JP4710367B2 - Motor drive system - Google Patents

Description

  The present invention relates to a motor drive system, and more particularly to a motor drive system having a zero point adjustment function of a current sensor (current detector).

  In controlling an electric motor (motor), it is necessary to detect a motor driving current with high accuracy. For this reason, the current sensor is configured so that the current sensor zero point (current sensor output value at current = 0) is learned over time by appropriately detecting the current offset of the current sensor and correcting the detected offset. The measurement accuracy is improved.

  For example, in Japanese Patent Laid-Open No. 10-80172 (Patent Document 1), regarding a current sensor (current detector) for detecting a drive current of an electric motor, a time point at which the detected current of the current sensor is maximized and a time point at which the detected current is minimized A configuration is disclosed in which a time interval is sequentially calculated, and a current offset generated in the current sensor is detected based on a change in the time interval between the maximum point and the minimum point obtained sequentially.

  According to the configuration disclosed in Patent Document 1, the offset correction can be performed by appropriately detecting the current offset generated by the current sensor regardless of the state of the electric motor.

  Japanese Patent Application Laid-Open No. 2004-191301 (Patent Document 2) discloses a current offset value calculation apparatus for a semiconductor magnetic sensor generally used as a current sensor mounted on an electric vehicle or the like.

According to the current sensor offset value calculation device disclosed in Patent Document 2, the positive / negative of the detected current is detected with respect to the magnetic flux detection type ammeter (current sensor) provided for measuring the input / output current to the secondary battery. A configuration has been proposed in which the current value detected by the current sensor is calculated as an offset value when the current sensor is switched and the non-energized state is determined. In particular, the current sensor value offset calculating device disclosed in Patent Document 2 detects that the ignition switch has been turned off and determines the non-energized state of the current sensor.
Japanese Patent Laid-Open No. 10-80172 JP 2004-191301 A

  In general, a motor drive device includes a power conversion circuit such as an inverter that converts DC power from a secondary battery into AC power for driving an AC motor. In the power conversion circuit, a switching operation at a high frequency is performed by the power semiconductor element, so that electromagnetic wave noise is generated along with the switching operation. For this reason, not only the spatial and temporal changes of the external magnetic field disclosed in Patent Document 2, but also electromagnetic waves associated with the switching operation of these power semiconductor elements can be noise for the current sensor. In particular, these electromagnetic wave noises may act on a control board on which an integrated circuit (IC) or the like for controlling a current sensor is mounted, thereby reducing the accuracy of offset correction (zero point adjustment).

  A vehicle drive motor mounted on a vehicle such as a hybrid vehicle or an electric vehicle is likely to have severe layout restrictions from the viewpoint of securing passenger space and storage space in the vehicle. Further, since the vehicle driving motor needs to be driven by a relatively large current, the intensity of electromagnetic wave noise accompanying the switching operation in the power conversion circuit is also relatively large.

  Therefore, in a motor drive system in which a plurality of motors and a plurality of motor drive devices are arranged close to each other, such as when a plurality of vehicle drive motors are mounted on a hybrid vehicle or the like, current sensors in each motor drive device In offset correction (zero point adjustment), an error may occur in zero point adjustment due to noise from another motor drive device. In this regard, Patent Documents 1 and 2 do not point out any problem.

  In particular, a vehicle drive motor mounted on a hybrid vehicle needs to control motor output with high accuracy in order to ensure drivability according to a driver's request. In general, motor drive control including output torque control is performed with feedback control of motor drive current. Therefore, if the zero adjustment of the current sensor is not performed properly, the motor drive current may be affected by the detection error of the motor drive current. If the output fluctuates (typically torque pulsation) and the detection error is particularly large, it may lead to the generation of vehicle vibration. Therefore, in such an application, it is particularly necessary to appropriately adjust the zero point of the current sensor to suppress the detection error of the motor drive current.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a motor drive system including a plurality of motors and a motor drive device corresponding to each motor. The zero point adjustment (offset correction) of the current sensor for measuring the current is executed with high accuracy.

  A motor drive system according to the present invention includes a plurality of motors, a motor drive device, a current detector, and a control circuit. The motor driving device is provided corresponding to each of the plurality of motors, and generates a motor driving current for driving the corresponding motor by the switching operation of the power semiconductor element. The current detector is provided corresponding to each motor drive device, and is configured to detect a corresponding motor drive current. The control circuit is configured to control the operation of each motor drive device based on at least the current detected by the current detector. This control circuit corresponds to the first detector for determining the non-energized state in each current detector and the current detector in the current detector determined to be in the non-conductive state by the first determining unit. A second determination means for determining a noise state from a motor drive apparatus other than the motor drive apparatus, and a zero point adjustment of the current detector determined to be in a non-energized state according to the determination by the second determination means Zero point adjusting means.

  According to the motor drive system described above, each current detector (current sensor) is further subjected to a noise state from another motor drive device when no current is supplied from the corresponding motor drive device (inverter circuit). The zero adjustment can be executed after the judgment. Therefore, it is possible to prevent the zero point adjustment from being performed in a state where the output of the current detector does not accurately correspond to the zero current state due to the influence of noise from another motor drive device (inverter circuit). As a result, since the zero point adjustment of the current detector (current sensor) can be performed with high accuracy, the detection accuracy of the motor drive current can be increased and the motor drive control can be performed with high accuracy.

  Preferably, in the motor drive system according to the present invention, the first determination means is that when the switching operation in the motor drive device corresponding to the current detector is stopped, the current detector is in a non-energized state. to decide.

  According to the motor drive system, for each current detector (current sensor), when the switching operation in the corresponding motor drive device (inverter circuit) is stopped, it is determined that the current detector is in a non-energized state. Therefore, the non-energized state of each current detector can be detected easily and accurately.

  Preferably, in the motor drive system according to the present invention, the second determination means executes the zero point adjustment by the zero point adjustment means for the current detector when the switching operation in the other motor drive device is stopped. to approve.

  In the motor drive system, when the switching operation is stopped in another motor drive device (inverter circuit) other than the motor drive device corresponding to the current detector determined to be in the non-energized state, the other motor drive It is determined that the influence of noise from the apparatus is small, and execution of zero adjustment is permitted. For this reason, the zero point adjustment is not performed on the current detector that is determined to be in the non-energized state in a situation where electromagnetic noise due to the switching operation in other motor drive devices has an adverse effect. Can be performed.

  Alternatively, preferably, in the motor drive system according to the present invention, the other motor drive device is stored in the same housing as the current detector determined to be in the non-energized state.

  According to the motor drive device described above, when the switching operation in another motor drive device (inverter circuit) stored in the same housing as the current detector determined to be in a non-energized state is stopped, this current detection is performed. The zero of the instrument is adjusted. Therefore, if the effect of noise from the outside of the housing is reduced by providing the housing with an electromagnetic wave shielding or magnetic shielding function, when switching operation is stopped in another motor drive device housed in the same housing as the current detector. By performing the zero point adjustment, the detection accuracy of the motor drive current can be increased.

  More preferably, the motor drive system according to the present invention is mounted on a vehicle. Each of the plurality of motors is an AC motor configured to generate a driving force of the vehicle, and each motor driving device is an inverter circuit configured to convert DC power into driving power of the AC motor. It is.

  According to the motor drive system described above, the zero adjustment of the current sensor that detects the motor drive current is highly accurate in the control system that controls the drive of an AC motor configured to generate a vehicle drive force such as a hybrid vehicle or an electric vehicle. Can be executed. As a result, the output control of the motor for generating vehicle driving force, which requires high-accuracy output control, has a strict layout constraint, and has a relatively large electromagnetic noise intensity associated with switching operation during driving. High accuracy is realized by improving the detection accuracy of the drive current. As a result, the drivability of the vehicle can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, in the motor drive system provided with the several motor and the motor drive device corresponding to each motor, the zero point adjustment (offset correction) of the current sensor which measures a motor drive current can be performed with high precision.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and detailed description thereof will not be repeated in principle.

  FIG. 1 is a circuit diagram showing a configuration of a motor drive system 100 according to the embodiment of the present invention. The motor drive system 100 is typically mounted on a hybrid vehicle or an electric vehicle.

  Referring to FIG. 1, motor drive system 100 according to an embodiment of the present invention includes a DC power supply 10, a control circuit 15, a discharge resistor 21, a smoothing capacitor 22, and a plurality of motor generators MG1 to be driven. , MG2, MGR, and inverter circuits 40, 50, 60 for supplying motor drive current to motor generators MG1, MG2, MGR, respectively. Inverter circuit 40 is provided with current sensors 41 and 42 for detecting the motor drive current of motor generator MG1. Similarly, the inverter circuit 50 is provided with current sensors 51 and 52 for detecting the motor drive current of the motor generator MG2, and the inverter circuit 60 is provided with current sensors 61 and 52 for detecting the motor drive current of the motor generator MGR. 62 is provided. Inverter circuits 40, 50, 60 and current sensors 41, 42, 51, 52, 61, 62 are housed in the same casing 105 and made into one unit in order to improve the arrangement.

The DC power supply 10 outputs a DC voltage between the power supply line 20 and the earth line 30.
The DC power supply 10 includes a rechargeable secondary battery. Alternatively, the DC power supply 10 may be configured to convert the output voltage of the secondary battery and output it between the power supply line 20 and the earth line 30 by a combination of the secondary battery and the buck-boost converter. In this case, it is possible to convert the DC voltage between the power supply line 20 and the earth line 30 into the charging voltage of the secondary battery by configuring the buck-boost converter so that bidirectional power conversion is possible.

  A discharge resistor 21 and a smoothing capacitor 22 are connected in parallel between the power supply line 20 and the earth line 30. The discharging resistor 21 is provided to discharge the electric charge held in the smoothing capacitor 22 when the DC power supply 10 is disconnected from the power supply line 20 and the earth line 30 by a relay (not shown).

  Inverter circuit 40 has a general three-phase inverter configuration, and includes power semiconductor switching elements (hereinafter also simply referred to as switching elements) Q11 and Q12 that constitute a U-phase arm, and a switching element that constitutes a V-phase arm. Q13, Q14 and switching elements Q15, Q16 constituting the W-phase arm are included. Further, anti-parallel diodes D11 to D16 that flow current from the emitter side to the collector side are connected between the collectors and emitters of the switching elements Q11 to Q16, respectively. As the switching element in this embodiment, for example, an IGBT (Insulated Gate Bipolar Transistor) is applied.

  The switching elements Q11 to Q16 are subjected to on / off control, that is, switching control, corresponding to the switching control signals SG11 to SG16 from the control circuit 15 by corresponding driving circuits T11 to T16.

  An intermediate point of switching elements Q11 and Q12 where a U-phase voltage is generated by switching control is electrically connected to U-phase coil 70U. Similarly, the intermediate point of switching elements Q13 and Q14 where a V-phase voltage is generated is electrically connected to V-phase coil 70V, and a W-phase voltage is generated. Furthermore, the intermediate point of switching elements Q15 and Q16 where W-phase voltage is generated is electrically connected to W-phase coil 70W. Motor generator MG1 is a three-phase permanent magnet motor configured by commonly connecting U-phase coil 70U, V-phase coil 70V and W-phase coil 70W to neutral point N1.

  Current sensors 41 and 42 are provided in at least two phases on the wiring connecting each phase arm of inverter circuit 40 and each phase coil of motor generator MG1. Since the sum of the U-phase, V-phase, and W-phase motor drive currents (instantaneous values) is zero, the motor drive current of each phase can be detected by arranging the current sensors 41 and 42 in two phases. . The current sensors 41 and 42 are typically constituted by semiconductor magnetic sensors using Hall elements, and generate an output voltage corresponding to the passing current of the corresponding wiring. Output voltages (current detection values) from the current sensors 41 and 42 are sent to the control circuit 15.

  Inverter circuit 50 is a three-phase inverter configured similarly to inverter circuit 40, and includes switching elements Q21 to Q26 and antiparallel diodes D21 to D26. Switching elements Q21 to Q26 are on / off controlled (ie, switching controlled) by corresponding driving circuits T21 to T26 in response to switching control signals SG21 to SG26 from control circuit 15, respectively.

  An intermediate point of each phase arm of inverter circuit 50 is electrically connected to U-phase coil 80U, V-phase coil 80V and W-phase coil 80W of motor generator MG2. Similarly to motor generator MG1, motor generator MG2 is a three-phase permanent magnet motor configured such that U-phase coil 80U, V-phase coil 80V, and W-phase coil 80W are commonly connected to neutral point N2.

Current sensors 51 and 52 are provided in at least two phases on the wiring connecting each phase arm of inverter circuit 50 and each phase coil of motor generator MG2. The current sensors 51 and 52 are also typically formed of semiconductor magnetic sensors, and the output voltage (current detection value) is sent to the control circuit 15. The inverter circuit 60 is also configured similarly to the inverter circuits 40 and 50. Switching elements Q31 to Q36 and antiparallel diodes D31 to D36. Switching elements Q31 to Q36 are on / off controlled (ie, switching controlled) by corresponding drive circuits T31 to T36 in response to switching control signals SG31 to SG36 from control circuit 15, respectively.

  An intermediate point of each phase arm of inverter circuit 60 is electrically connected to U-phase coil 90U, V-phase coil 90V and W-phase coil 90W of motor generator MGR, respectively. Similarly to motor generators MG1 and MG2, motor generator MGR is a three-phase permanent magnet motor configured by commonly connecting U-phase coil 90U, V-phase coil 90V and W-phase coil 90W to neutral point Nr.

Current sensors 61 and 62 are provided in at least two phases on the wiring connecting each phase arm of inverter circuit 60 and each phase coil of motor generator MGR. Current sensors 61 and 62 are also typically formed of semiconductor magnetic sensors, and their output voltages (current detection values) are sent to control circuit 15. Motor generators MG1 and MG2 are equipped with motor drive system 100 during powering control. While generating the driving force of the front wheels of the vehicle, the power is generated during regenerative braking control to generate an AC voltage that is the source of the charging voltage of the secondary battery included in the DC power supply 10. The regenerative braking here refers to braking with regenerative power generation when a driver operating a hybrid vehicle or electric vehicle performs a footbrake operation, or turning off the accelerator pedal while driving without operating the footbrake. This includes decelerating the vehicle (or stopping acceleration) while generating regenerative power. Motor generator MGR generates a driving force for the rear wheels of the vehicle on which motor driving system 100 is mounted during powering control. The motor generator MGR also generates power during regenerative braking control, and generates an AC voltage that is a source of charging voltage for the secondary battery included in the DC power supply 10.

  Control circuit 15 controls the operation of motor drive system 100 so that motor drive control is performed in accordance with drive commands (torque command, rotation speed command) of motor generators MG1, MG2, and MGR. In addition to the current detection values obtained by the current sensors 41, 41, 51, 52, 61, 62, the control circuit 15 includes each inverter circuit 40, 50, detected by an appropriately provided sensor (not shown). The input voltage to 60, the rotational speed of motor generators MG1, MG2, and MGR, the coil terminal voltage, and the like are input and used for motor drive control.

  The control circuit 15 applies a DC voltage between the power supply line 20 and the earth line 30 to each phase coil of the motor generator MG1 so that a motor drive current corresponding to the torque command value of the motor generator MG1 is supplied. Switching control signals SG11 to SG16 are generated for conversion to. During regenerative braking control of motor generator MG1, control circuit 15 outputs switching control signals SG11 to SG16 so as to convert the AC voltage generated by motor generator MG1 into a DC voltage between power supply line 20 and ground line 30. appear.

  Further, control circuit 15 generates switching control signals SG21 to SG26, SG31 to SG36 for driving and controlling motor generators MG2 and MGR in the same manner as switching control signals SG11 to SG16.

  For the motor drive control as described above, the control circuit 15 performs feedback control that causes the actual value of the motor drive current to follow the current target value corresponding to the torque command value of the motor generator. The actual value Iact of the motor drive current used for this feedback control is calculated according to the following equation (1), where Idet is the value measured by the corresponding current sensor.

Iact = Idet−Iz (1)
Iz in the equation (1) is a zero value reflecting the current offset, and corresponds to a current sensor detection value when the actual current is zero (Iact = 0). That is, in order to improve the detection accuracy of the motor drive current by the current sensor and perform the motor drive control by the motor drive system 100 with high accuracy, it is necessary to appropriately adjust the zero point of each current sensor.

  FIG. 2 is a flowchart illustrating a zero point adjustment routine of the current sensor in the motor drive system according to the embodiment of the present invention. FIG. 2 shows a zero adjustment routine of current sensors 41 and 42 corresponding to the inverter circuit 40 as an example.

  Referring to FIG. 2, control circuit 15 determines in step S100 whether the operation of inverter circuit 40 corresponding to current sensors 41, 42 is stopped, that is, whether the switching operation of switching elements Q11-Q16 is stopped. Based on the above, it is determined whether or not the current sensors 41 and 42 are in a non-energized state.

  When the operation of the inverter circuit 40 is not stopped (NO determination in step S100), the zero point adjustment cannot be performed because the current sensors 41 and 42 are energized. For this reason, the zero point adjustment routine is ended without performing zero point adjustment.

  On the other hand, when it is determined that the current sensors 41 and 42 are in the non-energized state, when the operation of the inverter circuit 40 is stopped (when YES is determined in step S100), the noise state of the current sensors 41 and 42 is determined. Whether or not the switching operation of other inverter circuits 50 and 60 is stopped is also determined.

  For example, when the operations of the other inverter circuits 50 and 60 are not stopped (when NO is determined in step S110), even if the current sensors 41 and 42 are in the non-energized state, the inverter circuits 50 and 60 There is a possibility that the detection values of the current sensors 41 and 42 do not accurately correspond to the zero current state due to electromagnetic wave noise generated by the switching operation. Therefore, in such a case, the control circuit 15 disables the zero point adjustment and prevents the zero point adjustment error from occurring.

  On the other hand, when the operations of the other inverter circuits 50 and 60 are stopped (when YES is determined in step S110), the control circuit 15 indicates that the current sensors 41 and 42 are in a non-energized state, and It is determined that the influence of noise from other inverter circuits is also small, and execution of zero adjustment is permitted (step S120).

  When executing the zero adjustment, the control circuit 15 samples the measurement data (output value) of each current sensor in a non-energized state (current = 0) a predetermined number of times. When this sampling is executed normally, the zero value (offset value) is updated with the average value of the sampled data (step S130). On the other hand, when sampling is not executed normally, such as when the number of sampling data is insufficient or the sampling data includes an abnormal value, the zero value is not updated.

  During the subsequent operation of the motor drive system, the motor drive current of the motor generator MG1 is detected based on the detection values of the current sensors 41 and 42 by the calculation according to the equation (1) using the zero point value (offset value).

  The current sensor 51 and 52 provided corresponding to the inverter circuit 50 and the current sensor adjustment routine of the current sensors 61 and 62 provided corresponding to the inverter circuit 60 are also configured in the same manner as in FIG. . That is, the non-energized state in step S100 is determined by stopping the operation of the inverter circuit corresponding to each current sensor. In step S110, the current sensor to be zero-adjusted is stopped by stopping the operation of other inverter circuits other than the corresponding inverter circuit. The noise state is determined.

  With such a configuration, in a motor drive system in which a plurality of motors and a plurality of motor drive devices (inverters) corresponding to the respective motors are mounted, the zero point adjustment of the current sensor corresponding to each inverter circuit is performed by another inverter circuit. Can be performed with high accuracy by eliminating the influence of noise.

  In addition, in a semiconductor magnetic sensor using a Hall element, the detection characteristics of the current sensor tend to change depending on the temperature. Therefore, the zero point adjustment of the current sensor can be performed sequentially when the operation of the inverter circuits 40 to 60 is stopped. By doing so, the detection accuracy of the motor drive current can be improved and the motor drive control can be made highly accurate.

  In particular, if the influence of noise from outside the casing is reduced by providing the casing 105 with an electromagnetic shielding function or a magnetic shielding function, high accuracy can be obtained when the operation of other inverter circuits in the same casing is stopped according to the flowchart shown in FIG. Zero adjustment can be performed.

  In addition, regarding the operation stop of each inverter circuit in steps S100 and S110 of FIG. 2, when the operation of the corresponding motor generator is not required depending on the operation situation and the inverter circuit is shut down, the operation stop of the inverter circuit is recognized. It can be set as the structure to do. The shutdown state of the inverter circuit as described above is set in response to, for example, shift position selection in a vehicle on which the motor drive system 100 is mounted.

  FIG. 3 is a block diagram showing the configuration of shift position selection in a vehicle on which the motor drive system 100 is mounted.

  Referring to FIG. 3, shift position selector 150 includes a guide path 155 of a shift lever (not shown), and in response to the position of the shift lever on guide path 155, the shift position selector 150 selects one shift position from a plurality of shift positions. Select one shift position. The driver can change the shift position by moving the shift lever against the urging force.

  On the guide path 155, a position sensor (not shown) for detecting which of the defined shift lever positions 161 to 164 is located is provided. According to the output from the position sensor, the parking position (P position) when the vehicle is stopped, the reverse position (R position) when the vehicle is reverse, the neutral position (N position), and the vehicle forward, respectively corresponding to the shift lever positions 161 to 164 One shift position is selected from the drive position (D position).

  For example, at the parking position (P position) when the vehicle is stopped, the inverter circuits 40 and 50 corresponding to the motor generators MG1 and MG2 can be operated to charge the battery, and the inverter circuit 60 corresponding to the motor generator MGR is shut down. On the other hand, at the neutral position (N position), the operation of each of the inverter circuits 40 to 60 can be shut down.

  As a result, when operating the shift lever from the parking position (P position) to the drive position (D position) via the neutral position (N position) when the vehicle starts to operate, the figure is shown when the neutral position (N position) passes. If a predetermined time (generally about several hundreds [ms]) for normally executing step S130 of step 2 is secured, the zero point adjustment of the current sensor can be performed before the vehicle operation is started. it can.

  In FIG. 3, in addition to the drive position (D position), there are provided subdivided drive positions (for example, 4 positions, 3 positions, 2 positions, L positions, etc.) that limit the number of shift speeds. Also good. In this case, the position sensor may be arranged so as to increase the number of defined shift lever positions according to the number of shift positions.

  Here, the correspondence between the configuration shown in the present embodiment and the configuration of the present invention will be described. Motor generators MG1, MG2, and MGR correspond to the “plurality of motors” of the present invention, and inverter circuits 40, 50, Each of 60 corresponds to a “motor drive device” in the present invention. Further, step S100 in FIG. 2 corresponds to “first determination means” in the present invention, step S110 corresponds to “second determination means” in the present invention, and step S120 corresponds to “zero adjustment means” in the present invention. Corresponding to

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a circuit diagram which shows the structure of the motor drive system according to the embodiment of the present invention. It is a flowchart explaining the zero point adjustment routine of the current sensor in the motor drive system according to the embodiment of the present invention. It is a figure explaining the shift position selection in the vehicle by which the motor drive system according to embodiment of this invention is mounted.

Explanation of symbols

  10 DC power supply, 15 control circuit, 20 power supply line, 21 discharge resistor, 22 smoothing capacitor, 30 ground line, 40, 50, 60 inverter circuit, 41, 41, 51, 52, 61, 62 current sensor, 70U, 80U , 90U U-phase coil, 70V, 80V, 90V V-phase coil, 70W, 80W, 90W W-phase coil, 100 motor drive system, 105 housing, 150 shift position selector, 155 guide path, 161-164 shift lever position, D11 D16, D21-D26, D31-D36 Anti-parallel diode, MG1, MG2, MGR Motor generator, N1, N2, Nr Neutral point, Q11-Q16, Q21-Q26, Q31-Q36 Power semiconductor switching element, SG11- SG13, SG21 to SG23, SG31 to SG33 switching control signals, T11 to T16, T21 to T26, T31 to T36 Power semiconductor switching elements.

Claims (4)

Multiple motors,
A motor driving device that is provided corresponding to each of the plurality of motors and generates a motor driving current for driving the corresponding motor by a switching operation of the power semiconductor element;
A current detector provided corresponding to each of the motor drive devices and configured to detect the corresponding motor drive current;
A control circuit configured to control the operation of each of the motor drive devices based on at least a current detected by the current detector;
The control circuit includes:
First determination means for determining a non-energized state in each of the current detectors;
Second determination for determining a noise state from a motor driving device other than the motor driving device corresponding to the current detector in the current detector determined to be in the non-energized state by the first determining means. Means,
Zero point adjusting means for performing zero point adjustment of the current detector determined to be in the non-energized state according to the determination by the second determining means,
It said first determining means, when the switching operation in the motor driving device corresponding to said current detector is stopped, it is determined that the current detector is the a non-energized state, motors drive system. Multiple motors,
A motor driving device that is provided corresponding to each of the plurality of motors and generates a motor driving current for driving the corresponding motor by a switching operation of the power semiconductor element;
A current detector provided corresponding to each of the motor drive devices and configured to detect the corresponding motor drive current;
A control circuit configured to control the operation of each of the motor drive devices based on at least a current detected by the current detector;
The control circuit includes:
First determination means for determining a non-energized state in each of the current detectors;
Second determination for determining a noise state from a motor driving device other than the motor driving device corresponding to the current detector in the current detector determined to be in the non-energized state by the first determining means. Means,
Zero point adjusting means for performing zero point adjustment of the current detector determined to be in the non-energized state according to the determination by the second determining means,
Said second determination means, when the switching operation in the other motor driving device is stopped, to allow the execution of the zero point adjustment by the zero point adjustment means for the current detector, motors drive system . 3. The motor drive system according to claim 1, wherein the other motor drive device is stored in the same housing as the current detector determined to be in the non-energized state. The motor drive system is mounted on a vehicle,
Each of the plurality of motors is an AC motor configured to generate a driving force of the vehicle,
Each said motor driving device is an inverter circuit configured to convert the DC power to driving power of the AC motor, a motor drive system according to any one of claims 1 to 3.

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