WO2019065545A1 - Motor drive control device, motor drive device, and electric vehicle having said motor drive device - Google Patents

Abstract

Provided is a motor drive control device capable of reducing the number of components, costs, and space and weight. This motor drive control device (22) is a motor drive control device for controlling motor equipment (MS) in which a plurality of systems of electrodes of the phases of a U-phase, a V-phase and a W-phase are provided in a plurality of three-phase motors (61), (62). This motor drive control device has: current sensors for detecting the currents flowing in the phases of the U-phase, V-phase, and W-phase of each system; and a motor drive control unit (19) which separately controls each system on the basis of the currents detected by the current sensors. At least one current sensor among the current sensors for detecting the currents of the three phases of each system is a contactless current sensor for commonly detecting the current of one phase in each of two systems, and the remaining phase current sensors are current sensors for performing detection separately.

Description

Motor drive control device, motor drive device, and electric vehicle equipped with the motor drive device Related application

This application claims priority of Japanese Patent Application No. 2017-184595 filed on September 26, 2017, and Japanese Patent Application No. 2018-026140 filed on February 16, 2018, the entire contents of which are incorporated herein by reference. It is quoted as making a part of the present application.

The present invention relates to a motor drive control device, and relates to a technology capable of reducing the number of parts, cost and weight. The present invention also relates to a motor drive device and an electric vehicle equipped with the motor drive device, and more particularly to a technology for improving control performance while providing redundancy for an abnormality of a current sensor provided in the motor drive device.

When current feedback control is performed on a three-phase motor, detection of three-phase current is performed using a current sensor or the like, and control is performed so that the detected current approaches the command current. It is also possible to detect two of the three phases and control using the fact that the sum of the three phases is zero, without detecting all three phase currents.

In addition, in order to detect an abnormality in the current sensor, it is possible to detect the current of all three phases by taking care of a part where the current detection of two phases is usually sufficient, and to detect an abnormality depending on whether the sum of three phases is zero or not. is there. Conventionally, there has been proposed a technique for determining an abnormality when the sum of three-phase current detection values deviates from a predetermined range (Patent Document 1).

Moreover, the three-phase alternating current motor currently used as a drive source in many electric vehicles can exhibit the performance by sending an optimal current according to a motor angle. Therefore, current feedback control is often performed by detecting the amount of current with a current sensor attached to a three-phase power line.

A method is often used in which current sensors are attached to two phases and the remaining one phase is obtained by calculation based on the principle that the current flowing through the three-phase power line of the three-phase AC motor becomes zero when summed. The merits are for size and weight reduction by cost reduction, cost reduction, and simplification of control by reducing the number of parts. Simplification of control means calculating the target value of the current when the calculation based on the actual measurement of the three-phase current does not mean that the total of the three-phase current becomes zero due to the error or noise of the current sensor Although it is necessary to handle the model equation of vector control operation for the purpose of including an error, if it is a method of obtaining the current value of the remaining one phase from the current value of two phases, the model equation of vector control operation is It is the point which can be applied as it is. Here, noise mainly refers to noise that is superimposed on the output of the current sensor due to switching noise when performing current control. As described above, when noise is superimposed on the output of the current sensor, for example, the control device undesirably performs current control to induce undesirable torque fluctuation, and this is observed as vibration or noise, so that this effect can be reduced It is a constant issue.

JP, 2015-173554, A Japanese Patent Application Laid-Open No. 6-253585 JP, 2014-72973, A JP 2006-352949 A

Patent Document 1 gives an example in which two sets of three-phase energizing circuits are provided, in which case six current sensors are required. Although Patent Document 1 exemplifies a motor provided with two energizing circuits (three-phase coils) in one motor, six currents can be used even when two motors provided with a pair of energizing circuits are used. A sensor is required. Using as many as six current sensors is disadvantageous in terms of cost, space and weight. In particular, when handling large currents, non-contact type current sensors such as Hall type, CT type, Rogowski coil type are often used for reasons of loss and safety. This is disadvantageous in cost, space and weight.

An object of the present invention is to provide a motor drive control device capable of reducing the number of parts, cost and space and weight.

In addition, as a demerit when attaching and controlling the current sensor in only two phases, if an abnormality occurs in either one of the current sensors, current control is performed based on the abnormal current value to be output, and the abnormal large current Can cause the motor or motor drive to overheat, or cause the vehicle to generate an unintended torque, which improves the safety performance of the vehicle and maintains the performance even when an abnormality occurs. Diagnostic methods or remedies have been proposed.

In patent document 2, when the current sensor is attached to all three phases and current is detected using the principle that the total of the previous three-phase current amounts becomes zero, the sum of the obtained current amounts does not become zero. There is proposed a configuration for detecting that any current sensor is abnormal (when the difference from zero exceeds a specified value). In this method, although the occurrence of an abnormal state of the current sensor can be detected, it can not be detected which current sensor is abnormal.

Focusing on this point, Patent Document 3 proposes a configuration adopting a process capable of specifying which current sensor is abnormal from current values obtained by attaching current sensors to all three phases. ing. In Patent Document 4, the purpose of detecting an abnormality is common, but providing another phase of the current sensor in addition to the two-phase current sensor necessary for control for the abnormality detection is a space and From the viewpoint of being disadvantageous in terms of cost, a method has been proposed in which a current of a specific pattern for detecting an abnormality is supplied to detect an abnormality of the current sensor.

In any case, the recognition of the importance of the abnormality detection of the current sensor is consistent. In Patent Document 3, an abnormal current sensor is identified, and it is emphasized to prevent a decrease in traveling performance with a normal current sensor that remains even in the case of a single phase abnormality. Patent Document 4 is proposed for the purpose of space reduction and cost reduction by eliminating the current sensor for one phase used only at the time of abnormality detection, which is unnecessary at normal times.

In any case, the number of current sensors installed above the minimum required number is used only for anomaly detection and anomaly substitution, and it is used for anomaly detection and anomaly substitution. There is room to contribute to the improvement of control performance.

Another object of the present invention is to provide a motor drive device capable of improving noise resistance performance and improving control performance while achieving redundancy of a control system, and an electric vehicle provided with this motor drive device. It is.

Hereinafter, the present invention will be described with reference to the reference numerals of the embodiments for the sake of convenience to facilitate understanding.

A motor drive control device 22 according to a first configuration of the present invention is a system of U-phase, V-phase and W-phase three-phase electrodes in one three-phase motor or a plurality of three-phase motors A motor drive control device for controlling a plurality of motor equipments MS provided across the motor,
The motor drive control unit 19 is provided with current sensors for detecting the currents flowing through the U-phase, V-phase and W-phase of the respective systems in all phases, and individually controlling the respective systems by the currents detected by these current sensors. Have
One of the current sensors for detecting the current flowing through the U phase, the V phase and the W phase of each system is a common current sensor for detecting the current of each phase in two systems, and this common Is a non-contact current sensor.

According to this configuration, the motor drive control unit 19 individually controls each system by means of a current sensor that detects the current flowing through each individual phase of each system. Among the current sensors, one current sensor is a common current sensor that detects the current of one phase in each of two systems, and the common current sensor is a non-contact current sensor. For example, the remaining phase current sensors are current sensors that are individually detected. When the motor installation MS includes two systems of three-phase electrodes, separate current sensors are used for any two phases of U-phase, V-phase and W-phase of each system, and the remaining phase of the two systems is used. Pass the non-contact current sensor common to (in phase).

For example, when each current sensor is normal, the motor drive control unit 19 can individually control each system using an individual current sensor of each system. When the current sensor is commonly used in two systems, the sum of the three phases can not simply be obtained, and therefore the sum of the currents is calculated including another system using the commonly used current sensor. Thus, the normal abnormality of the current sensor can be determined. As described above, the current of one phase in the two systems is passed through a common non-contact current sensor, thereby reducing the number of component current sensors, reducing cost, space and weight. Can be

A control target in the current detected by the common current sensor using the fact that the sum of three-phase currents is zero from the currents respectively detected by the common current sensor and the current sensors of the remaining phases The current detection unit 23 may be provided to calculate the current flowing through the system of In this case, the motor drive control unit 19 can individually control each system finely using the current calculated by the current detection unit 23. The term "to be zero" includes a "range around zero" in which the detection error of the current sensor is taken into consideration. The following "being zero" also includes "a range near zero" in consideration of the detection error of the current sensor. The “near-zero range” is set, for example, from a test or simulation.

When the sum of the currents respectively detected by the common current sensor and the current sensors of the remaining phases becomes zero, the common current sensor and the current sensors of the remaining phases are determined to be normal, and When the sum does not become zero, the common current sensor and the remaining phase current sensor may have an abnormality detection unit 24 that determines that one or both of the current sensors are abnormal. In this case, the motor drive control unit 19 can control each system individually based on the determination result by the abnormality detection unit 24.

The motor drive control unit 19 may control the respective systems individually using only the current detected by the current sensor of the remaining phase. In this case, the control system can be simplified and the processing load can be reduced.

When any of the current sensors is determined to be abnormal by the abnormality detection unit 24, the motor drive control unit 19 stops the energizing circuit 16 connected to all the systems for driving the motor 6, and the abnormality is detected. The detection unit 24 may detect the current with each current sensor and determine that the current sensor whose current does not become zero is abnormal. In this case, it is possible to easily determine an abnormal current sensor by temporarily stopping the energizing circuits 16 connected to all the systems.

When any one of the current sensors is determined to be abnormal by the abnormality detection unit 24, the motor drive control unit 19 stops the conduction circuit 16 connected to one system, and the common current sensor performs one phase The abnormality detection unit 24 determines whether or not the sum of the currents respectively detected by the common current sensor and the current sensors of the remaining phases becomes zero with respect to the system in which the current flows. The current sensor which becomes In this case, it is possible to determine the abnormal current sensor without completely stopping the driving of the motor 6 while maintaining the system in which the current flows.

When the motor drive control unit 19 stops the energizing circuit 16 connected to one system, the abnormality detection unit 24 detects the current detected by the current sensor of the remaining phase for the stopped system. The current sensor which becomes abnormal may be determined depending on whether it becomes zero or not. Also in this case, it is possible to determine the abnormal current sensor without completely stopping the driving of the motor 6.

When one of the current sensors is determined to be abnormal by the abnormality detection unit 24, the motor drive control unit 19 stops the energizing circuit 16 connected to one system, and the abnormality detection unit 24 causes a current to flow. With regard to the system, when there is a system in which the sum of the currents respectively detected by the common current sensor and the current sensors of the remaining phases is zero, it may be determined that the common current sensor is normal.

The rotational speed detection means 26 for detecting the rotational speed of the motor 6 is provided, and the abnormality detection unit 24 calculates a back electromotive voltage according to a condition determined from the rotational speed detected by the rotational speed detection means 26. Abnormality detection may be performed when the back electromotive force does not exceed the power supply voltage. The predetermined condition is a condition arbitrarily determined by design or the like, and is determined by, for example, finding an appropriate condition by either or both of a test and a simulation. The "rotational speed" is a rotational speed per unit time, and is synonymous with "rotational speed". According to this configuration, the abnormality detection of the current sensor can be performed with high accuracy by performing the abnormality detection when the calculated back electromotive force does not exceed the power supply voltage. When the back electromotive force exceeds the power supply voltage, even if the energizing circuit 16 is stopped, the electric power generated by the motor 6 causes a current to flow from the motor 6 to the battery 18 via the energizing circuit 16. The current of the system that has stopped is not zero.

When the motor equipment MS includes two or more motors 6 and the motor drive control unit 19 stops the energizing circuit 16 connected to the system of a part of the motors 6 among the plurality of motors 6, the motor is energized. The command torque of the motor 6 in which the energizing circuit 16 is stopped may be increased with respect to the command torque of the motor 6 in which the circuit 16 is not stopped. A desired motor torque can be maintained by thus increasing the command torque of the stopped motor 6.

When a current sensor that detects a current of one phase of any one system is determined to be abnormal by the abnormality detection unit 24, the motor drive control unit 19 individually detects another phase of the one system. From the sum of individual current sensors that detect the current of another system phase and a common current sensor to the common current sensor of the energizing circuit 16 connected to the one system The current of may be calculated to perform current control. In this case, even if it is determined that the current sensor that detects the current of one phase of any one system is abnormal, the current control can be performed by the remaining current sensors.

A motor drive device according to a second configuration of the present invention is a motor drive device 106 for driving a three-phase AC motor 104 serving as a drive source for traveling an electric vehicle, comprising: a current drive circuit 108; A current sensor S for detecting the current flowing to the circuit 104, and a control device 109 for providing a drive signal of the current to the current drive circuit 108 based on the given torque command and the current detected by the current sensor S;
As the current sensor S, a pair of current sensors capable of detecting the magnitude and the direction of the current are provided in directions facing each other and in any two phases in three phases, respectively.
The control device 109 superimposes the difference between the currents respectively detected by the pair of current sensors for each phase in the two phases including the pair of current sensors, and superimposes them on the output of the pair of current sensors And differential operation means 116 for performing current control using each of the obtained current values.

According to this configuration, controller 109 provides a current drive signal to current drive circuit 108 based on the torque command and the current detected by current sensor S. For example, when all the current sensors are normal, among the current values received by the differential operation means 116, the output of the current sensor as a pair attached in two phases is adopted. The differential operation means 116 takes, for example, the difference between the two outputs of the current sensors facing each other, applies a gain so as to make the magnification a factor of 1 if necessary, and uses it as the current value used for current control.

By the way, if it is an ideal state without noise, even if the difference of the output of a pair of current sensors is taken, there is no difference even if the output of one current sensor is used without taking the difference. However, in-phase noise may be superimposed on the output of each of the oppositely mounted current sensors. The cause of the in-phase noise is, for example, switching noise when performing current control. Therefore, the differential operation means 116 takes the difference between the currents respectively detected by the pair of current sensors, cancels out the common phase noise superimposed on the output of the pair of current sensors, and obtains the obtained current value Each is used to perform current control. Thereby, an effect similar to that of a so-called operation amplification circuit is expected, and removal of in-phase noise can be expected. Therefore, by preventing undesired current control, undesired torque fluctuation can be suppressed, and improvement in control performance can be expected.

The control device 109 has an abnormality detection means 114 which takes in the output of the current sensor as the pair, determines whether the obtained current value satisfies a predetermined conditional expression, and detects an abnormality of the current sensor. It may be The “determining whether the obtained current value satisfies a predetermined conditional expression” is, for example, comparing the sum of the obtained current values with a threshold value. The threshold is a threshold arbitrarily determined by design or the like, and is determined by finding an appropriate threshold by, for example, one or both of a test and a simulation. In this case, the absolute values of the obtained current values will match if both of the current sensors that are mounted opposite to each other are normal, but if either one of the current sensors has an abnormality, the result is different It is possible to detect an abnormality in the current sensor on the basis of the occurrence of

When the difference between the current value obtained by adding the outputs of the pair of current sensors and the threshold value arises, the abnormality detection unit 114 determines that one of the current sensors of the pair is abnormal. You may diagnose that there is. The threshold is a threshold arbitrarily determined by design or the like, and is determined by finding an appropriate threshold by, for example, one or both of a test and a simulation. In this case, when the outputs of the oppositely attached current sensors are added, if the paired current sensors are both normal, the result of the addition is approximately zero or a constant, and the abnormality of the current sensors is diagnosed be able to.

When the abnormality detection means 114 determines that one of the current sensors in the pair is abnormal, the control device 109 causes a current to flow as an abnormal point diagnosis current only in the phase provided with the current sensor. In addition, the current drive circuit 108 may be operated, and the abnormal point diagnosis unit 115 may be provided to identify the abnormal current sensor by detecting the abnormal point diagnosis current with the current sensor. By specifying the current sensor that is abnormal as described above, the control device 109 can perform current control using the remaining current sensors that are not diagnosed as abnormal. Therefore, control performance can be improved.

The current sensor S includes the pair of current sensors provided in the two phases, and a current sensor detecting a current flowing in the remaining one phase of the three phases,
The control device 109 sums the outputs of the current sensors respectively provided for the three phases, one by one from each phase, and when the sum exceeds a threshold without becoming zero, any current It is also possible to have an abnormal point diagnosis means 115 for identifying a current sensor that is abnormal by judging that the sensor is abnormal and changing the combination for obtaining the sum.
The threshold is a threshold arbitrarily determined by design or the like, and is determined by finding an appropriate threshold by, for example, one or both of a test and a simulation. By specifying the current sensor that is abnormal as described above, the control device 109 can perform current control using the remaining current sensors that are not diagnosed as abnormal. Therefore, control performance can be improved.

When the abnormal point diagnostic means 115 identifies the abnormal current sensor, the control device 109 does not use the output current value of the abnormal current sensor, and uses the output current value of the remaining current sensors. Control may be performed. In this case, even if an abnormality occurs in any of the current sensors, control performance can be improved and redundancy can be secured.

The electric vehicle of the present invention is provided with the motor drive device 106 described in any of the above-mentioned in the present invention. In this case, the above-described effects can be obtained for the motor drive device 106 of the present invention. In addition, the drivability of the electric vehicle can be improved.

Any combination of the at least two configurations disclosed in the claims and / or the description and / or the drawings is included in the invention. In particular, any combination of two or more of the claims is included in the invention.

The invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the embodiments and the drawings are for the purpose of illustration and description only and are not to be taken as limiting the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the conceptual structure which shows the electric vehicle carrying the motor drive control apparatus which concerns on 1st Embodiment of this invention by a top view. It is sectional drawing of the in-wheel motor drive device in the electric vehicle. It is a block diagram of a control system of the motor drive control device. It is a flowchart which shows the abnormality detection method of the motor drive control apparatus. It is a flow chart which shows a part of the flow chart. It is a flow chart which shows a part of the flow chart. It is a flowchart which shows the abnormality detection method of the motor drive control apparatus which concerns on the modification of this embodiment. It is a flow chart which shows a part of the flow chart. It is a flow chart which shows a part of the flow chart. It is a block diagram which shows the example of arrangement | positioning of the current sensor of the motor drive control apparatus which concerns on the other modification of this embodiment. It is a flowchart which shows the abnormality detection method of the motor drive control apparatus. It is a flow chart which shows a part of the flow chart. It is a flow chart which shows a part of the flow chart. FIG. 14 is a block diagram of a control system of a motor drive control device according to still another modification of this embodiment. It is a block diagram of the conceptual structure which shows the electric vehicle provided with the motor drive unit based on 2nd Embodiment of this invention by a top view. It is a block diagram which shows schematic structure of the motor drive device. It is a block diagram which shows the structure of the control apparatus of the motor drive device. It is a figure which shows the output of two opposing current sensors of the motor drive device. It is a figure explaining the removal of the in-phase noise by the differential calculation of the control apparatus. It is a flowchart which shows the execution order of each means in the control apparatus. It is a block diagram showing composition of a control device of a motor drive concerning a modification of a 2nd embodiment. It is a block diagram of a conceptual composition which shows an electric vehicle provided with a motor drive concerning a modification of a 2nd embodiment by a top view. It is a block diagram of a conceptual composition which shows an electric vehicle provided with a motor drive concerning a modification of a 2nd embodiment by a top view.

A first embodiment of the present invention will be described in conjunction with FIGS.

<About the conceptual composition of this electric car>
FIG. 1 is a block diagram of a conceptual configuration showing a plan view of an electric vehicle equipped with a motor drive control device according to this embodiment. This electric vehicle is a four-wheeled vehicle in which the wheels 2 serving as the left and right rear wheels of the vehicle body 1 are drive wheels and the wheels 3 serving as the left and right front wheels are driven wheels. The front wheel 3 is a steered wheel. The left and right wheels 2, 2 serving as drive wheels are driven by independent traveling motors 6, respectively. Each motor 6 constitutes an in-wheel motor drive device IWM described later. Each wheel 2 and 3 is provided with a brake. Further, the wheels 3 which are steered wheels serving as the left and right front wheels are steerable via a steering mechanism (not shown), and are steered by the steering means 15 such as a steering wheel.

<About schematic configuration of in-wheel motor drive device IWM>
As shown in FIG. 2, the left and right in-wheel motor drive devices IWM which are motor equipment respectively have a motor 6, a reduction gear 7 and a bearing 4 for a wheel, and a part or all of these are disposed in the wheel Ru. The rotation of the motor 6 is transmitted to the wheel 2 which is a driving wheel via the reduction gear 7 and the wheel bearing 4. The brake rotor 5 constituting the brake is fixed to the flange portion of the hub wheel 4 a of the wheel bearing 4, and the brake rotor 5 rotates integrally with the wheel 2. The motor 6 is a three-phase motor, and is, for example, an embedded magnet synchronous motor in which a permanent magnet is built in the core portion of the rotor 6a. The motor 6 is a motor in which a radial gap is provided between a stator 6 b fixed to the housing 8 and a rotor 6 a attached to the rotation output shaft 9.

<About control system>
FIG. 3 is a block diagram of a control system of the motor drive control device 22. As shown in FIG. The motor drive control device 22 controls a motor installation MS including a plurality of (two in this example) three-phase motors 6 of a system of U-phase, V-phase, and W-phase three-phase electrodes. The motor drive control device 22 has an ECU 14 that is an electronic control unit that controls the entire vehicle, and an inverter device 13 that controls the left and right motors 6 for traveling in accordance with an instruction from the ECU 14. In the case of an electric vehicle, the ECU 14 is also referred to as a VCU (Vehicle Control Unit).

The inverter device 13 has power circuit units 16 and 16 provided for the respective motors 6, and a motor control unit 17 that controls the power circuit units 16. The motor control unit 17 includes motor drive control units 19 and 19 corresponding to the respective motors 6, a current detection unit 23, and an abnormality detection unit 24. The motor control unit 17 has a function of outputting each information such as each detection value and control value regarding the in-wheel motor drive device IWM which the motor control unit 17 has to the ECU 14.

The power circuit unit 16 includes an inverter 16a that converts DC power of the battery 18 into three-phase AC power used to drive the motor 6, and a gate drive circuit 16b that drives the inverter 16a. The inverter 16 a is composed of U-phase, V-phase and W-phase semiconductor switching elements 25. The gate drive circuit 16b drives each of the semiconductor switching elements 25 based on the input on / off command.

The motor control unit 17 is configured by a computer, a program executed by the computer, and an electronic circuit, and includes motor drive control units 19 and 19 as a control unit that is a basis of the computer. Each motor drive control unit 19 controls each system individually. The ECU 14 generates an acceleration command, a deceleration command, and a steering unit from the signal (acceleration command) of the accelerator opening output from the accelerator operation unit 20 (FIG. 1) and the deceleration command output from the brake operation unit 21 (FIG. 1). An acceleration / deceleration command to be given to the motors 6, 6 of the left and right rear wheels 2, 2 (FIG. 1) is generated as a torque command from the turning command output from the step 15 (FIG. 1), and output to the inverter device 13.

Each motor drive control unit 19 converts an acceleration / deceleration command into a current command in accordance with an acceleration / deceleration command according to a torque command or the like (command value) given from the ECU 14 which is a higher order control means. The motor drive control unit 19 obtains the current flowing from the inverter 16a to the motor 6 from the current sensors U1, V1, W, U2, V2, and performs current feedback control to make the detected current follow the command value. The command voltage is calculated by feedback control, and the command voltage is made a pulse width modulation signal to give an on / off command to the gate drive circuit 16b.

<About current sensor>
The current sensor detects the current flowing through each of the U phase, V phase, and W phase of each system. Of the current sensors for detecting the three-phase currents of each system, one (in this example, W-phase) current sensors W is commonly used to detect the current of each one phase (in-phase) in the two systems. It is a non-contact current sensor. The current sensor W is also referred to as a current sensor W1 / W2. The remaining two (in this example, U-phase and V-phase) current sensors U1, V1, U2, and V2 are four non-contact current sensors that individually detect one system. A total of five current sensors are provided.

Since a large current is applied to the motor equipment MS for driving the vehicle, the current sensor is often a non-contact current sensor for reasons such as loss and safety. In this embodiment, non-contact current sensors are applied to the common current sensor W and the individual current sensors U1, V1, W, U2, and V2. As a non-contact current sensor, for example, a non-contact current sensor such as a Hall sensor, a CT sensor, or a Rogowski coil sensor is applied. In a motor installation, for example, when a large current is not applied, and a condition in which losses can be tolerated and safety can be satisfied, individual current sensors may also be used as contact current sensors provided with a shunt resistor or the like. Good. However, the common current sensor must be a non-contact current sensor in order to collectively detect the currents flowing through the plurality of conductors (phases) to be measured.

The current detection unit 23 uses the fact that the sum of three-phase currents is zero from the currents detected by the common (commonized) current sensor W and the individual current sensors U1, V1, U2, and V2, respectively. In the current detected by the current sensor W common to a plurality of systems, the current flowing to the system to be controlled is calculated. Specifically, the current flowing to the system to be controlled can be calculated from the following formula.
iu1 + iv1 + iw + iu2 + iv2 = 0 (while all motors are driven)
iu1 + iv1 + iw = 0 (the second motor _{6 2} only stop)
iu2 + iv2 + iw = 0 (first motor _{6 1} only stop)
However, iu1, iv1: in the first motor ₆₁ of the system, the detection value of the U-phase, separate current sensor V-phase U1, V1, iu2, iv2: in the second motor _{6 2} strains, U-phase, Detection values of the individual V-phase current sensors U2 and V2, iw: detection values of the common current sensor W.

When the sum of currents respectively detected by the common current sensor W and the individual current sensors U1, V1, U2, V2 becomes zero, the abnormality detection unit 24 detects the common current sensor W and the individual current sensors U1, V1, U1. When it is determined that U2 and V2 are normal and the sum of the currents does not become zero, it is determined that one or both of the common current sensor W and the individual current sensors U1, V1, U2, and V2 are abnormal. When each of the current sensors U1, V1, W, U2, and V2 is determined to be normal by the abnormality detection unit 24, each motor drive control unit 19 only detects the current detected by the individual current sensors U1, V1, U2, and V2. It may be used to control each system individually. In this case, the control system can be simplified to reduce the computational processing load.

By the way, there are abnormalities in the current sensor, for example, an abnormality in which the output is stuck or shorted on the Hi side, an abnormality in which the output is stuck or shorted on the Lo side, an offset abnormality in which the output is not 0A when deenergized, In the case of the method, if a shift in the gain of the output of the current sensor, a shift in the halfway output, or the like occurs, the abnormality may not be detected in some cases. Therefore, in addition to these anomaly detection methods, anomaly detection is performed using the fact that the sum of three-phase currents is zero.

As in this embodiment, when the common current sensor W is used in a plurality of systems, the sum of the three phases can not simply be obtained, so the energizing circuit of another system using the common current sensor W It is necessary to find the sum including it. Also, since you want to determine possible abnormal current sensor, for example, another for and detect the individual sensor output all of the motor 6 _1, 6 ₂ outputs once stopped, using common current sensor W Stop the output of the power supply circuit of the system of and perform abnormality detection. Examples of the abnormality detection in driving of the motor 6 ₁ or 6 ₂ illustrates a flow chart in FIGS. 4 to 6.

<Flow chart>
FIG. 4 is a flowchart showing a method of detecting an abnormality in the motor drive control device. 5 and 6 are flowcharts showing a part of the flowchart. The following description will be given with reference to FIG. 3 as appropriate. All motor ₆ 1, _{6 2} starts the process during operation, the abnormality detection unit 24, the sum of five pieces all current sensors U1, V1, W, U2, V2 determines whether 0A ( Step a1). When the sum of current sensors U1, V1, W, U2, V2 is 0 A (step a1: Yes), abnormality detection unit 24 determines that all current sensors U1, V1, W, U2, V2 are normal, and The motor drive control unit 19 controls the motor based on the determination result (step a2), and ends the present process.

When the sum of the current sensors U1, V1, W, U2, and V2 is not 0 A (step a1: No), the abnormality detection unit 24 determines that any one of the current sensors is abnormal, and each motor drive control unit 19 , power circuit connected to all the system for driving the second motor 6 _and 62 (the current supply circuit) 16 is stopped, stop all motor output (step a3). Next, the abnormality detection unit 24 detects current by each current sensor and determines whether each sensor output is 0 A (step a4). The abnormality detection unit 24 determines that the current sensor does not become 0 A (step a4: No) and the current sensor is abnormal (step a5). Thereafter, the process proceeds to step a2. The control continuation method at the time of abnormality of the current sensor in step a2 will be described later.

When the sensor outputs of all of the current sensor is determined to be 0A (Step a4: Yes), the motor drive control unit 19, a state in which a current flows only in the first motor 6 ₁ lineage (step a6), abnormality detection unit 24, the first motor ₆₁ of the system in which current flows, it is determined whether the sum of the current detected respectively by a common current sensors W and individual current sensors U1, V1 becomes 0A ( Step a7).

In the determination of the sum of the current becomes 0A (step a7: Yes), the motor drive control unit 19, a state in which a current flows only in the second motor 6 ₂ strains (step a8), the abnormality detecting section 24 , the second motor 6 ₂ strains which current flows, it is determined whether the sum of the common current sensors W and individual current sensor U2, current detected respectively V2 becomes 0A (step a9). If it is determined that the sum of the currents becomes 0 A (step a9: Yes), the process returns to step a1. In the determination of the sum of the currents does not become 0A (Step a9: No), the abnormality detecting unit 24, U-phase of the second motor _{6 2} strains, the current sensor U2 to detect a current of the V-phase, V2 of At least one is determined to be abnormal (step a10). Thereafter, the process proceeds to step a2.

In step a7, the first motor ₆₁ of the system in which current flows, in the determination of the sum of the current detected respectively by a common current sensors W and individual current sensors U1, V1 does not become 0A (Step a7: No ), the motor drive control unit 19, a state in which a current flows only in the second motor _{6 2} strains (step a11). Next, the abnormality detecting unit 24, the second motor 6 ₂ strains which current flows, whether the sum of the common current sensors W and individual current sensor U2, current detected respectively V2 becomes 0A It determines (step a12).

In the determination of the sum of the current becomes 0A (Step a12: Yes), the abnormality detecting unit 24, U-phase of the first motor ₆₁ of the system, the current sensor U1, V1 for detecting the current of the V phase at least One is determined to be abnormal (step a13). Thereafter, the process proceeds to step a2. When the sum of the currents does not become 0A (Step a12: No), the abnormality detecting unit 24 can not determine the abnormal current sensor is determined as abnormal any of the current sensors of the motors 6 _and 62 ( Step a14). Thereafter, the process proceeds to step a2.

Although the flowchart described above describes a method of stopping all motor outputs to detect abnormality and a method of stopping motor outputs other than the motor to be detected to detect abnormalities, the order of detection may be reversed. If there is no problem or an abnormal part can be determined, either one may be used. Further, separately from this method, an abnormality that can be determined by Hi side abnormality detection, Lo side abnormality detection or the like should be determined.

Table 1 shows the according to the first embodiment, two of the motor ₆ 1, _{6 2} in five pieces of current sensors U1, V1, W, U2, V2 control continuation method when an abnormal case. The control continuation method is the same for the embodiments of FIGS. 7 to 9 described later. If an abnormal current sensor can not be determined, current control can not be continued.

<About effect>
According to the motor drive control device 22 described above, when the current sensor is commonly used in the same phase of the two systems, the sum of three phases can not simply be output, so the commonly used current is used. It is possible to determine the normal abnormality of the current sensor by calculating the sum of the current including another system using the sensor. As described above, since the non-contact current sensor that commonly detects the current of each phase in the two systems passes, the number of current sensors, which is the number of parts, is reduced, cost, space and weight are reduced. The reduction can be achieved.

<Variations of this embodiment>
In the following description, parts corresponding to the items described above are denoted by the same reference numerals, and redundant description will be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding embodiment unless otherwise stated. The same function and effect are exhibited from the same configuration. Not only the combination of the parts specifically described in each embodiment, but also the combinations of each embodiment may be partially combined unless any problem arises in the combination.

7 to 9 are similar to the embodiment described above, first, when the second motor _{6 and 62} after five pieces of current sensors U1, V1, W, U2, V2, as much as possible motor output It is a flowchart at the time of detecting abnormality so that it might not stop. FIG. 3 will also be described with appropriate reference. All motor ₆ 1, _{6 2} starts the process during operation, the abnormality detection unit 24, the sum of five pieces all current sensors U1, V1, W, U2, V2 determines whether 0A ( Step b1). When the total sum of the current sensors is 0 A (step b1: Yes), the abnormality detection unit 24 determines that all the current sensors are normal, and each motor drive control unit 19 controls the motor based on the determination result ( Step b2), end this processing.

The sum of the current sensor not equal 0A (Step b1: No), the motor drive control unit 19, a power circuit connected to the system for driving the second motor 6 ₂ (energization circuit) 16 is stopped, the second Only the motor output of is stopped (step b3). Next, the abnormality detection unit 24 determines whether or not the outputs of the individual current sensors of U2 and V2 of the system which has been deenergized become 0 A (step b4). In the determination of no (step b4: No), the abnormality detection unit 24 determines that the current sensor whose sensor output does not become 0 A among the individual current sensors of U2 and V2 is abnormal (step b5). Thereafter, the process proceeds to step b2.

U2, when the output of the individual current sensor V2 becomes 0A (Step b4: Yes), the abnormality detecting section 24, the first motor ₆₁ of the system in which a current flows, a common current sensors W and U1, V1 It is determined whether the sum of the currents respectively detected by the individual current sensors in the above becomes 0 A (step b6). In the determination of the sum of the current becomes 0A (Step b6: Yes), the motor drive control unit 19, a state in which a current flows only in the second motor 6 ₂ strains (step b7), the abnormality detecting section 24 , for the first motor ₆₁ of the system in which current is not flowing, and determines whether the U1, the output of the individual current sensor V1 becomes 0A (step b8).

In the determination of no (step b8: No), the abnormality detection unit 24 determines that the current sensor whose sensor output does not become 0 A among the individual current sensors of U1 and V1 is abnormal (step b9). Thereafter, the process proceeds to step b2. U1, when the output of the individual current sensor V1 becomes 0A (Step b8: Yes), the abnormality detecting unit 24, the second motor _{6 2} strains which current flows, a common current sensors W and U2, V2 It is determined whether the sum of the currents respectively detected by the individual current sensors in the above becomes 0 A (step b10).

If it is determined that the sum of the currents becomes 0 A (step b10: Yes), the process returns to step b1. If it is determined that the sum of the currents does not become 0 A (step b10: No), the abnormality detection unit 24 determines that at least one of the current sensors U2 and V2 is abnormal (step b11). Thereafter, the process proceeds to step b2.

In step b6, the first motor ₆₁ of the system, the determination of the sum of the currents does not become 0A (Step b6: No), the motor drive control unit 19, current only to the second motor _{6 2} strains a state in which the flow (step b12), the abnormality detecting section 24, the first motor ₆₁ of the system in which current is not flowing, and determines whether the U1, the output of the individual current sensor V1 is 0A (Step b13).

In the determination of no (step b13: No), the abnormality detection unit 24 determines that the current sensor whose sensor output does not become 0 A among the individual current sensors of U1 and V1 is abnormal (step b14). Thereafter, the process proceeds to step b2. U1, when the output of the individual current sensor V1 becomes 0A (Step b13: Yes), the abnormality detecting unit 24, the second motor _{6 2} strains which current flows, a common current sensors W and U2, V2 It is determined whether the sum of the currents respectively detected by the individual current sensors in the above becomes 0 A (step b15).

If it is determined that the sum of the currents becomes 0 A (step b15: Yes), the abnormality detection unit 24 determines that at least one of the current sensors U1 and V1 is abnormal (step b16). Thereafter, the process proceeds to step b2. When the sum of the currents does not become 0A (Step b15: No), the abnormality detecting unit 24 can not determine the abnormal current sensor is determined as abnormal any of the current sensors of the motors 6 _and 62 ( Step b17). Thereafter, the process proceeds to step b2.

According to the flowchart of FIGS. 7-9, the motor 6 _1, 6 without completely stopping the _second drive, it is possible to perform abnormality detection. Therefore, it is possible to prevent the driver from feeling discomfort when detecting an abnormality.

In the flowchart of FIGS. 4-6 or 7-9, when the abnormality detection to stop the motor 6 _1, 6 ₂ each side, so that the drive torque is not reduced, that amount of torque of the motor to continue driving It may be many. That is, when the motor drive control unit 19 stops the power circuit unit 16 connected to the system of one motor, the motor drive control unit 19 stops the power circuit unit 16 with respect to the command torque of the motor not stopping the power circuit unit 16. You may make it increase the command torque of the made motor. As described above, by increasing the command torque of the stopped motor, a desired motor torque can be maintained.

As shown in FIG. 10, three motors 6 _{and 62,} 6 ₃ seven pieces of current sensors (of which, a common current sensor two is) may be used. In this case, first, mutually the same phase of the second motor 6 _and 62 of the two systems through the current sensor W1 / W2 of a common non-contact type in (W phase in this example), the second, third The common non-contact current sensor U2 / U3 passes through the same phase (in this example, the U phase) of the motors 6 ₂ and 6 _{3 of the} two motors, and the individual current sensors U1 , V1, V2, V3, and W3. In this example, a non-contact current sensor common to the same phase of the two systems is used, but may not be the same phase.

11 to 13 are flowcharts illustrating a method for detecting abnormality the three motors 6 _{and 62,} 6 ₃ motor drive control device in the case of using seven pieces of current sensor. Description will be made with reference to FIG. 10 and the like as appropriate. This process is started while all the motors 6 ₁ , 6 ₂ and 6 ₃ are driven, and the abnormality detection unit 24 (FIG. 3) determines whether or not the sum of all seven current sensors is 0 A (step c1). ). When the sum of the current sensors is 0 A (step c1: Yes), the abnormality detection unit 24 (FIG. 3) determines that all current sensors are normal, and each motor drive control unit 19 (FIG. 3) The motor is controlled on the basis of (step c2), and this processing is ended.

When the sum of the current sensors is not 0 A (step c1: No), the abnormality detection unit 19 (FIG. 3) determines that any current sensor is abnormal, and each motor drive control unit 19 (FIG. 3) the energizing circuit which is connected to all of the system for driving the second and third motor 6 _1, 6 _2, 6 ₃ is stopped, stop all motor output (step c3). Next, the abnormality detection unit detects the current with each current sensor and determines whether each sensor output is 0 A (step c4). The abnormality detection unit determines that the current sensor does not become 0 A (step c4: No) and the current sensor is abnormal (step c5). Thereafter, the process proceeds to step c2. The control continuation method at the time of abnormality of the current sensor in step c2 will be described later.

When the sensor outputs of all of the current sensor is 0A, (Step c4: Yes), the motor drive control unit includes a state in which the first, current flows through the third motor ₆ 1, _{6 3} of the system (step c6) , the abnormality detecting unit determines whether the sum of the current detected respectively common current sensor of the first motor 6 U1 in _one lineage, V1 individual current sensor and W1 / W2 becomes 0A ( Step c7).

In the determination of the sum of the current becomes 0A (step c7: Yes), the abnormality detection unit, a common current sensor of the third motor ₆ U3 in ₃ strains, W3 individual current sensor and U2 / U3 It is determined whether the sum of each detected current is 0 A (step c8).

In the determination of the sum of the current becomes 0A (Step c8: Yes), the motor drive control unit includes a state in which a current flows only in the second motor 6 ₂ strains (step c9), the abnormality detection unit, a current second for system 6 ₂ motors, separate current sensor V2, (step of determining whether the sum of the current detected respectively by a common current sensor W1 / W2, U2 / U3 becomes 0A flows c10). If it is determined that the sum of the currents becomes 0 A (step c10: Yes), the process returns to step c1. When it is determined that the sum of the currents does not become 0 A (step c10: No), the abnormality detection unit determines that the individual current sensor of V2 is abnormal (step c11). Thereafter, the process proceeds to step c2.

In step c8, when the sum of the currents does not become 0A (Step c8: No), motor drive control section, a state in which a current flows only in the second motor 6 ₂ strains (Step c12), the abnormality detection unit, a second motor 6 ₂ strains which current flows, a separate current sensor V2, determines whether the sum of the current detected respectively become 0A a common current sensor W1 / W2, U2 / U3 ( Step c13).

If it is determined that the sum of the currents becomes 0 A (step c13: Yes), the abnormality detection unit determines that at least one of the V3 and W3 individual current sensors is abnormal (step c14). Thereafter, the process proceeds to step c2. When the sum of the currents does not become 0A (Step c13: No), the abnormality detection unit, a second, but in abnormal third current sensor of the motor ₆ 2, _{6 3} is, can not be determined (step c15). Thereafter, the process proceeds to step c2.

In step c7, when a sum of the currents does not become 0A (step c7: No), the abnormality detection unit, a common current sensor of the third motor ₆ U3 in ₃ strains, W3 individual current sensor and U2 / U3 At step c16, it is determined whether the sum of the currents respectively detected is 0A. When the sum of the current becomes 0A (Step c16: Yes), the motor drive control unit includes a state in which a current flows only in the second motor _{6 2} strains (Step c17), the abnormality detection unit, the second the system of the motor _{6 2,} separate current sensor V2, determines whether the sum of the current detected respectively become 0A a common current sensor W1 / W2, U2 / U3 (step c18).

When the sum of the currents becomes 0 A (step c18: Yes), the abnormality detection unit determines that at least one of the individual current sensors U1 and V1 is abnormal (step c19). Thereafter, the process proceeds to step c2. When the sum of the currents does not become 0A (Step c18: No), the abnormality detection unit, first, although abnormalities second motor ₆ 1, _{6 2} of the current sensor is, it can not be determined (step c 20). Thereafter, the process proceeds to step c2.

In step c16, when the sum of the currents does not become 0A (Step c16: No), motor drive control section, a state in which a current flows only in the second motor _{6 2} strains (Step c21), the abnormality detection unit, a second motor _{6 2} strains, the individual current sensor V2, determines whether the sum of the current detected respectively become 0A a common current sensor W1 / W2, U2 / U3 (step c22) .

When the sum of the currents becomes 0 A (step c22: Yes), the abnormality detection unit detects at least one of U1 and V1 individual current sensors and at least one of V3 and W3 individual current sensors. Is determined to be abnormal (step c23). Thereafter, the process proceeds to step c2. When the sum of the currents does not become 0A (Step c22: No), the first, second, third motor _{6 1,} 6 2, ₆ is abnormality in ₃ current sensor, can not be determined (Step c24) . Thereafter, the process proceeds to step c2.

Table 2 shows the control continuation method at the time of abnormality in the case of three current sensors and seven current sensors according to the first embodiment. If an abnormal current sensor can not be determined, current control can not be continued.

As shown in FIG. 14, a plurality of systems (two systems in this example) of U-phase, V-phase, and W-phase three-phase electrodes may be provided in one three-phase motor 6. The individual current sensors may be, for example, contact current sensors with shunt resistors. The motor drive device may be a two-motor on-board type in which the vehicle body is installed in the motor other than the in-wheel motor type. It is also possible to apply the motor drive control device according to any one of the embodiments to a hybrid vehicle including an internal combustion engine and a vehicle drive motor, an electric power steering device, a train, a robot or the like.

As shown in FIG. 3, it comprises a rotation speed detecting means 26 for detecting the rotational speed of the motor 6 _1, 6 _2, the abnormality detecting unit 24 in accordance with conditions determined from the rotational speed detected by the rotational speed detecting means 26 A back electromotive voltage may be calculated, and abnormality detection may be performed when the back electromotive voltage does not exceed the power supply voltage. The rotational speed, for example, can be determined by, for example differentiating the rotation angle of the motor 6 _1, 6 _2. According to this configuration, the abnormality detection of the current sensor can be performed with high accuracy by performing the abnormality detection when the calculated back electromotive force does not exceed the power supply voltage.

A motor drive apparatus according to a second embodiment of the present invention will be described with reference to FIGS.
<About the conceptual composition of this electric car>
FIG. 15 is a block diagram of a conceptual configuration showing a plan view of an electric vehicle provided with a motor drive device according to this embodiment. This electric vehicle is a four-wheeled vehicle in which the wheels 102 serving as the left and right rear wheels of the vehicle body 101 are drive wheels and the wheels 103 serving as the left and right front wheels are driven wheels. The wheel 103 serving as the front wheel is a steered wheel.

The electric vehicle of this example is a motor-on-board type in which the left and right wheels 102, 102 are driven by a single three-phase AC motor (simply referred to as a "motor") 104 serving as a drive source for traveling. The motor 104 is, for example, an embedded magnet synchronous motor in which permanent magnets are built in a core portion of a rotor. The motor 104 is a motor in which a radial gap is provided between a stator fixed to the housing and a rotor attached to the rotation output shaft. The wheels 102 are driven by a motor 104 via a reduction gear not shown. Each of the wheels 102 and 103 is provided with a brake. The wheels 103, 103, which are steered wheels on the left and right front wheels, can be steered via a steering mechanism (not shown), and are steered by steering means 105 such as steering wheels.

<Schematic Configuration of Motor Drive Device>
As shown in FIG. 16, for example, the motor drive device 106 receives a torque command from the upper control device 107 that controls the vehicle and drives the motor 104. The motor drive device 106 drives the current to the current drive circuit 108 based on the current drive circuit 108, the current sensor S for detecting the current flowing to the motor 104, and the torque command given and the current detected by the current sensor S. And a controller 109 for providing a signal. The control device 109 and the current drive circuit 108 constitute an inverter device.

<About the current sensor S to be used>
As the current sensor S, two current sensors that respectively detect current in opposite directions are paired with each other in any direction opposite to each other and in any two phases in three phases (in this example, U phase, And a current sensor for detecting the current flowing through the remaining one phase (in this example, the W phase). The output current value obtained by the current sensor S is input to the control device 109.

For example, a clamp-type current sensor is used as the current sensor S attached to each phase. There is no limitation on the type of clamp-type current sensor, but the current sensor described here is a single power supply, which exhibits a predetermined offset voltage at 0 A current, and outputs a signal according to it when positive or negative current flows It shall be. Note that any current sensor other than the clamp type can be adopted as long as it is independent and the direction of the current can be determined and the influence of the abnormality of one current sensor does not affect the other current sensor.

The control device 109 is, for example, a control board on which a CPU for calculation and peripheral parts are mounted. In the control device 109, each means described later is stored as a program in the memory of the CPU, and each means is implemented based on the processing flow. Further, the control device 109 outputs the current drive circuit drive signal determined after each process to the current drive circuit 108. The output current from the current drive circuit 108 is output to the motor 104 through the three-phase AC transmission line 10. In the actual configuration, an angle sensor or the like for controlling the motor 104 is often attached, but this is omitted in the description of the present embodiment.

As shown in FIGS. 16 and 17, the current drive circuit 108 drives a plurality of switching elements 112 for converting the power of the DC power supply 11 into three-phase AC power used for driving the motor 104, and the switching elements 112. And a gate drive circuit Gd. As each switching element 112, for example, an insulated gate bipolar transistor (abbreviated as IGBT), a field effect transistor (abbreviated as FET) or the like is applied.

<Configuration of Control Device 109 of Motor Drive Device 106>
The control device 109 has current control means 113 for controlling the current drive circuit 108, abnormality detection means 114, abnormality point diagnosis means 115, and differential operation means 116. In addition, known means such as external communication means for communicating with the outside shall be appropriately implemented.

As shown in FIG. 15 and FIG. 17, the upper control device 107 uses an accelerator opening signal (acceleration command) output from the accelerator operation unit 17 and a deceleration command output from the brake operation unit 118 or an acceleration command. An acceleration / deceleration command to be given to the motor 104 is generated as a torque command from the deceleration command and the turning command output from the steering means 105, and is output to the control device 109. The current control means 113 is generally a part corresponding to vector control, and converts a torque command given from the upper control device 107 into current target values of the respective three phases. The three-phase currents detected by the current sensor S are supplied to the current control means 113.

<Detailed processing procedure in each means>
The current sensor S exemplified below is a voltage output type current sensor S, and as shown in FIG. 18, shows an offset value (voltage) C at 0 A, and when current flows in the positive direction of the current sensor, this current sensor The output of the current sensor changes in the direction smaller than the offset value C when the current flows in the negative direction of the current sensor.

<Specific operation of abnormality detection means>
As shown in FIG. 17 and FIG. 18, the abnormality detection means 114 takes in the output of the current sensor as a pair, compares the obtained current value with a threshold, and detects an abnormality of the current sensor. When a certain current is applied to a pair of current sensors attached facing a certain phase, the outputs of the respective current sensors have the same absolute value with respect to the offset value C, and the current directions are opposite to each other. Show. Therefore, if there is no influence of noise or error, the sum of the outputs of the pair of current sensors should offset the detected current value, and the result will be a value twice the offset value.

In practice, the error and noise of the current sensor cause a difference from this value, but the threshold value S1 of the allowable difference is determined with reference to the guaranteed value of the error of the current sensor and the noise level. If the difference becomes large beyond this threshold, it is predicted that the current sensor is not outputting the correct value for some reason, and the abnormality is diagnosed. That is, when the difference between the current value obtained by adding the outputs of the current sensors to be paired and the threshold value is large, the abnormality detecting unit 114 has an abnormality in one of the current sensors of the pair of current sensors. Diagnose that there is. Note that since there is a possibility that the threshold value is exceeded momentarily due to spike noise etc., the current value obtained by adding the outputs of the paired current sensors exceeds the threshold value and the difference for a fixed time (for example, 100 ms) is large. If the condition of (1) continues, it may be diagnosed as abnormal.

Here, current sensors UU1 and UU2 are attached as two opposing current sensors for the U phase, and current sensors VV1 and VV2 are attached as two opposing current sensors for the V phase. It is assumed that one current sensor WW1 is attached to the W-phase in the same direction as the current sensors UU1 and VV1. In this case, the abnormality detection unit 114 determines whether the following conditional expression is satisfied. Hereinafter, values (voltages) obtained from the current sensors UU1, UU2, VV1, and VV2 are shown as UU1, UU2, VV1, and VV2, respectively.

| UU1 + UU2-2C | <S1 (Equation 1)
| VV1 + VV2-2C | <S1 (Equation 2)
At this time, it is assumed that the judgment result of each expression is Expression 1: True, Expression 2: False. Therefore, the difference between the outputs of the U-phase current sensors UU1 and UU2 is within an allowable range, and no abnormality is recognized. Further, the calculation result on the left side of Expression 2 exceeds S1 which is a threshold for determining abnormality, and the outputs of the V-phase current sensors VV1 and VV2 are predetermined whether the absolute values of the obtained results are largely different It is predicted that the value greatly deviates from the offset value C, and the abnormality is diagnosed. The deviation of the offset value may be, for example, an output of zero when power is not supplied from the power supply to be supplied to the current sensor.

By performing the above-described process, it is possible to diagnose whether or not any one of the current sensors in the phase is abnormal with respect to the current sensors attached to each other so as to face each other in pairs. The results are shown in Table 3. In Table 3, the circle indicates normal, and the x indicates abnormality.

<Specific Operation of Abnormal Point Diagnostic Means 115>
Up to this point, the current sensors UU1 and UU2 attached to the U phase are both normal by the diagnosis of the abnormality detection means 114, and any one of the current sensors VV1 and VV2 attached to the V phase is either Is diagnosed as abnormal. Further, it is not determined whether the W-phase current sensor WW1 is abnormal. Although the abnormality detection means 114 can diagnose whether there is a current sensor that is abnormal in that phase, it is not possible to determine which one of the current sensors that is a pair of that phase is abnormal. Therefore, the abnormal point diagnosing means 115 performs processing for determining this.

The abnormal point diagnosis means 115 sums the outputs of the UVW-phase current sensors, as described below, and determines whether the result is substantially zero. In practice, although the error and noise of the current sensor cause a difference from "zero", the threshold value S2 of the allowable difference is determined with reference to the guaranteed value of the error of the current sensor and the noise level. Therefore, the abnormal point diagnosis means 115 determines whether the following conditional expression is satisfied. Hereinafter, values (voltages) obtained from the current sensors UU1, UU2, VV1, VV2, and WW1 are shown as UU1, UU2, VV1, VV2, and WW1, respectively.

| UU1 + VV1 + WW1-3C | <S2 (Equation 3)
| UU2 + VV2 + (-1) × WW1-C | <S2 (Equation 4)
Here, WW1 is multiplied by -1 in Equation 4 because the current sensor WW1 is attached in the reverse direction with respect to the current direction with respect to the current sensor UU2 and the current sensor VV2, and WW1 is multiplied by -1. By doing this, the current directions of the current sensor UU2 and the current sensor VV2 are made to coincide with the current direction of the current sensor WW1. Further, the offset value is also offset because -1 × WW1 is added, and Equation 4 is obtained.

In the above conditional expression, assuming that Expression 3: True, Expression 4: False, the calculation result on the left side of Expression 4 exceeds the threshold value S2 for judging abnormality, and any one of the current sensors UU2, VV2 and WW1 is abnormal. You can diagnose that there is. Since the current sensor of any of the V-phases is diagnosed as abnormal according to Equation 2 of the calculation of the abnormality detection unit 114 described above, the abnormal current sensor can be determined as the current sensor VV2. By combining the above processing with the processing result of the abnormality detection unit 114, it is possible to specify which current sensor is abnormal. The result of the abnormality diagnosis is recorded in a variable that stores the state of each current sensor, and is used as a determination standard of whether or not to use in the subsequent calculation.

Table 4 is the summary of the above contents. In Table 4, the circle indicates normal, and the x indicates abnormality.

<Specific Operation of Differential Operation Means 116>
<< Operation at normal current sensor >>
First, the operation when there is no abnormality in the current sensor is shown.
The value (voltage) obtained by the current sensor UU1 and the current sensor UU2 is a value including the offset value C. Here, the respective sensor outputs and the current IU flowing in the U phase have the following relationship.
(UU1-UU2) / 2 = IU
The current IV flowing through the V phase can be determined by performing the same process for the V phase. From the above, it is possible to obtain the current value necessary for control by the current control at the subsequent stage of the processing of the differential operation means 116.

<< Operation at the time of current sensor abnormality >>
Next, the operation when there is an abnormality in the current sensor is shown. Based on the information received from the abnormal point diagnosis means 115 indicating which current sensor is abnormal, for example, when an abnormality occurs in any one current sensor, the differential operation may not be performed.

Specifically, ENU1 = 1 when no abnormality occurs in current sensor UU1 (valid), similarly ENU2 = 1 when current sensor UU2 is valid, and ENU1 = 0 when ENA1 and UU2 are abnormal, respectively. A variable to be 0 may be prepared, and the abnormality detection unit 115 may cause the abnormality detection unit 114 to update the value. In addition, together with the obtained ENU1 and ENU2 and the outputs UU1 and UU2 of the respective current sensors, calculation may be performed as follows.
IU = (UU1 × ENU1-UU2 × ENU2) / (ENU1 + ENU2)
However, when ENU1 = ENU2 = 0, the operation is not performed and the driving of the motor 104 is stopped.
Similarly, the same operation is performed in the V phase or the W phase depending on the configuration.

<Removal of common mode noise by differential operation>
The differential operation means 116 takes the difference between the currents respectively detected by the current sensors serving as the pair for the two phases (in this example, the U phase and the V phase in this example) including the pair of current sensors, and forms the pair. The common mode noise superimposed on the output of the current sensor is canceled and removed, and current control is performed using the obtained current values. In the ideal state without noise, there is no difference in using the output of one current sensor without taking the difference between the currents respectively detected by the paired current sensors. However, when in-phase noise is superimposed on the output of each of the oppositely mounted current sensors, the difference between the results obtained from the two paired current sensors is the same effect as the operation amplification circuit. Is expected, and removal of common mode noise can be expected.

Here, it is assumed that in-phase noise as shown in FIG. 19 is superimposed on UU1 and UU2 which are the outputs of the current sensor UU1 and the current sensor UU2 attached to the U phase. Here, UU1-UU2 obtained by taking the difference between the two signals is also shown in FIG. As shown in FIG. 19, spiked in-phase noise observed in UU1 and UU2 can not be seen in UU1-UU2. By performing differential operation in the differential operation means 116 as described above, it is possible to remove in-phase noise. The cause of this common-mode noise is, for example, switching noise when performing current control. When the generated noise is superimposed on the power supply of the current sensor, the noise may also be superimposed on the output of the current sensor, or switching noise may be directly superimposed on the output signal of the current sensor.

<Specific Operation of Current Control Means 113>
As shown in FIGS. 16 and 17, the current control means 113 implements current control represented by vector control. In this example, the current control unit 113 performs current control based on the U-phase and V-phase currents which are the outputs of the differential operation unit 116. The current control means 113 further increases the current target value if the detected current is smaller than the calculated current target value, and further decreases the current target value if the detected current is larger than the calculated current target value. Feedback control of the motor current. The current control unit 113 calculates a command voltage by feedback control, converts the command voltage into a pulse width modulation signal, and gives an on / off command to the gate drive circuit Gd. The current is changed by changing the pulse width in the PWM operation.

<About the execution order of each means in the control device>
FIG. 20 is a flow chart showing the execution order of each means in this control device. Hereinafter, description will be made with reference to FIGS. 16 and 17 as appropriate. After the start of this process, the controller 109 reads the current values output by all the current sensors (step S1). The read current value is delivered to the abnormality detection means 114 (step S2). As described above, the abnormality detection unit 114 determines whether or not an abnormality occurs in any of the current sensors and outputs an abnormal signal based on the received current value, and outputs a result (step S3).

When all the current sensors are normal and there is no abnormality (step S3: no), the current value read by the control device 109 is passed to the differential operation means 116 as it is. Assuming that all current sensors are normal, among the current values received by the differential operation means 116, the outputs of two pairs of current sensors attached to two phases (in this example, U phase and V phase) are adopted. . The differential operation means 116 takes the difference between the two outputs of the current sensors mounted opposite to each other, and if necessary, applies a gain so that the result is 1 × magnification, and the current value used for current control (Step S4).

The current value used for current control obtained by the operation of the differential operation means 116 is passed to the current control means 113. The current control means 113 performs calculations based on the three-phase current values (or the measured values of the two-phase current values and the one-phase current values determined therefrom) to calculate the current target values of the three phases. (Step S5). Generally, the current drive circuit 108 is PWM-controlled, and the current control means 113 calculates and outputs the duty ratio of PWM.

The control device 109 outputs a current drive circuit drive signal to the current drive circuit 108 based on the PWM duty ratio determined by the current control unit 113 (step S6). The current drive circuit drive signal is generally a pulse signal of PWM. Thereafter, the process ends.

If the abnormality detection unit 114 diagnoses that the current sensor is abnormal (step S3: yes), the process proceeds to step S7. For example, it is assumed that the difference between the outputs of the pair of opposing current sensors is larger than the threshold value, and the abnormality detection unit 114 diagnoses that the difference is abnormal. When it is diagnosed that the current sensor is abnormal, it is known which of the three phases the current sensor is abnormal. However, it is unclear which of the pair of current sensors attached facing each other is abnormal.

Therefore, in a state in which a phase of the current sensor which is abnormal is identified by the abnormality detection means 114, the abnormal point diagnosis means 115 determines which of the current sensors in the phase is abnormal (step S7). The abnormal point diagnostic means 115 updates the abnormal information indicating which current sensor is abnormal (in other words, information indicating which output of the current sensor can not be adopted), which is found as a result, and the updated The abnormality information is delivered to the differential operation means 116 (step S8). Thereafter, the process proceeds to step S4. In the subsequent processing, current control for driving is performed without using the current value obtained by the current sensor diagnosed as abnormal. Thereby, even if an abnormality occurs in any of the current sensors, control performance can be improved and redundancy can be secured. The above is one cycle of the control flow related to the current control, and is processed once per calculation cycle.

<About effect>
In-phase noise may be superimposed on the output of each of the oppositely mounted current sensors. The cause of the in-phase noise is, for example, switching noise when performing current control. Therefore, the differential operation means 116 takes the difference between the currents respectively detected by the pair of current sensors, cancels out the common phase noise superimposed on the output of the pair of current sensors, and obtains the obtained current value Each is used to perform current control. Thereby, an effect similar to that of a so-called operation amplification circuit is expected, and removal of in-phase noise can be expected. Therefore, it is possible to prevent the undesirable current limitation caused by the common mode noise and to improve the control performance. In addition, since the current value obtained by the current sensor diagnosed as abnormal is not used and current control for driving is performed, control performance can be improved even if an abnormality occurs in any of the current sensors, Redundancy can be ensured.

Regarding Modification of Second Embodiment>
In the following description, parts corresponding to the items described above are denoted by the same reference numerals, and redundant description will be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding embodiment unless otherwise stated. The same function and effect are exhibited from the same configuration. Not only the combination of the parts specifically described in each embodiment, but also the combinations of each embodiment may be partially combined unless any problem arises in the combination.

<Example of adding a procedure to investigate W phase abnormalities each time>
In the processing of the abnormality detection means 114 and the abnormality point diagnosis means 115 described above, the diagnosis of the abnormality point diagnosis means 115 is performed for the phase to which only one current sensor is attached (the W phase current sensor WW1 in the example of Table 3). Among the above, it is determined that the condition is not abnormal if Equation 3 or Equation 4 holds. However, if processing is performed according to the procedure shown in FIG. 20, it is not possible to detect that the current sensor WW1 is abnormal, and if an abnormality occurs in the current sensor VV2 while the current sensor WW1 is abnormal, the abnormal point The output of the current sensor WW1 necessary for carrying out the diagnosis by the diagnosis means 115 is not normal, and the abnormal point diagnosis means 115 can not be completed normally.

Therefore, after diagnosing that all the paired current sensors are normal, the abnormality detection unit 114 checks in advance whether there is an abnormality in the current sensor WW1 in advance by checking whether the following conditions are satisfied. Good.
| UU1 + VV1 + WW1-3C | <S2 (Equation 5)
As a result, the current sensor WW1 can always be monitored for any abnormality. If it is first diagnosed that only the current sensor WW1 is abnormal based on the diagnosis result of whether the WW1 obtained from the current sensor WW1 is normal or abnormal, the current control is stopped without implementing the abnormal point diagnosis means 115. If it is determined that the current sensor WW1 is normal until just before any one of the U-phase and V-phase current sensors is abnormal, the result of the current sensor WW1 is You can take measures to trust.

<Example of using current sensor offset as variable>
So far, constant C has been used as the offset of the current sensor, but depending on the current sensor used, the offset may change due to the machine difference or temperature, and this difference causes the deterioration of control performance. It is conceivable to update the actual measured value of. Therefore, the offsets used in the abnormality detection means 114 and the abnormality point diagnosis means 115 described above may not be constants but may be numerical values updated by measurement.

<Configurations other than those illustrated>
Up to this point, a configuration using a total of five current sensors, two in two phases and one in one phase has been shown. However, a total of six current sensors forming a pair are used for each of the three phases, and all phases are diagnosed by the abnormality detection means 114 for any abnormality, and the abnormality is diagnosed and the abnormality is detected. Even when an abnormality is identified by the diagnosis unit 115, for example, in the case of an abnormality in one current sensor, the remaining five current sensors perform calculations according to the procedure described above to further increase redundancy. It is also good. If only two current sensors are attached to the two phases and no current sensor is attached to the remaining one phase, the abnormal point using the relation that the sum of the three phases proposed in the abnormal point diagnosis means 115 is zero is used. The determination method can not be used.

As shown in FIG. 21, as a current sensor, two pairs of current sensors that respectively detect current in opposite directions of the current are directed to face each other and any two phases in three phases ( In this example, U-phase and V-phase may be respectively provided, and the current sensor may not be attached to the other one phase (W-phase in this example).

Here, it is assumed that current sensors UU1 and UU2 are attached as two opposing current sensors for the U-phase, and current sensors VV1 and VV2 are attached as two opposing current sensors for the V-phase. In this case, the abnormality detection means 114 (FIG. 17) determines whether the following conditional expressions are satisfied. Hereinafter, values (voltages) obtained from the current sensors UU1, UU2, VV1, and VV2 are shown as UU1, UU2, VV1, and VV2, respectively.

| UU1 + UU2-2C | <S1 (Equation 6)
| VV1 + VV2-2C | <S1 (Equation 7)
At this time, it is assumed that the determination result of each expression is Expression 6: True, Expression 7: False. Therefore, the difference in the output of the U-phase current sensor is within an acceptable range, and no abnormality is recognized. In addition, the calculation result on the left side of Equation 7 exceeds S1 which is a threshold for determining abnormality, and the output of the V-phase current sensor has a significantly different absolute value of the obtained result or a predetermined offset value A large deviation from C is expected, and it is diagnosed as abnormal. The deviation of the offset value may be, for example, an output of zero when power is not supplied from the power supply to be supplied to the current sensor.

By performing the above-described process, it is possible to diagnose whether or not any one of the current sensors in the phase is abnormal with respect to the current sensors attached to each other so as to face each other in pairs. The results are shown in Table 5. In Table 5, the circle indicates normal, and the x indicates abnormality.

<Concrete operation of the abnormal point diagnostic means>
At this point, according to the diagnosis of the abnormality detection means 114 (FIG. 17), the paired current sensors attached to the U phase are both normal, and one of the paired current sensors attached to the V phase is abnormal Have been diagnosed.
Although the abnormality detection means 114 (FIG. 17) can diagnose whether there is a current sensor that is abnormal in that phase, it is possible to determine which one of the current sensors that is the pair of the phase is abnormal. Can not. Therefore, the abnormal point diagnosis means 115 (FIG. 17) performs a process to determine this.

The abnormal point diagnosing means 115 (FIG. 17) is a current driving circuit 108 so that a current flows as an abnormal point diagnostic current only in the phase (in this example, the U phase and the V phase in this example) to which the current sensor is attached. Is operated, and the abnormal point diagnostic current is detected by the current sensor to identify the abnormal current sensor.
To flow current only to the U and V phases, the high side of the U phase switching element 112 (FIG. 17) and the low side of the V phase switching element 112 (FIG. 17), W phase switching element 112 (FIG. 17) is realized by turning off both. At this time, since the sum of the three-phase alternating current is zero and the W-phase current is zero, the following relationship is established.

(U-phase current) + (V-phase current) + (W-phase current) = 0 ... (Equation 8)
Here, from W-phase current = 0,
(U-phase current) =-(V-phase current) ... (Equation 9)
Therefore, although ideally UU1-VV1 = 0 and UU2-VV2 = 0, in reality, the error or noise of the current sensor causes a difference from “zero”, so the error value of the current sensor and the noise The threshold value S2 of the allowable difference is determined with reference to the level. Therefore, the abnormal point diagnosis means 115 (FIG. 17) determines whether the following conditional expression is satisfied.
| UU1-VV1 | <S2 (Equation 10)
| UU2-VV2 | <S2 (Equation 11)

In the above conditional expressions, when Expression 10: True, Expression 11: False, it is understood that the current sensor UU2 or the current sensor VV2 is abnormal. Here, since it is known from the abnormality detection means 114 (FIG. 17) that there is an abnormality in the V-phase current sensor, it is possible to determine that the current sensor VV2 is abnormal. By combining the above processing with the processing result of the abnormality detection means 114 (FIG. 17), it is possible to specify which current sensor is abnormal. The result of the abnormality diagnosis is recorded in a variable that stores the state of each current sensor, and is used as a determination standard of whether or not to use in the subsequent calculation.

Table 6 is the summary of the above contents. In Table 6, the circle indicates normal, and the x indicates abnormality.

The other configuration is the same as that of the second embodiment, and the same function and effect as the second embodiment can be obtained. Further, according to the configuration of FIG. 21, cost reduction can be achieved by reducing the number of current sensors compared to the second embodiment.

The electric vehicle provided with the motor drive device according to any one of the embodiments is not limited to the above-described one motor on board type. For example, as shown in FIG. 22A, a two-motor on board in which two motors 104, 104 and a reduction gear corresponding to each motor 104 are provided on a vehicle body 101 and the left and right wheels 103, 103 are driven by these motors 104, 104. The motor drive 106, 106 may be provided in a type of electric vehicle. As shown in FIG. 22B, the in-wheel motor type electric vehicle in which the left and right wheels 102, 102 are respectively driven by the motor 104 constituting the in-wheel motor drive device IWM is provided with the motor drive devices 106, 106 It is also good. In FIGS. 22A and 22B, the left and right wheels driven by the motor 104 may be either of the front and rear wheels 3 and 2. Also, four-wheel drive may be used.

As described above, although the preferred embodiments have been described with reference to the drawings, various additions, modifications, and deletions can be made without departing from the spirit of the present invention. Therefore, such is also included in the scope of the present invention.

6 ... Motor 16 ... Power circuit section (electric circuit)
22 ... motor drive control device 23 ... current detection unit 24 ... abnormality detection unit 26 ... rotational speed detection means U1, V1, W, U2, V2 ... current sensor 104 ... three-phase AC motor 106 ... motor drive device 108 ... current drive circuit 109: Control device 114: Abnormality detection means 115: Abnormality point diagnosis means 116: Differential operation means S: Current sensor

Claims (18)

1. A motor drive control device for controlling a plurality of motor facilities including a plurality of U-phase, V-phase and W-phase three-phase electrode systems in one three-phase motor or across a plurality of three-phase motors ,
   Current sensors for detecting the current flowing through the U phase, V phase and W phase of each system are provided in all phases, and there is a motor drive control unit for individually controlling each system by the current detected by these current sensors. And
   One of the current sensors for detecting the current flowing through the U phase, the V phase and the W phase of each system is a common current sensor for detecting the current of each phase in two systems, and this common Motor drive control device in which the integrated current sensor is a non-contact current sensor.
2. The motor drive control device according to claim 1, wherein the current detected by the common current sensor and the current sensors of the remaining phases respectively makes use of the fact that the sum of three-phase currents is zero. A motor drive control device comprising a current detection unit for calculating a current flowing through a control target system among currents detected by the integrated current sensor.
3. The motor drive control device according to claim 1 or 2, wherein when the sum of currents respectively detected by the common current sensor and the current sensors of the remaining phases becomes zero, the common current sensor and the common current sensor Abnormality detection in which the current sensor in the common phase and the current sensor in the remaining phase are determined as abnormal when the current sensors in the remaining phases are determined to be normal and the sum of the currents does not become zero. Motor drive control device having a control unit.
4. The motor drive control device according to any one of claims 1 to 3, wherein the motor drive control unit individually controls the respective systems using only the current detected by the current sensor of the remaining phase. Motor drive control device.
5. The motor drive control device according to claim 3 or 4, wherein when any one of the current sensors is determined to be abnormal by the abnormality detection unit, the motor drive control unit is all systems for driving the motor. A motor drive control device for stopping a current-carrying circuit connected to the motor drive control device, wherein the abnormality detection unit detects current with each current sensor and determines that the current sensor whose current does not become zero is abnormal.
6. The motor drive control device according to any one of claims 3 to 5, wherein when any one of the current sensors is determined to be abnormal by the abnormality detection unit, the motor drive control unit is connected to one system. And the abnormality detection unit is configured to stop the current passing through the common current sensor and the current of the remaining phase for the system through which the current flows. A motor drive control device that determines a current sensor that becomes abnormal depending on whether or not the sum of currents respectively detected by the sensor becomes zero.
7. The motor drive control device according to claim 6, wherein when the motor drive control unit stops the energizing circuit connected to one system, the abnormality detection unit is configured to determine the remaining phases of the stopped system. The motor drive control device determines the current sensor which becomes abnormal depending on whether or not the current detected by each of the current sensors becomes zero.
8. The motor drive control device according to claim 6 or 7, wherein when any one of the current sensors is determined to be abnormal by the abnormality detection unit, the motor drive control unit is configured to have an energizing circuit connected to one system. When there is a system in which the sum of the currents respectively detected by the common current sensor and the current sensors of the remaining phases becomes zero, the abnormality detection unit stops the system in which current flows. Motor drive control unit that determines that the sensor is normal.
9. The motor drive control device according to any one of claims 3 to 8, further comprising: a rotation number detection unit that detects the rotation number of the motor, wherein the abnormality detection unit is detected by the rotation number detection unit. A motor drive control device that calculates a back electromotive force according to a condition determined from the number of revolutions, and performs abnormality detection when the back electromotive voltage does not exceed the power supply voltage.
10. The motor drive control device according to any one of claims 6 to 8, wherein the motor equipment includes two or more motors, and the motor drive control unit is a part of a plurality of motors. And a motor drive control device for increasing the command torque of the motor having the energizing circuit stopped with respect to the command torque of the motor not having the energizing circuit stopped when the energizing circuit connected to the system is stopped.
11. The motor drive control device according to any one of claims 3 to 10, wherein the abnormality detection unit determines that the current sensor that detects the current of one phase of any one system is abnormal. The motor drive control unit may use the sum of an individual current sensor that detects another phase of the one system, or an individual current sensor that detects the current of another system phase and a common current sensor. A motor drive control device that performs current control by calculating the current of the phase flowing to the common current sensor of the energizing circuit connected to one system.
12. A motor drive device for driving a three-phase AC motor as a drive source for traveling an electric vehicle, comprising: a current drive circuit, a current sensor detecting a current flowing through the three-phase AC motor, a torque command given and the current A control device for providing a drive signal of the current to the current drive circuit based on the current detected by the sensor;
    As the current sensor, two pairs of current sensors capable of detecting the magnitude and the direction of the current are provided in directions facing each other and in any two phases in three phases, respectively.
    The control device obtains the difference between currents respectively detected by the pair of current sensors for each phase in the two phases including the pair of current sensors, and superimposes them on the output of the pair of current sensors A motor drive device comprising: differential operation means for performing current control by canceling out common mode noise and using obtained current values.
13. The motor drive device according to claim 12, wherein the control device takes in the output of the current sensor as the pair, determines whether the obtained current value satisfies a predetermined conditional expression, and the abnormality of the current sensor Motor drive device having an abnormality detection means for detecting
14. 14. The motor drive device according to claim 13, wherein the abnormality detection unit detects the current sensor as a pair when there is a difference between the current value obtained by adding the outputs of the pair of current sensors and a threshold value. A motor drive device that diagnoses that one of the current sensors is abnormal.
15. The motor drive device according to claim 14, wherein the control device is configured to detect only a phase provided with a current sensor when one of the current sensors of the current sensors to be paired is judged to be abnormal by the abnormality detection means. A motor drive having abnormal point diagnosis means for specifying a current sensor which is abnormal by operating the current drive circuit so that current flows as an abnormal point diagnosis current and detecting the abnormal point diagnosis current by the current sensor. apparatus.
16. The motor drive device according to any one of claims 12 to 14, wherein the current sensor includes the current sensor of the pair in the two phases, and the current flowing in the remaining one phase of the three phases. And a current sensor to detect
    The control device sums the outputs of the respective current sensors respectively provided in the three phases from the respective phases, and when the sum exceeds a threshold without becoming zero, either current sensor A motor drive apparatus having abnormal point diagnosis means for identifying a current sensor that is abnormal by judging that an abnormality has occurred and changing a combination for obtaining the sum.
17. The motor drive device according to claim 15 or 16, wherein when the abnormal point diagnostic means identifies a current sensor that is abnormal, the control device does not use the output current value of the abnormal current sensor and remains. The motor drive device which performs current control using the output current value of the current sensor.
18. An electric vehicle provided with the motor drive device according to any one of claims 12 to 17.

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