Power converter

• US 8,829,861 B2
• Filed: 05/11/2011
• Issued: 09/09/2014
• Est. Priority Date: 05/11/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hamanaka, Yoshiyuki, Sakata, Koichi
• Primary Examiner(s): Santana, Eduardo Colon
• Assistant Examiner(s): Dhakal, Bickey
• Application Number:
  US13/513,383
• Publication Number:
  US 20120236617A1
• Time in Patent Office: 1,217 Days
• Field of Search: 318/139, 318/176, 318/801, 320/166, 307/110
• US Class Current: 320/166
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 7/53873 with digital control

Abstract

A motor control apparatus includes an inverter, a smoothing capacitor, power-converting drivers, a power-converting power supply circuit, and discharging drivers. The inverter includes switching circuits comprised of series-connected two IGBTs. The power-converting drivers apply an output voltage of the power-converting power supply circuit to the switching circuits to drive them, thus performing power conversion. The discharging drivers simultaneously turn on IGBTs of the switching circuit to discharge the smoothing capacitor when the output voltage of the power-converting power supply circuit is equal to or lower than a threshold. This prevents discharging of the smoothing capacitor during power converting operations.

Claims

1. A power converter comprising:

a switching circuit comprised of a plurality of switching elements connected in series;

a smoothing capacitor connected in parallel to the switching circuit;

a power-converting driver that drives the plurality of switching elements for power conversion;

a power-converting power supply circuit that outputs, to the power-converting driver, a voltage that drives the plurality of switching elements to perform the power conversion;

a discharging driver that drives the plurality of switching elements for discharging charge stored in the smoothing capacitor; and

a discharging power supply circuit that supplies, to the discharging driver, a voltage for driving the plurality of switching elements,

wherein the discharging driver drives, based on the voltage outputted from the power-converting power supply circuit, the plurality of switching elements to discharge the charge stored in the smoothing capacitor.

2. The power converter according to claim 1, wherein the discharging driver drives the plurality of switching elements to discharge the charge stored in the smoothing capacitor when the voltage outputted from the power-converting power supply circuit becomes equal to or lower than a threshold.

3. The power converter according to claim 1, further comprising a control circuit that controls the power-converting power supply circuit and the discharging driver,

wherein the discharging driver drives the plurality of switching elements based on the voltage outputted from the power-converting power supply circuit and a discharging instruction inputted to the discharging driver from the control circuit to discharge the charge stored in the smoothing capacitor.

4. The power converter according to claim 1, wherein the discharging power supply circuit generates, based on the charge stored in the smoothing capacitor, the voltage for driving the plurality of switching elements.

5. The power converter according to claim 1, wherein the power converter is installed in a vehicle, and converts power of a DC power source, and supplies converted power to an electric device.

6. The power converter according to claim 2, wherein the discharging power supply circuit generates, based on the charge stored in the smoothing capacitor, the voltage for driving the plurality of switching elements.

7. The power converter according to claim 2, wherein the power converter is installed in a vehicle, converts power of a DC power source, and supplies converted power to an electric device.

8. The power converter according to claim 3, wherein the discharging driver drives the plurality of switching elements based on the voltage outputted from the power-converting power supply circuit and an instruction inputted to the discharging driver from the control circuit to discharge the charge stored in the smoothing capacitor when the voltage outputted from the power-converting power supply circuit becomes equal to or lower than a threshold, and the discharging instruction is inputted thereto from the control circuit.

9. The power converter according to claim 3, wherein the discharging power supply circuit generates, based on the charge stored in the smoothing capacitor, the voltage for driving the plurality of switching elements.

10. The power converter according to claim 3, wherein the power converter is installed in a vehicle, converts power of a DC power source, and supplies converted power to an electric device.

11. The power converter according to claim 4, wherein the power converter is installed in a vehicle, converts power of a DC power source, and supplies converted power to an electric device.

12. The power converter according to claim 8, wherein the discharging power supply circuit generates, based on the charge stored in the smoothing capacitor, the voltage for driving the plurality of switching elements.

13. The power converter according to claim 8, wherein the power converter is installed in a vehicle, converts power of a DC power source, and supplies converted power to an electric device.

14. A power converter comprising:

a switching circuit comprised of a plurality of switching elements connected in series;

a smoothing capacitor connected in parallel to the switching circuit;

a power-converting driver that drives the plurality of switching elements for power conversion;

a power-converting power supply circuit that outputs, to the power-converting driver, a voltage for driving the plurality of switching elements;

a discharging driver that drives the plurality of switching elements for discharging charge stored in the smoothing capacitor; and

a discharging power supply circuit that supplies, to the discharging driver, a voltage for driving the plurality of switching elements,

wherein the discharging driver drives, based on the voltage outputted from the power-converting power supply circuit, the plurality of switching elements to discharge the charge stored in the smoothing capacitor; and

the plurality of switching elements are a first switching element and a second switching element, and the discharging driver repeatedly turns on and off the second switching element while keeping the first switching element in on state.

15. A power converter comprising:

a switching circuit comprised of a plurality of switching elements connected in series;

a first smoothing capacitor connected in parallel to the switching circuit;

a power-converting driver that drives the plurality of switching elements for power conversion;

a power-converting power supply circuit that outputs, to the power-converting driver, a voltage for driving the plurality of switching elements;

a second smoothing capacitor connected in parallel to the power-converting power supply circuit;

a discharging driver comprising;

a first driver that drives a first switching element in the plurality of switching elements for discharging charge stored in the first smoothing capacitor; and

a second driver that drives a second switching element in the plurality of switching elements for discharging charge stored in the second smoothing capacitor; and

a discharging power supply circuit that supplies, to the discharging driver, a voltage for driving the plurality of switching elements,

wherein;

the discharging driver drives, based on the voltage outputted from the power-converting power supply circuit, the plurality of switching elements to discharge the charge stored in each of the first and second smoothing capacitors, the first smoothing capacitor is configured such that the charge stored in the first smoothing capacitor is discharged to be stored in the second smoothing capacitor with the first switching element being in on state, and the first and second drivers alternately turn on and off the first and second switching elements.