram illustrating a configuration of the abnormality determination processing unit 114A of the inverter control device according to the present embodiment. The abnormality determination processing unit 114A is different from the abnormality determination processing unit 114 of the first embodiment in that the moving average calculation units 70-1 and 70-2 are added and that a comparison unit 60A is provided instead of the comparison unit 60.

The moving average calculation unit 70-1 calculates the moving average of the torque command value input from the command input processing unit 110, and outputs the calculation result to the comparison unit 60A. The moving average calculation unit 70-2 calculates a moving average of the actual torque estimated value τ ^# input from the actual torque estimation unit 50, and outputs the calculation result to the comparison unit 60A. The moving average calculation units 70-1 and 70-2 are functional units that calculate the moving average of the input signal, although the input signal is a torque command value or an actual torque estimation value. When the moving average calculators 70-1 and 70-2 are not distinguished, they are referred to as a moving average calculator 70.

  FIG. 10 is a block diagram illustrating a configuration of the moving average calculation unit 70. An input signal is given to the moving average calculation unit 70 at a predetermined sampling period. The moving average calculation unit 70 includes delay units 71, 72 and 73, an adder 74 and a multiplier 75. The delay unit 71 stores the input signal x (k−1) input once before the current input signal x (k). The delay device 72 stores the input signal x (k−2) input twice before the current input signal x (k). The delay unit 73 stores the input signal x (k−3) input three times before the current input signal x (k). When the input signal x (k) is input, the moving average calculator 70 stores the input signal x (k), the input signal x (k−1) stored in the delay device 71, and the delay device 72. The input signal x (k−2) and the input signal x (k−3) stored in the delay unit 73 are supplied to the adder 74. The adder 74 adds the given input signals x (k), x (k−1), x (k−2) and x (k−3), and gives the addition result to the multiplier 75. Multiplier 75 multiplies the addition result of adder 74 by ¼ and outputs the multiplication result. Thus, every time an input signal is given, the moving average calculation unit 70 calculates the average (that is, moving average) of the input signals for the previous four times including the input signal. In the example of FIG. 10, the number of samples is four, but the number of samples for calculating the moving average is not limited to four.

  The comparison unit 60A differs from the comparison unit 60 in that the comparison object is a moving average of torque command values and a moving average of actual torque estimation values. The comparison method in the comparison unit 60A is the same as that in the first embodiment.

  As described above, in the inverter control device of the present embodiment, the moving average is calculated for each of the torque command value and the actual torque estimated value. Thereby, ripples and noise can be removed from each of the torque command value and the actual torque estimated value. And in the inverter control apparatus of this embodiment, in order to compare the moving average of the torque command value from which ripples and noise have been removed and the moving average of the actual torque estimated value, compared with the first embodiment, in the comparison unit 60A. The comparison can be performed with higher accuracy, and the reliability of the abnormality determination signal of the abnormality determination processing unit 114A can be further increased.

  In the present embodiment, the moving average calculation unit 70 is provided, but a low pass filter may be provided instead of the moving average calculation unit 70. Further, an integrator may be provided in place of the moving average calculation unit 70, and the torque command value and the actual torque estimated value may be integrated within a predetermined period. This is because the ripples and noise of the torque command value and the actual torque estimated value can be removed also in these modes.

(Third embodiment)
FIG. 11 is a block diagram showing a configuration of a motor drive system 1B according to the third embodiment of the present invention. The motor drive system 1B of this embodiment is different from the motor drive system 1 of the first embodiment in that an inverter control device 10B is provided instead of the inverter control device 10. The inverter control device 10B is different from the inverter control device 10 in that the motor control CPU 11 includes an abnormality determination processing unit 114B instead of the abnormality determination processing unit 114. The abnormality determination processing unit 114B differs from the abnormality determination processing unit 114 in that a current detection value is given from the current detector 42 in addition to the torque command value and the current frequency.

  FIG. 12 is a block diagram illustrating a configuration of the abnormality determination processing unit 114B. The abnormality determination processing unit 114B is different from the abnormality determination processing unit 114 in that an actual torque estimation unit 50B is provided instead of the actual torque estimation unit 50. The actual torque estimating unit 50B is different from the actual torque estimating unit 50 in that an actual torque estimated value is calculated from the current frequency and the detected current value.

FIG. 13 is a block diagram showing a configuration of the actual torque estimation unit 50B. The actual torque estimation unit 50B calculates the magnetic flux calculation value φ _2d ^# using the frequency of the current supplied from the frequency calculation unit 116. The actual torque estimation unit 50B calculates the magnetized current calculation value i _1d ^# by multiplying the calculated magnetic flux calculation value φ _2d ^# by a conversion constant. Further, the actual torque estimation unit 50B calculates a current amplitude value | i ₁ | from the current detection value given from the current detector 42. The actual torque estimation unit 50B calculates a torque current calculation value i _1q ^# from the magnetization current calculation value i _1d ^# and the current amplitude value | i ₁ |. The actual torque estimation unit 50B multiplies the calculated torque current calculation value i _1q ^# by the magnetic flux calculation value φ _2d ^# , and further multiplies the multiplication result by a conversion coefficient to calculate an actual torque estimation value τ ^# .

As described above, in the inverter control device 10B of the present embodiment, the actual torque estimated value τ ^# is calculated using the current frequency and the current amplitude value calculated from the detected current value. Similarly to the inverter control device 10 of the first embodiment, the inverter control device 10B determines the presence or absence of abnormality using the calculated actual torque estimated value τ ^# and the torque command value. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

(Fourth embodiment)
FIG. 14 is a block diagram showing a configuration of a motor drive system 1C according to the fourth embodiment of the present invention. The motor drive system 1C according to the present embodiment is different from the motor drive system 1B according to the third embodiment in that an inverter control device 10C is provided instead of the inverter control device 10B. The inverter control device 10C is different from the inverter control device 10B in that the motor control CPU 11 includes an abnormality determination processing unit 114C instead of the abnormality determination processing unit 114B. The abnormality determination processing unit 114C is different from the abnormality determination processing unit 114B in that a voltage command value is given from the motor control processing unit 112 in addition to the torque command value, current frequency, and current detection value.

FIG. 15 is a block diagram illustrating a configuration of the abnormality determination processing unit 114C. The abnormality determination processing unit 114C is different from the abnormality determination processing unit 114B in that an actual torque estimation unit 50C is provided instead of the actual torque estimation unit 50B. The actual torque estimation unit 50C is different from the actual torque estimation unit 50B in that the actual torque estimation value τ ^# is calculated from the current frequency, the current detection value, and the voltage command value. The actual torque estimation unit 50C performs a process according to the following equation (3) to calculate the actual torque estimated value τ ^# .
τ ^# = K _τ (v ₁ · i ₁ −R ₁ | i ₁ | ² ) / ω ₁ ^# (3)
In the above equation (3), R ₁ is a primary resistance, K _τ is a conversion coefficient, ω ₁ ^# is a current frequency, i ₁ is a current detection value (vector), and v ₁ is a voltage command value or voltage detection value (vector). , V ₁ · i ₁ is the inner product (ie, active power) of the voltage vector and the current vector.

As described above, in the inverter control device 10C of the present embodiment, the actual torque estimated value τ _# is calculated using the current frequency, the current detection value, and the voltage command value. Similarly to the inverter control device 10 of the first embodiment, the inverter control device 10C determines whether there is an abnormality using the calculated actual torque estimated value τ _# and the torque command value. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

(Fifth embodiment)
FIG. 16 is a block diagram showing a configuration of a motor drive system 1D according to the fifth embodiment of the present invention. The motor drive system 1D of this embodiment has an inverter control device 10D instead of the inverter control device 10C, and is different from the motor drive system 1C of the fourth embodiment in that a voltage detector 43 is added.

  The voltage detector 43 is a device that detects a voltage output from the inverter main circuit 20 and supplied to the motor 40. The voltage detector 43 delivers a voltage detection value as a detection result to the motor control CPU 11.

The inverter control device 10D is different from the inverter control device 10C in that the motor control CPU 11 includes an abnormality determination processing unit 114D instead of the abnormality determination processing unit 114C. The abnormality determination processing unit 114D is different from the abnormality determination processing unit 114C in that a voltage detection value is given from the voltage detector 46 instead of the voltage command value from the motor control processing unit 112. That is, the abnormality determination processing unit 114D calculates the actual torque estimated value τ ^# from the current frequency, the detected current value, and the detected voltage value, and compares the calculated actual torque estimated value τ ^# with the torque command value. Specifically, a voltage detection value may be used as v ₁ in the expression (3) in the fourth embodiment.

As described above, the inverter control device 10D of the present embodiment determines the presence or absence of abnormality using the calculated actual torque estimated value τ ^# and the torque command value, similarly to the inverter control device 10 of the first embodiment. ing. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

(Sixth embodiment)
The inverter control device according to the sixth embodiment of the present invention is different from the inverter control device 10 of the first embodiment in that an abnormality determination processing unit 114E is provided instead of the abnormality determination processing unit 114. FIG. 17 is a block diagram illustrating a configuration of the abnormality determination processing unit 114E of the inverter control device of the present embodiment.

  The abnormality determination processing unit 114E has an acceleration calculation unit 50E instead of the actual torque estimation unit 50, a comparison unit 60E instead of the comparison unit 60, and an abnormality determination processing unit in that a conversion coefficient multiplication unit 80E is added. 114.

  The acceleration calculation unit 50E calculates an acceleration calculation value by performing time differentiation on the frequency of the current supplied from the frequency calculation unit 116, and delivers the calculation result to the comparison unit 60E. This acceleration calculation value corresponds to the estimated value of the rotational acceleration of the motor 40.

  The conversion coefficient multiplication unit 80E calculates an acceleration command value by multiplying the torque command value given from the command input processing unit 110 by the conversion coefficient, and delivers the calculation result to the comparison unit 60E.

  The comparison unit 60E compares the acceleration command value calculated by the conversion coefficient multiplication unit 80E with the acceleration calculation value calculated by the acceleration calculation unit 50E and outputs an abnormality determination signal. As shown in FIG. 18B, the comparison unit 60E may output an abnormality determination signal indicating an abnormality when the absolute value of the difference between the acceleration calculation value and the acceleration command value exceeds a threshold value. Then, as shown in FIG. 18A, an abnormality determination signal indicating an abnormality may be output when the magnitude of the acceleration calculation value is equal to or greater than a threshold value.

As shown in the following formula (4), the acceleration comparison threshold value α _th in the comparison unit 60E is obtained by adding a margin M to the gravitational acceleration α _L on the slope applied to the vehicle on which the inverter control device of this embodiment is mounted. Determined by value.
α _th = α _L + M (4)
The gravitational acceleration α _L on the slope is applied to the vehicle stopped on the slope. The gravitational acceleration α _L on the slope may be determined based on the slope angle θ of the slope as shown in the following equation (5).
α _L = g · sin θ (5)
Specifically, the gravitational acceleration α _L on the slope may be a value (α _L = 0.97 m / s ² ) calculated with the gradient being 10% which is the most severe condition. Further, the margin M may be, for example, such as 2 times the gravitational acceleration alpha _L in such and slope 1 m / s ^2.

  As described above, the inverter control device of the present embodiment converts the torque command value into the acceleration command value, and compares with the acceleration instead of the torque. Since the inverter control device of the present embodiment determines the presence or absence of abnormality based on the current frequency and the torque command value, similarly to the inverter control device 10 of the first embodiment, the first embodiment is also the first in this embodiment. The same effect as the embodiment can be obtained.

  Further, in the inverter control device of the present embodiment, in order to compare the acceleration command value and the acceleration calculation value, a sudden acceleration unintended by the driver, such as sudden acceleration or sudden deceleration of the vehicle on which the inverter control device 10 is mounted. Changes can be detected.

(Seventh embodiment)
The inverter control device of the seventh embodiment of the present invention is different from the inverter control device 10 of the first embodiment in that an abnormality determination processing unit 114F is provided instead of the abnormality determination processing unit 114. FIG. 19 is a block diagram illustrating a configuration of the abnormality determination processing unit 114F of the inverter control device according to the present embodiment. The abnormality determination processing unit 114F is different from the abnormality determination processing unit 114 of the first embodiment in that the time differentiation calculation units 77-1 and 77-2 are added and that the comparison unit 60F is provided instead of the comparison unit 60.

  The time differentiation calculation unit 77-1 performs time differentiation on the torque command value input from the command input processing unit 110, and outputs the calculation result to the comparison unit 60F. The time differentiation calculation unit 77-2 performs time differentiation on the actual torque estimated value input from the actual torque estimation unit 50, and outputs the calculation result to the comparison unit 60F.

  The comparison unit 60F compares the rate of change of the torque command value, which is the calculation result of the time differentiation calculation unit 77-1, with the rate of change of the actual torque estimated value, which is the calculation result of the time differentiation calculation unit 77-2. The result abnormality judgment signal is output. For example, when the absolute value of the difference between the change rate of the actual torque estimation value and the change rate of the torque command value is equal to or greater than a threshold value, the comparison unit 60F outputs an abnormality determination signal indicating that the abnormality is present.

  As described above, the inverter control device according to the present embodiment determines the presence or absence of abnormality using the current frequency and the torque command value, similarly to the inverter control device 10 according to the first embodiment. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

(Eighth embodiment)
The inverter control device of the eighth embodiment of the present invention is different from the inverter control device of the sixth embodiment in that an abnormality determination processing unit 114G is provided instead of the abnormality determination processing unit 114E. FIG. 20 is a block diagram illustrating a configuration of the abnormality determination processing unit 114G of the inverter control device according to the present embodiment. The abnormality determination processing unit 114G is different from the abnormality determination processing unit 114E of the sixth embodiment in that the time differentiation calculation units 78-1 and 78-2 are added and that the comparison unit 60E is provided instead of the comparison unit 60E.

  The time differentiation calculation unit 78-1 performs time differentiation on the acceleration command value input from the conversion coefficient multiplication unit 80E, and outputs the calculation result to the comparison unit 60G. The time differentiation calculation unit 78-2 performs time differentiation on the acceleration calculation value input from the acceleration calculation unit 50E, and outputs the calculation result to the comparison unit 60G.

  The comparison unit 60G compares the rate of change of the acceleration command value, which is the calculation result of the time differentiation calculation unit 78-1, with the rate of change of the acceleration calculation value, which is the calculation result of the time differentiation calculation unit 78-2. An abnormality judgment signal is output. For example, when the absolute value of the difference between the change rate of the acceleration calculation value and the change rate of the acceleration command value is equal to or greater than the threshold value, the comparison unit 60G outputs an abnormality determination signal indicating that the abnormality is present.

  As described above, the inverter control device according to the present embodiment determines the presence or absence of abnormality using the current frequency and the torque command value, similarly to the inverter control device according to the sixth embodiment. Therefore, the same effect as that of the sixth embodiment can be obtained in this embodiment.

(Ninth embodiment)
FIG. 21 is a block diagram showing a configuration of a motor drive system 1H according to the ninth embodiment of the present invention. The motor drive system 1H of the present embodiment is different from the motor drive system 1 of the first embodiment in that an inverter control device 10H is provided instead of the inverter control device 10 and a blocking switch 23 is added. The inverter control device 10H differs from the inverter control device 10 in that a safety control CPU 12 is added.

  The blocking switch 23 is provided in the supply path of the gate signal supplied from the motor control CPU 11 to the inverter main circuit 20, and is connected in series to the blocking switch 22. The blocking switch 23 has the same configuration as the blocking switch 22.

  In parallel with the motor control CPU 11, the safety control CPU 12 separately determines abnormality of the control system extending from the inverter control device 10H to the inverter main circuit. The safety control CPU 12 includes a command input processing unit 120, an abnormality determination processing unit 124, a safety output processing unit 125, and a frequency calculation unit 126. Each of these units is a functional unit realized by the safety control CPU 12 executing a program stored in a storage unit (not shown).

  The frequency calculation unit 126 performs the same processing as the frequency calculation unit 116 in the motor control CPU 11, and delivers the resulting current frequency to the abnormality determination processing unit 124.

  The command input processing unit 120 is in charge of communication with the command input processing unit 110 of the motor control CPU 11. The command input processing unit 120 acquires from the command input processing unit 110 data similar to the data that the command input processing unit 110 transmits to and receives from the host controller 30. In order to realize such a configuration, the command input processing unit 110 of the motor control CPU 11 of the present embodiment includes a gateway function that mediates communication between the safety control CPU 12 and the host controller 30. Further, the command input processing unit 110 of the motor control CPU 11 may include a function for synchronizing the reception of data from the host controller 30 in the motor control CPU 11 and the reception of data from the host controller 30 in the safety control CPU 12. Further, the command input processing unit 110 of the motor control CPU 11 may include a function of transmitting a logical sum response of the response from the motor control CPU 11 and the response from the safety control CPU 12 to the host controller 30 in response to the host controller 30. good.

  The abnormality determination processing unit 124 controls the control system from the inverter control device 10H to the inverter main circuit 20 based on the torque command value given via the command input processing units 110 and 120 and the frequency of the current given from the frequency calculation unit 126. The abnormality determination signal that is the result of the abnormality determination process is output to the safety output processing unit 125. The abnormality determination processing unit 124 performs such abnormality determination processing separately from the abnormality determination processing unit 114 of the motor control CPU 11.

  The safety output processing unit 125 outputs a blocking switch-off signal to the blocking switch 23 when the content of the abnormality determination signal given from the abnormality determination processing unit 124 indicates an abnormality, and the inverter main circuit is connected to the blocking switch 23. The supply of the gate signal to 20 is cut off.

  As described above, in the inverter control device 10H of the present embodiment, the abnormality determination processing unit 114 of the motor control CPU 11 performs the abnormality determination processing, and the abnormality determination processing unit 124 of the safety control CPU 12 also performs the abnormality determination processing. Therefore, in the inverter control device 10H, even if the abnormality determination processing unit 114 of the motor control CPU 11 cannot normally determine whether there is an abnormality, the abnormality determination processing unit 124 of the safety control CPU 12 determines whether there is an abnormality. can do. As described above, in the inverter control device 10H, the abnormality determination processing is made redundant, so that the safety output can be performed by more reliably determining the presence or absence of abnormality compared to the inverter control device 10 of the first embodiment. .

  Further, the safety control CPU 12 of this embodiment is an independent CPU different from the motor control CPU 11. Thereby, in this embodiment, it is not necessary to include the lock step function and memory partition function for improving safety in the motor control CPU 11. Therefore, in this embodiment, the motor control CPU 11 can be configured with an inexpensive CPU.

  Further, the abnormality determination processing unit 124 of the safety control CPU 12 may communicate with the abnormality determination processing unit 114 of the motor control CPU 11 to transmit / receive intermediate data. For example, the abnormality determination processing unit 124 receives an abnormality determination signal that is a processing result of the abnormality determination processing unit 114 from the abnormality determination processing unit 114, and determines whether or not it matches the abnormality determination signal of its own processing result. You may do it. Further, the abnormality determination processing unit 124 may perform an abnormality determination process having a content different from that of the abnormality determination processing unit 114. In this way, it is possible to avoid or reduce abnormalities caused by causes common to the motor control CPU 11 and the safety control CPU 12.

(10th Embodiment)
When the absolute value of the difference between the actual torque estimated value and the torque command value is greater than or equal to the threshold value, the comparison unit 60 in the first embodiment outputs an abnormality determination signal indicating an abnormality. The tenth embodiment of the present invention is an improvement of the processing of the comparison unit 60 of the first embodiment. The configuration of the inverter control device of this embodiment is the same as that of the first embodiment.

  The comparison unit of the present embodiment determines whether or not a state where the absolute value of the difference between the actual torque estimated value and the torque command value is equal to or greater than a threshold has continued for a predetermined time. Then, the comparison unit of the present embodiment outputs an abnormality determination signal indicating that the state is abnormal when the state continues for a predetermined time, and an abnormality determination signal indicating that the state is safe if the state does not continue for the predetermined time. Maintain the output of.

  FIG. 22 is a time chart showing processing when the comparison unit of this embodiment does not determine that there is an abnormality. In the example of FIG. 22, the absolute value of the difference between the actual torque estimated value and the torque command value becomes equal to or greater than the threshold th at time t11. When the absolute value of the difference becomes equal to or greater than the threshold value, the motor control CPU 11 starts measuring the internal timer at the time t11. The comparison unit maintains the output of the abnormality determination signal indicating that it is safe at the time t11 (L level abnormality determination signal in FIG. 22), and continues the actual torque estimated value and the torque command value after time t11. It is determined whether or not the absolute value of the difference is greater than or equal to the threshold th. In the example of FIG. 22, the absolute value of the difference that is equal to or greater than the threshold th is less than the threshold th at time t12 before the internal timer measures a predetermined time. When the absolute value of the difference becomes less than the threshold, the motor control CPU 11 resets the time count of the internal timer at the time t12. Then, the comparison unit continues to output the abnormality determination signal indicating that it is safe.

  FIG. 23 is a time chart showing processing when it is determined that there is an abnormality in the comparison unit of the present embodiment. Also in FIG. 23, as in FIG. 22, the absolute value of the difference between the actual torque estimated value and the torque command value becomes equal to or greater than the threshold th at time t11. In the example of FIG. 23, the absolute value of the difference does not become less than the threshold th between time t11 and time t13, and the internal timer measures a predetermined time at time t13. At time t13, the comparison unit outputs an abnormality determination signal indicating that an abnormality has been detected (in FIG. 23, an H level abnormality determination signal).

  As described above, in the inverter control device according to the present embodiment, the actual torque estimated value is determined when the state where the absolute value of the difference between the actual torque estimated value and the torque command value is equal to or greater than the threshold value continues for a predetermined time. When a transient phenomenon such as overshoot occurs in the absolute value of the difference between the torque command value and the torque command value, it is possible to prevent erroneous determination of an abnormality.

  In the comparison unit of the present embodiment, it has been determined whether or not the state in which the absolute value of the difference between the actual torque estimated value and the torque command value is equal to or greater than the threshold has continued for a predetermined time. It may be determined whether or not a state in which the absolute value of the difference between the acceleration command values is equal to or greater than a threshold has continued for a predetermined time.

(Eleventh embodiment)
The inverter control device according to the eleventh embodiment of the present invention differs from the inverter control device of the second embodiment in that an abnormality determination processing unit 114J is provided instead of the abnormality determination processing unit 114A. FIG. 24 is a block diagram illustrating a configuration of the abnormality determination processing unit 114J of the inverter control device of the present embodiment. The abnormality determination processing unit 114J includes an acceleration calculation unit 50E instead of the actual torque estimation unit 50, includes a moving average calculation unit 70-4 instead of the moving average calculation unit 70-2, and replaces the comparison unit 60E. It differs from the abnormality determination processing unit 114A in that it includes a comparison unit 60J.

  The acceleration calculation unit 50E is the same as the acceleration calculation unit 50E of the sixth embodiment. The moving average calculation unit 70-4 calculates the moving average of the acceleration calculation values input from the acceleration calculation unit 50E, and outputs the calculation result to the comparison unit 60J. Hereinafter, characteristics of the moving average calculation unit 70-4 will be described.

  FIGS. 25 to 27 are time charts showing acceleration calculation values and torque command values when an abnormality occurs in the inverter control device and the vehicle suddenly accelerates or decelerates regardless of the driver's intention. FIG. 25 shows a case of sudden acceleration from a stopped state or a case of sudden acceleration from a slow speed (for example, 10 km / h or less). FIG. 26 shows a state of normal speed (for example, about 40 km / h). FIG. 27 shows a case where the vehicle is suddenly decelerated from the normal speed state.

  When the vehicle suddenly accelerates or decelerates regardless of the driver's intention, the driver operates the brake and the accelerator in response to such a situation. The time from when an abnormality occurs until the driver performs such an operation is called the driver's reaction time. This reaction time varies among individuals. For this reason, in this embodiment, the average reaction time which averaged the reaction time of the several driver | operator is assumed. The average reaction time of the driver is, for example, 500 ms. 25 and 26, a negative torque command value representing a brake is given after the average reaction time of the driver has elapsed, and in FIG. 27, a positive torque command value representing the accelerator after the average reaction time of the driver has elapsed. A value is given.

  Here, there is an index called a fault tolerant time interval (hereinafter referred to as FTTI), which is a time interval from the occurrence of a failure of a component (inverter control device in the present embodiment) to the occurrence of a dangerous event of the vehicle. FIG. 28 is a diagram illustrating a relationship among the vehicle speed, FTTI, the average reaction time of the driver, and the abnormality determination timing. As shown in FIG. 28, FTTI has a different value depending on the speed of the vehicle.

  It is assumed that the driver drives the vehicle at a slow speed or less because the vehicle is very likely to approach the pedestrian. In such a situation, even if the driver operates the brake with an average reaction time, there is a risk that a traffic accident will occur in contact with the pedestrian. Considering such a situation, when the vehicle speed is equal to or less than the slow speed, FTTI is assumed to be equal to or less than the average reaction time of the driver. Considering FTTI, it is necessary to determine whether or not there is an abnormality within FTTI. Therefore, in the inverter control device of the present embodiment, when the vehicle speed is equal to or less than the slow speed, the abnormality determination process is performed so that the abnormality determination timing tf (timing for determining that there is an abnormality) overlaps the FTTI end time. I do. In order to perform the abnormality determination process at such abnormality determination timing tf, as shown in FIG. 25, the moving average calculation unit 70-4 uses a sample of acceleration calculation values obtained in substantially the same time interval as FTTI to accelerate the acceleration. Calculate the moving average of the computed values.

  On the other hand, it is assumed that the inter-vehicle distance is sufficiently secured under the situation where the driver drives at the normal speed. In such a situation, there is a surplus in the time from the occurrence of an abnormality to a traffic accident, compared to the case where the speed is lower than the slow speed. For this reason, when the speed of the vehicle is a normal speed, the FTTI is assumed to be longer than the average reaction time of the driver. If a sudden change in acceleration occurs due to a failure of a part or the like while traveling at a normal speed and the driver reacts sensitively, there is a risk that an erroneous operation such as a brake or an accelerator may be performed. The average reaction rate in this case is considered to be shorter than FTTI. Therefore, in the inverter control device of the present embodiment, when the vehicle speed is the normal speed, the abnormality determination process is performed so that the abnormality determination timing tf overlaps the end time of the average reaction time of the driver. In order to perform the abnormality determination process at such abnormality determination timing tf, as shown in FIG. 26 and FIG. 27, the moving average calculation unit 70-4 obtains acceleration obtained in a time interval substantially the same as the average reaction time of the driver. A moving average of acceleration calculation values is calculated using a sample of calculation values.

  In FIG. 24, the comparison unit 60J is different from the comparison unit 60A in that the presence or absence of abnormality is determined based on the moving average of torque command values and the moving average of acceleration calculation values.

  Incidentally, the motor control processing unit 112 performs feedback control on the torque command value. Therefore, as shown in FIGS. 25 to 27, the comparison unit 60 </ b> J makes an abnormality determination using a moving average of torque command values calculated and held in the past by the time constant of the feedback control from the abnormality determination time point. Do. Thereby, it is possible to avoid erroneous determination due to the fact that the acceleration calculation value is obtained with a delay with respect to the torque command value.

The comparison unit 60J outputs an abnormality determination signal indicating an abnormality when the moving average of the acceleration calculation values is equal to or greater than the positive acceleration threshold value _αth and the moving average of the torque command value is a negative value. . This is because the vehicle is accelerating beyond the tolerance while it is instructing deceleration. In addition, the comparison unit 60J generates an abnormality determination signal indicating an abnormality when the moving average of the acceleration calculation values is equal to or less than the negative acceleration threshold _αth and the moving average of the torque command value is a positive value. Output. This is because the acceleration is instructed but the vehicle is decelerating beyond tolerance.

  As described above, in the inverter control device of the present embodiment, the sample time interval for calculating the moving average of the acceleration calculation values is determined based on the vehicle speed, the average reaction time of the driver, and the FTTI. Yes. For this reason, in the inverter control apparatus of this embodiment, even if an abnormality occurs, a dangerous event can be avoided in advance and a safe state can be maintained.

(Deformation)
Although each embodiment of the present invention has been described above, it goes without saying that the following modifications may be added to these embodiments.

(1) In the comparison part 60 in the inverter control apparatus 10 of 1st Embodiment, it was judged whether the absolute value of the difference of an actual torque estimated value and a torque command value is more than a threshold value. Such a threshold value for torque comparison may be determined by using the threshold value α _th for acceleration comparison shown in the sixth embodiment. Specifically, the torque comparison threshold value may be determined using a conversion formula in which the acceleration calculation value α ^# is replaced with the acceleration comparison threshold value _αth in the equation (2) of the first embodiment.

(2) You may combine the technical feature of each embodiment suitably. For example, the technical features of the second embodiment and the technical features of the sixth embodiment may be combined. The abnormality determination processing unit of this aspect converts the torque command value into an acceleration command value, calculates a moving average of the acceleration command value, calculates an acceleration calculation value from the current frequency, and calculates the moving average of the acceleration calculation value. In other words, when the absolute value of the difference between the moving average of the acceleration calculation values and the moving average of the acceleration command values is equal to or greater than the threshold value, an abnormality determination signal indicating an abnormality is output.

(3) In the sixth embodiment, the acceleration comparison threshold α _th is determined based on the gravitational acceleration α _L applied to the vehicle stopped on the slope. However, the inverter control device may be provided with vehicle inclination angle information and may determine the threshold α _th based on the inclination angle information.

(4) The inverter control device of each embodiment is mounted on an electric vehicle. However, the inverter control device may be mounted on a hybrid electric vehicle using a motor and a prime mover as power sources.

(5) In the inverter control device of each embodiment, the presence or absence of abnormality is determined based on the frequency of the current. However, the inverter control device may determine the presence / absence of an abnormality based on the speed detection value which is the detection result of the rotation speed sensor 44 instead of the current frequency. However, in this case, the inverter control device is affected by the presence or absence of a failure of the rotational speed sensor 44 in the determination of the presence or absence of abnormality. Therefore, as in each embodiment, it is more preferable to determine the presence or absence of abnormality based on the current frequency.

  1, 1B, 1C, 1D, 1H ... motor drive system, 5, 5B, 5C, 5D, 5H ... inverter device, 10, 10B, 10C, 10D, 10H ... inverter control device, 11 ... motor control CPU, 12 ... safety Control CPU, 20 ... inverter main circuit, 22, 23 ... blocking switch, 30 ... host controller, 40 ... motor, 42 ... current detector, 43 ... voltage detector, 44 ... rotational speed sensor, 45 ... power transmission device, 46 ... Transmission, 47 ... Differential, 48 ... Drive wheels, 50, 50B, 50C, 50E ... Actual torque estimation unit, 50E ... Acceleration calculation unit, 60, 60A, 60E, 60F, 60G, 60J ... Comparison unit, 70, 70 -1, 70-2, 70-4... Moving average calculation unit, 71, 72, 73... Register, 74 ... adder, 75. 8-1, 78-2 ... time differentiation calculation unit, 80E ... conversion coefficient multiplication unit, 110, 120 ... command input processing unit, 111 ... control command input processing unit, 112 ... motor control processing unit, 113 ... control output processing unit 114, 114A, 114B, 114C, 114D, 114E, 114F, 114G, 114J, 124 ... abnormality determination processing unit, 115, 125 ... safety output unit, 116, 126 ... frequency calculation unit.

Claims (19)

An inverter control device that performs operation control of an inverter main circuit that drives a motor under the control of a host controller,
Frequency calculating means for calculating the frequency of the current based on the current detection value of the output current of the inverter main circuit;
An abnormality determining means for determining the presence or absence of an abnormality based on the frequency of the current calculated by the frequency calculating means and a torque command value given from the host controller;
An inverter control device comprising: The abnormality determining means is
The inverter control device according to claim 1, wherein an actual torque estimated value of the motor is calculated based on the frequency of the current, and the actual torque estimated value is compared with the torque command value. The abnormality determining means is
3. The inverter control according to claim 2, wherein when the absolute value of the difference between the actual torque estimated value and the torque command value is greater than or equal to a threshold value, an abnormality determination signal indicating an abnormality is output. apparatus. The abnormality determining means is
3. An abnormality determination signal indicating an abnormality is output when a state where an absolute value of a difference between the actual torque estimated value and the torque command value is equal to or greater than a threshold value continues for a predetermined time. The inverter control device described in 1. The abnormality determining means is
The moving average of the actual torque estimated value and the moving average of the torque command value are calculated, and the absolute value of the difference between the moving average of the actual torque estimated value and the moving average of the torque command value is equal to or greater than a threshold value. The inverter control device according to claim 2, wherein an abnormality determination signal indicating an abnormality is output. The abnormality determining means is
The actual torque estimated value is time-differentiated to calculate the rate of change of the actual torque estimated value,
Calculating the rate of change of the torque command value by differentiating the torque command value with respect to time,
The abnormality determination signal indicating an abnormality is output when an absolute value of a difference between the change rate of the actual torque estimated value and the change rate of the torque command value is equal to or greater than a threshold value. The inverter control device according to 2. The abnormality determining means is
Calculate the acceleration calculation value by time differentiation of the frequency of the current,
An acceleration command value is calculated by multiplying the torque command value by a conversion factor,
The inverter control device according to claim 1, wherein the acceleration calculation value is compared with the acceleration command value. The abnormality determining means is
8. The inverter control device according to claim 7, wherein an abnormality determination signal indicating an abnormality is output when an absolute value of a difference between the acceleration calculation value and the acceleration command value is equal to or greater than a threshold value. 9. . The abnormality determining means is
8. The abnormality determination signal indicating that the abnormality is output when a state where an absolute value of a difference between the acceleration calculation value and the acceleration command value is equal to or greater than a threshold value continues for a predetermined time. The inverter control device described. The abnormality determining means is
When the moving average of the acceleration calculation value and the moving average of the acceleration command value are calculated, and the absolute value of the difference between the moving average of the acceleration calculation value and the moving average of the acceleration command value is greater than or equal to a threshold value The inverter control device according to claim 7, wherein an abnormality determination signal indicating an abnormality is output. The abnormality determining means is
Time-differentiating the acceleration calculation value to calculate the rate of change of the acceleration calculation value,
The acceleration command value is differentiated with respect to time to calculate the rate of change of the acceleration command value,
8. An abnormality determination signal indicating an abnormality is output when an absolute value of a difference between the change rate of the acceleration calculation value and the change rate of the acceleration command value is equal to or greater than a threshold value. The inverter control device described in 1. The threshold is
The inverter control device according to any one of claims 8 to 11, wherein the inverter control device is determined based on a value of gravitational acceleration on a slope applied to a vehicle on which the inverter control device is mounted. The abnormality determining means is
Calculate the moving average of the torque command value,
Calculate a moving average of acceleration calculation values based on the frequency of the current,
The inverter control device according to claim 1, wherein presence or absence of abnormality is determined based on a moving average of the torque command value and a moving average of the acceleration calculation value. The abnormality determining means is
A time interval of a sample for calculating a moving average of the acceleration calculation values is determined based on a speed of a vehicle on which the inverter control device is mounted, an average reaction time of a driver, and a fault tolerant time interval. The inverter control device according to claim 13. The abnormality determining means is
When the speed of the vehicle is equal to or less than the slowing speed, a moving average of acceleration calculation values is calculated using a sample of acceleration calculation values obtained in substantially the same time interval as the fault tolerant time interval,
The moving average of acceleration calculation values is calculated using a sample of acceleration calculation values obtained in a time interval substantially the same as the average reaction time of the driver when the vehicle speed is a normal speed. The inverter control device described in 1. The abnormality determining means is
The presence / absence of abnormality is determined based on the moving average of acceleration calculation values at the time of abnormality determination and the moving average of torque command values calculated and held in the past by the time constant of feedback control from the abnormality determination time. The inverter control device according to any one of claims 13 to 15, wherein   The inverter control device according to any one of claims 1 to 16, wherein the frequency calculation means calculates a reciprocal of a current cycle represented by the current detection value as a current frequency. The frequency calculation means includes
The current detection value is captured at a sampling period,
Calculate the phase angle of the current vector represented by the current detection value for each sampling period,
The inverter control device according to any one of claims 1 to 16, wherein a frequency of a current is calculated by dividing a difference in phase angle of the current vector for each sampling cycle by the sampling cycle. . Motor control processing means for controlling the operation of the inverter main circuit, the frequency calculation means, and control means for motor control functioning as the abnormality determination means,
Separately from the control means for controlling the motor, the frequency calculation means, and a control means for safety control functioning as the abnormality determination means,
The inverter control device according to any one of claims 1 to 18, characterized by comprising:

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