Power conversion device

Abstract

The utility model provides a power supply conversion device, comprising a first-path first-stage filter circuit used for connecting two terminals of a first power supply end; the second primary filter circuit is used for connecting two terminals of a second power supply end; the first end and the second end of the relay unit are respectively connected with the third end and the fourth end of the first primary filter circuit, and the third end and the fourth end of the relay unit are respectively connected with the third end and the fourth end of the second primary filter circuit; the first end and the second end of the second-stage filter circuit are connected with the fifth end and the sixth end of the relay unit respectively, and the third end and the fourth end of the second-stage filter circuit are used for being connected with a power conversion circuit; the first rectifying and filtering circuit comprises a rectifying unit and a filtering unit which are connected in series, and the first end and the second end of the first rectifying and filtering circuit are connected with the third end and the fourth end of the first primary filtering circuit respectively; and the second rectifying and filtering circuit comprises a rectifying unit and a filtering unit which are connected in series, and the first end and the second end of the second rectifying and filtering circuit are respectively connected with the third end and the fourth end of the second primary filtering circuit.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of power supply, especially a power conversion device. BACKGROUND

[0002] With the development of power supply technology, higher requirements are put forward for the reliability of power conversion devices. In order to avoid the failure of input, the power conversion device with redundancy function is born.

[0003] The power conversion device with redundancy function usually includes a main input and an auxiliary input. When the main input fails, the relay is controlled to switch to the auxiliary input to supply power to the load, thereby improving the reliability of the power conversion device.

[0004] For the power conversion device with redundancy function, higher requirements are also put forward for its electromagnetic compatibility. However, the existing electromagnetic compatibility design has the problems of complex filter circuit and inability to achieve the expected filtering effect. INVENTION CONTENTS

[0005] The application provides a power conversion device, which comprises: a first-stage filter circuit of a first path, a first end and a second end of which are used for connecting two terminals of a first power supply end; a first-stage filter circuit of a second path, a first end and a second end of which are used for connecting two terminals of a second power supply end; a relay unit, a first end and a second end of which are connected to a third end and a fourth end of the first-stage filter circuit of the first path, and a third end and a fourth end of which are connected to a third end and a fourth end of the first-stage filter circuit of the second path; a second-stage filter circuit, a first end and a second end of which are connected to a fifth end and a sixth end of the relay unit, and a third end and a fourth end of which are used for connecting a power conversion circuit; a first rectifier filter circuit, comprising a rectifier unit and a filter unit connected in series, a first end and a second end of which are connected to the third end and the fourth end of the first-stage filter circuit of the first path, and a third end of which is used for connecting a control circuit; and a second rectifier filter circuit, comprising a rectifier unit and a filter unit connected in series, a first end and a second end of which are connected to the third end and the fourth end of the first-stage filter circuit of the second path, and a third end of which is used for connecting the control circuit.

[0006] Further, the application further comprises: a first surge suppression circuit connected between the third end and the fourth end of the first-stage filter circuit of the first path and the first end and the second end of the relay unit; and a second surge suppression circuit connected between the third end and the fourth end of the first-stage filter circuit of the second path and the third end and the fourth end of the relay unit.

[0007] Further, the first-path first-stage filter circuit comprises a first capacitor unit, two ends of the first capacitor unit form the first end and the third end and the second end and the fourth end of the first-path first-stage filter circuit; the second-path first-stage filter circuit comprises a second capacitor unit, two ends of the second capacitor unit form the first end and the third end and the second end and the fourth end of the second-path first-stage filter circuit.

[0008] Further, the first-path first-stage filter circuit further comprises a third capacitor unit and a fourth capacitor unit, the third capacitor unit is used to be connected between the first end of the first-path first-stage filter circuit and a ground end, and the fourth capacitor unit is used to be connected between the second end of the first-path first-stage filter circuit and the ground end; the second-path first-stage filter circuit further comprises a fifth capacitor unit and a sixth capacitor unit, the fifth capacitor unit is used to be connected between the first end of the second-path first-stage filter circuit and a ground end, and the sixth capacitor unit is used to be connected between the second end of the second-path first-stage filter circuit and the ground end.

[0009] Further, the second-stage filter circuit comprises a seventh capacitor unit, a first end of the seventh capacitor unit forms a first end of the second-stage filter circuit, and a second end of the seventh capacitor unit is connected to a ground end; an eighth capacitor unit, a first end of the eighth capacitor unit forms a second end of the second-stage filter circuit, and a second end of the eighth capacitor unit is connected to a ground end; a first common-mode inductor unit, a first end of the first common-mode inductor unit is connected to the first end of the seventh capacitor unit, a second end of the first common-mode inductor unit is connected to the first end of the eighth capacitor unit, a third end and a fourth end of the first common-mode inductor unit form a third end and a fourth end of the second-stage filter circuit respectively; and a ninth capacitor unit, the ninth capacitor unit is connected between the third end and the fourth end of the first common-mode inductor unit.

[0010] Further, the second-stage filter circuit further comprises a tenth capacitor unit, the tenth capacitor unit is connected between the third end of the first common-mode inductor unit and a ground end; an eleventh capacitor unit, the eleventh capacitor unit is connected between the fourth end of the first common-mode inductor unit and a ground end; and a second common-mode inductor unit, a first end of the second common-mode inductor unit is connected to the third end of the first common-mode inductor unit, a second end of the second common-mode inductor unit is connected to the fourth end of the first common-mode inductor unit, and a third end and a fourth end of the second common-mode inductor unit are used to be connected to a power conversion circuit.

[0011] Further, the first rectifying and filtering circuit comprises: a filtering unit comprising: a third common-mode inductor unit, a first end of which forms a first end of the first rectifying and filtering circuit, and a second end of which forms a second end of the first rectifying and filtering circuit; a twelfth capacitor unit connected between a third end of the third common-mode inductor unit and a ground end; and a thirteenth capacitor unit connected between a fourth end of the third common-mode inductor unit and the ground end; and a rectifying unit, input ends of which are connected to the third end and the fourth end of the third common-mode inductor unit respectively, and an output end of which forms a third end of the first rectifying and filtering circuit; and the second rectifying and filtering circuit comprises: a filtering unit comprising: a fourth common-mode inductor unit, a first end of which forms a first end of the second rectifying and filtering circuit, and a second end of which forms a second end of the second rectifying and filtering circuit; a fourteenth capacitor unit connected between a third end of the fourth common-mode inductor unit and a ground end; and a fifteenth capacitor unit connected between a fourth end of the fourth common-mode inductor unit and the ground end; and a rectifying unit, input ends of which are connected to the third end and the fourth end of the fourth common-mode inductor unit respectively, and an output end of which forms a third end of the second rectifying and filtering circuit.

[0012] Further, the first rectifying and filtering circuit comprises: a rectifying unit, a first input end of which forms a first end of the first rectifying and filtering circuit, and a second input end of which forms a second end of the first rectifying and filtering circuit; and a filtering unit comprising: a third common-mode inductor unit, a first end of which is connected to a first output end of the rectifying unit, and a second end of which is connected to a second output end of the rectifying unit; a twelfth capacitor unit connected between a third end of the third common-mode inductor unit and a ground end, the third end of the third common-mode inductor unit also forming a third end of the first rectifying and filtering circuit; and a thirteenth capacitor unit connected between a fourth end of the third common-mode inductor unit and the ground end, the fourth end of the third common-mode inductor unit also forming a fourth end of the first rectifying and filtering circuit; and the second rectifying and filtering circuit comprises: a rectifying unit, a first input end of which forms a first end of the second rectifying and filtering circuit, and a second input end of which forms a second end of the second rectifying and filtering circuit; and a filtering unit comprising: a fourth common-mode inductor unit, a first end of which is connected to a first output end of the rectifying unit, and a second end of which is connected to a second output end of the rectifying unit; a sixteenth capacitor unit connected between a third end of the fourth common-mode inductor unit and a ground end, the third end of the fourth common-mode inductor unit also forming a third end of the second rectifying and filtering circuit; and a seventeenth capacitor unit connected between a fourth end of the fourth common-mode inductor unit and the ground end, the fourth end of the fourth common-mode inductor unit also forming a fourth end of the second rectifying and filtering circuit.

[0013] Further, the first path surge suppression circuit comprises: a first voltage-dependent resistor connected between the third terminal of the first path primary filter circuit and a first terminal of a first switch unit, a second terminal of the first switch unit being grounded; a second voltage-dependent resistor connected between the fourth terminal of the first path primary filter circuit and the first terminal of the first switch unit; and a third voltage-dependent resistor connected between the third terminal and the fourth terminal of the first path primary filter circuit; and the second path surge suppression circuit comprises: a fourth voltage-dependent resistor connected between the third terminal of the second path primary filter circuit and a first terminal of a second switch unit, a second terminal of the second switch unit being grounded; a fifth voltage-dependent resistor connected between the fourth terminal of the second path primary filter circuit and the first terminal of the second switch unit; and a sixth voltage-dependent resistor connected between the third terminal and the fourth terminal of the second path primary filter circuit.

[0014] Further, the power source input to the first power supply terminal is an alternating voltage or a direct voltage; and the power source input to the second power supply terminal is an alternating voltage or a direct voltage. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A schematic diagram of a power conversion device according to an embodiment of the present application.

[0016] Figure 2 A schematic diagram of a power conversion device according to another embodiment of the present application.

[0017] Figure 3 A schematic diagram of a first path primary filter circuit according to an embodiment of the present application.

[0018] Figure 4 A schematic diagram of a first path primary filter circuit according to another embodiment of the present application.

[0019] Figure 5 A schematic diagram of a second path primary filter circuit according to an embodiment of the present application.

[0020] Figure 6 A schematic diagram of a second path primary filter circuit according to another embodiment of the present application.

[0021] Figure 7 A schematic diagram of a first rectifier filter circuit according to an embodiment of the present application.

[0022] Figure 8 A schematic diagram of a first rectifier filter circuit according to another embodiment of the present application.

[0023] Figure 9 A schematic diagram of a first path surge suppression circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts are within the scope of the present application.

[0025] In an embodiment of the present application, a power conversion device is provided, which can be seen from Figure 1 The power conversion device includes

[0026] The first-stage filter circuit 110 has a first end and a second end, and the first end and the second end are respectively connected to two terminals of the first power supply end VA.

[0027] The second-stage filter circuit 120 has a first end and a second end, and the first end and the second end are respectively connected to two terminals of the second power supply end VB.

[0028] The relay unit 200 has a first end and a second end, and the first end and the second end are respectively connected to the third end and the fourth end of the first-stage filter circuit 110; the relay unit 200 has a third end and a fourth end, and the third end and the fourth end are respectively connected to the third end and the fourth end of the second-stage filter circuit 120.

[0029] The second-stage filter circuit 300 has a first end and a second end, and the first end and the second end are respectively connected to the fifth end and the sixth end of the relay unit 200; the second-stage filter circuit 300 has a third end and a fourth end, and the third end and the fourth end are respectively connected to a power conversion circuit 400.

[0030] The first rectifier filter circuit 510 includes a rectifier unit and a filter unit connected in series, and the first rectifier filter circuit 510 has a first end and a second end, and the first end and the second end are respectively connected to the third end and the fourth end of the first-stage filter circuit 110; the first rectifier filter circuit 510 has a third end, and the third end is connected to a control circuit 600.

[0031] The second rectifier filter circuit 520 includes a rectifier unit and a filter circuit connected in series, and the second rectifier filter circuit 520 has a first end and a second end, and the first end and the second end are respectively connected to the third end and the fourth end of the second-stage filter circuit 120; the second rectifier filter circuit 520 has a third end, and the third end is connected to the control circuit 600.

[0032] The control circuit 600 is used for outputting a relay control signal DRV Rc to the relay unit 200, so as to select the first power supply end VA or the second power supply end VB as an input power source by controlling the relay unit 200, thereby realizing the power conversion device with the redundancy function. It can be seen that the first rectifier filter circuit 510 and the second rectifier filter circuit 520 are located on a signal feedback path.

[0033] In actual implementation, the relay unit 200 can be any applicable unit that includes at least one relay. This application does not limit its specific structure, as long as the switching between the first power supply terminal VA and the second power supply terminal VB can be achieved by controlling the relay inside.

[0034] For this application, either the first power supply terminal VA or the second power supply terminal VB can be selected as the main input.

[0035] In actual implementation, the power source input to the first power supply terminal VA and the second power supply terminal VB can be either AC voltage or DC voltage, and this application does not limit it.

[0036] like Figure 1 As shown, filter circuits are arranged at the input ports of the first power supply terminal VA and the second power supply terminal VB. Filter circuits are also arranged after the relay unit 200 and before the power conversion circuit 400. Furthermore, filter circuits are arranged at the input port of the feedback path before the feedback signal enters the control circuit 600. It can be seen that this application arranges filter circuits at the ports of both the power path and the signal path, which greatly improves the EMI performance of the power conversion device.

[0037] For further details, please refer to... Figure 2 The schematic diagram of another embodiment of the power conversion device shown in this application further includes: a first surge suppression circuit 710 and a second surge suppression circuit 720.

[0038] like Figure 2 As shown, the first surge suppression circuit 710 is connected between the third and fourth terminals of the first primary filter circuit 110 and the first and second terminals of the relay unit 200. The second surge suppression circuit 720 is connected between the third and fourth terminals of the second primary filter circuit 120 and the third and fourth terminals of the relay unit 200. This achieves the function of suppressing surge voltage.

[0039] For further details, please refer to... Figure 3 The diagram shown is a schematic of the first-stage filter circuit according to an embodiment of this application. Figure 3 As shown, the first-stage filter circuit 110 includes a first capacitor unit C1. The two ends of the first capacitor unit C1 form the first end and the third end, and the second end and the fourth end of the first-stage filter circuit 110. That is, the first capacitor unit C1 is connected between the first end and the second end of the first-stage filter circuit 110, and is also connected between the third end and the fourth end of the first-stage filter circuit 110.

[0040] Similar to the first-stage filter circuit 110, the second-stage filter circuit 120 also includes a second capacitor unit, two ends of the second capacitor unit form the first end and the third end of the second-stage filter circuit 120 and the second end and the fourth end, that is, the second capacitor unit is connected between the first end and the second end of the second-stage filter circuit 120, and also connected between the third end and the fourth end of the second-stage filter circuit 120. Since the same as Figure 3 The figure of the second-stage filter circuit 120 is omitted here.

[0041] Further, refer to the first-stage filter circuit diagram of another embodiment of the present application shown in Figure 4 As shown in Figure 4 The first-stage filter circuit 110 also includes a third capacitor unit C3 and a fourth capacitor unit C4, the third capacitor unit C3 is used for connecting between the first end and the first ground end GND1 of the first-stage filter circuit 110, and the fourth capacitor unit C4 is used for connecting between the second end and the first ground end GND1 of the first-stage filter circuit 110.

[0042] Similar to the first-stage filter circuit 110, the second-stage filter circuit 120 also includes a fifth capacitor unit and a sixth capacitor unit, the fifth capacitor unit is used for connecting between the first end and the first ground end GND1 of the second-stage filter circuit 120, and the sixth capacitor unit is used for connecting between the second end and the first ground end GND1 of the second-stage filter circuit 120. Since the same as Figure 4 The figure of the second-stage filter circuit 120 is omitted here.

[0043] But the present application also does not limit the first-stage filter circuit 110 and the second-stage filter circuit 120 to be Figure 3 and Figure 4 As shown in

[0044] Further, refer to the second-stage filter circuit diagram of an embodiment of the present application shown in Figure 5 As shown in Figure 5As shown in the figure, the second-stage filter circuit 300 comprises: a seventh capacitor unit C7, a first end of which forms a first end of the second-stage filter circuit 300, and a second end of which is connected to the first ground end GND1; an eighth capacitor unit C8, a first end of which forms a second end of the second-stage filter circuit 300, and a second end of which is connected to the first ground end GND1; a first common-mode inductor unit L1, a first end of which is connected to the first end of the seventh capacitor unit C7, a second end of which is connected to the first end of the eighth capacitor unit C8, and a third end and a fourth end of which form a third end and a fourth end of the second-stage filter circuit 300 respectively; and a ninth capacitor unit C9, which is connected between the third end and the fourth end of the first common-mode inductor unit L1. That is, the seventh capacitor unit C7 is connected between the fifth end of the relay unit 200 and the first ground end GND1; the eighth capacitor unit C8 is connected between the sixth end of the relay unit 200 and the first ground end GND1; the first end of the first common-mode inductor unit L1 is connected to the fifth end of the relay unit 200, and the second end of the first common-mode inductor unit L1 is connected to the sixth end of the relay unit 200; and the ninth capacitor unit C9 is connected between the third end and the fourth end of the first common-mode inductor unit L1. The third end and the fourth end of the first common-mode inductor unit L1 are used to connect the power conversion circuit 400.

[0045] Further, refer to Figure 6 As shown in the figure, the second-stage filter circuit of another embodiment of the present application is shown in the figure. In Figure 5 On the basis of the second-stage filter circuit 300 shown in the figure, the second-stage filter circuit 300 further comprises: a tenth capacitor unit C10, which is connected between the third end of the first common-mode inductor unit L1 and the first ground end GND1; an eleventh capacitor unit C11, which is connected between the fourth end of the first common-mode inductor unit L1 and the first ground end GND1; and a second common-mode inductor unit L2, a first end of which is connected to the third end of the first common-mode inductor unit L1, a second end of which is connected to the fourth end of the first common-mode inductor unit L1, and a third end and a fourth end of which are used to connect the power conversion circuit 400.

[0046] That is, as Figure 6 As shown in the figure, the second-stage filter circuit 300 is a two-stage filter, and the ninth capacitor unit C9 can be shared, which not only improves the filtering effect but also saves the number and size of devices. In actual implementation, the present application does not limit the second-stage filter circuit 300 to be a few-stage filter, for example, it can also be a three-stage filter circuit.

[0047] Further, refer to Figure 7 As shown in the figure, the first rectifier filter circuit of an embodiment of the present application is shown in the figure. As Figure 7As shown, the first rectifier-filter circuit 510 includes: a filter unit 511, comprising: a third common-mode inductor unit L3, whose first end forms the first terminal of the first rectifier-filter circuit 510, and whose second end forms the second terminal of the first rectifier-filter circuit 510; a twelfth capacitor unit C12, connected between the third terminal of the third common-mode inductor unit L3 and the first ground terminal GND1; a thirteenth capacitor unit C13, connected between the fourth terminal of the third common-mode inductor unit L3 and the first ground terminal GND1; and a rectifier unit 512, whose input terminals are respectively connected to the third and fourth terminals of the third common-mode inductor unit L3, and whose output terminal forms the third terminal of the first rectifier-filter circuit 510. That is, the filter unit 511 and the rectifier unit 512 are connected in series to form the first rectifier-filter circuit 510.

[0048] Similar to the first rectifier-filter circuit 510, the second rectifier-filter circuit 520 includes: a filter unit comprising: a fourth common-mode inductor unit, the first end of which forms the first terminal of the second rectifier-filter circuit 520, and the second terminal of which forms the second terminal of the second rectifier-filter circuit 520; a fourteenth capacitor unit connected between the third terminal of the fourth common-mode inductor unit and the first ground terminal GND1; a fifteenth capacitor unit connected between the fourth terminal of the fourth common-mode inductor unit and the first ground terminal GND1; and a rectifier unit, the input terminals of which are respectively connected to the third and fourth terminals of the fourth common-mode inductor unit, and the output terminal of which forms the third terminal of the second rectifier-filter circuit 520. Because of its similarity to... Figure 7 Similarly, the attached diagram of the second-stage filter circuit 120 is omitted here.

[0049] For further details, please refer to... Figure 8 The diagram shows a first rectifier filter circuit according to another embodiment of this application. Figure 8 As shown, the first rectifier-filter circuit 510 includes: a rectifier unit 512, whose first input terminal forms the first terminal of the first rectifier-filter circuit 510, and whose second input terminal forms the second terminal of the first rectifier-filter circuit 510; and a filter unit 511, including: a third common-mode inductor unit L3, whose first terminal is connected to the first output terminal of the rectifier unit 512, and whose second terminal is connected to the second output terminal of the rectifier unit 512; a twelfth capacitor unit C12, connected between the third terminal of the third common-mode inductor unit L3 and the first ground terminal GND1, the third terminal of the third common-mode inductor unit L3 also forming the third terminal of the first rectifier-filter circuit 510; and a thirteenth capacitor unit C13, connected between the fourth terminal of the third common-mode inductor unit L3 and the first ground terminal GND1, the fourth terminal of the third common-mode inductor unit L3 also forming the fourth terminal of the first rectifier-filter circuit 510. That is, the rectifier unit 512 and the filter unit 511 are connected in series to form the first rectifier-filter circuit 510.

[0050] Similar to the first rectifying and filtering circuit 510, the second rectifying and filtering circuit 520 comprises: a rectifying unit 512, a first input end of which forms a first end of the second rectifying and filtering circuit 520, and a second input end of which forms a second end of the second rectifying and filtering circuit 520; a filtering unit 511, comprising: a fourth common-mode inductance unit, a first end of which is connected to a first output end of the rectifying unit 512, and a second end of which is connected to a second output end of the rectifying unit 512; a sixteenth capacitance unit, connected between a third end of the fourth common-mode inductance unit and a first ground end GND1, the third end of the fourth common-mode inductance unit also forming the third end of the second rectifying and filtering circuit; a seventeenth capacitance unit, connected between a fourth end of the fourth common-mode inductance unit and the first ground end GND1, the fourth end of the fourth common-mode inductance unit also forming the fourth end of the second rectifying and filtering circuit. Since the same as Figure 8 the second-stage filter circuit 120 of the second path is omitted here.

[0051] Furthermore, in actual implementation, as shown in Figure 7 and Figure 8 , a resistance unit R is connected between the rectifying unit 512 and the filtering unit 511, so as to control the current size.

[0052] In actual implementation, the rectifying unit 512 can be implemented as a diode full-bridge rectifying unit as shown in Figure 7 and Figure 8 , but the specific structure is not limited in the present application.

[0053] Furthermore, reference can be made to the first surge suppression circuit schematic diagram of an embodiment of the present application as shown in Figure 9 . As shown in Figure 9 , the first surge suppression circuit 710 comprises: a first pressure-sensitive resistor RV1, connected between the third end of the first-stage filter circuit 110 of the first path and the first end of the first switch unit, the second end of the switch unit being grounded; a second pressure-sensitive resistor RV2, connected between the fourth end of the first-stage filter circuit 110 of the first path and the first end of the first switch unit; and a third pressure-sensitive resistor RV3, connected between the third end and the fourth end of the first-stage filter circuit 110 of the first path.

[0054] Similar to the first surge suppression circuit 710, the second surge suppression circuit 720 comprises: a fourth pressure-sensitive resistor, connected between the third end of the second-stage filter circuit 120 of the second path and the first end of the second switch unit, the second end of the second switch unit being grounded; a fifth pressure-sensitive resistor, connected between the fourth end of the second-stage filter circuit 120 of the second path and the first end of the second switch unit; and a sixth pressure-sensitive resistor, connected between the third end and the fourth end of the second-stage filter circuit 120 of the second path. Since the same as Figure 9 , the diagram of the second surge suppression circuit 720 of the second path is omitted here.

[0055] As shown in the figure, the first switch unit is implemented as a thyristor, and the second switch unit is also implemented as a thyristor, but the application is not limited thereto. Figure 9

[0056] In actual implementation, the voltage-dependent resistor can be selected according to actual surge suppression requirements.

[0057] In an embodiment, the first ground terminal GND1 can be embodied as a case.

[0058] In actual implementation, a discharge circuit such as a discharge resistor can be connected in parallel across the first capacitor C1. Similarly, a discharge circuit such as a discharge resistor can also be connected in parallel across the second capacitor unit.

[0059] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.​

Claims

1. A power conversion device, characterized in that, include: The first stage filter circuit has its first and second terminals respectively used to connect to the two terminals of the first power supply terminal. The first and second terminals of the second primary filter circuit are respectively used to connect to the two terminals of the second power supply. The relay unit has its first and second terminals connected to the third and fourth terminals of the first-stage filter circuit, respectively, and its third and fourth terminals connected to the third and fourth terminals of the second-stage filter circuit, respectively. The second-stage filter circuit has its first and second terminals connected to the fifth and sixth terminals of the relay unit, respectively, and its third and fourth terminals used to connect to a power conversion circuit. The first rectifier and filter circuit includes a rectifier unit and a filter unit connected in series. Its first end and second end are respectively connected to the third end and the fourth end of the first-stage filter circuit. Its third end is used to connect to the control circuit. The second rectifier and filter circuit includes a rectifier unit and a filter unit connected in series. Its first and second ends are respectively connected to the third and fourth ends of the second primary filter circuit, and its third end is used to connect to the control circuit.

2. The power conversion device according to claim 1, characterized in that, Also includes: The first surge suppression circuit is connected between the third and fourth terminals of the first-stage filter circuit and the first and second terminals of the relay unit. The second surge suppression circuit is connected between the third and fourth terminals of the second primary filter circuit and the third and fourth terminals of the relay unit.

3. The power conversion device according to claim 1 or 2, characterized in that, The first-stage filter circuit includes a first capacitor unit, and the two ends of the first capacitor unit form the first end and the third end of the first-stage filter circuit, and the second end and the fourth end of the first-stage filter circuit. The second primary filter circuit includes a second capacitor unit, the two ends of which form the first end and the third end of the second primary filter circuit, and the second end and the fourth end.

4. The power conversion device according to claim 3, characterized in that, The first-stage filter circuit further includes a third capacitor unit and a fourth capacitor unit. The third capacitor unit is used to connect between the first terminal of the first-stage filter circuit and the ground terminal, and the fourth capacitor unit is used to connect between the second terminal of the first-stage filter circuit and the ground terminal. The second primary filter circuit further includes a fifth capacitor unit and a sixth capacitor unit. The fifth capacitor unit is used to connect between the first terminal of the second primary filter circuit and the ground terminal, and the sixth capacitor unit is used to connect between the second terminal of the second primary filter circuit and the ground terminal.

5. The power conversion device according to claim 1 or 2, characterized in that, The second-stage filter circuit includes: The seventh capacitor unit has its first end forming the first end of the second-stage filter circuit, and its second end connected to the ground terminal. The eighth capacitor unit has its first end forming the second end of the second-stage filter circuit, and its second end is connected to the ground terminal. The first common-mode inductor unit has its first end connected to the first end of the seventh capacitor unit, its second end connected to the first end of the eighth capacitor unit, and its third and fourth ends forming the third and fourth ends of the second-stage filter circuit, respectively. The ninth capacitor unit is connected between the third and fourth terminals of the first common-mode inductor unit.

6. The power conversion device according to claim 5, characterized in that, The second-stage filter circuit also includes: The tenth capacitor unit is connected between the third terminal of the first common-mode inductor unit and the ground terminal; The eleventh capacitor unit is connected between the fourth terminal of the first common-mode inductor unit and the ground terminal; The second common-mode inductor unit has a first end connected to the third end of the first common-mode inductor unit and a second end connected to the fourth end of the first common-mode inductor unit. The third and fourth ends are used to connect to the power conversion circuit.

7. The power conversion device according to claim 1 or 2, characterized in that, The first rectifier and filter circuit includes: The filtering unit includes: The third common-mode inductor unit has its first end forming the first end of the first rectifier and filter circuit, and its second end forming the second end of the first rectifier and filter circuit. The twelfth capacitor unit is connected between the third terminal of the third common-mode inductor unit and the ground terminal; The thirteenth capacitor unit is connected between the fourth terminal of the third common-mode inductor unit and the ground terminal; The rectifier unit has its input terminals connected to the third and fourth terminals of the third common-mode inductor unit, respectively, and its output terminal forms the third terminal of the first rectifier filter circuit. The second rectifier and filter circuit includes: The filtering unit includes: The fourth common-mode inductor unit has its first end forming the first end of the second rectifier and filter circuit, and its second end forming the second end of the second rectifier and filter circuit. The fourteenth capacitor unit is connected between the third terminal of the fourth common-mode inductor unit and the ground terminal; The fifteenth capacitor unit is connected between the fourth terminal of the fourth common-mode inductor unit and the ground terminal; The rectifier unit has its input terminals connected to the third and fourth terminals of the fourth common-mode inductor unit, respectively, and its output terminal forms the third terminal of the second rectifier filter circuit.

8. The power conversion device according to claim 1 or 2, characterized in that, The first rectifier and filter circuit includes: The rectifier unit has its first input terminal forming the first terminal of the first rectifier and filter circuit, and its second input terminal forming the second terminal of the first rectifier and filter circuit. The filtering unit includes: The third common-mode inductor unit has its first end connected to the first output terminal of the rectifier unit and its second end connected to the second output terminal of the rectifier unit. The twelfth capacitor unit is connected between the third terminal of the third common-mode inductor unit and the ground terminal, and the third terminal of the third common-mode inductor unit also forms the third terminal of the first rectifier filter circuit; The thirteenth capacitor unit is connected between the fourth terminal of the third common-mode inductor unit and the ground terminal. The fourth terminal of the third common-mode inductor unit also forms the fourth terminal of the first rectifier filter circuit. The second rectifier and filter circuit includes: A rectifier unit, wherein its first input terminal forms the first terminal of the second rectifier-filter circuit, and its second input terminal forms the second terminal of the second rectifier-filter circuit; The filtering unit includes: The fourth common-mode inductor unit has its first end connected to the first output terminal of the rectifier unit and its second end connected to the second output terminal of the rectifier unit. The sixteenth capacitor unit is connected between the third terminal of the fourth common-mode inductor unit and the ground terminal, and the third terminal of the fourth common-mode inductor unit also forms the third terminal of the second rectifier filter circuit; The seventeenth capacitor unit is connected between the fourth terminal of the fourth common-mode inductor unit and the ground terminal. The fourth terminal of the fourth common-mode inductor unit also forms the fourth terminal of the second rectifier filter circuit.

9. The power conversion device according to claim 2, characterized in that, The first surge suppression circuit includes: The first varistor is connected between the third terminal of the first primary filter circuit and the first terminal of the first switching unit, and the second terminal of the switching unit is grounded. The second varistor is connected between the fourth terminal of the first-stage filter circuit and the first terminal of the first switching unit. The third varistor is connected between the third and fourth terminals of the first-stage filter circuit. The second surge suppression circuit includes: The fourth varistor is connected between the third terminal of the second primary filter circuit and the first terminal of the second switching unit, and the second terminal of the second switching unit is grounded. The fifth varistor is connected between the fourth terminal of the second primary filter circuit and the first terminal of the second switching unit; The sixth varistor is connected between the third and fourth terminals of the second-stage filter circuit.

10. The power conversion device according to claim 1, characterized in that, The power source input to the first power supply terminal is either AC voltage or DC voltage; The power source input to the second power supply terminal is either AC voltage or DC voltage.

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