JP2017221005A - Electric motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor drive device capable of suppressing generation of counter-electromotive force in an electric motor without using a dedicated protection circuit that is complicated, large-scaled, and high in cost.SOLUTION: An electric motor drive device mounted on a vehicle comprises: an electric motor of multiple phases; a motor control unit that drives the electric motor; and an auxiliary unit provided on the wiring of at least one phase among a plurality of wirings for connecting between the electric motor and the motor control unit, and in which a path for electrically grounding the wiring of one phase is formed when a fuse used for power supply wiring of the vehicle is attached at a predetermined position in the unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric motor drive device mounted on a vehicle.

  Various electric motor driving devices that drive an electric motor using a motor control unit and control the state of the vehicle using a rotation output of the electric motor are mounted on the vehicle. For example, Patent Literature 1 discloses, as an example of an electric motor drive device, an electric active stabilizer system that controls a roll restraining force when a vehicle is turning.

  An electric active stabilizer system described in Patent Literature 1 includes a three-phase input electric motor incorporated into a stabilizer via an actuator mechanism, an inverter circuit that converts a control signal into a three-phase drive signal, and drives the electric motor. And an electronic control unit (ECU: Electronic Control Unit) that outputs a control signal to the inverter circuit. With these configurations, the electric active stabilizer system changes the rotation output of the electric motor to change the roll suppression force based on the control signal corresponding to the vehicle status (steering angle, traveling speed, etc.) output by the electronic control unit. Do proper control.

  By the way, for example, when a vehicle completed in a factory is transported by sea or land, some systems such as an electric active stabilizer system perform unnecessary control during transportation so that the battery power of the vehicle is not wasted. Therefore, the operation of the system is stopped.

  In particular, in an electric active stabilizer system in which an electric motor is incorporated in a stabilizer, when an input is applied to the stabilizer due to a lateral vibration of the vehicle body that occurs during transportation, the electric motor incorporated in the stabilizer may be rotated. In this case, the electric motor operates as a generator, and a back electromotive force is generated in the electric motor. The back electromotive force generated in the electric motor may have adverse effects such as breakage of a switching element included in the inverter circuit and back flow of electromotive current to the battery power source.

JP 2007-195331 A

  In the conventional electric active stabilizer system described in Patent Document 1, a counter electromotive force generated in an electric motor caused by an external input such as an input to the stabilizer due to vehicle body vibration in order not to adversely affect the inverter circuit. Is consumed using a complicated and large-scale dedicated protection circuit.

  However, the conventional electric active stabilizer system requires a dedicated protection circuit for suppressing the counter electromotive force generated in the electric motor, so that the inverter circuit becomes complicated and large-scale, and the entire system is There is a problem that the cost becomes high.

  The present invention has been made in view of the above problems, and an electric motor capable of suppressing the occurrence of back electromotive force in an electric motor without using a complicated and large-scale dedicated protection circuit. An object is to provide a drive device.

  In order to solve the above-described problems, the present invention provides an electric motor drive device mounted on a vehicle, comprising: a multi-phase electric motor; a motor control unit that drives the electric motor; an electric motor and a motor control unit; A path that is provided in at least one phase wiring among a plurality of wirings to be connected and electrically grounds the one phase wiring when a fuse used for a power supply wiring of a vehicle is mounted at a predetermined position in the unit is formed. And an auxiliary unit to be provided.

  In the present invention, if a fuse is attached, an auxiliary unit capable of electrically grounding (connecting to GND) the wiring via the fuse is provided on at least one phase wiring (input terminal) of the electric motor. As a result, when the auxiliary unit is made to function by attaching a fuse, a path is formed in which the at least one-phase wiring is connected to the other-phase wiring via the GND. By this path, the counter electromotive force generated in the electric motor can be consumed by the electric motor itself, so that the brake torque is applied to the electric motor and the rotation is suppressed.

  Therefore, for example, when the electric motor drive device is not operated, such as during transportation without using a vehicle, the auxiliary unit functions by attaching a fuse, thereby generating back electromotive force in the electric motor caused by external input (electric Motor rotation). On the other hand, when the electric motor driving device is operated, for example, when the vehicle is normally used, the electric motor can be normally driven by the motor control unit by not operating the auxiliary unit without mounting the fuse.

  Since this auxiliary unit can be realized with a simple configuration, for example, connected to GND via a fuse holder, the motor control unit does not become complicated and does not become large-scale.

  In addition, as a scene where the fuse is attached and the auxiliary unit functions, it is assumed that the electric motor driving device is not operated, for example, when the vehicle is transported. Therefore, in such a situation, as a fuse to be attached to the auxiliary unit, for example, it is normally used for the power supply wiring of the vehicle, but the power supply wiring of the vehicle is used for the purpose of preventing unnecessary consumption of the battery power supply when the vehicle is transported. A fuse that is temporarily removed from can be used.

  Therefore, the cost of the auxiliary unit, that is, the cost of the entire electric motor drive device can be suppressed by diverting the fuse temporarily removed from the power supply wiring of the vehicle when the vehicle is transported.

  Further, the auxiliary unit is configured to electrically connect at least one-phase wiring (input terminal) of the electric motor to GND. Therefore, for example, simply passing a small current from the motor drive unit to each phase of the electric motor and checking whether the potential of each phase is at the ground level (0 V) makes it easy to forget to remove the fuse from the auxiliary unit. Can be checked.

  According to the electric motor driving device of the present invention described above, it is possible to suppress the occurrence of counter electromotive force in the electric motor without using a complicated and large-scale high-cost dedicated protection circuit.

The figure which shows the circuit structure of the electric motor drive device which concerns on one Embodiment of this invention. The figure explaining an example of the scene which operates the electric motor drive device of this embodiment The figure explaining an example of the scene which does not operate the electric motor drive device of this embodiment

[Overview]
The electric motor driving device of the present invention is provided with an auxiliary circuit capable of electrically grounding the wiring by attaching a fuse to at least one phase wiring of the electric motor. Therefore, when the electric motor driving device is not operated, the generation of the counter electromotive force caused by, for example, an external input to the electric motor can be suppressed by mounting a fuse and causing the auxiliary circuit to function.

[Configuration of Electric Motor Drive Device]
FIG. 1 is a diagram conceptually showing the configuration of an electric motor drive device 1 according to an embodiment of the present invention. In FIG. 1, the electric motor drive device 1 includes a motor control unit 10, an actuator unit (hereinafter referred to as “ACT unit”) 20, and an auxiliary unit 30.

  The ACT unit 20 includes a multi-phase electric motor 21 and is configured to change the state of a predetermined device (not shown) of the vehicle based on the rotational output of the electric motor 21. The multi-phase electric motor 21 can be a three-phase DC brushless motor, for example. The electric motor 21 is connected to a predetermined device included in the vehicle via an actuator mechanism (not shown), and is configured to be able to give an output to a predetermined device included in the vehicle.

  For example, when the electric motor driving device 1 is the electric active stabilizer system described in the above prior art, the electric motor 21 is incorporated into a stabilizer (corresponding to a predetermined device) via an actuator mechanism (not shown). It becomes.

  The motor control unit 10 is a device having a function of controlling and driving the electric motor 21 of the ACT unit 20. The motor control unit 10 includes an inverter control circuit 11 and an inverter circuit 12 in the configuration.

  The inverter circuit 12 includes six switching elements SW1 to SW6. As the switching elements SW1 to SW6, MOS (metal oxide semiconductor) transistors, IGBTs (insulated gate bipolar transistors), or the like can be used. In the present embodiment, as shown in FIG. 1, an example is shown in which an element in which an N-channel MOS transistor and a free-wheeling diode are connected in antiparallel is used for each of the six switching elements SW1 to SW6.

  The inverter circuit 12 forms a three-phase bridge circuit with six switching elements SW1 to SW6. Specifically, the switching elements SW1 to SW6 are divided into three switching element pairs (SW1 and SW4, SW2 and SW5, SW3 and SW6) corresponding to each phase of the electric motor 21. In each pair of switching element pairs, the elements are connected in series, and are inserted between the power source + B and the ground point GND. A connection point between the source terminal S and the drain terminal D in each pair of switching element pairs is connected to any one phase input terminal of the electric motor 21.

  Due to the configuration of the above-described three-phase bridge circuit, each of the switching elements SW1 to SW6 performs a complementary on / off operation based on a control signal individually applied to each gate terminal G by an inverter control circuit 11 described later. Thus, a three-phase drive signal can be output to the electric motor 21.

  The inverter control circuit 11 outputs a control signal to the inverter circuit 12 in order to appropriately drive the electric motor 21 in accordance with the state of the vehicle detected inside the circuit or supplied from the outside of the circuit. This control signal is a signal for causing the switching elements SW1 to SW6 to perform complementary on / off operations so that the inverter circuit 12 generates a three-phase drive signal having a phase difference of 120 degrees between the phases. It is. The control signal is individually applied to each gate terminal G of the six switching elements SW1 to SW6.

  Note that all or part of the inverter control circuit 11 is typically configured as an electronic control unit (ECU) including a central processing unit (CPU), a memory, and an input / output interface. The CPU reads out the stored program, interprets and executes it, thereby realizing a predetermined function.

  The auxiliary unit 30 has a structure that can be switched between electrical conduction / interruption depending on the presence or absence of the fuse 31, and is provided between any one-phase input terminal of the electric motor 21 and the ground point GND. Yes. Such a structure can be realized, for example, by inserting a fuse holder in which the fuse 31 can be attached and detached between the input terminal and the ground point GND.

  When the auxiliary unit 30 has a fuse 31 (for example, is attached to a fuse holder), the auxiliary unit 30 is electrically grounded by connecting any one-phase wiring (input terminal) of the electric motor 21 to the ground point GND. Let On the other hand, the auxiliary unit 30 electrically disconnects any one-phase wiring (input terminal) of the electric motor 21 from the ground point GND when there is no fuse 31 (for example, removed from the fuse holder).

[Attached state of fuse in auxiliary unit]
With reference to FIG. 2A and FIG. 2B further, the attachment of the fuse 31 in the auxiliary unit 30 will be described.

  In the present invention, the mounting state of the fuse 31 in the auxiliary unit 30 is changed as follows in a scene where the electric motor drive device 1 is operated and a scene where the electric motor drive device 1 is not operated.

(1) Scene where the electric motor driving device 1 is operated (FIG. 2A)
The scene in which the electric motor driving device 1 is operated is a scene in which a control signal is output from the inverter control circuit 11 to the inverter circuit 12, and the electric motor 21 is driven by the inverter circuit 12 that operates based on the control signal. For example, a scene where the vehicle is normally used by running the vehicle corresponds to a scene where the electric motor driving device 1 is operated. In such a situation, in order to prevent the auxiliary unit 30 from functioning, the auxiliary unit 30 is not attached with the fuse 31. In the electric system of the vehicle, power is supplied from the battery power supply 50 to each device (not shown) of the vehicle via the power supply wiring.

  In a state where the fuse 31 is not attached to the auxiliary unit 30, any one-phase input terminal of the electric motor 21 provided with the auxiliary unit 30 is not electrically connected to the ground point GND. For this reason, the electric motor drive device 1 can normally drive the electric motor 21 of the ACT unit 20 by the motor control unit 10.

(2) Scene in which the electric motor drive device 1 is not operated (FIG. 2B)
The scene in which the electric motor driving device 1 is not operated is a scene in which the control signal is not output from the inverter control circuit 11 to the inverter circuit 12 and the electric motor 21 is not driven by the inverter circuit 12. For example, a scene during transportation without using a vehicle corresponds to a scene where the electric motor drive device 1 is not operated. In such a situation, in order to make the auxiliary unit 30 function, the auxiliary unit 30 is in a state where the fuse 31 is mounted.

  In particular, in the case of a scene during transportation that does not use a vehicle, as illustrated in FIG. 2B, it is normally used for the power supply wiring of the vehicle. A fuse that is temporarily removed from the power supply wiring of the vehicle for the purpose can be used as the fuse 31 of the auxiliary unit 30. Therefore, when the fuse is used in this way, an increase in cost of the electric motor drive device 1 can be suppressed.

  In this state, any one-phase input terminal of the electric motor 21 provided with the auxiliary unit 30 is electrically connected to the ground point GND. For this reason, in the electric motor drive device 1, a path is formed in which at least one phase wiring (input terminal) of the electric motor 21 is connected to the other phase wiring via the ground point GND. See FIG. More specifically, the ground point GND to which the fuse 31 is connected is also connected to the ground point GND of the inverter circuit 12. The ground point GND of the inverter circuit 12 is connected to the wiring (input terminal) of the other phase of the electric motor 21 through the free wheel diode of the switching element SW4 or SW5.

  By forming the above-described path, the energy of the counter electromotive force generated by the electric motor 21 can be consumed by the electric motor 21 itself. This energy consumption acts in the direction in which the brake torque is applied to the electric motor 21, and the rotation of the electric motor 21 is suppressed. Thereby, generation | occurrence | production of the counter electromotive force in the electric motor 21 resulting from an external input, ie, rotation of the electric motor 21, can be suppressed.

[Auxiliary unit check method]
In the electric motor drive device 1, the state of the fuse holder is visually checked to determine whether or not the fuse 31 attached to the auxiliary unit 30 during transportation of the vehicle is removed during normal vehicle use. It is possible to check easily.

  In addition to the method for visually confirming the state of the fuse holder, it is also possible to check whether or not the fuse 31 is mounted by performing an electrical simple test as follows, for example.

  The auxiliary unit 30 of the present embodiment has a configuration in which at least one-phase wiring (input terminal) of the electric motor 21 is electrically connected to the ground point GND. For this reason, if the electric potential of each phase of the electric motor 21 is not at the ground level (0 V), it can be determined that the fuse 31 is not attached to the auxiliary unit 30, and one of them is at the ground level (0 V). If so, it can be determined that the fuse 31 is attached to the auxiliary unit 30.

  For this reason, for example, only a small current is supplied from the motor control unit 10 to each phase of the electric motor 21 to check whether the potential of each phase is at the ground level (0 V). It is possible to easily check the mounting state of the fuse 31, that is, forgetting to remove the fuse 31.

[Operational effects in this embodiment]
According to the electric motor drive device 1 according to the embodiment of the present invention, the auxiliary unit 30 that can electrically connect the wiring to the ground point GND via the fuse 31 when the fuse 31 is mounted, that is, the grounding auxiliary unit 30 can be grounded. It is provided on at least one phase wiring (input terminal) of the electric motor 21. As a result, when the fuse 31 is mounted and the auxiliary unit 30 functions, a path is formed in which the at least one-phase wiring is connected to the other-phase wiring via the ground point GND. By this path, the counter electromotive force generated in the electric motor 21 can be consumed by the electric motor itself, so that the brake torque is applied to the electric motor 21 and rotation is suppressed.

  Accordingly, in a situation where the electric motor drive device 1 is not operated, for example, during transport without using a vehicle, the auxiliary unit 30 is made to function by attaching the fuse 31 to thereby function the counter electromotive force in the electric motor 21 caused by an external input. Generation, that is, rotation of the electric motor 21 can be suppressed. On the other hand, when the electric motor drive device 1 is operated, for example, when the vehicle is normally used by running the vehicle, the motor control unit 10 does not function the auxiliary unit 30 without attaching the fuse 31. The electric motor 21 can be driven normally.

  Since the auxiliary unit 30 can be realized with a simple configuration such as being connected to the ground point GND via a fuse holder, the motor control unit 10 does not become complicated and does not become large-scale.

  In addition, as a scene where the fuse 31 is mounted and the auxiliary unit 30 functions, a scene where the electric motor driving device 1 is not operated, for example, during transportation of a vehicle is assumed. Therefore, in such a situation, the fuse 31 to be attached to the auxiliary unit 30 is normally used for, for example, the power supply wiring of the vehicle, but the vehicle is used for the purpose of preventing unnecessary consumption of the battery power supply 50 when the vehicle is transported. A fuse that is temporarily removed from the power supply wiring, that is, not used when the vehicle is transported can be used.

  Therefore, the cost of the auxiliary unit 30, that is, the electric motor drive device can be obtained by diverting the fuse that is temporarily removed from the power supply wiring of the vehicle and transporting the vehicle to the fuse 31 that is attached to the auxiliary unit 30. The cost of the whole 1 can be suppressed.

Further, the auxiliary unit 30 is configured to electrically connect at least one-phase wiring (input terminal) of the electric motor 21 to the ground point GND. Therefore, for example, only a small current is supplied from the motor control unit 10 to each phase of the electric motor 21 and it is confirmed whether the potential of each phase is at the ground level (0 V). That is, forgetting to remove the fuse 31 can be easily checked.

  In the above embodiment, the electric motor driving device mounted on the vehicle has been described. However, the electric motor drive device of the present invention can be used in various systems using the rotation output of the electric motor, and can also be mounted other than the vehicle.

  The electric motor drive device of the present invention can be used for a system in which a counter electromotive force caused by an external input is generated in the electric motor when the system is not operating, such as an electric active stabilizer system.

DESCRIPTION OF SYMBOLS 1 Electric motor drive device 10 Motor control unit 11 Inverter control circuit (ECU)
12 Inverter circuit 20 Actuator unit (ACT unit)
21 Electric motor 30 Auxiliary unit 31 Fuse 50 Battery power supply

Claims (1)

An electric motor drive device mounted on a vehicle,
A multi-phase electric motor;
A motor control unit for driving the electric motor;
Among the plurality of wirings connecting the electric motor and the motor control unit, the wiring is provided in at least one phase wiring, and when a predetermined fuse used for a power supply wiring of a vehicle is mounted at a predetermined position in the unit An auxiliary unit formed with a path for electrically grounding the one-phase wiring,
Electric motor drive device.

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