POWER CONVERSION DEVICE

• US 20120020137A1
• Filed: 07/22/2011
• Published: 01/26/2012
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: ABE, Yasushi
• Granted Patent: US 9,509,230 B2
• Time in Patent Office: Days
• US Class Current: 363/132
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H02M 7/538 in a push-pull configuration H02M7/5375 takes precedence ; with oscillating arrangements H02M7/53832, H02M7/53846

Abstract

A single phase three-level power converter can include a first half bridge and a second half bridge. A half bridge operation is implemented in either the first half bridge or second half bridge when outputting a single phase alternating current voltage having an amplitude a half or less than that of a direct current input voltage, and also, by alternately switching between the bridges carrying out the half bridge operation. In certain configurations, the power converter can convert a direct current input voltage into alternating current phase voltages having three levels of potential, which are positive, negative, and intermediate voltages, by controlling on-off conditions of a plurality of switch elements, and a controller that, by supplying gate signals to the switch elements configuring the first half bridge and second half bridge, controls the related on-off conditions.

Claims

1. A single phase three-level power conversion device, including a power converter formed of a first half bridge and second half bridge, that acts in half bridge mode in either the first half bridge or second half bridge in accordance with an output voltage.

7. The power conversion device according to claim 1, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having first, second, third, and fourth switch elements connected in series and first, second, third, and fourth diodes connected in inverse parallel to the first, second, third, and fourth switch elements respectively, wherein either end of a series circuit in which the first, second, third, and fourth switch elements are connected in series is connected to the first terminal and second terminal, and the connection point of the second switch element and third switch element is an alternating current output terminal;

a fifth diode connected between the third terminal and the connection point of the first switch element and second switch element; and

a sixth diode connected between the connection point of the third switch element and fourth switch element and the third terminal.

8. The power conversion device according to claim 1, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element having reverse withstand voltage are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

9. The power conversion device according to claim 1, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element, to each of which a diode is connected in inverse parallel, are connected in series in a reverse direction, one connection point connected in series is connected to the third terminal, and the other connection point connected in series is connected to the alternating current output terminal.

10. The power conversion device according to claim 1, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a circuit in which a second switch element and diode are connected in series, and a circuit in which a third switch element and diode are connected in series, are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

2. A single phase three-level power conversion device, including a power converter formed of a first half bridge and second half bridge, that acts in half bridge mode in either the first half bridge or second half bridge in accordance with an input voltage.

11. The power conversion device according to claim 2, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having first, second, third, and fourth switch elements connected in series and first, second, third, and fourth diodes connected in inverse parallel to the first, second, third, and fourth switch elements respectively, wherein either end of a series circuit in which the first, second, third, and fourth switch elements are connected in series is connected to the first terminal and second terminal, and the connection point of the second switch element and third switch element is an alternating current output terminal;

a fifth diode connected between the third terminal and the connection point of the first switch element and second switch element; and

a sixth diode connected between the connection point of the third switch element and fourth switch element and the third terminal.

14. The power conversion device according to claim 2, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element having reverse withstand voltage are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

17. The power conversion device according to claim 2, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element, to each of which a diode is connected in inverse parallel, are connected in series in a reverse direction, one connection point connected in series is connected to the third terminal, and the other connection point connected in series is connected to the alternating current output terminal.

20. The power conversion device according to claim 2, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a circuit in which a second switch element and diode are connected in series, and a circuit in which a third switch element and diode are connected in series, are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

3. A power conversion device comprising:

a power converter formed of a first half bridge and second half bridge that converts a direct current input voltage into alternating current phase voltages having three levels of potential, which are positive, negative, and intermediate voltages, by controlling on-off conditions of a plurality of switch elements; and

a controller that, by supplying gate signals to the switch elements configuring the first half bridge and second half bridge, controls the on-off conditions thereof, wherein

the controller includes;

a first PWM controller that outputs gate signals for causing the power converter to act in full bridge mode;

a second PWM controller that outputs gate signals for causing the power converter to act in half bridge mode; and

a gate signal selector that outputs either the output of the first PWM controller or the output of the second PWM controller as gate signals of the switch elements.

5. The power conversion device according to claim 3, wherein

the gate signal selector, when it is possible to output the alternating current phase voltages by on-off controlling only the switch elements of either the first or second half bridge, outputs the output of the second PWM controller as the gate signals of the switch elements.

6. The power conversion device according to claim 3, wherein

the direct current input voltage is evenly divided in series by a first direct current voltage source and second direct current voltage source, and

the gate signal selector, when the voltage values of the first power source and second power source are larger than the amplitude value of the alternating current phase voltage command, outputs the output of the second PWM controller as the gate signals of the switch elements.

12. The power conversion device according to claim 3, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having first, second, third, and fourth switch elements connected in series and first, second, third, and fourth diodes connected in inverse parallel to the first, second, third, and fourth switch elements respectively, wherein either end of a series circuit in which the first, second, third, and fourth switch elements are connected in series is connected to the first terminal and second terminal, and the connection point of the second switch element and third switch element is an alternating current output terminal;

a fifth diode connected between the third terminal and the connection point of the first switch element and second switch element; and

a sixth diode connected between the connection point of the third switch element and fourth switch element and the third terminal.

15. The power conversion device according to claim 3, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element having reverse withstand voltage are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

18. The power conversion device according to claim 3, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element, to each of which a diode is connected in inverse parallel, are connected in series in a reverse direction, one connection point connected in series is connected to the third terminal, and the other connection point connected in series is connected to the alternating current output terminal.

21. The power conversion device according to claim 3, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a circuit in which a second switch element and diode are connected in series, and a circuit in which a third switch element and diode are connected in series, are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

4. A power conversion device comprising:

a power converter formed of a first half bridge and second half bridge that converts a direct current input voltage into alternating current phase voltages having three levels of potential, which are positive, negative, and intermediate voltages, by controlling on-off conditions of a plurality of switch elements; and

a controller that, by supplying gate signals to the switch elements configuring the first half bridge and second half bridge, controls the on-off conditions thereof, wherein

the controller includes;

a first PWM controller that outputs gate signals for causing the power converter to act in full bridge mode

a second PWM controller that outputs gate signals for causing the power converter to act in half bridge mode;

a gate signal selector that outputs either the output of the first PWM controller or the output of the second PWM controller as gate signals of the switch elements; and

a bridge switching unit that causes the first half bridge and second half bridge to act alternately when causing the power converter to act in half bridge mode.

13. The power conversion device according to claim 4, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having first, second, third, and fourth switch elements connected in series and first, second, third, and fourth diodes connected in inverse parallel to the first, second, third, and fourth switch elements respectively, wherein either end of a series circuit in which the first, second, third, and fourth switch elements are connected in series is connected to the first terminal and second terminal, and the connection point of the second switch element and third switch element is an alternating current output terminal;

a fifth diode connected between the third terminal and the connection point of the first switch element and second switch element; and

a sixth diode connected between the connection point of the third switch element and fourth switch element and the third terminal.

16. The power conversion device according to claim 4, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element having reverse withstand voltage are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

19. The power conversion device according to claim 4, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a second switch element and third switch element, to each of which a diode is connected in inverse parallel, are connected in series in a reverse direction, one connection point connected in series is connected to the third terminal, and the other connection point connected in series is connected to the alternating current output terminal.

22. The power conversion device according to claim 4, wherein

the half bridge of the power converter includes:

a first terminal and second terminal connected to either end of a first direct current voltage source and second direct current voltage source connected in series;

a third terminal connected to the connection point of the first direct current voltage source and second direct current voltage source;

a first circuit having a first switch element and fourth switch element connected in series and a diode connected in inverse parallel to the first switch element and fourth switch element, wherein either end of the first switch element and fourth switch element connected in series is connected to the first terminal and second terminal, and the connection point of the first switch element and fourth switch element is an alternating current output terminal; and

a second circuit in which a circuit in which a second switch element and diode are connected in series, and a circuit in which a third switch element and diode are connected in series, are connected in inverse parallel, one connection point connected in inverse parallel is connected to the third terminal, and the other connection point connected in inverse parallel is connected to the alternating current output terminal.

23. The power conversion device according to claim 4, wherein

the gate signal selector, when it is possible to output the alternating current phase voltages by on-off controlling only the switch elements of either the first or second half bridge, outputs the output of the second PWM controller as the gate signals of the switch elements.

24. The power conversion device according to claim 4, wherein

the direct current input voltage is evenly divided in series by a first direct current voltage source and second direct current voltage source, and

the gate signal selector, when the voltage values of the first power source and second power source are larger than the amplitude value of the alternating current phase voltage command, outputs the output of the second PWM controller as the gate signals of the switch elements.