WO2024057878A1 - Motor control device and electric steering device - Google Patents

Motor control device and electric steering device Download PDF

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Publication number
WO2024057878A1
WO2024057878A1 PCT/JP2023/030676 JP2023030676W WO2024057878A1 WO 2024057878 A1 WO2024057878 A1 WO 2024057878A1 JP 2023030676 W JP2023030676 W JP 2023030676W WO 2024057878 A1 WO2024057878 A1 WO 2024057878A1
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WO
WIPO (PCT)
Prior art keywords
semiconductor switching
motor
control device
switching element
voltage
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PCT/JP2023/030676
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French (fr)
Japanese (ja)
Inventor
啓太 安
亨典 平木
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日立Astemo株式会社
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Publication of WO2024057878A1 publication Critical patent/WO2024057878A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
    • H02P29/02—Providing protection against overload without automatic interruption of supply

Definitions

  • the present invention relates to a motor control device and an electric steering device.
  • the power conversion device of Patent Document 1 includes a first inverter connected to one end of the winding of each phase of the motor, a second inverter connected to the other end of the winding of each phase, and a second inverter connected to the other end of the winding of each phase of the motor. It includes a first relay circuit connected between one end and one of the power supply and GND, and a second relay circuit connected between the other end of each phase winding and one of the power supply and GND.
  • the first relay circuit is turned on to form a neutral point, and the remaining in the circuit is Release zero-sequence current to the outside.
  • a drive circuit that supplies power to the windings of a polyphase winding set of the motor and a neutral point of the polyphase winding set are It may be equipped with a motor relay that connects the energized path intermittently.
  • a back electromotive force is generated in the motor when the wheels are steered at high speed in conjunction with steering wheel operation or when the motor is rotated by a large reverse input from the wheels, this The back electromotive voltage flows around to the gate of the semiconductor switching element that constitutes the motor relay, and the gate voltage becomes high.
  • the semiconductor switching element constituting the motor relay in this state, the semiconductor switching element will generate heat, potentially damaging the semiconductor switching element.
  • some abnormality occurs in the electric steering system and the motor generates a back electromotive force when the motor relay is turned off to stop the current supply to the motor, the gate of the semiconductor switching element that makes up the motor relay.
  • the semiconductor switching elements that make up the motor relay would be damaged due to the back electromotive force being passed around to the motor relay.
  • the present invention has been made in view of the conventional situation, and an object thereof is to provide a semiconductor switching element that connects and connects the current-carrying path between the drive circuit and the neutral point of the motor's polyphase winding set.
  • An object of the present invention is to provide a motor control device and an electric steering device that can be prevented from being damaged by back electromotive force.
  • a motor control device is a motor control device that controls a motor having a multiphase winding set, and includes a drive circuit that supplies power to the windings of the multiphase winding set; a semiconductor switching element that connects and disconnects a current-carrying path between the drive circuit and the neutral point of the multiphase winding set; a control section that controls the drive circuit and the semiconductor switching element; and a ground and the control section that output is provided in a ground path that connects a signal path of a control signal of the semiconductor switching element, and when the potential on the side of the winding of the semiconductor switching element and the potential of the ground reach a predetermined potential difference, the A control element that turns on the semiconductor switching element.
  • the electric steering device is an electric steering device mounted on a vehicle, the motor having a multiphase winding set, and comprising a motor with a steering force for steering wheels of the vehicle.
  • the motor and a motor control device that controls the motor, and the motor control device includes a drive circuit that supplies power to the windings of the polyphase winding set, and a drive circuit that supplies power to the windings of the multiphase winding set.
  • a semiconductor switching element that connects and disconnects a current-carrying path between the neutral point of the multiphase winding set; a control unit that controls the drive circuit and the semiconductor switching element; and a semiconductor switching element that controls the drive circuit and the semiconductor switching element; Provided in a ground path connecting a signal path of a control signal of the element, when the potential on the side of the winding of the semiconductor switching element and the potential of the ground reach a predetermined potential difference, the semiconductor switching element is activated. and a control element that turns on.
  • the semiconductor switching element that connects and disconnects the current-carrying path between the drive circuit and the neutral point of the multiphase winding set of the motor from being damaged by the back electromotive force of the motor.
  • FIG. 1 is a configuration diagram of an electric power steering device.
  • FIG. 3 is a diagram showing functional blocks of a motor drive circuit and a control device.
  • FIG. 3 is a diagram showing a state in which a back electromotive force is generated in the motor.
  • FIG. 3 is a diagram for explaining an effect of protecting a semiconductor switching element from a back electromotive voltage of a motor.
  • FIG. 6 is a diagram showing a state in which a motor relay is protected by forming a return flow path. It is a flowchart which shows the diagnostic procedure of a Zener diode and a diagnostic voltage output circuit.
  • an electric power steering device installed in a vehicle is an electric power steering device that uses torque generated by a motor to supplement the force required to operate the steering wheel, and a motor control device is applied to the electric power steering device.
  • FIG. 1 is a configuration diagram showing one aspect of an electric power steering device 200 attached to a vehicle 100.
  • the steering mechanism 210 of the electric power steering device 200 includes a steering wheel 201, a steering shaft 202 which is a rotation axis of the steering wheel 201, a pinion shaft 203 provided at an end of the steering shaft 202, a rack bar 204, and a rack bar 204. It has a rack housing 205 that accommodates the.
  • the steering shaft 202 is provided with a steering angle sensor 206 that detects a steering angle ⁇ , which is a rotation angle of the steering shaft 202, and a steering torque sensor 207 that detects a steering torque TS of the steering wheel 201.
  • the steering mechanism 210 includes a motor 220 that is a steering actuator that applies a steering torque to the rack bar 204, in other words, a steering actuator that generates a steering force that moves the rack bar 204 in the axial direction.
  • the rotational motion of the motor 220 is transmitted to the rack bar 204 via a transmission mechanism 208 that includes a belt, a ball screw, or the like.
  • the application of steering torque by the motor 220 is performed to assist the driver's steering operation. Note that the steering torque applied by the motor 220 allows autonomous steering, in other words, automatic steering.
  • the motor 220 is a DC motor having a multi-phase winding set, for example, a three-phase brushless DC motor having a motor rotor and a winding set including a U-phase winding, a V-phase winding, and a W-phase winding.
  • the drive circuit 245 includes a three-phase bridge inverter made up of six semiconductor switching elements, and controls the power supplied to each winding of the motor 220 by controlling on/off of the semiconductor switching elements.
  • the control device 230 is an electronic control device including a microprocessor (in other words, a control section), and together with the drive circuit 245 constitutes a motor control device 260 .
  • the control device 230 then outputs a control signal for controlling the drive circuit 245.
  • the control device 230 receives a sensor signal related to the operating angle ⁇ of the steering shaft 202 outputted by the operating angle sensor 206, a sensor signal related to the steering torque TS outputted by the steering torque sensor 207, and a vehicle speed outputted by the vehicle speed sensor 211 (or wheel speed sensor).
  • a sensor signal related to VS, a sensor signal related to the rotor rotation angle ⁇ of the motor 220 outputted by the motor rotation angle sensor 209, and the like are acquired.
  • control device 230 calculates the steering torque output by the motor 220, in other words, the command torque that is the target value of the assist torque, based on the acquired various sensor signals. Then, the control device 230 outputs a control signal to the drive circuit 245 based on the command torque, and performs PWM (Pulse Width Modulation) control on the drive current of the motor 220.
  • PWM Pulse Width Modulation
  • FIG. 2 is a diagram showing the drive circuit 245 and the motor 220, and also represents the functions of the control device 230 in blocks.
  • Drive circuit 245 includes a three-phase bridge inverter 245A and a PWM control driver 245B.
  • the three-phase bridge inverter 245A has a U-phase arm, a V-phase arm, and a W-phase arm connected in parallel between the system power supply 246 and the ground GND.
  • the U-phase arm is configured by connecting an upper semiconductor switching element UH and a lower semiconductor switching element UL in series.
  • the V-phase arm is configured by connecting an upper semiconductor switching element VH and a lower semiconductor switching element VL in series.
  • the W-phase arm is configured by connecting an upper semiconductor switching element WH and a lower semiconductor switching element WL in series.
  • the two semiconductor switching elements in each phase arm of the three-phase bridge inverter 245A are connected to the windings of the corresponding phases of the motor 220, forming a three-phase bridge circuit.
  • the connection between the two semiconductor switching elements UH and UL of the U-phase arm is connected to the end of the U-phase winding 220U
  • the connection between the two semiconductor switching elements VH and VL of the V-phase arm is connected to the end of the U-phase winding 220U. It is connected to the end of the wire 220V
  • the portion between the two semiconductor switching elements WH and WL of the W-phase arm is connected to the end of the W-phase winding 220W.
  • the semiconductor switching elements UH, UL, VH, VL, WH, and WL that constitute the three-phase bridge inverter 245A are semiconductor elements having externally controllable control terminals, such as Metal Oxide Semiconductor Metal Field Effect Transistor (MOSFET). , Insulated Gate Bipolar Transistor (IGBT), etc. are used.
  • MOSFET Metal Oxide Semiconductor Metal Field Effect Transistor
  • IGBT Insulated Gate Bipolar Transistor
  • the semiconductor switching elements UH, UL, VH, VL, WH, and WL are N-channel MOSFETs, and parasitic diodes D1, D2, D3, D4, It has D5 and D6.
  • the parasitic diodes D1, D2, D3, D4, D5, and D6 have their anodes connected to the ground GND, cathodes connected to the system power supply 246, and allow current to flow from the ground GND toward the system power supply 246. Further, a capacitor C1 for smoothing the power supply voltage is connected between the system power supply 246 and the ground GND in parallel with the three-phase bridge inverter 245A.
  • the PWM control driver 245B is composed of a plurality of drivers that generate drive signals for each of the semiconductor switching elements UH, UL, VH, VL, WH, and WL. Each driver of the PWM control driver 245B generates a drive signal to turn on and off the semiconductor switching elements UH, UL, VH, VL, WH, and WL, in other words, a gate signal, based on the control signal output from the control device 230. and output it.
  • the windings 220U, 220V, and 220W of the motor 220 are connected in a star connection (in other words, a Y connection) that are connected together at the neutral point NP.
  • a motor relay 222 that connects and disconnects the current-carrying paths 221U, 221V, and 221W between the neutral point NP and each of the windings 220U, 220V, and 220W is arranged in the current-carrying paths 221U, 221V, and 221W.
  • the motor relay 222 is a protection relay that connects and connects the energized paths 221U, 221V, and 221W by turning on and off a semiconductor switching element. Note that the motor relay 222 can be a circuit provided in the current-carrying paths 221U, 221V, and 221W between the three-phase bridge inverter 245A and each of the windings 220U, 220V, and 220W.
  • N-channel MOSFETs are used as the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222.
  • Resistors (not shown) are mounted between the gates and sources of the semiconductor switching elements 222U, 222V, and 222W. This gate-source resistance functions to prevent the semiconductor switching elements 222U, 222V, and 222W from turning on when there is no gate control signal.
  • the N-channel MOSFETs serving as the semiconductor switching elements 222U, 222V, and 222W include parasitic diodes DU, DV, and DW that cause current to flow from the neutral point NP toward each of the windings 220U, 220V, and 220W. That is, the anodes of the parasitic diodes DU, DV, and DW are connected to the neutral point NP, and the cathodes are connected to the windings 220U, 220V, and 220W.
  • the motor relay control unit 232 controls the semiconductor switching elements by making the voltage applied to the gates of the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222 a positive voltage with respect to the source. 222U, 222V, and 222W are turned on, that is, the current-carrying paths 221U, 221V, and 221W are brought into conduction. On the other hand, when stopping the motor 220 or when some abnormality occurs in the motor control device 260, the motor relay control unit 232 turns off the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222, that is, The energizing paths 221U, 221V, and 221W are cut off.
  • the signal path 223 for giving the motor relay control signal (in other words, gate signal) output by the motor relay control unit 232 to the gate terminals of the semiconductor switching elements 222U, 222V, 222W connects to the ground GND at the connection point CP1.
  • a Zener diode ZD1 is arranged in a ground path 224 that connects the connection point CP1 and the ground GND.
  • the anode of the Zener diode ZD1 is connected to the connection point CP1 (signal path 223), and the cathode of the Zener diode ZD1 is connected to the ground GND.
  • a diode D11 is arranged in the ground path 224 between the Zener diode ZD1 and the ground GND.
  • the anode of the diode D11 is connected to the ground GND
  • the cathode of the diode D11 is connected to the Zener diode ZD1. That is, the connection point CP1 of the signal path 223 is connected to the ground GND via a series connection circuit of the Zener diode ZD1 and the diode D11, and the cathode of the Zener diode ZD1 and the cathode of the diode D11 are connected.
  • the neutral point voltage monitor circuit 233 is connected to the neutral point NP via a monitor path 234, and monitors the voltage at the neutral point NP.
  • the signal path 223 and the monitor path 234 are connected via a resistor R1.
  • the voltage monitor circuit 235 is connected via a monitor path 236 to a connection point CP2 provided in the ground path 224 between the Zener diode ZD1 and the diode D11. Furthermore, the diagnostic voltage output circuit 237 is connected to the connection point CP3 of the monitor path 236 via the voltage output path 238, and applies a predetermined diagnostic voltage to the ground path 224 between the Zener diode ZD1 and the diode D11. .
  • the Zener diode diagnosis section 239 controls the output of the diagnostic voltage from the diagnostic voltage output circuit 237, and detects the failure of the Zener diode ZD1 based on the neutral point voltage monitored by the neutral point voltage monitor circuit 233. Diagnose the presence or absence.
  • the failure of the Zener diode ZD1 diagnosed by the Zener diode diagnostic unit 239 is a failure in which the Zener diode ZD1 causes current to flow in the reverse direction at a voltage lower than that in normal times, and in this application, such a failure is referred to as a short-circuit failure.
  • the voltage output diagnosis unit 240 controls the output of the diagnostic voltage from the diagnostic voltage output circuit 237, and based on the control state of the diagnostic voltage output circuit 237 and the voltage monitored by the voltage monitor circuit 235, The presence or absence of a failure in the voltage output circuit 237 is diagnosed. That is, the voltage output diagnostic unit 240 diagnoses whether the diagnostic voltage output circuit 237 is outputting or stopping the diagnostic voltage in accordance with the command.
  • FIG. 3 shows that when a back electromotive voltage is generated in the motor 220, a voltage is applied in the direction indicated by the arrow, and the semiconductor switching elements UH, UL, VH, VL, WH, WL, and , indicates that a high load is applied to the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222.
  • the semiconductor switching elements UH, UL, VH, VL, WH, and WL that make up the three-phase bridge inverter 245A and the semiconductor switching elements 222U, 222V, and 222W that make up the motor relay 222 may be damaged by the back electromotive voltage. There is sex. Therefore, the motor control device 260 reverses the semiconductor switching elements UH, UL, VH, VL, WH, and WL that make up the three-phase bridge inverter 245A, and the semiconductor switching elements 222U, 222V, and 222W that make up the motor relay 222. It has the function of protecting against electromotive force.
  • FIG. 4 is a diagram illustrating the above protection function. Note that when the protection function operates, the semiconductor switching elements UH, UL, VH, VL, WH, WL forming the three-phase bridge inverter 245A and the semiconductor switching elements 222U, 222V, 222W forming the motor relay 222, Controlled to off state.
  • the back electromotive force generated by the motor 220 is applied to the semiconductor switching elements UH, UL, VH, VL, WH, and WL of the three-phase bridge inverter 245A.
  • the semiconductor switching elements UH, VH, and WH of the upper arm of the three-phase bridge inverter 245A have parasitic diodes D1, D3, and D5, and the anodes of the parasitic diodes D1, D3, and D5 are connected to the ground GND, and the parasitic The cathodes of diodes D1, D3, and D5 are connected to system power supply 246. Therefore, even if the upper arm semiconductor switching elements UH, VH, WH are in the off state, the back electromotive force will flow to the drains of the semiconductor switching elements UH, VH, WH via the parasitic diodes D1, D3, D5. become.
  • the back electromotive force is applied to the smoothing capacitor C1 provided in parallel with the three-phase bridge inverter 245A, and charges the capacitor C1. Therefore, even if a back electromotive force is generated in the motor 220, a high load is prevented from being applied to the semiconductor switching elements UH, UL, VH, VL, WH, WL of the three-phase bridge inverter 245A, and the semiconductor switching elements UH, UL , VH, VL, WH, and WL are prevented from being damaged by back electromotive force.
  • the back electromotive force generated in the motor 220 is blocked by the drains of the semiconductor switching elements 222U, 222V, and 222W of the motor relay 222.
  • the back electromotive force is alternating current and changes instantaneously, the alternating current voltage is blocked by the semiconductor switching element 222U. , 222V, and 222W, and the gate potential becomes the same as the drain potential.
  • the Zener diode ZD1 blocks the current (the direction shown by the dotted line in the figure).
  • this negative voltage exceeds the breakdown voltage of the Zener diode ZD1
  • the voltage is offset by the breakdown voltage, and the gate potentials of the semiconductor switching elements 222U, 222V, and 222W rise.
  • FIG. 5 shows a state in which the gate potentials of the semiconductor switching elements 222U, 222V, and 222W have increased due to the back electromotive force (in other words, negative voltage) generated by the motor 220.
  • the gate potential of the semiconductor switching elements 222U, 222V, 222W rises, a voltage difference occurs between the sources and gates of the semiconductor switching elements 222U, 222V, 222W, so that the semiconductor switching elements 222U, 222V, 222W become conductive (in other words, Then, it becomes on state).
  • the Zener diode ZD1 switches between the semiconductor switching elements 222U, 222V, 222W when the potential on the side of the windings 220U, 220V, 220W of the semiconductor switching elements 222U, 222V, 222W and the potential of the ground GND reach a predetermined potential difference. It functions as a control element that turns on 222W.
  • the Zener diode ZD1 switches the semiconductor switching elements 222U, 222V, 222W when a negative voltage of a predetermined level or more occurs between the windings 220U, 220V, 220W and the semiconductor switching elements 222U, 222V, 222W. Turn on to form a reflux path. By forming such a circulation path, the semiconductor switching elements 222U, 222V, and 222W are protected from back electromotive force.
  • Zener diode ZD1 is used to protect the semiconductor switching elements 222U, 222V, and 222W from back electromotive force, there is no need to control the on/off of the elements to achieve the protection function, and the system can be Even in this state, the semiconductor switching elements 222U, 222V, and 222W can be protected from back electromotive force. Further, since no control operation is required to implement the protection function, there is no need for logic to be controlled by software processing.
  • a failure mode of the Zener diode ZD1 is a short-circuit failure, that is, a state in which the Zener diode ZD1 flows a current in the opposite direction at a voltage lower than that in a normal state.
  • a redundant motor control device means, for example, that the motor 220 has a first winding set and a second winding set, and a first drive system that controls power supply to the first winding set, and a first drive system that controls power supply to the first winding set.
  • the motor control device includes a second drive system that controls power supply to two winding sets. In other words, this is a system that includes the circuit shown in FIG. 2 in duplicate.
  • the rotation of the motor 220 changes. Accordingly, a back electromotive force is generated in the first winding set.
  • the Zener diode ZD1 of the first system is short-circuited, a current due to the back electromotive force flows in the motor 220, and the current due to the back electromotive force conflicts with the energization control by the second system. Braking torque may be generated in the system.
  • the motor control device 260 includes a Zener diode diagnostic section 239, which is a functional section that diagnoses whether or not the Zener diode ZD1 has a failure.
  • the Zener diode diagnostic unit 239 performs diagnosis from the diagnostic voltage output circuit 237 while the motor drive is stopped, that is, the three-phase bridge inverter 245A and the motor relay 222 are in the off state. output voltage.
  • the diagnostic voltage output by the diagnostic voltage output circuit 237 is applied to the gates of the semiconductor switching elements 222U, 222V, 222W when the Zener diode ZD1 has a short-circuit failure, and is applied to the gates of the semiconductor switching elements 222U, 222V, 222W.
  • the neutral point voltage monitoring circuit 233 (neutral point voltage monitoring unit) observes the voltage through a source-to-source resistance (not shown). On the other hand, if the Zener diode ZD1 is normal and there is no short-circuit failure, no current will flow through the Zener diode ZD1 and no increase in gate potential of the semiconductor switching elements 222U, 222V, 222W will occur, so the neutral point voltage monitor Circuit 233 does not detect voltage.
  • the Zener diode diagnostic unit 239 determines that the Zener diode ZD1 is normal if the neutral point voltage monitor circuit 233 does not detect a voltage when the diagnostic voltage output circuit 237 outputs the diagnostic voltage. . On the other hand, if the neutral point voltage monitor circuit 233 detects a voltage when the diagnostic voltage output circuit 237 outputs the diagnostic voltage, the Zener diode diagnostic unit 239 determines that a short-circuit failure has occurred in the Zener diode ZD1. .
  • the voltage output diagnosis section 240 diagnoses whether or not the diagnostic voltage output circuit 237 has a failure.
  • Voltage output diagnosis section 240 outputs a diagnostic voltage from diagnostic voltage output circuit 237 when motor drive is stopped, that is, when three-phase bridge inverter 245A and motor relay 222 are off.
  • the voltage output diagnostic unit 240 determines that the diagnostic voltage output circuit 237 is normal, and the voltage monitor circuit 235 detects the diagnostic voltage. If not detected, it is determined that a failure has occurred in the diagnostic voltage output circuit 237. Further, the voltage output diagnosis unit 240 detects that the diagnostic voltage output circuit 237 has failed if the voltage monitor circuit 235 detects a voltage equal to or higher than the threshold while the diagnostic voltage output circuit 237 is not outputting the diagnostic voltage. If it is determined that the voltage detection value by the voltage monitor circuit 235 is less than the threshold value, it can be determined that the diagnostic voltage output circuit 237 is normal.
  • FIG. 6 is a flowchart showing a procedure for diagnosing the Zener diode ZD1 and the diagnostic voltage output circuit 237.
  • the control device 230 causes the diagnostic voltage output circuit 237 to stop outputting the diagnostic voltage.
  • the control device 230 determines whether the voltage monitor circuit 235 has detected a voltage equal to or higher than the first threshold value.
  • the control device 230 causes the diagnostic voltage output circuit 237 to output a diagnostic voltage. It is determined that the state is not commensurate with the output stop command, and the process proceeds to step S503, where it is determined whether or not a failure has occurred in the diagnostic voltage output circuit 237.
  • step S502 determines in step S502 that the voltage detected by the voltage monitor circuit 235 is less than the first threshold.
  • the control device 230 proceeds to step S504.
  • step S504 the control device 230 causes the diagnostic voltage output circuit 237 to output a diagnostic voltage.
  • step S505 the control device 230 determines whether the voltage monitor circuit 235 has detected a voltage equal to or higher than the second threshold (second threshold ⁇ first threshold).
  • the control device 230 determines that the diagnostic voltage output circuit 237 is not outputting a regular diagnostic voltage in response to the output command. Then, the process proceeds to step S506, and it is determined whether a failure has occurred in the diagnostic voltage output circuit 237.
  • step S507 the control device 230 determines whether the neutral point voltage monitor circuit 233 is detecting voltage while the diagnostic voltage output circuit 237 is outputting the diagnostic voltage.
  • step S508 determines whether a failure of the Zener diode ZD1 has occurred, specifically, whether a short circuit failure has occurred. On the other hand, if the neutral point voltage monitor circuit 233 does not detect any voltage, the control device 230 determines that the Zener diode ZD1 is normal and ends this diagnostic routine.
  • the electric steering device to which the motor control device 260 is applied is the electric power steering device 200, but the electric steering device is an electric power steering device where the steering wheel 201 and the wheels 110, 110 are mechanically connected
  • the electric steering device can be a steer-by-wire steering device in which the steering wheel 201 and the wheels 110, 110 are not mechanically connected, and the motor generates the steering force to steer the wheels 110, 110.
  • SYMBOLS 100... Vehicle, 110... Wheel, 200... Electric power steering device (electric steering device), 220... Motor, 220U, 220V, 220W... Winding wire, 222... Motor relay, 222U, 222V, 222W... Semiconductor switching element, 223... Signal path, 224... Ground path, 230... Control device (control unit), 245... Drive circuit, 245A... Three-phase bridge inverter, 260... Motor control device, ZD1... Zener diode (control element), D11... Diode

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Power Steering Mechanism (AREA)

Abstract

A motor control device and an electric steering device according to the present invention comprise: a driving circuit for a motor; a semiconductor switching element that connects and disconnects a conduction path between the driving circuit and a neutral point of a multiphase winding set of the motor; a control unit that controls the driving circuit and the semiconductor switching element; and a control element that is provided in a ground path connecting a signal path for a control signal of the semiconductor switching element to the ground and that turns on the semiconductor switching element when a predetermined potential difference is reached between the potential on the winding side of the semiconductor switching element and the potential of the ground. Thus, the semiconductor switching element can be inhibited from being damaged by the counter electromotive voltage of the motor.

Description

モータ制御装置及び電動操舵装置Motor control device and electric steering device
　本発明は、モータ制御装置及び電動操舵装置に関する。 The present invention relates to a motor control device and an electric steering device.
　特許文献１の電力変換装置は、モータの各相の巻線の一端に接続される第１インバータと、各相の巻線の他端に接続される第２インバータと、各相の巻線の一端と電源およびＧＮＤの一方との間に接続される第１リレー回路と、各相の巻線の他端と電源およびＧＮＤの一方との間に接続される第２リレー回路とを備える。
　そして、特許文献１の電力変換装置では、たとえば、第１インバータのＡ相の上下アームが故障したときに、第１リレー回路をオンにして中性点を構成し、回路内に残存していた零相電流を外部に逃がす。 The power conversion device of Patent Document 1 includes a first inverter connected to one end of the winding of each phase of the motor, a second inverter connected to the other end of the winding of each phase, and a second inverter connected to the other end of the winding of each phase of the motor. It includes a first relay circuit connected between one end and one of the power supply and GND, and a second relay circuit connected between the other end of each phase winding and one of the power supply and GND.
In the power conversion device of Patent Document 1, for example, when the upper and lower arms of the A phase of the first inverter fail, the first relay circuit is turned on to form a neutral point, and the remaining in the circuit is Release zero-sequence current to the outside.
国際公開第２０１９／１５９６６４号International Publication No. 2019/159664
　ところで、操舵力を発生するモータを備えた電動操舵装置においては、モータの多相巻線組の巻線に電力を供給する駆動回路と、前記多相巻線組の中性点との間の通電経路を断続するモータリレーを備える場合がある。
　係る電動操舵装置において、ステアリングホイールの操作に連動して車輪が高速に転舵されるときや、車輪からの大きな逆入力によってモータが回されるときに、モータに逆起電圧が発生すると、この逆起電圧がモータリレーを構成する半導体スイッチング素子のゲートに回り込み、ゲート電圧が高電圧となる。 By the way, in an electric steering device equipped with a motor that generates steering force, a drive circuit that supplies power to the windings of a polyphase winding set of the motor and a neutral point of the polyphase winding set are It may be equipped with a motor relay that connects the energized path intermittently.
In such an electric steering system, if a back electromotive force is generated in the motor when the wheels are steered at high speed in conjunction with steering wheel operation or when the motor is rotated by a large reverse input from the wheels, this The back electromotive voltage flows around to the gate of the semiconductor switching element that constitutes the motor relay, and the gate voltage becomes high.
　この状態でモータリレーを構成する半導体スイッチング素子に電流が流れ続けると、半導体スイッチング素子が発熱し、半導体スイッチング素子が破損する可能性があった。
　また、電動操舵装置において何らかの異常が発生し、モータリレーをオフしてモータへの電流供給を停止させるときに、モータが逆起電圧を発生する場合も、モータリレーを構成する半導体スイッチング素子のゲートに逆起電圧が回り込むことで、モータリレーを構成する半導体スイッチング素子が破損する可能性があった。 If current continues to flow through the semiconductor switching element constituting the motor relay in this state, the semiconductor switching element will generate heat, potentially damaging the semiconductor switching element.
In addition, if some abnormality occurs in the electric steering system and the motor generates a back electromotive force when the motor relay is turned off to stop the current supply to the motor, the gate of the semiconductor switching element that makes up the motor relay There was a possibility that the semiconductor switching elements that make up the motor relay would be damaged due to the back electromotive force being passed around to the motor relay.
　本発明は、従来の実情に鑑みてなされたものであり、その目的は、駆動回路とモータの多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子が、モータの逆起電圧によって破損することを抑止できる、モータ制御装置及び電動操舵装置を提供することにある。 The present invention has been made in view of the conventional situation, and an object thereof is to provide a semiconductor switching element that connects and connects the current-carrying path between the drive circuit and the neutral point of the motor's polyphase winding set. An object of the present invention is to provide a motor control device and an electric steering device that can be prevented from being damaged by back electromotive force.
　本発明に係るモータ制御装置は、その一態様において、多相巻線組を有するモータを制御するモータ制御装置であって、前記多相巻線組の巻線に電力を供給する駆動回路と、前記駆動回路と前記多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子と、前記駆動回路及び前記半導体スイッチング素子を制御する制御部と、グランドと前記制御部が出力する前記半導体スイッチング素子の制御信号の信号経路とを接続するグランド経路に設けられ、前記半導体スイッチング素子の前記巻線の側の電位と前記グランドの電位とが所定の電位差になったときに、前記半導体スイッチング素子をオンさせる制御素子と、を備える。 In one aspect, a motor control device according to the present invention is a motor control device that controls a motor having a multiphase winding set, and includes a drive circuit that supplies power to the windings of the multiphase winding set; a semiconductor switching element that connects and disconnects a current-carrying path between the drive circuit and the neutral point of the multiphase winding set; a control section that controls the drive circuit and the semiconductor switching element; and a ground and the control section that output is provided in a ground path that connects a signal path of a control signal of the semiconductor switching element, and when the potential on the side of the winding of the semiconductor switching element and the potential of the ground reach a predetermined potential difference, the A control element that turns on the semiconductor switching element.
　また、本発明に係る電動操舵装置は、その一態様において、車両に搭載される電動操舵装置であって、多相巻線組を有したモータであって、前記車両の車輪を操舵する操舵力を発生する、前記モータと、前記モータを制御するモータ制御装置と、を有し、前記モータ制御装置は、前記多相巻線組の巻線に電力を供給する駆動回路と、前記駆動回路と前記多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子と、前記駆動回路及び前記半導体スイッチング素子を制御する制御部と、グランドと前記制御部が出力する前記半導体スイッチング素子の制御信号の信号経路とを接続するグランド経路に設けられ、前記半導体スイッチング素子の前記巻線の側の電位と前記グランドの電位とが所定の電位差になったときに、前記半導体スイッチング素子をオンさせる制御素子と、を備える。 Further, in one aspect, the electric steering device according to the present invention is an electric steering device mounted on a vehicle, the motor having a multiphase winding set, and comprising a motor with a steering force for steering wheels of the vehicle. the motor, and a motor control device that controls the motor, and the motor control device includes a drive circuit that supplies power to the windings of the polyphase winding set, and a drive circuit that supplies power to the windings of the multiphase winding set. a semiconductor switching element that connects and disconnects a current-carrying path between the neutral point of the multiphase winding set; a control unit that controls the drive circuit and the semiconductor switching element; and a semiconductor switching element that controls the drive circuit and the semiconductor switching element; Provided in a ground path connecting a signal path of a control signal of the element, when the potential on the side of the winding of the semiconductor switching element and the potential of the ground reach a predetermined potential difference, the semiconductor switching element is activated. and a control element that turns on.
　本発明によれば、駆動回路とモータの多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子が、モータの逆起電圧によって破損することを抑止できる。 According to the present invention, it is possible to prevent the semiconductor switching element that connects and disconnects the current-carrying path between the drive circuit and the neutral point of the multiphase winding set of the motor from being damaged by the back electromotive force of the motor.
電動パワーステアリング装置の構成図である。FIG. 1 is a configuration diagram of an electric power steering device. モータの駆動回路及び制御装置の機能ブロックを示す図である。FIG. 3 is a diagram showing functional blocks of a motor drive circuit and a control device. モータで逆起電圧が発生した状態を示す図である。FIG. 3 is a diagram showing a state in which a back electromotive force is generated in the motor. モータの逆起電圧から半導体スイッチング素子を保護する作用を説明するための図である。FIG. 3 is a diagram for explaining an effect of protecting a semiconductor switching element from a back electromotive voltage of a motor. 還流路の形成によってモータリレーが保護される状態を示す図である。FIG. 6 is a diagram showing a state in which a motor relay is protected by forming a return flow path. ツェナーダイオード及び診断用電圧出力回路の診断手順を示すフローチャートである。It is a flowchart which shows the diagnostic procedure of a Zener diode and a diagnostic voltage output circuit.
　以下、添付した図面を参照し、本発明に係るモータ制御装置及び電動操舵装置の実施形態を詳述する。
　以下の実施形態では、車両に搭載される電動操舵装置を、ステアリングホイールの操作に必要な力をモータが発生するトルクで補助する電動パワーステアリング装置とし、モータ制御装置が電動パワーステアリング装置に適用される場合について説明する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a motor control device and an electric steering device according to the present invention will be described in detail with reference to the attached drawings.
In the following embodiments, an electric power steering device installed in a vehicle is an electric power steering device that uses torque generated by a motor to supplement the force required to operate the steering wheel, and a motor control device is applied to the electric power steering device. We will explain the case when
　図１は、車両１００に取り付けられる電動パワーステアリング装置２００の一態様を示す構成図である。
　電動パワーステアリング装置２００の操舵機構２１０は、ステアリングホイール２０１、ステアリングホイール２０１の回転軸であるステアリングシャフト２０２、ステアリングシャフト２０２の端部に設けられたピニオン軸２０３、ラックバー２０４、及び、ラックバー２０４を収容するラックハウジング２０５を有する。 FIG. 1 is a configuration diagram showing one aspect of an electric power steering device 200 attached to a vehicle 100.
The steering mechanism 210 of the electric power steering device 200 includes a steering wheel 201, a steering shaft 202 which is a rotation axis of the steering wheel 201, a pinion shaft 203 provided at an end of the steering shaft 202, a rack bar 204, and a rack bar 204. It has a rack housing 205 that accommodates the.
　係る操舵機構２１０において、車両１００の運転者がステアリングホイール２０１を回転操作すると、ステアリングホイール２０１の操舵トルクがステアリングシャフト２０２を介してピニオン軸２０３に伝達される。
　そして、ピニオン軸２０３の回転運動がラックバー２０４の直線運動に変換されることによって、ラックバー２０４の両端にタイロッド２５０を介して連結された左右の車輪（前輪）１１０，１１０の舵角、換言すれば、タイヤ角が変更される。 In such a steering mechanism 210, when the driver of the vehicle 100 rotates the steering wheel 201, the steering torque of the steering wheel 201 is transmitted to the pinion shaft 203 via the steering shaft 202.
By converting the rotational motion of the pinion shaft 203 into linear motion of the rack bar 204, the steering angle of the left and right wheels (front wheels) 110, 110 connected to both ends of the rack bar 204 via tie rods 250, in other words, This will change the tire angle.
　つまり、ピニオン軸２０３と、ラックバー２０４に形成したラック歯との噛み合いによるラックアンドピニオン方式で、ステアリングシャフト２０２の回転運動がラックバー２０４の直線運動に変換されることで、ステアリングホイール２０１の回転操作に応じて車輪１１０，１１０の舵角が変更される。 In other words, in a rack and pinion system in which the pinion shaft 203 and the rack teeth formed on the rack bar 204 mesh with each other, the rotational motion of the steering shaft 202 is converted into the linear motion of the rack bar 204, thereby rotating the steering wheel 201. The steering angles of the wheels 110, 110 are changed according to the operation.
　ステアリングシャフト２０２には、ステアリングシャフト２０２の回転角である操作角βを検出する操作角センサ２０６と、ステアリングホイール２０１の操舵トルクＴＳを検出する操舵トルクセンサ２０７と、が設けられている。
　また、操舵機構２１０は、ラックバー２０４に操舵トルクを付与する操舵アクチュエータ、換言すれば、ラックバー２０４を軸方向に動かす操舵力を発生する操舵アクチュエータである、モータ２２０を備えている。 The steering shaft 202 is provided with a steering angle sensor 206 that detects a steering angle β, which is a rotation angle of the steering shaft 202, and a steering torque sensor 207 that detects a steering torque TS of the steering wheel 201.
Further, the steering mechanism 210 includes a motor 220 that is a steering actuator that applies a steering torque to the rack bar 204, in other words, a steering actuator that generates a steering force that moves the rack bar 204 in the axial direction.
　モータ２２０の回転運動は、ベルトやボールねじなどを備えた伝達機構２０８を介してラックバー２０４に伝達される。
　そして、モータ２２０による操舵トルクの付与は、運転者の操舵操作を補助するために行われる。
　なお、モータ２２０が付与する操舵トルクによって、自律的な操舵、換言すれば、自動操舵を行わせることが可能である。 The rotational motion of the motor 220 is transmitted to the rack bar 204 via a transmission mechanism 208 that includes a belt, a ball screw, or the like.
The application of steering torque by the motor 220 is performed to assist the driver's steering operation.
Note that the steering torque applied by the motor 220 allows autonomous steering, in other words, automatic steering.
　モータ２２０は、多相巻線組を有するＤＣモータであり、たとえば、Ｕ相巻線、Ｖ相巻線、及びＷ相巻線を含む巻線組やモータロータを有した、３相ブラシレスＤＣモータである。
　駆動回路２４５は、６個の半導体スイッチング素子からなる３相ブリッジインバータを備え、半導体スイッチング素子のオンオフが制御されることで、モータ２２０の各巻線に供給する電力を制御する。 The motor 220 is a DC motor having a multi-phase winding set, for example, a three-phase brushless DC motor having a motor rotor and a winding set including a U-phase winding, a V-phase winding, and a W-phase winding. be.
The drive circuit 245 includes a three-phase bridge inverter made up of six semiconductor switching elements, and controls the power supplied to each winding of the motor 220 by controlling on/off of the semiconductor switching elements.
　制御装置２３０は、マイクロプロセッサ（換言すれば、制御部）を備えた電子制御装置であって、駆動回路２４５と共にモータ制御装置２６０を構成する。
　そして、制御装置２３０は、駆動回路２４５を制御するための制御信号を出力する。
　制御装置２３０は、操作角センサ２０６が出力するステアリングシャフト２０２の操作角βに関するセンサ信号、操舵トルクセンサ２０７が出力する操舵トルクＴＳに関するセンサ信号、車速センサ２１１（若しくは車輪速センサ）が出力する車速ＶＳに関するセンサ信号、さらに、モータ回転角センサ２０９が出力するモータ２２０のロータ回転角θに関するセンサ信号などを取得する。 The control device 230 is an electronic control device including a microprocessor (in other words, a control section), and together with the drive circuit 245 constitutes a motor control device 260 .
The control device 230 then outputs a control signal for controlling the drive circuit 245.
The control device 230 receives a sensor signal related to the operating angle β of the steering shaft 202 outputted by the operating angle sensor 206, a sensor signal related to the steering torque TS outputted by the steering torque sensor 207, and a vehicle speed outputted by the vehicle speed sensor 211 (or wheel speed sensor). A sensor signal related to VS, a sensor signal related to the rotor rotation angle θ of the motor 220 outputted by the motor rotation angle sensor 209, and the like are acquired.
　ここで、制御装置２３０は、取得した各種のセンサ信号に基づいて、モータ２２０が出力する操舵トルク、換言すれば、アシストトルクの目標値である指令トルクを演算する。
　そして、制御装置２３０は、指令トルクに基づき駆動回路２４５に制御信号を出力して、モータ２２０の駆動電流をＰＷＭ（Pulse Width Modulation）制御する。 Here, the control device 230 calculates the steering torque output by the motor 220, in other words, the command torque that is the target value of the assist torque, based on the acquired various sensor signals.
Then, the control device 230 outputs a control signal to the drive circuit 245 based on the command torque, and performs PWM (Pulse Width Modulation) control on the drive current of the motor 220.
　図２は、駆動回路２４５及びモータ２２０を示すとともに、制御装置２３０の機能をブロックで表した図である。
　駆動回路２４５は、３相ブリッジインバータ２４５Ａと、ＰＷＭ制御ドライバ２４５Ｂとを有する。 FIG. 2 is a diagram showing the drive circuit 245 and the motor 220, and also represents the functions of the control device 230 in blocks.
Drive circuit 245 includes a three-phase bridge inverter 245A and a PWM control driver 245B.
　３相ブリッジインバータ２４５Ａは、システム電源２４６とグランドＧＮＤとの間に、Ｕ相アーム、Ｖ相アーム及びＷ相アームが並列に接続される。
　Ｕ相アームは、上段半導体スイッチング素子ＵＨと下段半導体スイッチング素子ＵＬとが直列接続されて構成される。 The three-phase bridge inverter 245A has a U-phase arm, a V-phase arm, and a W-phase arm connected in parallel between the system power supply 246 and the ground GND.
The U-phase arm is configured by connecting an upper semiconductor switching element UH and a lower semiconductor switching element UL in series.
　Ｖ相アームは、上段半導体スイッチング素子ＶＨと下段半導体スイッチング素子ＶＬとが直列接続されて構成される。
　Ｗ相アームは、上段半導体スイッチング素子ＷＨと下段半導体スイッチング素子ＷＬとが直列接続されて構成される。 The V-phase arm is configured by connecting an upper semiconductor switching element VH and a lower semiconductor switching element VL in series.
The W-phase arm is configured by connecting an upper semiconductor switching element WH and a lower semiconductor switching element WL in series.
　そして、３相ブリッジインバータ２４５Ａの各相アームにおける２つの半導体スイッチング素子の間は、モータ２２０の対応する相の巻線に接続されて、３相ブリッジ回路が構成されている。
　具体的には、Ｕ相アームの２つの半導体スイッチング素子ＵＨ，ＵＬの間はＵ相巻線２２０Ｕの端部に接続され、Ｖ相アームの２つの半導体スイッチング素子ＶＨ，ＶＬの間はＶ相巻線２２０Ｖの端部に接続され、Ｗ相アームの２つの半導体スイッチング素子ＷＨ，ＷＬの間はＷ相巻線２２０Ｗの端部に接続される。 The two semiconductor switching elements in each phase arm of the three-phase bridge inverter 245A are connected to the windings of the corresponding phases of the motor 220, forming a three-phase bridge circuit.
Specifically, the connection between the two semiconductor switching elements UH and UL of the U-phase arm is connected to the end of the U-phase winding 220U, and the connection between the two semiconductor switching elements VH and VL of the V-phase arm is connected to the end of the U-phase winding 220U. It is connected to the end of the wire 220V, and the portion between the two semiconductor switching elements WH and WL of the W-phase arm is connected to the end of the W-phase winding 220W.
　３相ブリッジインバータ２４５Ａを構成する半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬは、外部から制御可能な制御端子を有する半導体素子であり、たとえば、Metal Oxide Semiconductor Metal Field Effect Transistor（ＭＯＳＦＥＴ）やInsulated Gate Bipolar Transistor（ＩＧＢＴ）などが用いられる。
　なお、本実施形態では、半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬは、ＮチャネルＭＯＳＦＥＴであり、製造過程でドレイン－ソース間に形成される寄生ダイオードＤ１，Ｄ２，Ｄ３，Ｄ４，Ｄ５，Ｄ６を有する。 The semiconductor switching elements UH, UL, VH, VL, WH, and WL that constitute the three-phase bridge inverter 245A are semiconductor elements having externally controllable control terminals, such as Metal Oxide Semiconductor Metal Field Effect Transistor (MOSFET). , Insulated Gate Bipolar Transistor (IGBT), etc. are used.
In this embodiment, the semiconductor switching elements UH, UL, VH, VL, WH, and WL are N-channel MOSFETs, and parasitic diodes D1, D2, D3, D4, It has D5 and D6.
　寄生ダイオードＤ１，Ｄ２，Ｄ３，Ｄ４，Ｄ５，Ｄ６は、アノードがグランドＧＮＤに接続され、カソードがシステム電源２４６に接続され、グランドＧＮＤからシステム電源２４６に向けて電流を流す。
　また、システム電源２４６とグランドＧＮＤとの間には、３相ブリッジインバータ２４５Ａと並列に、電源電圧の平滑用のコンデンサＣ１が接続されている。 The parasitic diodes D1, D2, D3, D4, D5, and D6 have their anodes connected to the ground GND, cathodes connected to the system power supply 246, and allow current to flow from the ground GND toward the system power supply 246.
Further, a capacitor C1 for smoothing the power supply voltage is connected between the system power supply 246 and the ground GND in parallel with the three-phase bridge inverter 245A.
　ＰＷＭ制御ドライバ２４５Ｂは、半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬそれぞれについて駆動信号を生成する複数のドライバで構成される。
　ＰＷＭ制御ドライバ２４５Ｂの各ドライバは、制御装置２３０から出力された制御信号に基づいて、半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬをオンオフさせる駆動信号、換言すれば、ゲート信号を生成して出力する。 The PWM control driver 245B is composed of a plurality of drivers that generate drive signals for each of the semiconductor switching elements UH, UL, VH, VL, WH, and WL.
Each driver of the PWM control driver 245B generates a drive signal to turn on and off the semiconductor switching elements UH, UL, VH, VL, WH, and WL, in other words, a gate signal, based on the control signal output from the control device 230. and output it.
　モータ２２０の各巻線２２０Ｕ，２２０Ｖ，２２０Ｗは、中性点ＮＰで一括して接続されるスター結線（換言すれば、Ｙ結線）で結線される。
　そして、中性点ＮＰと各巻線２２０Ｕ，２２０Ｖ，２２０Ｗとの間の通電経路２２１Ｕ，２２１Ｖ，２２１Ｗには、当該通電経路２２１Ｕ，２２１Ｖ，２２１Ｗを接続、遮断するモータリレー２２２が配されている。 The windings 220U, 220V, and 220W of the motor 220 are connected in a star connection (in other words, a Y connection) that are connected together at the neutral point NP.
A motor relay 222 that connects and disconnects the current-carrying paths 221U, 221V, and 221W between the neutral point NP and each of the windings 220U, 220V, and 220W is arranged in the current-carrying paths 221U, 221V, and 221W.
　モータリレー２２２は、半導体スイッチング素子のオンオフで通電経路２２１Ｕ，２２１Ｖ，２２１Ｗを断続する保護リレーである。
　なお、モータリレー２２２を、３相ブリッジインバータ２４５Ａと各巻線２２０Ｕ，２２０Ｖ，２２０Ｗとの間の通電経路２２１Ｕ，２２１Ｖ，２２１Ｗに有する回路とすることができる。 The motor relay 222 is a protection relay that connects and connects the energized paths 221U, 221V, and 221W by turning on and off a semiconductor switching element.
Note that the motor relay 222 can be a circuit provided in the current-carrying paths 221U, 221V, and 221W between the three-phase bridge inverter 245A and each of the windings 220U, 220V, and 220W.
　モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗとして、本実施形態では、ＮチャネルＭＯＳＦＥＴを用いる。
　半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート－ソース間には抵抗（図示省略）が実装される。
　このゲート－ソース間抵抗は、ゲート制御信号がないときに半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのオンを防ぐ機能などを奏する。 In this embodiment, N-channel MOSFETs are used as the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222.
Resistors (not shown) are mounted between the gates and sources of the semiconductor switching elements 222U, 222V, and 222W.
This gate-source resistance functions to prevent the semiconductor switching elements 222U, 222V, and 222W from turning on when there is no gate control signal.
　また、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２ＷとしてのＮチャネルＭＯＳＦＥＴは、中性点ＮＰから各巻線２２０Ｕ，２２０Ｖ，２２０Ｗに向けて電流を流す寄生ダイオードＤＵ，ＤＶ，ＤＷを備える。
　つまり、寄生ダイオードＤＵ，ＤＶ，ＤＷは、アノードが中性点ＮＰに接続され、カソードが巻線２２０Ｕ，２２０Ｖ，２２０Ｗに接続される。 Further, the N-channel MOSFETs serving as the semiconductor switching elements 222U, 222V, and 222W include parasitic diodes DU, DV, and DW that cause current to flow from the neutral point NP toward each of the windings 220U, 220V, and 220W.
That is, the anodes of the parasitic diodes DU, DV, and DW are connected to the neutral point NP, and the cathodes are connected to the windings 220U, 220V, and 220W.
　モータリレー制御部２３２は、モータ２２０が駆動されるとき、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲートに与える電圧をソースに対してプラスの電圧とすることで、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗをオン状態、つまり、通電経路２２１Ｕ，２２１Ｖ，２２１Ｗの導通状態にする。
　一方、モータリレー制御部２３２は、モータ２２０を停止させるときや、モータ制御装置２６０に何らかの異常が発生したときに、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗをオフ状態、つまり、通電経路２２１Ｕ，２２１Ｖ，２２１Ｗの遮断状態にする。 When the motor 220 is driven, the motor relay control unit 232 controls the semiconductor switching elements by making the voltage applied to the gates of the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222 a positive voltage with respect to the source. 222U, 222V, and 222W are turned on, that is, the current-carrying paths 221U, 221V, and 221W are brought into conduction.
On the other hand, when stopping the motor 220 or when some abnormality occurs in the motor control device 260, the motor relay control unit 232 turns off the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222, that is, The energizing paths 221U, 221V, and 221W are cut off.
　ここで、モータリレー制御部２３２が出力するモータリレー制御信号（換言すれば、ゲート信号）を半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート端子に与えるための信号経路２２３は、接続点ＣＰ１においてグランドＧＮＤに接続される。
　そして、接続点ＣＰ１とグランドＧＮＤとを接続するグランド経路２２４には、ツェナーダイオードＺＤ１が配される。
　ここで、ツェナーダイオードＺＤ１のアノードは接続点ＣＰ１（信号経路２２３）に接続され、ツェナーダイオードＺＤ１のカソードはグランドＧＮＤに接続される。 Here, the signal path 223 for giving the motor relay control signal (in other words, gate signal) output by the motor relay control unit 232 to the gate terminals of the semiconductor switching elements 222U, 222V, 222W connects to the ground GND at the connection point CP1. connected to.
A Zener diode ZD1 is arranged in a ground path 224 that connects the connection point CP1 and the ground GND.
Here, the anode of the Zener diode ZD1 is connected to the connection point CP1 (signal path 223), and the cathode of the Zener diode ZD1 is connected to the ground GND.
　更に、ツェナーダイオードＺＤ１とグランドＧＮＤとの間のグランド経路２２４には、ダイオードＤ１１が配される。
　ここで、ダイオードＤ１１のアノードはグランドＧＮＤに接続され、ダイオードＤ１１のカソードはツェナーダイオードＺＤ１に接続される。
　つまり、信号経路２２３の接続点ＣＰ１は、ツェナーダイオードＺＤ１とダイオードＤ１１との直列接続回路を介してグランドＧＮＤに接続され、ツェナーダイオードＺＤ１のカソードとダイオードＤ１１のカソードとが接続される。 Furthermore, a diode D11 is arranged in the ground path 224 between the Zener diode ZD1 and the ground GND.
Here, the anode of the diode D11 is connected to the ground GND, and the cathode of the diode D11 is connected to the Zener diode ZD1.
That is, the connection point CP1 of the signal path 223 is connected to the ground GND via a series connection circuit of the Zener diode ZD1 and the diode D11, and the cathode of the Zener diode ZD1 and the cathode of the diode D11 are connected.
　また、中性点電圧モニタ回路２３３は、モニタ経路２３４を介して中性点ＮＰに接続され、中性点ＮＰの電圧をモニタする。
　ここで、信号経路２２３とモニタ経路２３４とは、抵抗Ｒ１を介して接続される。 Further, the neutral point voltage monitor circuit 233 is connected to the neutral point NP via a monitor path 234, and monitors the voltage at the neutral point NP.
Here, the signal path 223 and the monitor path 234 are connected via a resistor R1.
　また、電圧モニタ回路２３５は、ツェナーダイオードＺＤ１とダイオードＤ１１との間のグランド経路２２４に設けた接続点ＣＰ２とモニタ経路２３６を介して接続される。
　さらに、診断用電圧出力回路２３７は、モニタ経路２３６の接続点ＣＰ３と電圧出力経路２３８を介して接続され、ツェナーダイオードＺＤ１とダイオードＤ１１との間のグランド経路２２４に所定の診断用電圧を印加する。 Further, the voltage monitor circuit 235 is connected via a monitor path 236 to a connection point CP2 provided in the ground path 224 between the Zener diode ZD1 and the diode D11.
Furthermore, the diagnostic voltage output circuit 237 is connected to the connection point CP3 of the monitor path 236 via the voltage output path 238, and applies a predetermined diagnostic voltage to the ground path 224 between the Zener diode ZD1 and the diode D11. .
　そして、ツェナーダイオード診断部２３９は、診断用電圧出力回路２３７からの診断用電圧の出力を制御し、中性点電圧モニタ回路２３３でモニタされた中性点電圧に基づき、ツェナーダイオードＺＤ１の故障の有無を診断する。
　なお、ツェナーダイオード診断部２３９が診断するツェナーダイオードＺＤ１の故障は、ツェナーダイオードＺＤ１が正常時よりも低い電圧で逆方向に電流を流す故障であって、本願では係る故障を短絡故障と称する。 Then, the Zener diode diagnosis section 239 controls the output of the diagnostic voltage from the diagnostic voltage output circuit 237, and detects the failure of the Zener diode ZD1 based on the neutral point voltage monitored by the neutral point voltage monitor circuit 233. Diagnose the presence or absence.
The failure of the Zener diode ZD1 diagnosed by the Zener diode diagnostic unit 239 is a failure in which the Zener diode ZD1 causes current to flow in the reverse direction at a voltage lower than that in normal times, and in this application, such a failure is referred to as a short-circuit failure.
　また、電圧出力診断部２４０は、診断用電圧出力回路２３７からの診断用電圧の出力を制御し、診断用電圧出力回路２３７の制御状態及び電圧モニタ回路２３５でモニタされた電圧に基づき、診断用電圧出力回路２３７の故障の有無を診断する。
　つまり、電圧出力診断部２４０は、診断用電圧出力回路２３７が指令に応じて診断用電圧の出力、停止を実施しているか否かを診断する。 Further, the voltage output diagnosis unit 240 controls the output of the diagnostic voltage from the diagnostic voltage output circuit 237, and based on the control state of the diagnostic voltage output circuit 237 and the voltage monitored by the voltage monitor circuit 235, The presence or absence of a failure in the voltage output circuit 237 is diagnosed.
That is, the voltage output diagnostic unit 240 diagnoses whether the diagnostic voltage output circuit 237 is outputting or stopping the diagnostic voltage in accordance with the command.
　以下では、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗを、モータ２２０が発生する逆起電圧から保護する機能を説明する。
　図３は、モータ２２０で逆起電圧が発生したときに、矢印で示す方向に電圧が印加され、３相ブリッジインバータ２４５Ａを構成する半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬ、及び、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗに高い負荷が加わることを示す。 Below, a function of protecting semiconductor switching elements 222U, 222V, and 222W that constitute motor relay 222 from back electromotive force generated by motor 220 will be described.
FIG. 3 shows that when a back electromotive voltage is generated in the motor 220, a voltage is applied in the direction indicated by the arrow, and the semiconductor switching elements UH, UL, VH, VL, WH, WL, and , indicates that a high load is applied to the semiconductor switching elements 222U, 222V, and 222W that constitute the motor relay 222.
　そのため、３相ブリッジインバータ２４５Ａを構成する半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬ、及び、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗが、逆起電圧によって破損する可能性がある。
　そこで、モータ制御装置２６０は、３相ブリッジインバータ２４５Ａを構成する半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬ、及び、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗを、逆起電圧から保護する機能を有している。 Therefore, the semiconductor switching elements UH, UL, VH, VL, WH, and WL that make up the three-phase bridge inverter 245A and the semiconductor switching elements 222U, 222V, and 222W that make up the motor relay 222 may be damaged by the back electromotive voltage. There is sex.
Therefore, the motor control device 260 reverses the semiconductor switching elements UH, UL, VH, VL, WH, and WL that make up the three-phase bridge inverter 245A, and the semiconductor switching elements 222U, 222V, and 222W that make up the motor relay 222. It has the function of protecting against electromotive force.
　図４は、上記の保護機能を説明する図である。
　なお、保護機能が動作するとき、３相ブリッジインバータ２４５Ａを構成する半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬ、及び、モータリレー２２２を構成する半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗは、オフ状態に制御されている。 FIG. 4 is a diagram illustrating the above protection function.
Note that when the protection function operates, the semiconductor switching elements UH, UL, VH, VL, WH, WL forming the three-phase bridge inverter 245A and the semiconductor switching elements 222U, 222V, 222W forming the motor relay 222, Controlled to off state.
　まず、モータ２２０で発生した逆起電圧から、３相ブリッジインバータ２４５Ａの半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬを保護する機能を説明する。
　モータ２２０で発生した逆起電圧は、３相ブリッジインバータ２４５Ａの半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬに印加される。 First, the function of protecting the semiconductor switching elements UH, UL, VH, VL, WH, and WL of the three-phase bridge inverter 245A from the back electromotive force generated by the motor 220 will be described.
The back electromotive force generated by the motor 220 is applied to the semiconductor switching elements UH, UL, VH, VL, WH, and WL of the three-phase bridge inverter 245A.
　ここで、３相ブリッジインバータ２４５Ａの上アームの半導体スイッチング素子ＵＨ，ＶＨ，ＷＨは、寄生ダイオードＤ１、Ｄ３，Ｄ５を有し、寄生ダイオードＤ１、Ｄ３，Ｄ５のアノードはグランドＧＮＤに接続され、寄生ダイオードＤ１、Ｄ３，Ｄ５のカソードはシステム電源２４６に接続される。
　このため、上アームの半導体スイッチング素子ＵＨ，ＶＨ，ＷＨがオフ状態であっても、逆起電圧は、寄生ダイオードＤ１、Ｄ３，Ｄ５を介して半導体スイッチング素子ＵＨ，ＶＨ，ＷＨのドレインに流れることになる。 Here, the semiconductor switching elements UH, VH, and WH of the upper arm of the three-phase bridge inverter 245A have parasitic diodes D1, D3, and D5, and the anodes of the parasitic diodes D1, D3, and D5 are connected to the ground GND, and the parasitic The cathodes of diodes D1, D3, and D5 are connected to system power supply 246.
Therefore, even if the upper arm semiconductor switching elements UH, VH, WH are in the off state, the back electromotive force will flow to the drains of the semiconductor switching elements UH, VH, WH via the parasitic diodes D1, D3, D5. become.
　その後、逆起電圧は、３相ブリッジインバータ２４５Ａと並列に設けられた平滑用のコンデンサＣ１に印加され、コンデンサＣ１を充電することになる。
　したがって、モータ２２０で逆起電圧が発生しても、３相ブリッジインバータ２４５Ａの半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬに高い負荷が加わることが抑止され、半導体スイッチング素子ＵＨ，ＵＬ，ＶＨ，ＶＬ，ＷＨ，ＷＬが逆起電圧によって破損することが抑止される。 Thereafter, the back electromotive force is applied to the smoothing capacitor C1 provided in parallel with the three-phase bridge inverter 245A, and charges the capacitor C1.
Therefore, even if a back electromotive force is generated in the motor 220, a high load is prevented from being applied to the semiconductor switching elements UH, UL, VH, VL, WH, WL of the three-phase bridge inverter 245A, and the semiconductor switching elements UH, UL , VH, VL, WH, and WL are prevented from being damaged by back electromotive force.
　次に、モータ２２０で発生した逆起電圧から、モータリレー２２２の半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗを保護する機能を説明する。
　モータ２２０で発生した逆起電圧は、モータリレー２２２の半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのドレインでせき止められるが、逆起電圧が交流であって瞬時に変化する場合、交流電圧は半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲートに流れ、ゲートの電位はドレインの電位と同じになる。 Next, the function of protecting the semiconductor switching elements 222U, 222V, and 222W of the motor relay 222 from the back electromotive force generated by the motor 220 will be explained.
The back electromotive force generated in the motor 220 is blocked by the drains of the semiconductor switching elements 222U, 222V, and 222W of the motor relay 222. However, if the back electromotive force is alternating current and changes instantaneously, the alternating current voltage is blocked by the semiconductor switching element 222U. , 222V, and 222W, and the gate potential becomes the same as the drain potential.
　さらに、逆起電圧が交流であるため、電圧が負になると、係る負の電圧は、ツェナーダイオードＺＤ１が電流をせき止める向き（図中に点線で示した向き）となる。
　この負の電圧がツェナーダイオードＺＤ１の降伏電圧を超えると、降伏電圧分だけ電圧がオフセットされ、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート電位が上昇する。 Further, since the back electromotive voltage is alternating current, when the voltage becomes negative, the Zener diode ZD1 blocks the current (the direction shown by the dotted line in the figure).
When this negative voltage exceeds the breakdown voltage of the Zener diode ZD1, the voltage is offset by the breakdown voltage, and the gate potentials of the semiconductor switching elements 222U, 222V, and 222W rise.
　図５は、モータ２２０で発生した逆起電圧（換言すれば、負の電圧）によって、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート電位が上昇した状態を示す。
　半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート電位が上昇すると、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのソースとゲートの間に電圧差が生じることで、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗが導通状態（換言すれば、オン状態）となる。 FIG. 5 shows a state in which the gate potentials of the semiconductor switching elements 222U, 222V, and 222W have increased due to the back electromotive force (in other words, negative voltage) generated by the motor 220.
When the gate potential of the semiconductor switching elements 222U, 222V, 222W rises, a voltage difference occurs between the sources and gates of the semiconductor switching elements 222U, 222V, 222W, so that the semiconductor switching elements 222U, 222V, 222W become conductive (in other words, Then, it becomes on state).
　半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗが導通状態になると、図５に矢印で示すような還流路が形成され、逆起電圧を、大電流を流す想定であるモータ２２０の巻線に逃がして、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗを逆起電圧から保護することができる。
　つまり、ツェナーダイオードＺＤ１は、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗの巻線２２０Ｕ，２２０Ｖ，２２０Ｗ側の電位と、グランドＧＮＤの電位とが所定の電位差になったときに、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗをオンさせる制御素子として機能する。 When the semiconductor switching elements 222U, 222V, and 222W become conductive, a return flow path as shown by the arrow in FIG. The switching elements 222U, 222V, and 222W can be protected from back electromotive force.
In other words, the Zener diode ZD1 switches between the semiconductor switching elements 222U, 222V, 222W when the potential on the side of the windings 220U, 220V, 220W of the semiconductor switching elements 222U, 222V, 222W and the potential of the ground GND reach a predetermined potential difference. It functions as a control element that turns on 222W.
　詳細には、ツェナーダイオードＺＤ１は、巻線２２０Ｕ，２２０Ｖ，２２０Ｗと半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗとの間に所定以上の負の電圧が発生したときに、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗをオンさせ、還流路を形成させる。
　係る還流路の形成によって、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗは、逆起電圧から保護される。 Specifically, the Zener diode ZD1 switches the semiconductor switching elements 222U, 222V, 222W when a negative voltage of a predetermined level or more occurs between the windings 220U, 220V, 220W and the semiconductor switching elements 222U, 222V, 222W. Turn on to form a reflux path.
By forming such a circulation path, the semiconductor switching elements 222U, 222V, and 222W are protected from back electromotive force.
　このように、ツェナーダイオードＺＤ１によって半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗを逆起電圧から保護する構成であれば、保護機能を実現するために素子のオンオフを制御する必要がなく、システムが非動作の状態でも、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗを逆起電圧から保護できる。
　また、保護機能を実現するための制御動作が不要であるため、ソフトウェア処理で制御するロジックも必要がない。 In this way, if the Zener diode ZD1 is used to protect the semiconductor switching elements 222U, 222V, and 222W from back electromotive force, there is no need to control the on/off of the elements to achieve the protection function, and the system can be Even in this state, the semiconductor switching elements 222U, 222V, and 222W can be protected from back electromotive force.
Further, since no control operation is required to implement the protection function, there is no need for logic to be controlled by software processing.
　また、逆起電圧による電流を、モータ２２０の巻線２２０Ｕ，２２０Ｖ，２２０Ｗに還流させるため、放熱用の素子を設ける必要がなく、モータ制御装置２６０の省スペースに寄与できる。
　さらに、電動パワーステアリング装置２００の電力回路において基本的に必要とされる電力線上を、逆起電圧による電流が還流するので、大電流用回路の増設は必要とせず、これによっても、モータ制御装置２６０の省スペースに寄与できる。 In addition, since the current due to the back electromotive voltage is returned to the windings 220U, 220V, and 220W of the motor 220, there is no need to provide a heat dissipation element, which contributes to space saving of the motor control device 260.
Furthermore, since the current caused by the back electromotive force flows back along the power lines that are fundamentally required in the power circuit of the electric power steering device 200, there is no need to add a large current circuit, which also contributes to saving space in the motor control device 260.
　次に、ツェナーダイオードＺＤ１の故障診断、及び、ツェナーダイオードＺＤ１の故障の診断に用いる診断用電圧出力回路２３７の故障診断について説明する。
　ツェナーダイオードＺＤ１の故障態様としては、短絡故障、つまり、正常時よりも低い電圧でツェナーダイオードＺＤ１が逆方向に電流を流す状態がある。 Next, a failure diagnosis of the Zener diode ZD1 and a failure diagnosis of the diagnostic voltage output circuit 237 used for diagnosing the failure of the Zener diode ZD1 will be described.
A failure mode of the Zener diode ZD1 is a short-circuit failure, that is, a state in which the Zener diode ZD1 flows a current in the opposite direction at a voltage lower than that in a normal state.
　そして、ツェナーダイオードＺＤ１の短絡故障が発生すると、たとえば、冗長化されたモータ制御装置においては、後述するような問題を生じる。
　冗長化されたモータ制御装置とは、たとえば、モータ２２０が第１巻線組と第２巻線組とを有し、第１巻線組への電力供給を制御する第１駆動系と、第２巻線組への電力供給を制御する第２駆動系とを備えるモータ制御装置である。
　つまり、図２に示した回路を、２重に備えたシステムである。 If a short-circuit failure occurs in the Zener diode ZD1, problems as described below will occur, for example, in a redundant motor control device.
A redundant motor control device means, for example, that the motor 220 has a first winding set and a second winding set, and a first drive system that controls power supply to the first winding set, and a first drive system that controls power supply to the first winding set. The motor control device includes a second drive system that controls power supply to two winding sets.
In other words, this is a system that includes the circuit shown in FIG. 2 in duplicate.
　冗長化されたモータ制御装置において、第１系統が動作を停止し、第２系統が動作を継続し、モータ２２０の回転駆動、つまり、アシストトルクの付与が継続される場合、モータ２２０の回転に伴って第１巻線組で逆起電圧が発生する。
　このときに、第１系統のツェナーダイオードＺＤ１が短絡故障していると、モータ２２０に逆起電圧による電流が流れ、係る逆起電圧による電流が第２系統による通電制御と相反して、第１系統で制動トルクが発生する場合がある。 In the redundant motor control device, when the first system stops operating and the second system continues to operate, and the rotational drive of the motor 220, that is, the application of assist torque, the rotation of the motor 220 changes. Accordingly, a back electromotive force is generated in the first winding set.
At this time, if the Zener diode ZD1 of the first system is short-circuited, a current due to the back electromotive force flows in the motor 220, and the current due to the back electromotive force conflicts with the energization control by the second system. Braking torque may be generated in the system.
　そこで、モータ制御装置２６０は、ツェナーダイオードＺＤ１の故障の有無を診断する機能部であるツェナーダイオード診断部２３９を備える。
　ツェナーダイオード診断部２３９は、ツェナーダイオードＺＤ１の短絡故障の有無を診断する場合、モータ駆動の停止状態、つまり、３相ブリッジインバータ２４５Ａ及びモータリレー２２２のオフ状態で、診断用電圧出力回路２３７から診断用電圧を出力させる。 Therefore, the motor control device 260 includes a Zener diode diagnostic section 239, which is a functional section that diagnoses whether or not the Zener diode ZD1 has a failure.
When diagnosing the presence or absence of a short-circuit failure in the Zener diode ZD1, the Zener diode diagnostic unit 239 performs diagnosis from the diagnostic voltage output circuit 237 while the motor drive is stopped, that is, the three-phase bridge inverter 245A and the motor relay 222 are in the off state. output voltage.
　診断用電圧出力回路２３７が出力する診断用電圧は、ツェナーダイオードＺＤ１が短絡故障している場合、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲートに印加され、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート－ソース間抵抗（図示省略）を通り、中性点電圧モニタ回路２３３（中性点電圧監視部）は電圧を観測する。
　一方、ツェナーダイオードＺＤ１が正常であって、短絡故障がない場合、ツェナーダイオードＺＤ１には電流が流れず、半導体スイッチング素子２２２Ｕ，２２２Ｖ，２２２Ｗのゲート電位の上昇も発生しないため、中性点電圧モニタ回路２３３は電圧を検出しない。 The diagnostic voltage output by the diagnostic voltage output circuit 237 is applied to the gates of the semiconductor switching elements 222U, 222V, 222W when the Zener diode ZD1 has a short-circuit failure, and is applied to the gates of the semiconductor switching elements 222U, 222V, 222W. The neutral point voltage monitoring circuit 233 (neutral point voltage monitoring unit) observes the voltage through a source-to-source resistance (not shown).
On the other hand, if the Zener diode ZD1 is normal and there is no short-circuit failure, no current will flow through the Zener diode ZD1 and no increase in gate potential of the semiconductor switching elements 222U, 222V, 222W will occur, so the neutral point voltage monitor Circuit 233 does not detect voltage.
　つまり、ツェナーダイオード診断部２３９は、診断用電圧出力回路２３７が診断用電圧を出力するときに、中性点電圧モニタ回路２３３が電圧を検出しなければ、ツェナーダイオードＺＤ１は正常であると判断する。
　一方、ツェナーダイオード診断部２３９は、診断用電圧出力回路２３７が診断用電圧を出力するときに、中性点電圧モニタ回路２３３が電圧を検出した場合、ツェナーダイオードＺＤ１の短絡故障の発生を判断する。 That is, the Zener diode diagnostic unit 239 determines that the Zener diode ZD1 is normal if the neutral point voltage monitor circuit 233 does not detect a voltage when the diagnostic voltage output circuit 237 outputs the diagnostic voltage. .
On the other hand, if the neutral point voltage monitor circuit 233 detects a voltage when the diagnostic voltage output circuit 237 outputs the diagnostic voltage, the Zener diode diagnostic unit 239 determines that a short-circuit failure has occurred in the Zener diode ZD1. .
　また、電圧出力診断部２４０は、診断用電圧出力回路２３７の故障の有無を診断する。
　電圧出力診断部２４０は、モータ駆動の停止状態、つまり、３相ブリッジインバータ２４５Ａ及びモータリレー２２２のオフ状態で、診断用電圧出力回路２３７から診断用電圧を出力させる。 Further, the voltage output diagnosis section 240 diagnoses whether or not the diagnostic voltage output circuit 237 has a failure.
Voltage output diagnosis section 240 outputs a diagnostic voltage from diagnostic voltage output circuit 237 when motor drive is stopped, that is, when three-phase bridge inverter 245A and motor relay 222 are off.
　そして、電圧出力診断部２４０は、電圧モニタ回路２３５（電圧監視部）が診断用電圧を検出すれば、診断用電圧出力回路２３７は正常であると判断し、電圧モニタ回路２３５が診断用電圧を検出しなければ、診断用電圧出力回路２３７に故障が発生していると判断する。
　また、電圧出力診断部２４０は、診断用電圧出力回路２３７から診断用電圧を出力させていないときに、電圧モニタ回路２３５が閾値以上の電圧を検出すれば、診断用電圧出力回路２３７が故障していると判断し、電圧モニタ回路２３５による電圧検出値が閾値未満でれば、診断用電圧出力回路２３７は正常であると判断することができる。 Then, if the voltage monitor circuit 235 (voltage monitor) detects the diagnostic voltage, the voltage output diagnostic unit 240 determines that the diagnostic voltage output circuit 237 is normal, and the voltage monitor circuit 235 detects the diagnostic voltage. If not detected, it is determined that a failure has occurred in the diagnostic voltage output circuit 237.
Further, the voltage output diagnosis unit 240 detects that the diagnostic voltage output circuit 237 has failed if the voltage monitor circuit 235 detects a voltage equal to or higher than the threshold while the diagnostic voltage output circuit 237 is not outputting the diagnostic voltage. If it is determined that the voltage detection value by the voltage monitor circuit 235 is less than the threshold value, it can be determined that the diagnostic voltage output circuit 237 is normal.
　図６は、ツェナーダイオードＺＤ１及び診断用電圧出力回路２３７の診断手順を示すフローチャートである。
　制御装置２３０は、まず、ステップＳ５０１で、診断用電圧出力回路２３７からの診断用電圧の出力を停止させた状態とする。 FIG. 6 is a flowchart showing a procedure for diagnosing the Zener diode ZD1 and the diagnostic voltage output circuit 237.
First, in step S501, the control device 230 causes the diagnostic voltage output circuit 237 to stop outputting the diagnostic voltage.
　そして、制御装置２３０は、次のステップＳ５０２で、電圧モニタ回路２３５が第１閾値以上の電圧を検出したか否かを判別する。
　ここで、制御装置２３０は、診断用電圧出力回路２３７から診断用電圧を出力させていないのに、電圧モニタ回路２３５が第１閾値以上の電圧を検出した場合は、診断用電圧出力回路２３７が出力停止指令に見合った状態になっていないと判断し、ステップＳ５０３に進んで、診断用電圧出力回路２３７の故障発生を判定する。 Then, in the next step S502, the control device 230 determines whether the voltage monitor circuit 235 has detected a voltage equal to or higher than the first threshold value.
Here, if the voltage monitor circuit 235 detects a voltage equal to or higher than the first threshold even though the diagnostic voltage output circuit 237 is not outputting a diagnostic voltage, the control device 230 causes the diagnostic voltage output circuit 237 to output a diagnostic voltage. It is determined that the state is not commensurate with the output stop command, and the process proceeds to step S503, where it is determined whether or not a failure has occurred in the diagnostic voltage output circuit 237.
　一方、制御装置２３０は、ステップＳ５０２で、電圧モニタ回路２３５の検出電圧が第１閾値未満であると判断すると、ステップＳ５０４に進む。
　制御装置２３０は、ステップＳ５０４で、診断用電圧出力回路２３７から診断用電圧を出力させる。 On the other hand, if the control device 230 determines in step S502 that the voltage detected by the voltage monitor circuit 235 is less than the first threshold, the control device 230 proceeds to step S504.
In step S504, the control device 230 causes the diagnostic voltage output circuit 237 to output a diagnostic voltage.
　そして、制御装置２３０は、次のステップＳ５０５で、電圧モニタ回路２３５が第２閾値（第２閾値≧第１閾値）以上の電圧を検出したか否かを判断する。
　ここで、制御装置２３０は、電圧モニタ回路２３５が第２閾値以上の電圧を検出していない場合、診断用電圧出力回路２３７が出力指令に対して正規の診断用電圧を出力していないと判断し、ステップＳ５０６に進んで、診断用電圧出力回路２３７の故障発生を判定する。 Then, in the next step S505, the control device 230 determines whether the voltage monitor circuit 235 has detected a voltage equal to or higher than the second threshold (second threshold≧first threshold).
Here, if the voltage monitor circuit 235 does not detect a voltage equal to or higher than the second threshold, the control device 230 determines that the diagnostic voltage output circuit 237 is not outputting a regular diagnostic voltage in response to the output command. Then, the process proceeds to step S506, and it is determined whether a failure has occurred in the diagnostic voltage output circuit 237.
　一方、制御装置２３０は、電圧モニタ回路２３５が第２閾値以上の電圧を検出していれば、診断用電圧出力回路２３７が出力指令、停止指令に対して診断用電圧の出力、停止を正常に実施している、つまり、診断用電圧出力回路２３７が正常であると判断して、ステップＳ５０７に進む。
　制御装置２３０は、ステップＳ５０７で、診断用電圧出力回路２３７が診断用電圧を出力している状態で、中性点電圧モニタ回路２３３が電圧を検出しているか否かを判断する。 On the other hand, if the voltage monitor circuit 235 detects a voltage equal to or higher than the second threshold, the control device 230 causes the diagnostic voltage output circuit 237 to normally output and stop the diagnostic voltage in response to the output command and stop command. It is determined that the diagnostic voltage output circuit 237 is being executed, that is, the diagnostic voltage output circuit 237 is normal, and the process advances to step S507.
In step S507, the control device 230 determines whether the neutral point voltage monitor circuit 233 is detecting voltage while the diagnostic voltage output circuit 237 is outputting the diagnostic voltage.
　そして、制御装置２３０は、中性点電圧モニタ回路２３３が電圧を検出していると判断すると、ステップＳ５０８に進んで、ツェナーダイオードＺＤ１の故障、詳細には、短絡故障の発生を判定する。
　一方、制御装置２３０は、中性点電圧モニタ回路２３３が電圧を検出していない場合、ツェナーダイオードＺＤ１は正常であると判断して、本診断ルーチンを終了させる。 When the control device 230 determines that the neutral point voltage monitor circuit 233 is detecting the voltage, the process proceeds to step S508, and determines whether a failure of the Zener diode ZD1 has occurred, specifically, whether a short circuit failure has occurred.
On the other hand, if the neutral point voltage monitor circuit 233 does not detect any voltage, the control device 230 determines that the Zener diode ZD1 is normal and ends this diagnostic routine.
　上記実施形態で説明した各技術的思想は、矛盾が生じない限りにおいて、適宜組み合わせて使用することができる。
　また、好ましい実施形態を参照して本発明の内容を具体的に説明したが、本発明の基本的技術思想及び教示に基づいて、当業者であれば、種々の変形態様を採り得ることは自明である。 The technical ideas described in the above embodiments can be used in combination as appropriate, as long as there is no contradiction.
Further, although the content of the present invention has been specifically explained with reference to preferred embodiments, it is obvious that those skilled in the art can make various modifications based on the basic technical idea and teachings of the present invention. It is.
　上記の実施形態では、モータ制御装置２６０を適用する電動操舵装置を、電動パワーステアリング装置２００としたが、電動操舵装置を、ステアリングホイール２０１と車輪１１０，１１０とが機械的に連結される電動パワーステアリング装置２００に限定するものではない。
　つまり、電動操舵装置は、ステアリングホイール２０１と車輪１１０，１１０とが機械的に連結されず、モータが車輪１１０，１１０を操舵する操舵力を発生するステアバイワイヤ式の操舵装置とすることができる。 In the above embodiment, the electric steering device to which the motor control device 260 is applied is the electric power steering device 200, but the electric steering device is an electric power steering device where the steering wheel 201 and the wheels 110, 110 are mechanically connected The present invention is not limited to the steering device 200.
In other words, the electric steering device can be a steer-by-wire steering device in which the steering wheel 201 and the wheels 110, 110 are not mechanically connected, and the motor generates the steering force to steer the wheels 110, 110.
　１００…車両、１１０…車輪、２００…電動パワーステアリング装置（電動操舵装置）、２２０…モータ、２２０Ｕ，２２０Ｖ，２２０Ｗ…巻線、２２２…モータリレー、２２２Ｕ，２２２Ｖ，２２２Ｗ…半導体スイッチング素子、２２３…信号経路、２２４…グランド経路、２３０…制御装置（制御部）、２４５…駆動回路、２４５Ａ…３相ブリッジインバータ、２６０…モータ制御装置、ＺＤ１…ツェナーダイオード（制御素子）、Ｄ１１…ダイオード DESCRIPTION OF SYMBOLS 100... Vehicle, 110... Wheel, 200... Electric power steering device (electric steering device), 220... Motor, 220U, 220V, 220W... Winding wire, 222... Motor relay, 222U, 222V, 222W... Semiconductor switching element, 223... Signal path, 224... Ground path, 230... Control device (control unit), 245... Drive circuit, 245A... Three-phase bridge inverter, 260... Motor control device, ZD1... Zener diode (control element), D11... Diode

Claims (10)

  1. 　多相巻線組を有するモータを制御するモータ制御装置であって、
    　前記多相巻線組の巻線に電力を供給する駆動回路と、
    　前記駆動回路と前記多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子と、
    　前記駆動回路及び前記半導体スイッチング素子を制御する制御部と、
    　前記制御部が出力する前記半導体スイッチング素子の制御信号の信号経路と、グランドとを接続するグランド経路に設けられ、前記半導体スイッチング素子の前記巻線の側の電位と前記グランドの電位とが所定の電位差になったときに、前記半導体スイッチング素子をオンさせる制御素子と、
    　を備えた、モータ制御装置。     A motor control device that controls a motor having a polyphase winding set,
    a drive circuit that supplies power to the windings of the multiphase winding set;
    a semiconductor switching element that connects and disconnects a current-carrying path between the drive circuit and a neutral point of the multiphase winding set;
    a control unit that controls the drive circuit and the semiconductor switching element;
    A ground path connecting a signal path of a control signal of the semiconductor switching element outputted by the control unit and a ground is provided, and the potential on the side of the winding of the semiconductor switching element and the potential of the ground are set to a predetermined level. a control element that turns on the semiconductor switching element when a potential difference is reached;
    A motor control device equipped with
  2. 　請求項１に記載のモータ制御装置であって、
    　前記半導体スイッチング素子は、前記巻線と前記中性点との間に配される、
    　モータ制御装置。     The motor control device according to claim 1,
    The semiconductor switching element is arranged between the winding and the neutral point,
    Motor control device.
  3. 　請求項２に記載のモータ制御装置であって、
    　前記制御素子は、前記巻線と前記半導体スイッチング素子との間に所定以上の電圧が発生したときに、前記半導体スイッチング素子をオンさせる、
    　モータ制御装置。     The motor control device according to claim 2,
    The control element turns on the semiconductor switching element when a voltage of a predetermined value or more is generated between the winding and the semiconductor switching element.
    Motor control device.
  4. 　請求項１に記載のモータ制御装置であって、
    　前記半導体スイッチング素子は、
    　前記モータを停止させるときに、前記制御部によってオフされるモータリレーである、
    　モータ制御装置。     The motor control device according to claim 1,
    The semiconductor switching element is
    a motor relay that is turned off by the control unit when stopping the motor;
    Motor control device.
  5. 　請求項３に記載のモータ制御装置であって、
    　前記制御素子はツェナーダイオードであり、
    　前記ツェナーダイオードは、カソードを前記グランドの側とし、アノードを前記信号経路の側として、前記グランド経路に設けられる、
    　モータ制御装置。     The motor control device according to claim 3,
    The control element is a Zener diode,
    The Zener diode is provided in the ground path with a cathode on the ground side and an anode on the signal path side.
    Motor control device.
  6. 　請求項５に記載のモータ制御装置であって、
    　前記ツェナーダイオードと前記グランドとの間の前記グランド経路にダイオードを有し、
    　前記ダイオードは、カソードを前記ツェナーダイオードの側とし、アノードを前記グランドの側として、前記グランド経路に設けられる、
    　モータ制御装置。     The motor control device according to claim 5,
    a diode in the ground path between the Zener diode and the ground;
    The diode is provided in the ground path with a cathode on the Zener diode side and an anode on the ground side.
    Motor control device.
  7. 　請求項６に記載のモータ制御装置であって、
    　前記ツェナーダイオードと前記ダイオードとの間の前記グランド経路に診断用電圧を印加する電圧出力回路と、
    　前記巻線の中性点の電圧を監視する中性点電圧監視部と、
    　前記電圧出力回路が前記診断用電圧を印加するときに、前記中性点電圧監視部で監視される前記中性点の電圧に基づき、前記ツェナーダイオードの故障の有無を診断するツェナーダイオード診断部と、
    　を有する、モータ制御装置。     The motor control device according to claim 6,
    a voltage output circuit that applies a diagnostic voltage to the ground path between the Zener diode and the diode;
    a neutral point voltage monitoring unit that monitors the voltage at the neutral point of the winding;
    a Zener diode diagnostic unit that diagnoses whether or not there is a failure in the Zener diode based on the voltage at the neutral point monitored by the neutral point voltage monitoring unit when the voltage output circuit applies the diagnostic voltage; ,
    A motor control device having:
  8. 　請求項７に記載のモータ制御装置であって、
    　前記ツェナーダイオードと前記ダイオードとの間の前記グランド経路の電圧を監視する電圧監視部と、
    　前記電圧出力回路による前記診断用電圧の出力、停止の制御状態と、前記電圧監視部で監視される前記グランド経路の電圧とに基づき、前記電圧出力回路の故障の有無を診断する電圧出力診断部と、
    　を有する、モータ制御装置。     The motor control device according to claim 7,
    a voltage monitoring unit that monitors the voltage of the ground path between the Zener diode and the diode;
    a voltage output diagnostic unit that diagnoses whether or not there is a failure in the voltage output circuit based on the control state of outputting and stopping the diagnostic voltage by the voltage output circuit and the voltage of the ground path monitored by the voltage monitoring unit; and,
    A motor control device having:
  9. 　多相巻線組を有するモータを制御するモータ制御装置であって、
    　前記多相巻線組の巻線に電力を供給する駆動回路と、
    　前記駆動回路と前記多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子と、
    　前記駆動回路及び前記半導体スイッチング素子を制御する制御部と、
    　前記制御部が出力する前記半導体スイッチング素子の制御信号の信号経路と、グランドとを接続するグランド経路に、カソードを前記グランドの側とし、アノードを前記信号経路の側として設けられたツェナーダイオードと、
    　前記ツェナーダイオードと前記グランドとの間の前記グランド経路に、カソードを前記ツェナーダイオードの側とし、アノードを前記グランドの側として設けられたダイオードと、
    　を備えた、モータ制御装置。     A motor control device that controls a motor having a polyphase winding set,
    a drive circuit that supplies power to the windings of the multiphase winding set;
    a semiconductor switching element that connects and disconnects a current-carrying path between the drive circuit and a neutral point of the multiphase winding set;
    a control unit that controls the drive circuit and the semiconductor switching element;
    a Zener diode having a cathode on the ground side and an anode on the signal path side, provided in a ground path connecting a signal path of a control signal of the semiconductor switching element outputted by the control unit and a ground;
    a diode provided in the ground path between the Zener diode and the ground, with a cathode on the Zener diode side and an anode on the ground side;
    A motor control device equipped with
  10. 　車両に搭載される電動操舵装置であって、
    　多相巻線組を有したモータであって、前記車両の車輪を操舵する操舵力を発生する、前記モータと、
    　前記モータを制御するモータ制御装置と、
    　を有し、
    　前記モータ制御装置は、
    　前記多相巻線組の巻線に電力を供給する駆動回路と、
    　前記駆動回路と前記多相巻線組の中性点との間の通電経路を断続する半導体スイッチング素子と、
    　前記駆動回路及び前記半導体スイッチング素子を制御する制御部と、
    　前記制御部が出力する前記半導体スイッチング素子の制御信号の信号経路と、グランドとを接続するグランド経路に設けられ、前記半導体スイッチング素子の前記巻線の側の電位と前記グランドの電位とが所定の電位差になったときに、前記半導体スイッチング素子をオンさせる制御素子と、
    　を備える、電動操舵装置。     An electric steering device mounted on a vehicle,
    a motor having a multiphase winding set, the motor generating a steering force for steering wheels of the vehicle;
    a motor control device that controls the motor;
    has
    The motor control device includes:
    a drive circuit that supplies power to the windings of the multiphase winding set;
    a semiconductor switching element that connects and disconnects a current-carrying path between the drive circuit and a neutral point of the multiphase winding set;
    a control unit that controls the drive circuit and the semiconductor switching element;
    A ground path connecting a signal path of a control signal of the semiconductor switching element outputted by the control unit and a ground is provided, and the potential on the side of the winding of the semiconductor switching element and the potential of the ground are set to a predetermined level. a control element that turns on the semiconductor switching element when a potential difference is reached;
    An electric steering device equipped with.
PCT/JP2023/030676 2022-09-13 2023-08-25 Motor control device and electric steering device WO2024057878A1 (en)

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022094457A (en) * 2020-12-15 2022-06-27 日立Astemo株式会社 Motor drive control device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022094457A (en) * 2020-12-15 2022-06-27 日立Astemo株式会社 Motor drive control device

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