JPH0851800A - Control of induction motor - Google Patents

Abstract

PURPOSE:To enable continuing control even when a voltage sensor has become defective. CONSTITUTION:When a voltage sensor output is abnormal (step 206) an estimate output is used (step 210) by using the relationship between a battery output PB or battery current IB and battery voltage VB. Thus, stable control can continue without generating a state of out-of-control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an induction motor according to the theory of high speed direct torque control.

[0002]

2. Description of the Related Art Vector control has been conventionally adopted as a method for controlling an induction motor. Although this control method is a method that can obtain good control characteristics, it has drawbacks such as complicated control and many parameters. In order to solve such problems, for example, "A new high-speed torque control method for induction motors based on instantaneous slip frequency control", Isao Takahashi et al.
IEICE Magazine B, Vol. 106, No. 1, January 1986, p.
p. 9-16, "High Performance Torque Control of Induction Motor Using Digital Signal Processor", Isao Takahashi et al., IEICE Journal, Vol. 107, No. 2, February 1987, pp.
High-speed direct torque control is proposed by 223-230.

FIG. 13 shows a system constructed according to this control method, and FIG. 14 shows a flow of operation of the arithmetic unit.

This system is a system for driving an electric vehicle by a three-phase induction motor 10. A battery 12 is provided as a drive power source of the motor 10, and the inverter 14 converts the discharge output PB of the battery 12 into a three-phase alternating current and supplies it to the motor 10. The operation of the inverter 14 is performed by the vehicle controller 16 and the motor controller 18
Is controlled by. The vehicle controller 16 uses the torque command T based on information such as the accelerator opening and the motor rotation speed.
ref and the magnetic flux command Φref are generated, and the motor controller 18 switches the switching patterns Su, Sv, and Sv of the inverter 14 so that these commands Tref and Φref are realized.
Determine Sw. U, V, W constituting the inverter 14
Each phase switching element switches according to the determined switching patterns Su, Sv, Sw. As a result, the output torque T of the motor 10 becomes a torque equivalent to the torque command Tref, and the primary magnetic flux Φ becomes a magnetic flux equivalent to the magnetic flux command Φref.

The motor controller 18 includes a calculation unit 20,
It is composed of a pattern table 22 and subtractors 24 and 26. The calculation unit 20 detects the primary current I1 of the motor 10 and the voltage VB of the battery 12, and the pattern table 2
Switching patterns Su and Sv output from 2 last time
, Sw are used together to calculate the estimated torque T and the estimated magnetic flux Φ in addition to the motor speed supplied to the vehicle controller 16. The subtractors 24 and 26 subtract the estimated torque T and the estimated magnetic flux Φ from the torque command Tref and the magnetic flux command Φref, respectively, and use the obtained control error to subtract the pattern table 22.
Refer to. As a result, new switching patterns Su, Sv, Sw are output to the inverter 14. The calculation unit 20 also determines the torque command Tref and the magnetic flux command Φref.
For determination, the rotation speed of the motor 10 is detected from the change in the phase of the magnetic flux Φ and supplied to the vehicle controller 16.

The motor controller 18 uses the estimated torque T
And when calculating the estimated magnetic flux Φ, the procedure shown in FIG. 14 is executed. As shown in this figure, the motor controller 18 receives the torque command Tref from the vehicle controller 16.
While the magnetic flux command Φref is input (100), the current sensor 28 outputs the primary current I1 (instantaneous value) of each phase of the motor 10, and the voltage sensor 30 outputs the voltage VB of the battery 12.
Is detected (102). The calculation unit 20 detects the detected battery voltage VB and the previously output switching pattern S.
The primary voltage V1 (instantaneous value) is calculated based on u, Sv, and Sw (104), and the primary interlinkage magnetic flux Φ is estimated based on the primary voltage V1 and the detected primary current I1 (106). The estimation formula is

[Expression 1] Φ = ∫ (V1−R1I1) dt However, R1 is the primary resistance of the motor 10 and is a known value. The calculation unit 20 further estimates the output torque T (instantaneous value) of the motor 10 based on the estimated magnetic flux Φ and the detected primary current I1 (108). The estimation formula is

## EQU2 ## It is expressed by T = Φ × I1. The calculation unit 20 outputs the estimated torque T and magnetic flux Φ to the subtractors 24 and 26. As a result, the torque T and the magnetic flux Φ are compared with the input torque command Tref and magnetic flux command Φref, and the switching patterns Su, Sv, Sw are determined based on the results (110). That is, for the magnetic flux Φ, for the magnetic flux command Φref

[Formula 3] Φ ref −ΔΦ ≦ Φ ≦ Φ ref + ΔΦ (ΔΦ:
To maintain the relationship of (allowable error), for example, Φ = Φref −ΔΦ and Φ
= Φref + ΔΦ is compared for binary hysteresis.

## EQU00004 ## Tref-.DELTA.T.ltoreq.T.ltoreq.Tref + .DELTA.T (.DELTA.T:
For example, T = Tref−ΔT, T
= Tref, T = Tref + ΔT three-value hysteresis comparison. The switching patterns Su, Sv, Sw are determined by a combination of the comparison result φ of the magnetic flux Φ, the comparison result τ of the torque T, and the phase θ of the magnetic flux Φ. φ = 0 is Φ = Φre
f −ΔΦ (demagnetization state), φ = 1 is Φ = Φ ref + ΔΦ
(Magnetization state), τ = −1, T = Tref −ΔT (negative deviation), τ = 0, T = Tref (zero deviation), and τ = + 1, T
= Tref + ΔT (positive deviation).

The determined switching patterns Su, S
v and Sw are output to the inverter 14 (112). The voltage output from the inverter 14 according to the determined switching patterns Su, Sv, Sw is set to a vector V1.
When represented by (Su, Sv, Sw), the comparison result φ of the magnetic flux Φ, the comparison result τ of the torque T, and the phase θ of the magnetic flux Φ.
And the vector V1 (Su, Sv, Sw) is shown in FIG.
It can be expressed as (a). Here, the inverter 14 is considered to be a switch circuit as shown in FIG. That is, it is considered that the inverter 14 is constituted by the switches Su, Sv, Sw that selectively connect the source side and the sink side to the U, V, W phase windings of the motor 10. Assuming that the state connected to the source side is "1" and the state connected to the sink side is "0" to represent the states of the switches Su, Sv, Sw, the output voltage vector V1 (S
u, Sv, Sw) are eight types shown in FIG.

As described above, by constructing the system according to the high speed direct torque control theory, the induction motor 10 can be controlled appropriately. For example, a voltage sensor for detecting the primary voltage V1 of the motor 10 is not necessary and the battery 1
The voltage sensor 3 provided to manage the state of 2
It is only necessary to detect the battery voltage VB by 0.

[0009]

On the other hand, in this theory, if the voltage sensor for detecting the battery voltage fails and accurate detection becomes impossible, control cannot be continued.

The present invention has been made to solve the above problems, and by providing an alternative means of a battery voltage sensor, the detected value of the battery voltage due to a failure, a momentary interruption, noise or the like. The purpose is to enable control to be continued in accordance with the high-speed direct torque control theory even when is an abnormal value.

[0011]

In order to achieve such an object, in the control method according to the first configuration of the present invention, the battery voltage is normally detected by the voltage sensor, and the output of the voltage sensor is abnormal. It is sometimes characterized in that the battery voltage is estimated based on the load state of the battery.

The control method according to the second aspect of the present invention is characterized in that the battery voltage is estimated based on the required motor output when the output of the voltage sensor is abnormal. The control method according to the third configuration of the present invention is characterized in that the battery voltage is estimated based on the battery current when the output of the voltage sensor is abnormal. In the control method according to the fourth configuration of the present invention, when the output of the voltage sensor is abnormal, the battery voltage is estimated based on the load state of the battery while sequentially correcting based on the information indicating the change in the state of charge (SOC) of the battery. It is characterized by doing. The control method according to the fifth configuration of the present invention, while using the battery voltage detected by the voltage sensor, to build a map in which the load state of the battery and the battery voltage are associated with each other in normal time, It is characterized in that the battery voltage is estimated by referring to the above map in the load state of the battery. In the control method according to the sixth configuration of the present invention, when the output of the voltage sensor is abnormal, it is estimated that the previous battery voltage is the current battery voltage until the period of the output abnormality exceeds a predetermined period. After the period is exceeded, the battery voltage is estimated based on the load state of the battery.

The control method according to the seventh aspect of the present invention is characterized in that the battery voltage is normally detected by the voltage sensor and it is assumed that the battery voltage has a predetermined value when the output of the voltage sensor is abnormal. And The control method according to the eighth configuration of the present invention is characterized in that the battery voltage detected by the voltage sensor immediately before the output becomes abnormal is set to the predetermined value.

The control method according to the ninth aspect of the present invention is characterized in that the user is warned that the voltage of the battery being used is not the value detected by the voltage sensor when the output of the voltage sensor is abnormal.

[0015]

In the first configuration of the present invention, the voltage sensor for detecting the battery voltage has a malfunction, or noise is superposed on the output of this sensor. If so, the estimated battery voltage is used. Therefore, the control based on the high-speed direct torque control theory can be continued even when the output of the voltage sensor is always incorrect. Even if the estimated value of the battery voltage includes an error, an unstable control state will not occur unless the error is extremely large. In this configuration, since the battery voltage is estimated based on the load state of the battery, a large error does not occur in the estimated value, and stable control is realized over a wide range.

In the second configuration of the present invention, the battery voltage is estimated based on the motor required output. Here, since the motor required output and the battery discharge output have a correlation, and the battery discharge output and the battery voltage also have a correlation, it is possible to accurately estimate the battery voltage based on the motor required output. Further, the required motor output can be easily obtained from the motor torque and the rotation speed. Therefore, in this configuration, the control error during the incorrect output of the voltage sensor is significantly suppressed. Furthermore, there is no need to add a new sensor.

In the third configuration of the present invention, the battery voltage is estimated based on the battery current. Since there is a correlation between the battery current and the battery voltage, it is possible to accurately estimate the battery voltage based on the battery current. Therefore, also in the present configuration, the control error during the incorrect output of the voltage sensor is significantly suppressed. In addition,
In this configuration, a current sensor for detecting the battery current is required, but it is not necessary to add a new sensor because a current sensor used for monitoring the battery state can be used. .

In the fourth structure of the present invention, the battery voltage is estimated based on the load state of the battery while the correction is sequentially performed based on the information indicating the change in the SOC of the battery. That is, in view of the fact that the correlation between the battery load state (for example, the battery current or the battery discharge output) and the battery voltage varies depending on the SOC, the estimation operation is corrected according to the change in the SOC. As a result, in this configuration, the control error during the incorrect output of the voltage sensor is further suppressed.

In the fifth configuration of the present invention, a map that correlates the load state of the battery and the battery voltage is normally constructed using the detected battery voltage. When the output of the voltage sensor becomes abnormal, the map is referred to in the battery load state and the battery voltage is estimated. That is, since the correlation between the battery voltage and the battery load state accumulated as a map before the output of the voltage sensor becomes abnormal is used, the control error in the output irregularity of the voltage sensor is further suppressed.

In the sixth configuration of the present invention, the previous battery voltage is estimated to be the current battery voltage until the abnormal output period exceeds the predetermined period, and after the predetermined period is exceeded, the battery load is increased. The battery voltage is estimated based on the state. Therefore, when the output of the voltage sensor becomes abnormal for a relatively short time due to noise or the like, the conventional battery voltage is substituted. As a result, an abnormal output for a short time can be dealt with by a relatively simple calculation.

In the seventh configuration of the present invention, it is assumed that the battery voltage has a predetermined value when the output of the voltage sensor is always incorrect. Therefore, even if the output of the voltage sensor is always incorrect, the control based on the high-speed direct torque control theory can be continued within a relatively narrow control range in which a control error does not pose a problem.

In the eighth configuration of the present invention, the battery voltage detected by the voltage sensor immediately before the output becomes abnormal is
It is used as the predetermined value. Thereby, the control error in the seventh configuration is suppressed.

In the ninth configuration of the present invention, the user is warned that the voltage of the battery being used is not the value detected by the voltage sensor when the output of the voltage sensor is always incorrect.
As a result, it is possible to prevent the motor from being continuously driven without noticing the incorrect output. In particular, when applied to the seventh configuration, a situation in which a control error is large is unlikely to occur or continue.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

(1) System Configuration FIG. 1 shows a system configuration suitable for each embodiment described later. The system shown in this figure is a system for driving an electric vehicle. As is clear from the comparison with FIG. 13, the current I of the battery 12 in FIG.
A current sensor 32 that detects B, an SOC sensor 34 that detects the SOC of the battery 12, and a display unit 36 that warns the user that the output of the voltage sensor 30 is abnormal and not in use are shown. ing. However, these members are not members added to carry out the present invention. For example, the current sensor 32 and the SOC sensor 34 are members that have been widely used conventionally for managing the battery 12, and the display unit 36 is a display unit that displays the state of the vehicle, and the output of the voltage sensor 30 is not displayed. Since it is normal, it is diverted or used for the purpose of warning that it is not used.

(2) First Embodiment FIG. 2 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the first embodiment of the present invention. The motor controller 18 in this embodiment also executes control in the procedure shown in FIG. 14 as in the conventional example. What is shown in this figure is the portion different from the conventional example, that is, the battery voltage VB input processing in step 102.

The arithmetic unit 20 inputs the battery voltage VB (200), while obtaining the battery output PB (20).
2). When obtaining the battery output PB, first,
The required motor output, that is, the output required for the motor 10, is obtained by calculating the product of the torque command Tref given to the motor 10 at the previous timing and the rotation speed of the motor 10, and the obtained required motor output Is divided by the system efficiency including the discharge efficiency of the battery 12 and the power conversion efficiency of the inverter 14.

The arithmetic unit 20 next determines the section number n on the PB-VB map (204). The PB-VB map mounted on the arithmetic unit 20 shows the relationship between the battery voltage VB and the battery output PB as shown in FIG. 3, and is discretized (sectioned) in the PB axis direction.
In this step, it is determined to which section the battery output PB obtained in step 202 belongs.

The operation unit 20 receives the input battery voltage VB
Is a normal value or an abnormal value (20
6). For example, it is determined whether or not it belongs to the range shown by the broken line in FIG. By such a section determination, it can be accurately determined whether the value is normal. If the result of this determination is "normal", the computing unit 20 replaces the battery voltage value stored in section n of the PB-VB map with the value of the input battery voltage VB (update, 208), After taking in the current I1 and the like, the process proceeds to step 104. In the case of "abnormal", the calculation unit 20 replaces the input battery voltage VB, which cannot be adopted, with
The battery voltage value stored in the section n of the PB-VB map is adopted (210), and after taking in the current I1, etc., the process proceeds to step 104. At that time, the calculation unit 20
Supplies a signal to the display unit 36 to warn the user that the battery voltage estimated value is being used for control due to an abnormality in the voltage sensor 30 (212).

Therefore, according to this embodiment, the voltage sensor 3
When the output of 0 becomes an abnormal value, the battery output PB is obtained based on the required output, the battery voltage VB is estimated based on the obtained battery output PB, and the detected value is used instead. The control based on the high-speed direct torque control theory can be continuously executed. Furthermore, since the battery output PB has a good correlation with the battery voltage VB, a large error does not occur in the estimated value, and stable and wide-range control can be easily executed. Further, since the battery output PB is used, the battery current sensor 32
It is possible to reflect the actual behavior of the battery 12 and its history in the control because the PB-VB map is used, and it is possible to suppress the control error when the estimated value is used. In addition, since the warning is issued in step 212, it is possible to prevent the user from continuing to drive the motor 10 without always noticing the incorrect output.

(3) Second Embodiment FIG. 4 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the second embodiment of the present invention. This embodiment is different from the first embodiment in that the battery output IB is not obtained and the PB-VB map is used, but the battery current IB is detected by the current sensor 32 (202A), and the IB-VB map is displayed. It is at the point (204A) where the section number is obtained. That is, the calculation unit 20
5 is equipped with an IB-VB map showing the relationship between the battery current IB and the battery voltage VB as shown in FIG. 5, and this IB-VB map is divided into sections along the IB axis. The calculation unit 20 executes the same processing as that of the first embodiment regarding the section to which the detected battery current IB belongs.

Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained. However, although the current sensor 32 is required in the present embodiment, it is not necessary to add a new sensor because a sensor used for SOC detection / management of the battery 12 can be diverted to this sensor.

(4) Third Embodiment FIG. 6 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the third embodiment of the present invention. This embodiment is an embodiment obtained by improving the first or second embodiment, and replaces step 210 with step 210.
A is running. As shown in FIG. 5, the relation between the battery current IB and the battery voltage VB is S of the battery 12.
Similarly, the relationship between the battery output PB and the battery voltage VB also depends on the SOC of the battery 12. Since the SOC of the battery 12 gradually decreases with discharge, the relationship between the battery current IB or the battery output PB and the battery voltage VB also changes accordingly. If the voltage sensor 30 is functioning normally, this change is reflected in the control by the updating (208) of the IB-VB or PB-VB map in the first or second embodiment. It is not reflected when the output is considered abnormal. In the present embodiment, when the battery voltage VB in the section n is adopted, the correction is performed according to the SOC change from the time when the output of the voltage sensor 30 becomes abnormal (210A). IB-VB or PB-
The change in VB relation is reflected in the control, and the control error is suppressed. However, although the SOC sensor 34 is required in the present embodiment, it is not necessary to add a new sensor because a sensor used for SOC detection / management of the battery 12 can be diverted to this sensor.

(5) Fourth Embodiment FIG. 7 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the fourth embodiment of the present invention. This embodiment is an embodiment obtained by improving the first or second embodiment, and steps 214, 216 and 218 are executed prior to steps 206, 208 and 210, respectively. In this embodiment, a plurality of IB-VB or PB-VB maps are used, and either map is used (214) according to the SOC input from the SOC sensor 34 (216, 218). Thereby, the same operation as that of the third embodiment is realized without the correction calculation in step 210A.

(6) Fifth Embodiment FIG. 8 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the fifth embodiment of the present invention. This embodiment is an embodiment obtained by improving the first or second embodiment, and replaces step 210 with step 210.
B, step 220 is executed when step 208 is executed, and step 222 is executed when step 210B is executed. In step 222, the battery current I after the result of the determination in step 206 turns to "abnormal"
The integrated value Q of B is calculated, and in step 210B, the battery voltage V in the section n is corrected while being corrected based on the integrated value Q.
B is adopted. In step 220, the integrated value Q is reset. Here, the SOC of the battery 12 is a value obtained by subtracting the discharge current amount (that is, the integrated value Q of the battery current IB) from the full charge capacity of the battery 12, and the SOC change can be represented by the integrated value Q. According to the embodiment, the same operation as that of the third and fourth embodiments can be realized by using the current sensor 32, that is, without the SOC sensor 34.

(7) Sixth Embodiment FIG. 9 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the sixth embodiment of the present invention. This embodiment is an embodiment obtained by improving the first or second embodiment, and replaces step 210 with step 210.
When C executes step 208, step 220A is executed, and when step 210C is executed step 222A is executed. In Step 222A, Step 20
The number N of times when the result of the determination in 6 is changed to "abnormal" and subsequently "abnormal" is determined is counted. At step 210C, the battery voltage VB of the section n is adopted while correcting based on the count value N. are doing. At step 220A, the count value N is reset. Here, the count value N is
Since it represents the discharge time of the battery 12 and has a correlation with the change in SOC, according to the present embodiment, the current sensor 32 and the SOC sensor 34 are not provided, and the third to fifth embodiments are not provided. The same effect can be realized.

(8) Seventh Embodiment FIG. 10 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the seventh embodiment of the present invention. This embodiment is an embodiment obtained by improving the sixth embodiment, and the step 210 or 210D is replaced with the step 210C when the step 208 is executed.
24, step 226 is executed prior to executing steps 210 and 210D, respectively. Step 22
At 6, it is determined whether or not the count value N exceeds the predetermined value N0. If not, the abnormal value set in step 224 is (210D), and if not, the interval n The battery voltage VB is adopted (210) respectively. In step 224, the voltage sensor 30
Since the output of the voltage sensor 30 is set to the abnormal value when the output of is normal, the abnormal value adopted in step 210D is the value immediately before the determination result of step 206 changes to "abnormal". Is the output value of the voltage sensor 30. Therefore, according to the present embodiment, the voltage sensor 30
The control becomes more stable because the value of the battery voltage VB, which is the basis for obtaining the primary voltage V1, does not change when the output of No. 1 becomes abnormal for a short time due to noise or the like.

(9) Eighth Embodiment FIG. 11 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the eighth embodiment of the present invention. This embodiment is a simplification of the seventh embodiment and does not use PB-VB or IB-VB maps. Therefore, when it is determined to be "normal" in step 206, the primary current I1 is immediately fetched and the process proceeds to step 104. “Abnormal” in step 206
If it is determined that, the calculation unit 20 adopts a predetermined abnormal value (210D). Therefore, according to this embodiment, the control error is not small and the control range is not wide as in the first to seventh embodiments, but the uncontrollable state can be prevented.

(10) Ninth Embodiment FIG. 12 shows a part of the operation flow of the motor controller 18, particularly the arithmetic unit 20, in the ninth embodiment of the present invention. This embodiment is an embodiment obtained by improving the eighth embodiment, and step 224 is executed when it is determined to be "normal" in step 206. Therefore, according to the present embodiment, when the output of the voltage sensor 30 becomes abnormal for only a short time due to noise or the like, the value of the battery voltage VB which is the basis for obtaining the primary voltage V1 does not change. Therefore, the control becomes more stable.

[0040]

As described above, according to the first configuration of the present invention, the estimated value of the battery voltage is used when the output of the voltage sensor for detecting the battery voltage becomes an abnormal value. As a result, the control based on the high-speed direct torque control theory can be continued even when the output of the voltage sensor is always incorrect. Further, since the battery voltage is estimated based on the load state of the battery, a large error does not occur in the estimated value, and stable control can be realized over a wide range.

According to the second configuration of the present invention, the battery voltage is estimated based on the required motor output.
The battery voltage can be accurately and easily estimated, and the control error can be significantly suppressed. Furthermore, there is no need to add a new sensor.

According to the third configuration of the present invention, since the battery voltage is estimated based on the battery current, the battery voltage can be estimated accurately and the control error can be significantly suppressed. Further, when detecting the battery current, a current sensor conventionally used for monitoring the state of the battery can be used.

According to the fourth configuration of the present invention, since the battery voltage is estimated based on the load state of the battery while the correction is sequentially performed based on the information indicating the change in the SOC of the battery, the control error is further suppressed. it can.

According to the fifth configuration of the present invention, since the battery voltage is estimated by utilizing the battery voltage vs. battery load state map constructed in the normal time, the control error can be further suppressed.

According to the sixth configuration of the present invention, it is estimated that the previous battery voltage is the current battery voltage until the abnormal output period exceeds the predetermined period, and the battery voltage is estimated after the predetermined period is exceeded. Since the battery voltage is estimated based on the load state, it is possible to deal with the abnormal output for a short time by a relatively simple calculation.

According to the seventh configuration of the present invention, since the battery voltage is assumed to be the predetermined value at all times when the output of the voltage sensor is incorrect, a high-speed direct control is possible in a relatively narrow control range in which control error does not matter. Control according to the torque control theory can be continued.

According to the eighth structure of the present invention, the battery voltage detected by the voltage sensor immediately before the output becomes abnormal is used as the predetermined value. Therefore, the control error in the seventh structure can be suppressed. .

According to the ninth configuration of the present invention, the output of the voltage sensor is always inaccurate, so that the user is warned that the battery voltage in use is not the value detected by the voltage sensor. It is possible to prevent the motor from being continuously driven without noticing it, and a situation in which a control error is large is difficult to occur or continue.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a system capable of implementing each embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a main part of a calculation unit in the first embodiment of the present invention.

FIG. 3 shows a PB-IB map used in this example.

FIG. 4 is a flowchart showing an operation of a main part of an arithmetic unit according to the second embodiment of the present invention.

FIG. 5 shows a VB-IB map used in this example.

FIG. 6 is a flowchart showing an operation of a main part of an arithmetic unit according to the third embodiment of the present invention.

FIG. 7 is a flowchart showing an operation of a main part of an arithmetic unit in the fourth embodiment of the present invention.

FIG. 8 is a flowchart showing an operation of a main part of an arithmetic unit in the fifth embodiment of the present invention.

FIG. 9 is a flowchart showing an operation of a main part of an arithmetic unit in the sixth embodiment of the present invention.

FIG. 10 is a flowchart showing an operation of a main part of an arithmetic unit in the seventh embodiment of the present invention.

FIG. 11 is a flowchart showing an operation of a main part of an arithmetic unit in the eighth embodiment of the present invention.

FIG. 12 is a flowchart showing an operation of a main part of a calculation unit in the ninth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a system according to a conventional example.

FIG. 14 is a flowchart showing the flow of control according to the high-speed direct torque control theory.

15A and 15B are diagrams showing a method of determining a switching pattern, wherein FIG. 15A shows a switching table, FIG. 15B shows an inverter equivalent circuit, and FIG. 15C shows an output voltage vector.

[Explanation of symbols]

 10 motor 12 battery 18 motor controller 20 arithmetic unit 22 pattern table 24, 26 subtractor 28, 32 current sensor 30 voltage sensor 34 SOC sensor 36 display unit Φref magnetic flux command Tref torque command Φ primary interlinkage magnetic flux T torque Su, Sv, Sw Switching pattern I1 Primary current VB Battery voltage IB Battery current PB Battery output Q Integrated value of battery current N Counted number of consecutive abnormalities

Claims (9)

[Claims] 1. The motor primary voltage is obtained based on the battery voltage and the previous switching pattern, the current values of the motor primary magnetic flux and the motor torque are estimated based on the motor primary voltage and the motor primary current, and the motor primary magnetic flux and the motor primary magnetic flux are calculated based on the required output. Determine the motor torque command value, compare the estimated current value of the motor primary magnetic flux and motor torque with the calculated motor primary magnetic flux and motor torque command values to determine the switching pattern, and determine the motor primary current according to the determined switching pattern. In the method of controlling the induction motor by alternating the above, the battery voltage is normally detected by the voltage sensor, and when the output of the voltage sensor is abnormal, the battery voltage is estimated based on the load state of the battery. Control method. 2. The control method according to claim 1, wherein when the output of the voltage sensor is abnormal, the battery voltage is estimated based on the required motor output. 3. The control method according to claim 1, wherein when the output of the voltage sensor is abnormal, the battery voltage is estimated based on the battery current. 4. The control method according to claim 1, wherein when the output of the voltage sensor is abnormal, the battery voltage is estimated based on the load state of the battery while sequentially correcting based on the information indicating the change in the charge state of the battery. A control method characterized by the above. 5. The control method according to claim 1, wherein a map that associates the behavior of the battery with the battery voltage is constructed in normal time while using the battery voltage detected by the voltage sensor, and when the output of the voltage sensor is abnormal. , A control method characterized by estimating a battery voltage by referring to the above map in a battery load state. 6. The control method according to claim 1, wherein when the output of the voltage sensor is abnormal, it is estimated that the previous battery voltage is the current battery voltage until the output abnormal period exceeds a predetermined period. The control method is characterized in that the battery voltage is estimated based on the load state of the battery after the predetermined period has passed. 7. The motor primary voltage is obtained based on the battery voltage and the previous switching pattern, the current values of the motor primary magnetic flux and the motor torque are estimated based on the motor primary voltage and the motor primary current, and the motor primary magnetic flux and the motor primary magnetic flux are calculated based on the required output. Determine the motor torque command value, compare the estimated current value of the motor primary magnetic flux and motor torque with the calculated motor primary magnetic flux and motor torque command values to determine the switching pattern, and determine the motor primary current according to the determined switching pattern. In the method of controlling the induction motor by alternating the above, the battery voltage is normally detected by the voltage sensor, and it is assumed that the battery voltage is a predetermined value when the output of the voltage sensor is abnormal. Control method. 8. The control method according to claim 7, wherein the battery voltage detected by the voltage sensor immediately before the output becomes abnormal is set to the predetermined value. 9. The control method according to claim 1, wherein the user is warned that the battery voltage being used is not a value detected by the voltage sensor when the output of the voltage sensor is abnormal. Control method.