JP2012065380A - Motor control apparatus - Google Patents

Abstract

A simple and inexpensive motor control device capable of continuing vehicle travel control even when an abnormality occurs in any one of current sensors in each phase.
A motor control device 100 includes first and second current sensors U1, U2, V1, and V2 that detect a U-phase or V-phase current, and a W-phase current sensor W that detects a W-phase current. When the difference between the current values detected by the first and second current sensors 130 is equal to or greater than a predetermined threshold value, an abnormality detection unit that detects that an abnormality has occurred in any of the first and second current sensors. And the abnormality detecting means detects an abnormality in the first or second current sensor based on the current value detected by the W-phase current sensor and the current value detected by the first and second current sensors. The three-phase motor is controlled using information detected by a current sensor that is not determined to be abnormal.
[Selection] Figure 1

Description

  The present invention relates to a motor control device, and more particularly to a motor control device that detects an abnormality of a current sensor in a three-phase motor.

  Recently, hybrid vehicles and electric vehicles in which a motor is incorporated in a drive device have become widespread as environmentally friendly vehicles. In general, a hybrid vehicle is provided with an AC motor for driving a wheel that is driven and controlled by an inverter device, and a current sensor that detects an AC current supplied to the motor is used to control the AC motor by the inverter device. .

And when abnormality has generate | occur | produced in the current sensor used for a motor control apparatus in this way, it becomes important to detect the said abnormality.

  Therefore, in the sensor abnormality detection device described in Patent Document 1, current values are detected by two current sensors, and the detected current values are compared. Then, when the difference between the detected current values exceeds a predetermined threshold value, the abnormal count value is incremented, and when the abnormal count value reaches the reference value, one of the two current sensors is selected. It is determined that an abnormality has occurred.

  In addition, the motor control device described in Patent Document 2 includes three current sensors in the U phase, the V phase, and the W phase, and the current value of each phase is detected by each current sensor. And when the sum total of the electric current value of each phase is larger than predetermined value, it determines with abnormality having generate | occur | produced in any of three electric current sensors.

JP 2010-139244 A JP 2009-131043 A

  However, the conventional motor control device includes a plurality of current sensors, and although it is determined that an abnormality has occurred in any of the plurality of current sensors, any of the plurality of current sensors is selected. It is not specified whether an abnormality has occurred in the current sensor.

  Generally, when it is determined that an abnormality has occurred in the current sensor, there is a system configuration that shifts to a retreat traveling control mode that is different from the normal vehicle traveling control mode, but in order to identify the current sensor in which the abnormality has occurred However, there is a problem that the system configuration becomes complicated and expensive, and further, the calculation load of a CPU (Central Processing Unit) becomes high and processing time is required.

  Therefore, an object of the present invention is to provide a simple and inexpensive configuration that enables vehicle travel control to be continued even when an abnormality occurs in any of the current sensors in each phase. It is providing the motor control apparatus which has.

  In order to achieve the above object, a motor control device of the present invention is a motor control device that controls a three-phase motor, and includes first and second current sensors that detect a U-phase or V-phase current, If the difference between the current values detected by the W-phase current sensor that detects the phase current and the first and second current sensors is equal to or greater than a predetermined threshold, there is an abnormality in either the first or second current sensor. An abnormality detecting means for detecting occurrence of the abnormality, and the abnormality detecting means adds the current value detected by the W-phase current sensor and one of the current values detected by the first and second current sensors. When the abnormality identification current value is less than a predetermined threshold, the first or second current sensor in which a current value not added when the abnormality identification current value is calculated is detected. If something is wrong with If the abnormality identification current value is equal to or greater than a predetermined threshold, an abnormality has occurred in the first or second current sensor in which the current value added when calculating the abnormality identification current value is detected. The three-phase motor is controlled using information detected and detected by a current sensor that is not determined to be abnormal by the abnormality detection means.

  As described above, according to the motor control device of the present invention, even when an abnormality occurs in any of the current sensors in each phase, the vehicle travel control is continued with a simple and inexpensive configuration. It becomes possible to do.

The figure which shows the motor control apparatus 100 which concerns on one Embodiment of this invention. The flowchart which shows the flow of a process when it determines with abnormality having generate | occur | produced in either the 1st U-phase current sensor U1 and the 2nd U-phase current sensor U2.

  A three-phase motor control ECU (Electronic Control Unit) of a hybrid vehicle is characterized by having two current sensor circuits for a U-phase and a V-phase for a single motor, and having a dual system configuration. In a dual system configuration, one current sensor circuit is normally used for actual motor control, and the other current sensor circuit is used to determine whether the current sensor circuit used for motor control is operating normally. It is used exclusively for diagnostic checking. Specifically, it is detected that an abnormality has occurred in either of the two current sensor circuits by comparing the current values detected by the two current sensor circuits.

  When it is detected that an abnormality has occurred in the U-phase or V-phase current sensor circuit, it is determined which of the dual-system current sensor circuits in the U-phase or V-phase has an abnormality. Then, the vehicle travel is continued by using information detected by a current sensor circuit that is not determined to be abnormal.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a motor control device 100 according to an embodiment of the present invention. In FIG. 1, the motor control device 100 includes a motor M, a high-voltage power supply unit 110, a motor drive circuit 120, a current sensor system 130, an HV control ECU 140, and a motor control ECU 150.

  The motor M performs vehicle travel or power generation.

  A rotation angle sensor (resolver) in the motor M is connected to the rotation shaft of the motor M, and sends signals (sin, cos) that are electrically 90 degrees out of phase to the R / D converter 154.

  The high voltage power supply unit 110 is a power supply that supplies a DC high voltage current for driving the motor M. For example, the high-voltage power supply unit 110 includes an HV battery and a boost converter.

  The motor driving circuit 120 converts the DC high-voltage current supplied from the high-voltage power supply unit 110 into a motor driving AC current for driving the motor M. When the motor M operates as a generator, the motor drive circuit 120 converts the alternating current generated during the regeneration into a direct current. The direct current is used to charge the high voltage power supply unit 110.

  The current sensor system 130 includes a first U-phase current sensor U1, a second U-phase current sensor U2, a first V-phase current sensor V1, a second V-phase current sensor V2, and a W-phase current sensor. W. Each current sensor in the current sensor system 130 detects U-phase, V-phase, and W-phase currents in the motor M, and sends an analog signal voltage proportional to the current value to the motor control ECU 150.

  In general, the first U-phase current sensor U1 is used for vehicle control as a U-phase energization current detection in the motor M, and the second U-phase current sensor U2 is the first U-phase current sensor. It is used for abnormality detection that checks whether U1 is operating normally. Then, the current values detected by the first U-phase current sensor U1 and the second U-phase current sensor U2 are compared, and if the difference between the current values is equal to or greater than a predetermined threshold, the first U-phase current sensor U1 It is determined that an abnormality has occurred in any of the second U-phase current sensor U2. Further, based on the current value detected by the W-phase current sensor W, it is determined which of the first U-phase current sensor U1 and the second U-phase current sensor U2 is abnormal. To do. Here, when it is determined that an abnormality has occurred in the first U-phase current sensor U1 used for vehicle control, the second U-phase current sensor U2 is used for vehicle control. To be controlled.

  Similarly, the first V-phase current sensor V1 is normally used for vehicle control for detecting a V-phase energization current in the motor M, and the second V-phase current sensor V2 is used for the first V-phase current sensor V1. It is used for detecting an abnormality for checking whether or not the phase current sensor V1 is operating normally. Then, the current values detected by the first V-phase current sensor V1 and the second V-phase current sensor V2 are compared, and if the difference between the current values is equal to or greater than a predetermined threshold, the first V-phase current sensor V1 It is determined that an abnormality has occurred in either of the second V-phase current sensor V2. Further, based on the current value detected by the W-phase current sensor W, it is determined which of the first V-phase current sensor V1 and the second V-phase current sensor V2 is abnormal. To do. Here, when it is determined that an abnormality has occurred in the first V-phase current sensor V1 used for vehicle control, the second V-phase current sensor V2 is used for vehicle control. To be controlled.

  The HV control ECU 140 sends an instruction or the like necessary for controlling the motor M to the motor control ECU 150 based on the power supply from the high voltage power supply unit 110.

  The motor control ECU 150 controls the motor drive circuit 120 for driving the motor M. More specifically, the motor control ECU 150 includes a microcomputer 151, input circuits a to d, a first selector 152 and a second selector 153, an R / D (resolver / digital) converter 154, and a communication interface (I / F) 155 and a three-phase drive circuit 156.

  The input circuits a to d convert each current information detected by the current sensor system 130 into an input signal level signal of the microcomputer 151. The currents detected by the current sensor system 130 are lu, which is the U-phase current that drives the motor M, lv, which is the V-phase current, and lw, which is the W-phase current.

  The first selector 152 and the second selector 153 switch the connection between each current sensor of the current sensor system 130 and the input circuits a to d. Thus, which current information among the pieces of current information detected by the current sensor system 130 is controlled to be input to the input circuits a to d. Note that the first selector 152 and the second selector 153 are controlled based on a switching signal from the microcomputer 151.

  The R / D converter 154 converts a signal output from the rotation angle sensor in the motor M into a digital value, and sends the converted digital signal to the microcomputer 151.

  The microcomputer 151 receives a signal output from the motor rotation angle sensor (resolver) digitally converted by the R / D converter 154, and receives each current information detected by the current sensor system 130 via the input circuits a to d. Receive. The microcomputer 151 generates a three-phase PWM (Pulse Width Modulation) signal based on the received signal and current information and an instruction from the HV control ECU 140 input via the communication I / F 155. Send to phase drive circuit 156. Communication I / F 155 includes an interface circuit and performs serial communication with HV control ECU 140.

  The three-phase drive circuit 156 sends the three-phase PWM signal generated by the microcomputer 151 to the motor drive circuit 120.

  The motor drive circuit 120 includes a drive element unit 121 configured by an IGBT and a control circuit unit 122 that controls the drive element unit 121. The control circuit unit 122 controls the IGBT based on a three-phase drive signal sent from the three-phase drive circuit 156 in the motor control ECU 150.

  Next, the control method executed by the motor control device 100 according to the embodiment of the present invention shown in FIG. 1 will be described in detail.

  First, during traveling of the vehicle, the motor control ECU 150 always compares the current value detected by the first U-phase current sensor U1 with the current value detected by the second U-phase current sensor U2. . When the difference between the current values is equal to or greater than a predetermined threshold, motor control ECU 150 determines that an abnormality has occurred in either first U-phase current sensor U1 or second U-phase current sensor U2. .

  Specifically, the current value detected by the first U-phase current sensor U1 is always input to the microcomputer 151 via the input circuit a. The terminal S1 in the first selector 152 is normally connected to the input circuit b, and the current value detected by the second U-phase current sensor U2 is passed through the first selector 152 and the input circuit b. Are input to the microcomputer 151. The microcomputer 151 compares the current value input from the input circuit a with the current value input from the input circuit b, and determines which of the first U-phase current sensor U1 and the second U-phase current sensor U2. It is determined whether a crab abnormality has occurred.

  Similarly, during vehicle travel, motor control ECU 150 always compares the current value detected by first V-phase current sensor V1 with the current value detected by second V-phase current sensor V2. Yes. When the difference between the current values is equal to or greater than a predetermined threshold, motor control ECU 150 determines that an abnormality has occurred in either first V-phase current sensor V1 or second V-phase current sensor V2. .

  Specifically, the current value detected by the first V-phase current sensor V1 is always input to the microcomputer 151 via the input circuit c. The terminal S3 in the second selector 153 is normally connected to the input circuit d, and the current value detected by the second V-phase current sensor V2 is passed through the second selector 153 and the input circuit d. Are input to the microcomputer 151. The microcomputer 151 compares the current value input from the input circuit c with the current value input from the input circuit d, and determines which of the first V-phase current sensor V1 and the second V-phase current sensor V2. It is determined whether a crab abnormality has occurred.

  Here, it is assumed that the motor control ECU 150 has determined that an abnormality has occurred in either the first U-phase current sensor U1 or the second U-phase current sensor U2 using the method described above. A control method in the control ECU 150 will be described in detail below.

  FIG. 2 is a flowchart showing a processing flow when it is determined that an abnormality has occurred in either the first U-phase current sensor U1 or the second U-phase current sensor U2.

  In step S <b> 210, the microcomputer 151 sends a connection switching signal to the second selector 153. The second selector 153 switches the connection with the input circuit d from the terminal S3 to the terminal S4 based on the connection switching signal. As a result, the current value detected by the W-phase current sensor W is input to the microcomputer 151 via the input circuit d.

  The current value detected by the first U-phase current sensor U1 is input to the microcomputer 151 via the input circuit a, and the current value detected by the first V-phase current sensor V1 is input. The signal is input to the microcomputer 151 via the circuit c.

  In step S220, the microcomputer 151 determines whether the sum of the current value input from the input circuit a, the current value input from the input circuit c, and the current value input from the input circuit d is zero. judge. In other words, the microcomputer 151 detects the current value detected by the first U-phase current sensor U1, the current value detected by the first V-phase current sensor V1, and the current detected by the W-phase current sensor W. It is determined whether or not the sum total with the value is zero.

  When it is determined in step S220 that the total sum of current values is 0, in step S230, the microcomputer 151 determines that an abnormality has occurred in the second U-phase current sensor U2 (Yes in step S220), The process proceeds to step S260.

  On the other hand, when it is determined in step S220 that the sum of the current values is not 0, in step S240, the microcomputer 151 determines that an abnormality has occurred in the first U-phase current sensor U1 (No in step S220). The process proceeds to step S250.

  In step S250, the microcomputer 151 normally uses the information detected by the first U-phase current sensor U1, but is detected by the second U-phase current sensor U2 that is not determined to be abnormal. To use the information that has been changed.

  In step S260, the microcomputer 151 does not determine that the first U-phase current sensor U1 that is normally used for vehicle control has an abnormality after the processing in step S230. Control of vehicle travel is continued using information input via the circuit a and the input circuit c. On the other hand, the microcomputer 151 determines that the first U-phase current sensor U1 that is normally used for vehicle control has an abnormality after the processing of step S250. And control of vehicle travel is continued using information inputted via input circuit c.

  In step S <b> 270, the microcomputer 151 sends a connection switching signal to the second selector 153. In the second selector 153, when the input circuit d and the terminal S4 are connected (step S210), the connection with the input circuit d can be switched from the terminal S4 to the terminal S3 based on the connection switching signal. The process is terminated.

  As described above, according to the motor control device 100 according to the embodiment of the present invention, it is a case where an abnormality has occurred in either the first U-phase current sensor U1 or the second U-phase current sensor U2. In addition, by switching the second selector 153, it is possible to determine which of the first U-phase current sensor U1 and the second U-phase current sensor U2 is abnormal. That is, by the switching control of the second selector 153, the vehicle travel control can be continued with a simple and inexpensive configuration without shifting to the retreat travel control mode different from the normal vehicle travel control mode.

  In this embodiment, in step S220, the microcomputer 151 determines the current value detected by the first U-phase current sensor U1, the current value detected by the first V-phase current sensor V1, and the W-phase current. By determining whether or not the sum of the current value detected by the sensor W is 0, any of the first U-phase current sensor U1 and the second U-phase current sensor U2 is abnormal. However, the present invention is not limited to this. For example, the microcomputer 151 includes a current value detected by the first U-phase current sensor U1, a current value detected by the first V-phase current sensor V1, and a current value detected by the W-phase current sensor W. Is less than the predetermined threshold value, it is determined that an abnormality has occurred in the second U-phase current sensor U2, the current value detected by the first U-phase current sensor U1, and the first V-phase current sensor U1 If the sum of the current value detected by current sensor V1 and the current value detected by W-phase current sensor W is equal to or greater than a predetermined threshold, it is determined that an abnormality has occurred in first U-phase current sensor U1. It doesn't matter.

  In the present embodiment, the processing when it is determined that an abnormality has occurred in either the first U-phase current sensor U1 or the second U-phase current sensor U2 has been described with reference to FIG. The same effect can be obtained by the switching control of the first selector 152 in the case where it is determined that an abnormality has occurred in either the first V-phase current sensor V1 or the second V-phase current sensor V2. It goes without saying that can be obtained.

  The present invention can be applied to a motor control device or the like mounted on a vehicle, and is particularly useful for a control system or the like that determines an abnormality of a current sensor with a simple and inexpensive configuration.

M Motors S1 to S4 Terminals U1, U2, V1, V2, W Current detection sensors a to d Input circuit 100 Motor controller 110 High voltage power supply unit 120 Motor drive circuit 121 Drive element unit 122 Control circuit unit 130 Current sensor system 140 HV Control ECU
150 Motor control ECU
151 Microcomputer 152, 153 Selector 154 R / D converter 155 Communication I / F
156 Three-phase drive circuit

Claims (1)

A motor control device for controlling a three-phase motor,
First and second current sensors for detecting U-phase or V-phase current;
A W-phase current sensor for detecting a W-phase current;
An abnormality detection means for detecting that an abnormality has occurred in one of the first and second current sensors when the difference between the current values detected by the first and second current sensors is equal to or greater than a predetermined threshold. And
The abnormality detection means is
Adding the current value detected by the W-phase current sensor and one of the current values detected by the first and second current sensors to calculate an abnormality identification current value;
When the abnormality identification current value is less than a predetermined threshold, an abnormality has occurred in the first or second current sensor in which a current value not added when the abnormality identification current value is calculated is detected. If the abnormality identification current value is greater than or equal to a predetermined threshold, an abnormality has occurred in the first or second current sensor in which the current value added when calculating the abnormality identification current value is detected. It is determined that
A motor control device that controls the three-phase motor using information detected by a current sensor that is not determined to be abnormal by the abnormality detection means.

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