JP3544338B2 - Control device for compressor motor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor control device for driving a compressor having a periodic load variation during one rotation. In particular, the present invention relates to a motor control device for driving a compressor such as an air conditioner and a refrigerator.
[0002]
[Prior art]
In the brushless motor, it is necessary to energize the stator windings of each phase in synchronization with the rotating rotor position. In compressors used in air conditioners, refrigerators, etc., the internal temperature is high, and it is difficult to provide a sensor to detect the rotor position such as a Hall IC. In general, a detection method for obtaining rotor position information is used.
[0003]
In this detection method, the rotor position is determined by detecting the induced voltage generated by the rotation of the rotor-side magnet by using the non-energized winding of the remaining one phase and energizing the two phases of the three-phase winding, and then determining the energized state. This is a method of sequentially switching the phases to be performed.
[0004]
The control of the brushless motor is usually performed by turning on and off the current supply to the stator winding using an inverter including a switching element. When the power is turned off, a surge voltage is generated from the stator winding, and a diode is usually connected in parallel to the switching element to absorb the surge voltage. Because the phase of the induced voltage of the stator winding used for detecting the rotor position advances due to the effect of the return current flowing through the diode, the rotor position is detected earlier than it actually is. Therefore, the timing of commutation switching (commutation) to the stator winding also shifts to the leading side, and the efficiency of the motor deteriorates.
[0005]
When the load fluctuation is large as in the case of a compressor motor, the return current also changes greatly. Therefore, if commutation is performed with a delay corresponding to the load and the number of rotations of the motor, the rotation can be efficiently continued. As a conventional example of a brushless motor control method that performs commutation by delaying the phase by a predetermined angle from the position detection timing, there is JP-A-8-163891.
[0006]
[Problems to be solved by the invention]
However, in the brushless motor control method, load fluctuation during one rotation of the rotor is not considered.
[0007]
On the other hand, as a method of driving a compressor having a single rotary structure having a large load variation during one rotation of the rotor with low vibration and low noise, a load torque variation during one rotation of the rotor is controlled so that the rotation speed during one rotation of the rotor is constant. A method of controlling the motor torque according to the above has been devised.
[0008]
In this motor torque control, in a section where the load torque is large, the motor torque is increased, so that the DC current supplied to the inverter is increased. On the other hand, in a section where the load torque is small, the DC current is small because the motor torque is small.
[0009]
Fluctuations in the load torque during one rotation are generally two to three times the average torque during one rotation. Therefore, when the motor torque control is performed, the amount of change in the DC current increases as compared to when the motor torque control is not performed.
[0010]
When the amount of change in the DC current increases, the amount of change in the return current also increases, so that the amount of change in the phase shift in rotor position detection increases, and as a result, the rotor position detection error also increases.
[0011]
FIG. 1 shows the phase shift of the rotor position detection due to the magnitude of the DC current. (A) in the figure indicates the state, and (B) indicates the mechanical position of the rotor. Here, as shown in FIG. 2, the state is obtained by dividing one rotation of the rotor for each energization mode, that is, for each commutation. In the case of a four-pole brushless motor, the state is divided into twelve, and the state is divided into twelve states (0) to (11). Has a state. However, the conduction modes of the state n and the state n + 6 (n: an integer of 0 to 5) are the same.
[0012]
When the rotational speed of the compressor motor is constant, the larger the load and the larger the DC current, the greater the magnitude of the return current that occurs when shifting from the energized section to the non-energized section, and the position detection signal indicates the mechanical position of the rotor. On the other hand, it is detected promptly. That is, the rotor position detection timing is T1 when the DC current is small, T2 when the DC current is medium, and T3 when the DC current is large, as shown in (c).
[0013]
Therefore, when the DC current changes in the states (4) to (9) as shown in (d), the position detection timing varies in each state as shown in (e).
[0014]
In such a case, when the commutation timing is corrected at a constant delay angle with respect to all the states as in the conventional method shown in (f) Ta, in the states (6) and (7), the rotor position and the commutation timing are corrected. However, in the states (4) and (5), the commutation timing is earlier than the rotor position, and in the states (8) and (9), the commutation timing is later than the rotor position. As a result, there has been a problem that vibration and noise increase and motor efficiency deteriorates.
[0015]
The present invention has been made in view of the above-described problems, and has as its object to provide a compressor motor control device that enables low vibration and low noise of a compressor and high efficiency of a brushless motor that drives the compressor. I do.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, in a compressor motor control device according to the present invention, there is provided a brushless motor driven by an inverter, and a compressor driven by the brushless motor and having periodicity in load fluctuation during one rotation. A rotor position detecting means for detecting a rotor position by detecting an induced voltage of the brushless motor; and a commutation signal of the brushless motor with a phase delayed by a predetermined angle with respect to a signal generation timing from the rotor position detecting means. And a control circuit configured to output the same.
And the control circuit comprises:
A storage unit that stores in advance a phase delay angle of the commutation signal with respect to a signal generation timing from the rotor position detection unit for each rotor position,
The phase delay angle is read from the storage means, and the phase delay angle is changed for each rotor position.
[0017]
[Action]
The control device for the compressor motor detects the mechanical position of the rotor and performs commutation of the motor based on the detected position, while confirming that there is periodicity in the load fluctuation when the compressor makes one rotation. Considering and changing the phase delay angle of the commutation signal using the commutation delay angle pattern stored in the storage means in advance according to the mechanical position of the rotor at the time of commutation, the rotor The mechanical position can be matched with the commutation timing.
[0018]
For example, in the states (4) to (9), when the DC current changes as shown in (d) of FIG. 1, the commutation delay angle is changed in the states (4) and (5) where the DC current is large. The commutation delay angle is set to be medium in the states (6) and (7) where the DC current is medium, and is set to be small in the states (8) and (9) where the DC current is small. The obtained commutation delay angle pattern is stored in the storage means in advance. As a result, the commutation timing can match the mechanical position of the rotor with the commutation timing in the states (4) to (9) as indicated by Tb in FIG.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing an embodiment of a compressor motor control device according to the present invention, and FIG. 4 shows voltage waveforms at various parts of the compressor motor control device of FIG.
[0020]
1 is a commercial AC power supply, 2 is a rectifier circuit for converting AC supplied from the commercial AC power supply 1 to DC, and a DC voltage output from the rectifier circuit 2 is smoothed by a capacitor 3 and then converted to an inverter 4. Supplied to In this figure, the circuit is a full-wave rectifier circuit, but may be a voltage doubler rectifier circuit. Further, a reactor 6 for improving a power factor is provided between the commercial AC power supply 1 and the rectifier circuit 2.
[0021]
The inverter 4 includes six switching transistors 4a to 4f and diodes 40a to 40f. Six switching transistors 4 a to 4 f are connected in a three-phase bridge, and are connected to the three-phase brushless motor 5. In order to protect the switching transistors, diodes 40a to 40f are connected in parallel to the switching transistors 4a to 4f, respectively.
[0022]
Reference numeral 12 denotes a rotor position detection circuit. In FIG. 4, Vu, Vv, and Vw indicate terminal voltage waveforms of three-phase windings of the brushless motor 5 input to the rotor position detection circuit 12.
[0023]
The terminal voltages Vu, Vv, and Vw include information on induced voltages, and are converted into sinusoidal induced voltage waveforms Eu, Ev, and Ew by the induced voltage detection circuits 7a to 7c. The phases of the induced voltage waveforms Eu, Ev, Ew are converted so as to be delayed by 90 ° with respect to the actual induced voltage. Further, in the reference voltage detecting circuit 8, create a virtual neutral point by connecting the 3-phase windings of the brushless motor 5, the reference voltage E _R is the voltage at the virtual neutral point is detected.
[0024]
If the rotor magnetic pole of the brushless motor has four magnetic poles, the rotation of the magnetic pole occurs four times when the rotor rotates once, so that the induced voltage waveforms Eu, Ev, and Ew are generated for two periods. Further, since the brushless motor 5 is connected in a three-phase star connection, the induced voltages generated in the respective windings are shifted from each other by 120 ° in phase.
[0025]
The induced voltage waveform Eu, Ev, compared with comparison detection circuit 9a~9c the Ew and the reference voltage _{E R.} The result of the comparison is the rotor position signal waveforms Hu, Hv, Hw. Induced voltage waveform Eu, Ev, Ew to the High level comparison result when is greater than the reference voltage E _R, assuming that outputs to be Low level when small Conversely, induced changes in the magnetic pole voltage waveform Eu, Ev , Ew, a pulse signal having an edge rising at the zero cross point and falling at the next zero cross point is obtained. Twelve edges of this pulse signal are generated in one rotation, and the absolute position of the rotor can be detected in twelve sections.
[0026]
However, the induced voltage waveforms Eu, Ev, and Ew should be converted into voltage waveforms having a phase delay of 90 ° with respect to the actual induced voltage, but actually flow through the diodes 40a to 40f as shown in FIG. Due to the influence of the return current, the voltage waveform has a phase advanced by θ from the voltage waveform, and the edge of the pulse signal also has a phase advanced by θ.
[0027]
Next, the control circuit 10 will be described. The control circuit 10 generates a drive signal for driving the switching transistors 4a to 4f of the inverter 4 so as to commutate based on the rotor position signal detected by the rotor position detection circuit 12.
[0028]
Here, since the load fluctuation during one rotation of the compressor has a periodicity, the error of the rotor position detection due to the effect of the return current also has a periodicity synchronized with the load fluctuation. Therefore, the commutation delay angle pattern for each mechanical position of the rotor determined empirically is stored in advance in the memory 10A of the control circuit 10 so as to correct the position detection timing detected on the leading side under the influence of the return current. Keep it. That is, data as shown in FIG. 5, which is a commutation delay pattern for each mechanical position of the rotor, is stored in ROM in the control circuit 10 in advance.
[0029]
In the data to be stored in the ROM, the commutation delay angle is set to be large at the mechanical position of the rotor where the position detection advance angle becomes large, and the commutation delay angle is made small at the mechanical position of the rotor where the position detection advance angle becomes small. In addition to the settings, adjustments are made by experiments and simulations so that the vibration and noise of the compressor are low and the efficiency of the brushless motor is high.
[0030]
Then, a predetermined commutation delay angle is read from the memory 10A of the control circuit 10 in accordance with the mechanical position of the rotor, and a drive signal for commutation with a predetermined angle delay is output to the drive circuit 11.
[0031]
The drive circuit 11 performs PWM chopping of the drive signal from the control circuit 10 at several to several tens of kHz, and supplies the PWM drive signal to base terminals of the switching transistors 4a to 4f.
[0032]
In the above embodiment, the commutation delay angle pattern for each mechanical position of the rotor is always constant. However, in order to improve control performance, it is preferable to have a plurality of commutation delay angle patterns. Hereinafter, an embodiment having a plurality of commutation delay angle patterns will be described.
[0033]
(Second embodiment)
In a single-rotor compressor, the load during one rotation greatly changes as shown in FIGS. An embodiment to which the present invention is applied when controlling the motor torque according to the load fluctuation will be described with reference to FIGS.
[0034]
In the motor torque control, the motor torque correction amount is large in the section where the load torque is large as in (b) and (b ′), and the motor torque correction amount is small in the section where the load torque is small. Here, the average load torque of (a) is N1, and the average torque of (a ') is N2. When the average load torques are different, the motor torque correction amounts are different from each other as shown in (b) and (b '). Since the DC current changes according to the motor torque correction amount, the lead angle also changes if the motor torque correction amount differs even at the same rotor position.
[0035]
Therefore, the correction amount of the motor torque is divided into a plurality of regions, and a plurality of commutation delay angle patterns for each rotor position are stored in advance in the memory 10A of the control circuit 10 for each region as shown in FIG. The control circuit 10 reads out the data of the commutation delay angle pattern corresponding to the motor torque correction amount from the memory 10A and uses it every time the mechanical position of the rotor is detected. Accordingly, even when the patterns of the motor torque correction amounts are different as shown in (b) and (b ') because the average load torques are different, according to the respective motor torque correction amounts as shown in (c) and (c'). Therefore, the control performance can be improved because the commutation delay angle pattern is created. The same applies to the case where a motor torque control method for correcting the motor torque using the torque pattern of the load torque is used.
[0036]
(Third embodiment)
FIG. 8 shows experimental data obtained by measuring the relationship between the rotation speed of the motor 5 and the error in detecting the rotor position signal when there is almost no load fluctuation during one rotation, and therefore there is almost no change in the DC current during one rotation. It can be seen that the position detection advance angle of the rotor position signal shifts to the delay side as the rotation speed of the motor 5 increases.
[0037]
Therefore, the range of the number of rotations of the motor 5 is divided into a plurality of regions, and a plurality of commutation delay angle patterns for each mechanical position of the rotor are stored in the memory 10A of the control circuit 10 in advance as shown in FIG. Remember. The control circuit 10 reads the commutation delay angle pattern corresponding to the rotation speed of the motor 5 from the memory 10A and uses it to improve control performance when the rotation speed of the motor 5 changes.
[0038]
(Fourth embodiment)
When a plurality of commutation delay angle patterns are stored in the memory 10A as in the third embodiment, when the commutation delay angle patterns are separately stored as the reference value and the correction amount as shown in FIGS. Space can be saved.
[0039]
In this case, as a procedure for determining the commutation delay angle, a reference value of the commutation delay angle is read from the data shown in FIG. The correction amount of the commutation delay angle according to the number is read from the data shown in FIG. 11 stored in the memory 10A. The finally set commutation delay angle is the sum of the two.
[0040]
For example, when the rotation speed of the motor 5 is 2050 rpm and the state is (5), the reference value 15 ° is read from the data shown in FIG. 10 and the correction amount 20 ° is read from the data shown in FIG. The added 35 ° becomes the actual commutation delay angle.
[0041]
In the present embodiment, the reference value and the correction amount are set such that the sum of the reference value and the correction amount becomes the commutation delay angle, but the value obtained by multiplying the reference value and the correction amount is the commutation delay angle. The reference value and the correction amount may be set so that the commutation delay angle is obtained by an operation other than addition, such as
[0042]
(Fifth embodiment)
FIG. 12 shows experimental data obtained by measuring the relationship between the rotational speed and the DC current of the motor 5 and the relationship between the detection error of the rotor position signal and the load when there is almost no change in load during one rotation and therefore there is almost no change in DC current during one rotation. It can be seen that the phase advance angle of the rotor position signal shifts to the delay side as the rotation speed of the motor 5 increases, and shifts to the advance side as the load increases and the DC current that increases increases.
[0043]
Therefore, a compressor that is driven by the motor 5 is provided with a load detector for detecting a load, a signal from the load detector is input to the control circuit 10, and the number of revolutions of the motor 5 and the load state of the compressor are set as parameters. By adjusting the commutation delay angle, the mechanical position of the rotor and the commutation timing can be more accurately matched. As a procedure for adjusting the commutation delay angle, the number of rotations of the motor and the load state of the compressor are divided into a plurality of regions, and a plurality of commutation delay angle patterns for each of the rotor positions are previously determined for each region as shown in FIG. It is stored in the memory 10A of the control circuit 10. The control circuit 10 reads out and uses the commutation delay angle pattern corresponding to the rotation speed and the load state of the motor 5 from the memory 10A, thereby controlling when the rotation speed of the motor 5 and the load state of the compressor change. Performance can be improved.
[0044]
(Sixth embodiment)
In the case where there are a plurality of commutation delay angle patterns as in the fifth embodiment, the ROM capacity of the control circuit 10 can be saved by storing them separately as the reference value and the correction amount as shown in FIGS. it can.
[0045]
In this case, as a procedure for determining the commutation delay angle, a reference value of the commutation delay angle is read from the data shown in FIG. Accordingly, the amount of correction of the commutation delay angle corresponding to the rotation speed of the motor and the load state of the compressor is read from the data shown in FIG. 14 stored in the memory 10A. The finally set commutation delay angle is the sum of the two.
[0046]
For example, when the rotation speed of the motor 5 is 2050 rpm, the load state of the compressor is the state II, and the state is (5), the reference value 15 ° is read from FIG. 10 and the correction amount 15 ° is read from FIG. 30 ° obtained by adding the two is the actual commutation delay angle.
[0047]
In the present embodiment, the reference value and the correction amount are set such that the sum of the reference value and the correction amount becomes the commutation delay angle, but the value obtained by multiplying the reference value and the correction amount is the commutation delay angle. The reference value and the correction amount may be set so that the commutation delay angle is obtained by an operation other than addition, such as
[0048]
(Seventh embodiment)
The relationship between the rotational speed of the motor, the DC current, and the detection error of the rotor position signal shown in FIG. 12 has the same relationship even if the DC current is replaced with a motor winding current or an AC power supply current. The magnitude of these currents which increases with an increase in the load increases from the value at the time of the reference load of the PWM duty for adjusting the voltage or current applied to the brushless motor 5 at the power consumption or the current rotational speed of the motor. It is also possible to estimate from the amount of reduction. Therefore, by using these as means for estimating the load in the fifth embodiment and the sixth embodiment, it is possible to make the mechanical position of the rotor coincide with the commutation timing.
[0049]
The above embodiments may be implemented in combination to improve the control performance.
[0050]
【The invention's effect】
According to the present invention, since the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal output from the rotor position detection means changes for each rotor position, the mechanical position of the rotor and the commutation timing are matched. It becomes possible. Thereby, low vibration and low noise of the compressor can be achieved.
[0051]
Further, according to the present invention, the motor torque is corrected according to the load fluctuation of the compressor, so that the load torque matches the motor torque. Further, since the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal output from the rotor position detecting means switches is changed for each rotor position in accordance with the correction amount of the motor torque, when the motor torque is corrected, Also, the commutation timing can be matched with the mechanical position of the rotor. Thereby, low vibration and low noise of the compressor can be achieved.
[0052]
Further, according to the present invention, the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal output from the rotor position detecting means switches is changed for each rotor position according to the number of rotations of the motor. Even when the number greatly varies, the mechanical position of the rotor and the commutation timing can be matched. Thereby, low vibration and low noise of the compressor can be achieved.
[0053]
Further, according to the present invention, the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal output from the rotor position detecting means switches to a reference angle corresponding to the motor speed and a correction angle for correcting the reference angle. Since they are stored separately, the storage capacity is reduced. Thereby, the capacity of the storage unit can be saved.
[0054]
Further, according to the present invention, the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal output from the rotor position detecting means switches is changed for each rotor position according to the rotation speed of the motor and the load state of the compressor. Therefore, even when the rotational speed of the motor or the load state of the compressor greatly fluctuates, the mechanical position of the rotor and the commutation timing can be matched. As a result, the number of rotations of the motor and the load range of the compressor that can reduce the vibration and noise of the compressor can be expanded.
[0055]
Further, according to the present invention, the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal output from the rotor position detecting means switches is set to a reference angle corresponding to the motor speed and the reference angle is set to the motor speed and compression. Since the data is stored separately for the correction angles to be corrected according to the load state of the machine, the storage capacity is reduced. Thereby, the capacity of the storage unit can be saved.
[0056]
Further, according to the present invention, the compressor is provided with the DC current detecting means for detecting the DC current supplied to the inverter, and the load state of the compressor is estimated based on the DC current. Therefore, the load torque detector is provided in the compressor. Eliminates the need.
[0057]
Thereby, cost reduction can be achieved.
[0058]
Further, according to the present invention, the rectifier circuit that supplies the DC current to the inverter includes the AC current detection unit that detects the AC current supplied from the commercial power supply, and estimates the load state of the compressor based on the AC current. Therefore, it is not necessary to provide a load torque detector in the compressor.
[0059]
Thereby, cost reduction can be achieved.
[0060]
Further, according to the present invention, a motor is provided with a motor current detecting means for detecting a motor current flowing through a winding of the brushless motor, and a load state of the compressor is estimated based on the motor current. There is no need to provide
[0061]
Thereby, cost reduction can be achieved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a shift in rotor position detection timing due to a change in DC current. FIG. 2 is a diagram showing a relationship between a state, a mechanical angle and an electrical angle, and each energizing mode. FIG. 3 is an embodiment of the present invention. FIG. 4 is a diagram showing a terminal voltage, an induced voltage, and a rotor position signal of a compressor motor according to an embodiment of the present invention. FIG. 5 is a diagram showing a rotor according to an embodiment of the present invention. FIG. 6 is a diagram showing a commutation delay angle pattern for each mechanical position of FIG. 6. FIG. 6 is a diagram showing a relationship between a motor torque correction amount and a commutation delay angle when motor torque control is performed. FIG. 8 is a diagram illustrating a commutation delay angle pattern for each mechanical position of the rotor according to the second embodiment. FIG. 8 is a characteristic diagram illustrating a relationship between a motor rotation speed and a detection error of a rotor position. Commutation delay angle pattern for each mechanical position of rotor of third embodiment FIG. 10 is a diagram showing a commutation delay angle reference value according to the fourth and sixth embodiments of the present invention. FIG. 11 is a mechanical position of a rotor according to a fourth embodiment of the present invention. FIG. 12 is a graph showing a commutation delay angle correction amount for each motor. FIG. 12 is a characteristic diagram showing characteristics of a detection error of a rotor position with respect to a rotation speed of a motor and a DC current. FIG. 14 is a diagram showing a commutation delay angle pattern for each mechanical position of FIG. 14. FIG. 14 is a diagram showing a commutation delay angle correction amount for each mechanical position of a rotor according to a sixth embodiment of the present invention.
1. 1. AC power from commercial power Rectifier circuit 3. Capacitor 4. Inverter 5. 5. Three-phase brushless motor Reactors 7a to 7c. 7. Induced voltage detection circuit Reference voltage detection circuits 9a to 9c. 10. Comparison detection circuit Control circuit 11. Drive circuit 12. Rotor position detecting circuits 4a to 4f. Switching transistors 40a to 40f. Diode 10A. memory

Claims (12)

A brushless motor driven by an inverter, a compressor driven by the brushless motor and having periodic load fluctuations during one rotation, and a rotor position detection for detecting an induced voltage of the brushless motor to detect a rotor position Means, and a control circuit configured to output a commutation signal of the brushless motor by delaying a phase by a predetermined angle with respect to a timing at which a signal level of a pulse signal output from the rotor position detection means switches. In the control device of the compressor motor,
The control circuit includes:
A storage unit that stores in advance the phase delay angle of the commutation signal with respect to the timing at which the signal level of the pulse signal switches for each rotor position,
A controller for a compressor motor, wherein the phase delay angle is read from the storage means and the phase delay angle is changed for each rotor position. The control circuit includes:
A storage unit that divides the correction amount of the motor torque into a plurality of regions and stores in advance the phase delay angle for each rotor position in each region,
Correcting the motor torque of the brushless motor so as to suppress a change in rotation speed during one rotation of the brushless motor according to a load change during one rotation of the compressor,
The compression according to claim 1, wherein the phase delay angle corresponding to the correction amount of the motor torque is read from the storage unit for each rotor position, and the phase delay angle is changed for each rotor position. Machine motor control device. The control circuit includes:
A plurality of motor torque patterns corresponding to a load change during one rotation of the compressor and storage means for storing in advance the phase delay angle for each rotor position for each motor torque pattern;
Correcting the torque of the brushless motor based on the motor torque pattern, reading the phase delay angle corresponding to the motor torque pattern from the storage unit for each rotor position, and changing the phase delay angle for each rotor position The control device for a compressor motor according to claim 1, wherein With a rotation speed calculation unit that calculates the rotation speed of the brushless motor based on a signal output from the position detection unit,
The control circuit includes:
The brushless motor includes a storage unit that divides a range of the number of rotations into a plurality of regions and stores the phase delay angle for each rotor position in advance for each region,
The compression according to claim 1, wherein the phase delay angle corresponding to the rotation speed of the brushless motor is read from the storage unit for each rotor position, and the phase delay angle is changed for each rotor position. Machine motor control device. A brushless motor driven by an inverter, a compressor driven by the brushless motor and having periodic load fluctuations during one rotation, and a rotor position detection for detecting an induced voltage of the brushless motor to detect a rotor position A control circuit configured to output a commutation signal of the brushless motor by delaying a phase by a predetermined angle with respect to a timing at which a signal level of a pulse signal output from the rotor position detection means switches; A rotation speed calculation means for calculating the rotation speed of the brushless motor based on a signal output from the means,
The control circuit includes:
The brushless motor further includes a storage unit that divides a range of the number of rotations of the brushless motor into a plurality of regions, and stores in advance a reference angle serving as a reference for each region and a correction angle for correcting the reference angle for each rotor position.
The reference angle and the correction angle corresponding to the number of rotations of the brushless motor are read from the storage unit for each of the rotor positions, and the calculation results of the reference angle and the correction angle with respect to the timing at which the signal level of the pulse signal is switched A controller for a compressor motor, wherein a phase delay angle of the commutation signal is used, and the phase delay angle is changed for each rotor position. Rotation speed calculation means for calculating the rotation speed of the brushless motor based on a signal from the position detection means,
Load detection means for detecting a load state of the compressor,
With
The control circuit includes:
Storage means for dividing the rotation speed of the brushless motor and the load state of the compressor into a plurality of regions, and storing the phase delay angle for each rotor position in advance for each region of the rotation speed and the load state,
The phase delay angle corresponding to the rotation speed of the brushless motor and the load state of the compressor is read from the storage unit for each rotor position, and the phase delay angle is changed for each rotor position. The control device for a compressor motor according to claim 1. A brushless motor driven by an inverter, a compressor driven by the brushless motor and having periodic load fluctuations during one rotation, and a rotor position detection for detecting an induced voltage of the brushless motor to detect a rotor position A control circuit configured to output a commutation signal of the brushless motor by delaying a phase by a predetermined angle with respect to a timing at which a signal level of a pulse signal output from the rotor position detection means switches; A control unit for a compressor motor, comprising: a rotation speed calculation unit that calculates a rotation speed of the brushless motor based on a signal output from the unit; and a load detection unit that detects a load state of the compressor.
The control circuit divides the number of rotations of the brushless motor and the load state of the compressor into a plurality of regions, and a reference angle serving as a reference for each region of the number of rotations and the number of rotations and the region of the load state. Storage means for storing in advance a correction angle for correcting the reference angle for each rotor position,
The reference angle and the correction angle corresponding to the rotation speed of the brushless motor and the load state of the compressor are read from the storage unit for each rotor position, and the calculation result of the reference angle and the correction angle is read by the pulse signal. A phase delay angle of the commutation signal with respect to a timing at which the signal level changes, and changing the phase delay angle for each rotor position. Along with a rotation speed calculation unit that calculates the rotation speed of the brushless motor based on a signal from the position detection unit,
The control circuit includes:
Storage means for dividing the rotation speed of the brushless motor and the load state of the compressor into a plurality of regions, and storing the phase delay angle for each rotor position in advance for each region of the rotation speed and the load state,
The load state of the compressor is estimated to read the phase delay angle corresponding to the rotation speed of the brushless motor and the load state of the compressor for each rotor position from the storage unit for each rotor position. The control device for a compressor motor according to claim 1, wherein the phase delay angle is changed. A brushless motor driven by an inverter, a compressor driven by the brushless motor and having periodic load fluctuations during one rotation, and a rotor position detection for detecting an induced voltage of the brushless motor to detect a rotor position A control circuit configured to output a commutation signal of the brushless motor by delaying a phase by a predetermined angle with respect to a timing at which a signal level of a pulse signal output from the rotor position detection means switches; A rotation speed calculation means for calculating the rotation speed of the brushless motor based on a signal output from the means,
The control circuit includes:
A rotation angle of the brushless motor and a load state of the compressor are divided into a plurality of regions, and a correction angle for correcting the reference angle for each of the rotation speed and the load state and a reference angle for each rotor position. Comprising storage means for storing in advance,
The reference angle and the correction angle corresponding to the rotation speed of the brushless motor and the load state of the compressor are read from the storage unit for each rotor position by estimating the load state of the compressor, and the reference angle is read. And calculating a result of calculating the correction angle as a phase delay angle of the commutation signal with respect to a timing at which the signal level of the pulse signal switches, and changing the phase delay angle for each rotor position. apparatus. A DC current detecting means for detecting a DC current supplied to the inverter;
The control circuit estimates a load state of the compressor based on the DC current. The control device for a compressor motor according to claim 8 or 9, wherein: A rectifier circuit that supplies a DC current to the inverter includes an AC current detection unit that detects an AC current supplied from a commercial power supply,
10. The compressor motor control device according to claim 8, wherein the control circuit estimates a load state of the compressor based on the AC current. A motor current detecting means for detecting a motor current flowing through the winding of the brushless motor by at least one current sensor,
10. The compressor motor control device according to claim 8, wherein the control circuit estimates a load state of the compressor based on the motor current.

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