JP5744072B2 - In-vehicle rotating electrical machine drive device - Google Patents

Description

  The present invention relates to a drive device for a vehicle-mounted rotating electrical machine that drives a rotating electrical machine (motor) mounted on a vehicle.

  Many in-vehicle drive devices and control methods therefor have been provided with an inverter for driving a motor, a battery for supplying electric power, and a boost converter for boosting the voltage of the battery between the battery and the inverter and supplying the boosted voltage to the inverter. Proposed.

  However, an excessive voltage is applied to the power line connecting the boost converter and the inverter in the operation of driving the motor by supplying the power from the battery to the inverter without boosting the boost converter due to a failure of the voltage sensor of the boost converter. Doing so can damage the battery. Therefore, it is necessary to protect an inverter or a battery that may be applied with an excessive voltage depending on the operating state of the boost converter.

  As a countermeasure, for example, in the power supply device and the control method thereof and the vehicle disclosed in Patent Document 1, an inverter that drives a motor for traveling, a battery, and a connection between two switching elements and the switching elements connected in series. Switching circuit connected to the positive side of the inverter and the positive side of the battery among the switching elements of the boost converter when the boost converter fails While the element is fixed on and the switching element connected to the positive side and the negative side of the battery is fixed off, the battery and the inverter are directly connected. When the pre-boost voltage exceeds the allowable voltage of the battery, the boost converter Shut off the inverter gate. Thereby, it is suppressed that an excessive voltage is applied to the battery.

JP 2008-289258 A

  However, the power supply device and the control method disclosed in Patent Document 1 do not consider measures against a failure mode such as a short circuit of the boost converter, and if the boost converter is short-circuited for some reason during traveling, the battery is excessively large. There is a problem that a large amount of current flows and this may cause damage to the battery.

  The present invention has been made to solve the above-described problems, and can prevent overcurrent of a DC power supply battery or the like even in a failure mode such as a short circuit of a boost converter that is a voltage converter, An object of the present invention is to provide a drive device for a vehicle-mounted rotating electrical machine that can avoid damage to a battery.

In order to solve the above-described problems, a drive device for a vehicle-mounted rotating electrical machine according to the present invention includes a chargeable / dischargeable DC power supply, an inverter that drives the rotating electrical machine, and a voltage of the DC power supply to supply power to the inverter. And a control device that controls power supply from the DC power supply to the voltage conversion device, the control device bypassing the voltage conversion device, and bypassing the DC power supply A switching device that supplies power to the inverter through a circuit or the voltage converter, a voltage sensor provided on each of the input and output sides of the voltage converter, and a control circuit that controls the switching device according to voltage information of the voltage sensor When, which includes a voltage measured by the voltage sensor provided to the voltage sensor or the output side is provided on the input side is equal to the ground potential Case, is characterized in that switching the DC power to the bypass circuit.

  According to the present invention, when the voltage conversion device is short-circuited, the control device cuts off the power supply from the DC power supply to the voltage conversion device, thereby preventing overcurrent from flowing through the DC power supply. There is a remarkable effect that damage can be avoided.

It is a figure which shows the schematic whole structure of the drive device of the vehicle-mounted rotary electric machine in Embodiment 1. FIG. FIG. 6 is a diagram showing a schematic overall configuration of a drive device for a vehicle-mounted rotating electrical machine according to a second embodiment.

  Hereinafter, a drive device for an in-vehicle rotating electrical machine according to an embodiment of the present invention will be described with reference to FIGS.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a schematic overall configuration of a drive device for a vehicle-mounted rotating electrical machine according to the first embodiment.

  In FIG. 1, a driving device 1 includes a battery 2 that is a DC power source that supplies power, a boost converter 3 that is a voltage converter that boosts the voltage of the battery 2, and a DC current supplied from the boost converter 3 in three phases. An inverter 4 for converting into an alternating current, an AC synchronous motor (hereinafter referred to as a motor) 5 that is a rotating electrical machine driven by the alternating current of the inverter 4, and a voltage sensor V1 that measures a voltage at the input 3a of the boost converter 3. And an open / close switch 6 that is an open / close device that opens and closes a circuit between the battery 2 and the boost converter 3, and a control circuit 7 that operates the open / close switch 6 based on voltage information from the voltage sensor V1. And a control device 8 for controlling.

  Next, the operation of the drive device for the on-vehicle rotating electrical machine in the first embodiment will be described with reference to FIG. In addition, since the main body of this invention exists in a drive device, description of operation | movement of a vehicle is abbreviate | omitted.

  First, the operation during normal driving of the motor 5 will be described. Power is supplied from the battery 2 to the boost converter 3 through the open / close switch 6, and the voltage is boosted to a predetermined voltage by the boost converter 3. The boosted power is supplied to the inverter 4 and converted from direct current to three-phase alternating current to drive the motor 5. By boosting the voltage of the battery 2 as necessary by the boost converter 3, the efficiency of the motor 5 can be improved and the output can be increased.

  Further, during regeneration of the motor 5, the electric power generated by the motor 5 is converted from three-phase alternating current to direct current by the inverter 4, the voltage is stepped down by the step-up converter 3, and is supplied to the battery 2 via the open / close switch 6. Charged. At this time, the voltage output from the inverter 4 may exceed the voltage of the battery 2, but is stepped down to a voltage suitable for charging the battery 2 by the boost converter 3.

Next, the operation when an abnormality occurs in boost converter 3 will be described. The voltage at the input 3a of the boost converter 3 is monitored by the voltage sensor V1, and if the measured voltage is equal to the ground potential, the control circuit 7 determines that the input 3a of the boost converter 3 is short-circuited. Then, the control circuit 7 issues an instruction to open the open / close switch 6, and the power supply to the boost converter 3 is cut off. Thereby, when the input part 3a of the boost converter 3 is short-circuited, an overcurrent is prevented from flowing through the battery 2, and damage to the battery 2 is avoided.

  As described above, in the drive device for the on-vehicle rotating electrical machine in the first embodiment, the input unit of the boost converter is short-circuited by installing the control device having the opening / closing device that cuts off the power supply on the battery side of the boost converter. In this case, the battery can be prevented from being short-circuited, and the battery can be prevented from being damaged due to overcurrent.

  In addition, although the case where the relay type opening / closing switch 6 shown in FIG. 1 is used as the opening / closing device used in the first embodiment has been described, other types such as a semiconductor switch may be used. Further, a breaker mounted in the battery in advance for the purpose of battery maintenance may be used. Moreover, you may use together with this breaker.

Embodiment 2. FIG.
FIG. 2 is a diagram showing a schematic overall configuration of a drive device for a vehicle-mounted rotating electrical machine according to the second embodiment.
As shown in FIG. 2, the drive device 1 in the second embodiment includes a bypass circuit 10 that bypasses the boost converter 3, and selector switches 9 a and 9 b that switch power from the battery 2 between the boost converter 3 and the bypass circuit 10. A voltage sensor V1 that measures the voltage at the input 3a of the boost converter 3, a voltage sensor V2 that measures the voltage at the output 3b of the boost converter 3, and a voltage sensor V4 that measures the voltage at the input 4a of the inverter 4. A voltage sensor V3 that measures the voltage of the output unit 2b of the battery 2, and a control circuit 7 that operates the changeover switches 9a and 9b based on voltage information from the voltage sensor V1 to the voltage sensor V4. It is composed of a control device 8 that controls supply, an auxiliary power source 11 and an auxiliary device 12 connected to the output side of the battery 2. Except for the above, a battery 2 that is a DC power source that supplies power, a boost converter 3 that is a voltage converter that boosts the voltage of the battery 2, and an inverter 4 that converts a DC current supplied from the boost converter 3 into a three-phase AC current. The motor 5 driven by the alternating current of the inverter 4 is the same as in the first embodiment.

Next, the operation of the drive device for the on-vehicle rotating electrical machine according to the second embodiment will be described with reference to FIG.
First, the operation during normal driving of the motor 5 will be described. Power is supplied from the battery 2 to the boost converter 3 via the changeover switch 9a, and the voltage is boosted to a predetermined voltage by the boost converter 3. The boosted power is supplied to the inverter 4 via the changeover switch 9b, and is converted from direct current to three-phase alternating current to drive the motor 5. As in the first embodiment, the boost converter 3 boosts the voltage of the battery 2 as necessary, thereby improving the efficiency of the motor 5 and increasing the output. Further, during regeneration of the motor 5, the electric power generated by the motor 5 is converted from three-phase AC to DC by the inverter 4, and the voltage is stepped down by the boost converter 3 via the changeover switch 9b, and the changeover switch 9a. The battery 2 is charged via At this time, the voltage output from the inverter 4 may exceed the voltage of the battery 2, but is stepped down to a voltage suitable for charging the battery 2 by the boost converter 3.

Next, the operation when an abnormality occurs in boost converter 3 will be described. The voltage at the input 3a of the boost converter 3 is monitored by the voltage sensor V1, and if the measured voltage is equal to the ground potential, the control circuit 7 determines that the input 3a of the boost converter 3 is short-circuited. Is done. Further, the voltage of the output unit 3b of the boost converter 3 is monitored by the voltage sensor V2, and when the measured voltage is equal to the ground potential, the output unit 3b of the boost converter 3 is short-circuited in the control circuit 7. It is determined. When a malfunction occurs in boost converter 3 due to one of these short circuits, control circuit 7 issues an instruction to switch selector switches 9a and 9b to bypass circuit 10 side, and power supply to boost converter 3 is shut off. The This prevents overcurrent from flowing to the battery 2 when the input unit 3a of the boost converter 3 is short-circuited, avoids damage to the battery 2, and passes through the bypass circuit 10 by switching the selector switches 9a and 9b. Thus, the power supply to the inverter 4 is continued, and the motor 5 can be driven. Thereby, even when the boost converter 3 is short-circuited, it is possible to continue supplying power to the inverter 4 via the bypass circuit 10 and to continue traveling of the vehicle.

  When the motor 5 is driven by supplying power from the battery 2 directly to the inverter 4 via the bypass circuit 10 when the boost converter 3 is short-circuited, the output voltage of the battery 2 cannot be boosted. Decreases the efficiency. Therefore, as a countermeasure, it is possible to suppress a reduction in motor efficiency by providing an upper limit value for both or one of the rotational speed and torque of the motor 5. From the relationship between the motor specific rotation speed and torque characteristics, it is necessary to operate the rotation speed below the upper limit value in order to obtain the required output torque, and conversely to obtain the required rotation speed. It is necessary to operate the output torque within the upper limit. About the control method of an upper limit value, when the value exceeding an upper limit value is input into the inverter 4 and the motor 5, the control apparatus 8 of the inverter 4 clips by the upper limit value.

  Further, since the output voltage of the battery 2 cannot be boosted, as a measure for suppressing a decrease in the output of the motor 5, the motor 4 is increased by changing the modulation factor of the inverter 4 and increasing the fundamental component of the output voltage from the inverter 4. 5 can be minimized. This is because the voltage component contributing to the output of the motor is determined by the fundamental wave component. In order to increase the fundamental wave component, the output of the motor 5 can be improved by changing the modulation factor of the inverter 4 and increasing the fundamental wave component of the voltage. Here, the modulation rate represents the ratio of the fundamental wave component of the output voltage waveform to the power supply voltage of the inverter. A voltage waveform capable of generating the maximum fundamental wave component by PWM (pulse width modulation) generally used, and the modulation rate is 0.78 (theoretical value). In order to increase the fundamental wave component, the output voltage waveform of the inverter 4 can be distorted, the fundamental wave component of the voltage can be increased, and the output of the motor 5 can be improved. Here, the modulation rate represents the ratio of the fundamental wave component of the output voltage waveform to the power supply voltage of the inverter. A voltage waveform capable of generating the maximum fundamental wave component by PWM (pulse width modulation) generally used, and the modulation rate is 0.78 (theoretical value).

  Further, when the boost converter 3 fails, since the auxiliary power supply 11 is connected to the output side of the battery 2 instead of the output side of the boost converter 3, the power supply to the auxiliary machine 12 can be performed without any problem. Can do.

  When charging the battery 2 with the regenerative power of the motor 5 via the bypass circuit 10 when the boost converter 3 is short-circuited, as a countermeasure when the regenerative amount is large, the modulation rate of the inverter 4 is changed, By reducing the output DC voltage, it is possible to prevent an excessive voltage from being applied to the battery 2, avoiding damage to the battery 2, and charging.

  Further, when the boost converter 3 is short-circuited, when charging the battery 2 with the regenerative power of the motor 5 via the bypass circuit 10, the voltage output from the inverter 4 is allowed to the battery 2 when the regenerative amount is large. May be exceeded. Therefore, as a countermeasure, a mechanical brake (not shown) provided in the vehicle is used, and the ratio is increased, thereby suppressing the regeneration amount and preventing an excessive voltage from being applied to the battery 2. The battery 2 can be charged while being prevented from being damaged.

As described above, in the drive device for the on-vehicle rotating electrical machine according to the second embodiment, by installing the bypass circuit that bypasses the boost converter and the control device that includes the changeover switch that switches the bypass circuit before and after the boost converter, When the input part and the output part of the battery are short-circuited, there is a remarkable effect that the battery can be prevented from being short-circuited and damage to the battery due to overcurrent can be avoided. Furthermore, when the boost converter is short-circuited, it is possible to continue supplying power to the inverter via the bypass circuit, and there is a remarkable effect that the vehicle can travel to a safe position.

  In the second embodiment, as shown in FIG. 2, the change-over switches 9a and 9b have been described with respect to the case where one three-terminal relay is used. . Further, the changeover switch is not limited to a relay type, and a semiconductor switch or the like may be used, but is not limited thereto. Moreover, although the case where the two changeover switches 9a and 9b are configured in combination has been described, either the changeover switch 9a or 9b is mounted singly, and only the input short circuit or the output short circuit of the boost converter 3 is configured. It is also possible.

  The DC power source used in the present invention may be of any type as long as it can be charged such as a lithium ion battery, a battery such as a nickel metal hydride battery or a capacitor. Further, the case of driving a vehicle-mounted motor has been described as a drive device for a vehicle-mounted rotating electrical machine. However, the present invention is not limited to a vehicle-mounted motor and can be applied to any motor that is driven by a DC power source.

  Further, the present invention is not limited to the above-described embodiment, and it goes without saying that these possible combinations are included.

  Moreover, in the figure, the same code | symbol shows the same or an equivalent part.

1 drive device, 2 battery, 3 boost converter, 4 inverter,
5 Motor, 6 Open / close switch, 7 Control circuit, 8 Control device,
9a, 9b changeover switch, 10 bypass circuit, 11 auxiliary power supply

Claims (6)

A chargeable / dischargeable DC power supply,
An inverter that drives the rotating electrical machine;
A voltage converter for converting the voltage of the DC power supply and supplying power to the inverter;
A control device for controlling power supply from the DC power source to the voltage converter;
With
The control device includes a bypass circuit that bypasses the voltage conversion device, a switching device that supplies power to the inverter through the bypass circuit or the voltage conversion device, and an input / output side of the voltage conversion device. A voltage sensor provided, and a control circuit that controls the switching device according to voltage information of the voltage sensor,
The in-vehicle rotation characterized by switching the DC power source to the bypass circuit when the voltage measured by the voltage sensor provided on the input side or the voltage sensor provided on the output side is equal to the ground potential Electric drive device.   When power is supplied from the DC power source to the inverter via the bypass circuit, the modulation factor of the inverter is controlled and the fundamental wave component of the voltage input from the inverter to the rotating electrical machine is increased. The drive device for a vehicle-mounted rotating electrical machine according to claim 1.   When supplying power to the inverter from the DC power source via the bypass circuit, an upper limit value is provided for either or both of the rotational speed and torque of the rotating electrical machine, and the inverter causes the upper limit value to be within the upper limit value. The drive device for an in-vehicle rotating electrical machine according to claim 1 or 2, wherein the rotating electrical machine is operated.   When supplying power to the DC power source via the bypass circuit during regeneration of the rotating electrical machine, the modulation rate of the inverter is controlled, and the DC voltage output from the inverter is reduced to reduce the DC power source. The drive device for the on-vehicle rotating electrical machine according to any one of claims 1 to 3, wherein charging is performed. A mechanical brake is provided, and when supplying power to the DC power supply via the bypass circuit during regeneration of the rotating electrical machine, the ratio of the mechanical brake is controlled, and the DC voltage output from the inverter is 5. The drive device for a vehicle-mounted rotating electrical machine according to claim 1, wherein the direct-current power source is charged by being controlled. 6.   The drive of the on-vehicle rotating electrical machine according to any one of claims 1 to 5, further comprising an auxiliary power source, wherein the auxiliary power source is connected to an output side of the DC power source. apparatus.

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