CN-121193124-B - Power supply circuit, driving device and power conversion apparatus

Abstract

The application relates to a power supply circuit, a driving device and a power conversion apparatus. The power supply circuit comprises a first buck conversion circuit, a secondary winding and a first bootstrap circuit, wherein the input end of the first buck conversion circuit is used for being connected with a direct-current power supply, the direct-current output end of the first buck conversion circuit is connected with the input end of the first bootstrap circuit, the first bootstrap circuit is used for supplying power to a driving circuit corresponding to a floating switch tube in a first bridge arm circuit, the direct-current output end of the first buck conversion circuit is also used for supplying power to a driving circuit corresponding to a grounding switch tube in the first bridge arm circuit, an inductive element in the first buck conversion circuit is used as a primary winding corresponding to the secondary winding, and the secondary winding is used for supplying power to driving circuits corresponding to all switch tubes in an alternating-current side conversion circuit in the power conversion circuit. The power conversion equipment with smaller volume can be realized by adopting the power supply circuit.

Inventors

• ZHOU JIANJIAN
• ZHANG ZHAO
• MENG HUI
• WANG JUN

Assignees

• 上海摩瓦新能源科技有限公司

Dates

Publication Date

20260508

Application Date

20250922

Claims (18)

1. 1. A power supply circuit is characterized in that the power supply circuit is used for supplying power to a driving circuit corresponding to each switching tube in a power conversion circuit, the power conversion circuit comprises a first bridge arm circuit at a direct current side, the power supply circuit comprises a first buck conversion circuit, a secondary winding and a first bootstrap circuit, The input end of the first buck conversion circuit is used for being connected with a direct current power supply, and the direct current output end of the first buck conversion circuit is connected with the input end of the first bootstrap circuit; The first bootstrap circuit is used for supplying power to a driving circuit corresponding to a floating switch tube in the first bridge arm circuit; the direct current output end of the first buck conversion circuit is also used for supplying power to a driving circuit corresponding to a grounding switch tube in the first bridge arm circuit; the inductive element in the first buck conversion circuit is used as a primary winding corresponding to the secondary winding, and the secondary winding is used for supplying power to a driving circuit corresponding to each switching tube in the alternating current side conversion circuit in the power conversion circuit.
2. 2. The power supply circuit of claim 1, wherein the dc side of the power conversion circuit further comprises a second leg circuit, the power supply circuit further comprising a second bootstrap circuit, wherein, The direct current output end of the first buck conversion circuit is also connected with the input end of the second bootstrap circuit; the second bootstrap circuit is used for supplying power to a driving circuit corresponding to a floating switch tube in the second bridge arm circuit; The direct current output end of the first buck conversion circuit is also used for supplying power to a driving circuit corresponding to the grounding switch tube in the second bridge arm circuit.
3. 3. The power supply circuit according to any one of claims 1-2, wherein the power conversion circuit comprises a third bridge arm circuit on the ac side, the third bridge arm circuit being connected to an ac side winding in the power conversion circuit for converting ac current and pulsating current corresponding to the ac side winding; the secondary winding comprises a first secondary winding and a second secondary winding, the power supply circuit further comprises a first voltage stabilizing circuit and a second voltage stabilizing circuit, wherein, The first voltage stabilizing circuit is connected with the first secondary winding and is used for supplying power to a driving circuit corresponding to a floating switch tube in the third bridge arm circuit; The second voltage stabilizing circuit is connected with the second secondary winding and is used for supplying power to a driving circuit corresponding to the grounding switch tube in the third bridge arm circuit.
4. 4. The power supply circuit of claim 3, wherein the power conversion circuit further comprises a fourth bridge arm circuit on the ac side, the fourth bridge arm circuit and the third bridge arm circuit forming a second full bridge circuit on the ac side of the power conversion circuit, the second full bridge circuit being configured to convert ac current and ripple current corresponding to the windings on the ac side; The secondary winding further comprises a third secondary winding, the power supply circuit further comprises a third voltage stabilizing circuit, wherein, The third voltage stabilizing circuit is connected with the third secondary winding and is used for supplying power to a driving circuit corresponding to the floating switch tube in the fourth bridge arm circuit; the second voltage stabilizing circuit is also used for supplying power to a driving circuit corresponding to the grounding switch tube in the fourth bridge arm circuit.
5. 5. The power supply circuit of claim 4, wherein the output terminal of the first voltage stabilizing circuit and the output terminal of the third voltage stabilizing circuit each comprise a positive voltage output terminal, a negative voltage output terminal and a floating ground output terminal; the output end of the second voltage stabilizing circuit comprises a positive voltage output end, a negative voltage output end and a grounding output end.
6. 6. The power supply circuit of claim 5, wherein the first voltage regulator circuit, the third voltage regulator circuit, and the second voltage regulator circuit employ the same circuit topology comprising a first resistor, a second resistor, a first diode, a second diode, a first capacitor, a second capacitor, and a third capacitor, wherein, The first end of the first resistor is connected with the first end of the corresponding secondary winding, the second end of the first resistor is connected with the positive electrode of the first diode, and the negative electrode of the first diode is used as a positive voltage output end of the circuit topological structure; The first end of the first capacitor, the first end of the second capacitor and the first end of the second resistor are all connected to the cathode of the first diode; The second end of the first capacitor is connected with the second end of the corresponding secondary winding; the second end of the second capacitor is connected with the first end of the third capacitor, and the second end of the third capacitor is connected with the second end of the first capacitor; the second end of the second resistor is connected with the second end of the second capacitor and the cathode of the second diode; The positive electrode of the second diode is connected with the second end of the third capacitor, and the second diode is a voltage clamping diode; the positive electrode of the second diode is used as a negative voltage output end of the circuit topological structure, and the negative electrode of the second diode is used as a grounding output end or a floating output end of the circuit topological structure.
7. 7. The power supply circuit of claim 5, wherein the positive voltage output of the first voltage regulator circuit, the positive voltage output of the second voltage regulator circuit, and the positive voltage output of the third voltage regulator circuit range from 15 volts to 20 volts; The output voltage of the negative pressure output end of the first voltage stabilizing circuit, the negative pressure output end of the second voltage stabilizing circuit and the negative pressure output end of the third voltage stabilizing circuit is in a range of-2 volts to-5 volts.
8. 8. The power supply circuit of claim 4, wherein the output of the first voltage regulator circuit and the output of the third voltage regulator circuit each comprise a positive voltage output and a floating ground output; the output end of the second voltage stabilizing circuit comprises a positive voltage output end and a grounding output end.
9. 9. A power supply circuit according to claim 3, wherein the power conversion circuit further comprises a third full-bridge circuit on the ac side for interconversion between pulsating current and grid ac current; The power supply circuit further comprises a third bootstrap circuit and a fourth bootstrap circuit, wherein, The third bootstrap circuit and the fourth bootstrap circuit are respectively used for supplying power to the driving circuits corresponding to the two floating switch tubes in the third full-bridge circuit, and the input end of the third bootstrap circuit and the input end of the fourth bootstrap circuit are both connected to the power supply ends of the driving circuits corresponding to the two grounding switch tubes in the third full-bridge circuit.
10. 10. The power supply circuit of claim 9, wherein the third full-bridge circuit is a power frequency commutation circuit.
11. 11. The power supply circuit of claim 10, wherein the bootstrap capacitance in the third bootstrap circuit and the bootstrap capacitance in the fourth bootstrap circuit are implemented using electrolytic capacitors.
12. 12. The power supply circuit according to claim 9, wherein an input terminal of the third bootstrap circuit and an input terminal of the fourth bootstrap circuit are respectively connected to an output terminal of the second voltage stabilizing circuit; The second voltage stabilizing circuit is also used for supplying power to the driving circuits corresponding to the two grounding switch tubes in the third full-bridge circuit.
13. 13. The power supply circuit of claim 9, wherein a turn-on voltage corresponding to a switching tube in the third full-bridge circuit is smaller than a turn-on voltage corresponding to a switching tube in the third bridge arm circuit, an output terminal of the second voltage stabilizing circuit comprises a positive voltage output terminal, a negative voltage output terminal and a ground output terminal, the power supply circuit further comprises a second buck conversion circuit, and the second buck conversion circuit comprises an input terminal and a positive voltage output terminal; the input end of the second buck conversion circuit is connected to the positive voltage output end and the grounding output end of the second voltage stabilizing circuit; The input end of the third bootstrap circuit and the input end of the fourth bootstrap circuit are respectively connected with the positive voltage output end of the second buck conversion circuit; The second buck conversion circuit is used for supplying power to the driving circuits corresponding to the two grounding switch tubes in the third full-bridge circuit.
14. 14. The power supply circuit of claim 1, wherein the secondary winding is wound from three layers of insulated wire.
15. 15. A driving device, characterized in that the driving device comprises: the driving circuits are respectively used for driving the switching tubes in the power conversion circuit to work; A power supply circuit as claimed in any one of claims 1 to 13, connected to each of said drive circuits for supplying power to each of said drive circuits.
16. 16. A power conversion apparatus, the power conversion apparatus comprising: the power conversion circuit further comprises a first bridge arm circuit at the direct current side; The drive device of claim 15.
17. 17. The power conversion device according to claim 16, characterized in that the power conversion circuit comprises a third leg circuit of an ac side, the third leg circuit being connected to an ac side winding in the power conversion device for mutual conversion between ac current and pulsating current corresponding to the ac side winding; and each switching tube in the third bridge arm circuit is a silicon carbide switching tube or a silicon switching tube.
18. 18. The power conversion apparatus according to claim 17, wherein in an operation mode, the two switching tubes of the first bridge arm circuit are conducted in high frequency complementation, and a value range of a driving duty ratio of each switching tube in the first bridge arm circuit is 40% to 50%; The switching tubes in the third bridge arm circuit are conducted in a high-frequency complementary mode, and the value range of the driving duty ratio of each switching tube in the third bridge arm circuit is 40-50%; the value range of the outward phase angle between the first bridge arm circuit and the third bridge arm circuit is-90 degrees to 90 degrees.

Description

Power supply circuit, driving device and power conversion apparatus Technical Field The present application relates to the field of power conversion technologies, and in particular, to a power supply circuit, a driving device, and a power conversion apparatus. Background The power conversion device generally comprises a plurality of active conversion circuits, wherein each switching tube in each active conversion circuit needs an independent driving circuit to provide driving voltage, wherein the positions of the emitters or the sources of the switching tubes are different, and the types of the switching tubes are not identical, so that the driving voltages of the switching tubes are not identical. In the related art, an isolated power supply mode is adopted to supply power to each driving circuit, so that more windings isolated from each other are needed to be used for secondary windings of a transformer in the power supply circuit, the transformer core in the power supply circuit needs a larger surface area, the transformer is larger, and further the power conversion equipment is larger. Disclosure of Invention In view of the foregoing, it is desirable to provide a power supply circuit, a driving device, and a power conversion apparatus that can reduce the size of the power conversion apparatus. In a first aspect, a power supply circuit is provided for supplying power to a driving circuit corresponding to each switching tube in a power conversion circuit, where the power conversion circuit includes a first bridge arm circuit on a dc side. The power supply circuit comprises a first buck conversion circuit, a secondary winding and a first bootstrap circuit, wherein, The input end of the first buck conversion circuit is used for being connected with a direct current power supply, and the direct current output end of the first buck conversion circuit is connected with the input end of the first bootstrap circuit; the first bootstrap circuit is used for supplying power to a driving circuit corresponding to the floating switch tube in the first bridge arm circuit; The direct current output end of the first buck conversion circuit is also used for supplying power to a driving circuit corresponding to a grounding switch tube in the first bridge arm circuit; the inductive element in the first buck conversion circuit is used as a primary winding corresponding to a secondary winding, and the secondary winding is used for supplying power to a driving circuit corresponding to each switching tube in the alternating current side conversion circuit in the power conversion circuit. In one embodiment, the dc side of the power conversion circuit further comprises a second leg circuit, the power supply circuit further comprises a second bootstrap circuit, wherein, The direct current output end of the first buck conversion circuit is also connected with the input end of the second bootstrap circuit; the second bootstrap circuit is used for supplying power to a driving circuit corresponding to the floating switch tube in the second bridge arm circuit; the direct current output end of the first buck conversion circuit is also used for supplying power to a driving circuit corresponding to the grounding switch tube in the second bridge arm circuit. In one embodiment, the power conversion circuit comprises a third bridge arm circuit on the alternating current side, and the third bridge arm circuit is connected to an alternating current side winding in the power conversion circuit and used for converting alternating current and pulsating current corresponding to the alternating current side winding; The secondary winding comprises a first secondary winding and a second secondary winding, the power supply circuit further comprises a first voltage stabilizing circuit and a second voltage stabilizing circuit, wherein, The first voltage stabilizing circuit is connected with the first secondary winding and is used for supplying power to a driving circuit corresponding to the floating switch tube in the third bridge arm circuit; the second voltage stabilizing circuit is connected with the second secondary winding and is used for supplying power to a driving circuit corresponding to the grounding switch tube in the third bridge arm circuit. In one embodiment, the power conversion circuit further includes a fourth bridge arm circuit on the ac side, where the fourth bridge arm circuit and the third bridge arm circuit form a second full bridge circuit on the ac side of the power conversion circuit, and the second full bridge circuit is used for converting ac current and pulsating current corresponding to the winding on the ac side; the secondary winding further comprises a third secondary winding, the supply circuit further comprises a third voltage stabilizing circuit, wherein, The third voltage stabilizing circuit is connected with the third secondary winding and is used for supplying power to a driving circuit corresponding to the floatin