Power supply circuit with double auxiliary power supplies, energy storage converter and energy storage system

Abstract

The utility model relates to the energy storage technology, and provides a double-auxiliary-power-supply power supply circuit for an energy storage converter, the energy storage converter and an energy storage system. The circuit comprises a DC auxiliary power supply loop, an AC auxiliary power supply loop and an MCU. The direct-current auxiliary power supply loop comprises a direct-current input port, a direct-current auxiliary power supply, a first direct-current output port and a first switch, the alternating-current auxiliary power supply loop comprises an alternating-current input port, an alternating-current auxiliary power supply, a second direct-current output port and a second switch, and the first direct-current output port and the second direct-current output port are standby for each other and are used alternately. The control end of the first switch and the control end of the second switch are both connected to the MCU. According to the invention, the high operation reliability of the weak current system of the energy storage converter is ensured, and the loss and waste of the weak current system are reduced.

Description

Technical Field

[0001] The present application relates to energy storage technology, and in particular to a dual auxiliary power supply circuit for an energy storage converter, an energy storage converter, and an energy storage system. Background Art

[0002] The PCS energy storage converter (Power Conversion System) is a core device in the energy storage system, which is responsible for realizing the energy conversion and bidirectional flow between the energy storage battery and the power grid. Simply put, the PCS can be regarded as a "bridge" connecting the energy storage battery and the power grid to ensure the efficient and stable operation of the energy storage system.

[0003] Currently, all PCSs adopt a dual auxiliary power supply scheme, that is, a DC auxiliary power supply that takes power from the DC side and an AC auxiliary power supply that takes power from the AC side. The two auxiliary power supplies output DC weak electricity at the same time, and the diodes are used in a butting manner at the junction point of the power supply circuit. The DC weak electricity can provide power for DC devices such as the rear-end fan, sampling circuit, relay, IGBT, and LED display.

[0004] This scheme can ensure that when there is no power on the AC side, it can be powered on from the DC side (battery power supply) to establish off-grid operation; it can also be powered on from the AC side (grid power supply) when there is no power on the DC side to establish the DC bus voltage. Configuring the two auxiliary power supplies at the same time can achieve higher operation reliability. However, since the two auxiliary power supplies supply power at the same time, it will also increase the loss and waste of the weak electricity circuit. Summary of the Utility Model

[0005] The present application provides a dual auxiliary power supply circuit for an energy storage converter, an energy storage converter, and an energy storage system, which reduces the loss and waste of the weak electricity system while ensuring the high operation reliability of the weak electricity system of the energy storage converter.

[0006] The present application provides a dual auxiliary power supply circuit, which includes a DC auxiliary power supply circuit, an AC auxiliary power supply circuit, and a micro control unit MCU;

[0007] The DC auxiliary power supply circuit includes a DC input port, a DC auxiliary power supply, a first DC output port, and a first switch, wherein the first switch is connected between the DC input port and the DC auxiliary power supply;

[0008] The AC auxiliary power supply circuit includes an AC input port, an AC auxiliary power supply, a second DC output port, and a second switch, wherein the second switch is arranged between the AC input port and the AC auxiliary power supply or in the AC auxiliary power supply;

[0009] The DC input port is adapted to be connected to a DC power supply, the AC input port is adapted to be connected to an AC power supply, the first DC output port and the second DC output port are backup to each other, and the control ends of the first switch and the second switch are both connected to the MCU.

[0010] In some embodiments of the present application, both the first switch and the second switch are normally closed switches.

[0011] In some embodiments of the present application, the AC auxiliary power supply includes a rectifier bridge;

[0012] The second switch is connected between the AC input port and the rectifying input end of the rectifier bridge.

[0013] In some embodiments of the present application, the second switch is a normally closed AC relay.

[0014] In some embodiments of the present application, the AC input port is a three-phase AC input port, and one of the second switches is connected between each phase of the AC input port and the corresponding phase rectifying input end of the rectifier bridge.

[0015] In some embodiments of the present application, the AC auxiliary power supply includes a rectifier bridge, and the second switch is arranged at the rectifying output end of the rectifier bridge.

[0016] In some embodiments of the present application, the second switch is a normally closed DC relay, IGBT or MOSFET.

[0017] In some embodiments of the present application, at least one of the first switch and / or the second switch is a relay, the electromagnetic circuit of the relay includes a triode, the control end of the triode is connected to the MCU, and the electromagnetic circuit is powered by the first DC output port and / or the second DC output port.

[0018] In some embodiments of the present application, a first voltage sampler is arranged at the first DC output port, the first voltage sampler is used to sample the voltage of the first DC output port, and the output end of the first voltage sampler is connected to the MCU; and / or,

[0019] A second voltage sampler is arranged at the second DC output port, the second voltage sampler is used to sample the voltage of the second DC output port, and the output end of the second voltage sampler is connected to the MCU.

[0020] The present application also provides an energy storage converter, and the energy storage converter has the dual auxiliary power supply circuit as described in any one of the above.

[0021] The present application also provides an energy storage system, which includes the energy storage converter as described above.

[0022] In the dual auxiliary power supply circuit for the energy storage converter provided by the embodiment of the present application, a first switch is arranged in the DC auxiliary power supply circuit, and a second switch is arranged in the AC auxiliary power supply circuit. The control ends of the first switch and the second switch are both connected to the MCU. Thus, the MCU can control the on / off of the first switch and the second switch according to the operating conditions. For example, one of them can be made conductive while the other is made non-conductive. In this way, the DC auxiliary power supply circuit and the AC auxiliary power supply circuit can be used as backups for each other and alternately used to provide reliable power supply for the weak current system of the energy storage converter. And since only one of the power supply circuits can be made conductive at the same time, the power loss is reduced. At the same time, it can also avoid making each auxiliary power supply operate continuously for a long time, thereby prolonging its service life.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0025] Figure 1 is a schematic diagram of a dual auxiliary power supply circuit provided by an embodiment of the present application;

[0026] Figure 2 is an exemplary schematic diagram of a DC auxiliary power supply circuit provided by an embodiment of the present application;

[0027] Figure 3 is an exemplary schematic diagram of the first switch provided by an embodiment of the present application;

[0028] Figure 4 is a first exemplary schematic diagram of an AC auxiliary power supply circuit provided by an embodiment of the present application;

[0029] Figures 5 - 7 is an exemplary schematic diagram of the second switch being a three-phase AC relay provided by an embodiment of the present application;

[0030] Figure 8 is a second exemplary schematic diagram of an AC auxiliary power supply circuit provided by an embodiment of the present application;

[0031] Figure 9 is an exemplary schematic diagram of the second switch being a DC relay provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To make the objectives, technical solutions, and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0033] The terms used in the embodiments of the present disclosure are only for explaining the embodiments of the present disclosure and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used herein should have the ordinary meaning understood by those of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", "third", and similar terms used in the specification and claims of the present patent application do not denote any order, quantity, or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0034] Figure 1 is a schematic diagram of a dual auxiliary power supply circuit provided by an embodiment of the present application. Refer to Figure 1 , the dual auxiliary power supply circuit includes a DC auxiliary power supply circuit 1, an AC auxiliary power supply circuit 2, and a microcontroller unit (MCU) 3. In Figure 1 , the DC auxiliary power supply circuit 1 is shown above the AC auxiliary power supply circuit 2, which is only an example and does not represent the actual layout.

[0035] The DC auxiliary power supply circuit 1 includes a DC input port 11, a DC auxiliary power supply 12, a first DC output port 13, and a first switch 14, where the first switch 14 is connected between the DC input port 11 and the DC auxiliary power supply 12. Thus, when the first switch 14 is closed, the DC auxiliary power supply circuit 1 is turned on for power supply, and when the first switch 14 is opened, the DC auxiliary power supply circuit 1 is turned off to stop power supply.

[0036] The AC auxiliary power supply circuit 2 includes an AC input port 21, an AC auxiliary power supply 22, a second DC output port 23, and a second switch 24. The second switch 24 is provided between the AC input port 21 and the AC auxiliary power supply, or the second switch 24 can be provided in the AC auxiliary power supply. These two cases will be described separately below. Thus, when the second switch 24 is closed, the AC auxiliary power supply circuit 2 is turned on for power supply, and when the second switch 24 is opened, the AC auxiliary power supply circuit 2 is turned off to stop power supply.

[0037] The DC input port 11 is adapted to be connected to a DC power supply, and the AC input port 21 is adapted to be connected to an AC power supply. The DC power supply is, for example, a battery pack or a DC bus of an energy storage converter, and the AC power supply is, for example, a power grid to which the energy storage converter is connected. The DC auxiliary power supply 12 performs DC-DC conversion, and the AC auxiliary power supply 22 performs AC-DC conversion, and both can output voltages at multiple different levels.

[0038] The first DC output port 13 and the second DC output port 23 are backup to each other. That is to say, both the first DC output port 13 and the second DC output port 23 are connected to the same DC power supply output component or the same DC low-voltage device, so that as long as one of them supplies power, the needs of the low-voltage system of the energy storage converter can be met.

[0039] The control end of the first switch 14 and the control end of the second switch 24 are both connected to the MCU 3. The micro control unit MCU, also known as a single-chip microcomputer, is a widely used control device and can be controlled according to a set program. Thus, the MCU 3 can control the on / off of the first switch 14 and the second switch 24 according to the operating conditions and requirements, and further control the on / off of the DC auxiliary power supply circuit 1 and the AC auxiliary power supply circuit 2.

[0040] In the dual auxiliary power supply circuit provided by the embodiment of the present application, a first switch is provided in the DC auxiliary power supply circuit, and a second switch is provided in the AC auxiliary power supply circuit. The control end of the first switch and the control end of the second switch are both connected to the MCU. Thus, the MCU can control the on / off of the first switch and the second switch according to the operating conditions, for example, making one of them conduct and the other disconnect. In this way, the DC auxiliary power supply circuit and the AC auxiliary power supply circuit can be backup to each other and alternately used, providing reliable power supply for the low-voltage system of the energy storage converter. And since only one of the power supply circuits can be conducted at the same time, the power loss is reduced, and at the same time, it can also avoid making each auxiliary power supply operate continuously for a long time, extending its service life.

[0041] In some embodiments of the present application, both the first switch 14 and the second switch 24 are normally closed switches. When no external force or activation signal is applied, the normally closed switch is in the closed state and current can flow through. When an external force or activation signal is applied, the normally closed switch is in the open state, interrupting the current flow. That is to say, without active control, the first switch 14 and the second switch 24 are closed under normal conditions, thus avoiding the situation where it cannot start by itself after a short power outage.

[0042] Continue to refer to Figure 1, in the DC auxiliary power supply circuit 1, a first voltage sampler 15 is provided at the first DC output port 13. The first voltage sampler 15 is used to sample the voltage of the first DC output port 13, and the output end of the first voltage sampler 15 is connected to the MCU 3. Thus, the MCU 3 can immediately know the voltage condition of the first DC output port 13, and further can judge whether there is an operation fault in the DC auxiliary power supply circuit 1 according to the voltage condition of the first DC output port 13. When there is an operation fault, a conduction signal can be output to the control end of the second switch 24 to make it conduct, and then a disconnection signal can be output to the control end of the first switch 14 to make it disconnect.

[0043] Meanwhile, in the AC auxiliary power supply circuit 2, a second voltage sampler 25 is provided at the second DC output port 23. The second voltage sampler 25 is used to sample the voltage of the second DC output port 23, and the output end of the second voltage sampler 25 is connected to the MCU 3. Thus, the MCU 3 can immediately know the voltage condition of the second DC output port 23, and further can judge whether there is an operation fault in the AC auxiliary power supply circuit 3 according to the voltage condition of the second DC output port 23. When there is an operation fault, a conduction signal can be output to the control end of the first switch 14 to make it conduct, and then a disconnection signal can be output to the control end of the second switch 24 to make it disconnect.

[0044] Through the above settings, active switching can be performed after a problem occurs in any one of the dual-power supply circuits, further improving the operation continuity and reliability. The first voltage sampler 15 and the second voltage sampler 25 can both be voltage transformers, for example. The first voltage sampler 15 and the second voltage sampler 25 can exist simultaneously, or only one of them can be used. For example, a voltage sampler is set on the circuit with low reliability and not set on the circuit with high reliability.

[0045] Next, refer to Figures 2 - 3 to introduce an exemplary embodiment of the DC auxiliary power supply circuit 1.

[0046] As Figure 2 shown, the positive pole of the DC input port is connected to the positive pole BAT+ of the battery and the positive pole BUS+ of the DC bus, while the negative pole of the DC input port is connected to the negative pole BAT- of the battery and the negative pole BUS- of the DC bus, whereby DC input can be obtained. The DC auxiliary power supply 12 has multiple outputs, that is, the first DC output port actually includes n ports, which are respectively connected to each voltage interface VCC1…VCCn and the ground interface GND, so as to supply power to weak-current devices with different voltage specifications. The weak-current devices are, for example, MCU, fan, sampling circuit, relay, etc. The first switch 11 can be a normally closed DC relay, which is connected between the positive pole of the DC input port and the DC auxiliary power supply 12. It should be understood that for simplicity, Figure 2The control connection lines from the first switch 11 and the first voltage sampler 15 to the MCU 3 are omitted.

[0047] Figure 3 An example of the first switch 14 is shown. In this example, the first switch 14 is a normally-closed DC relay, and the electromagnetic circuit of the relay includes a triode (or transistor) N1, and the control terminal of the triode N1 is connected to the MCU 3. The electromagnetic circuit is connected to the voltage interface VCC1 or other voltage interfaces, and each voltage interface is connected to at least one of the first DC output port 13 and the second DC output port 23, so that the electromagnetic circuit can be powered by the first DC output port 13 and / or the second DC output port 23.

[0048] When the DC auxiliary power supply 12 needs to output power, the MCU 3 controls the triode N1 not to conduct, so that no current passes through the electromagnetic circuit of the relay, the electromagnet does not generate a magnetic field, and the first switch 14 remains closed, and the DC auxiliary power supply 12 continuously outputs power; when it is necessary to cut off the DC auxiliary power supply 12, the MCU 3 controls the triode N1 to conduct, the electromagnetic circuit generates current, the electromagnet of the relay generates a magnetic field, and the moving contact of the first switch 14 is magnetically attracted to disconnect from the static contact, so that the first switch 14 opens and the DC auxiliary power supply 12 stops outputting power.

[0049] The following refers to Figures 4 - 7 Describe an exemplary embodiment of the AC auxiliary power supply circuit 2.

[0050] As Figure 4 shown, the AC input port 21 is divided into three-phase AC ports GriD-R, GriD-S, and GriD-T, which are respectively powered by one of the three phases of the power grid. The AC auxiliary power supply 22 includes a rectifier bridge Z2 and a cascaded DC source J2. The rectifier bridge Z2 rectifies the alternating current into direct current, and then outputs the direct current through multiple ports of the cascaded DC source J2. Each phase of the AC input port is connected to the rectifier bridge Z2, and the rectifier bridge Z2 is then connected to the cascaded DC source J2. The second switch includes three AC switches in this example, namely the first AC switch K2, the second AC switch K3, and the third AC switch K4, which are respectively arranged between each phase of the AC input port GriD-R, GriD-S, and GriD-T and the rectifying input terminal of the rectifier bridge Z2, that is to say, the second switch is connected between the AC input port 21 and the rectifying input terminal of the rectifier bridge Z2. In this example, each AC switch of the second switch can be a normally-closed AC relay. The second DC output port may include n ports, which are respectively connected to each voltage interface VCC1...VCCn and the ground interface GND, so as to supply power to weak-current devices with different voltage specifications. The weak-current devices are, for example, MCU, fan, sampling circuit, and relay, etc. It should be understood that for simplicity, Figure 4The control connection lines of each AC switch and the second voltage sampler 25 to the MCU 3 are omitted.

[0051] Figure 5 An example of the first AC switch K2 is shown. In this example, the first AC switch K2 is a normally closed AC relay, and the electromagnetic circuit of the relay includes a triode (or transistor) N2, and the control end of the triode N2 is connected to the MCU 3. The electromagnetic circuit is connected to the voltage interface VCC1 or other voltage interfaces, and each voltage interface is connected to at least one of the first DC output port 13 and the second DC output port 23, so that the electromagnetic circuit can be powered by the first DC output port 13 and / or the second DC output port 23. Figure 6 、 7 Examples of the second AC switch K3 and the third AC switch K4 are respectively shown. Their structures can be the same as or similar to that of the first AC switch K2, and they are also normally closed AC relays. The electromagnetic circuits of the relays respectively include triodes N3 and N4.

[0052] When the AC auxiliary power supply 22 needs to output power, the MCU 3 controls the triodes N2, N3, and N4 to be non-conductive. Therefore, no current passes through the electromagnetic circuits of the relays, and no magnetic field is generated by the electromagnets of the relays. The first AC switch K2, the second AC switch K3, and the third AC switch K4 are all in the closed state, and the AC auxiliary power supply 22 continuously outputs power; when it is necessary to cut off the AC auxiliary power supply 22, the MCU 3 controls the triodes N2, N3, and N4 to be conductive, currents are generated in each electromagnetic circuit, and magnetic fields are generated by each electromagnet, so as to magnetically attract the moving contacts of the first AC switch K2, the second AC switch K3, and the third AC switch K4 to disconnect from the corresponding static contacts. Therefore, the first AC switch K2, the second AC switch K3, and the third AC switch K4 are all opened, and the AC auxiliary power supply 22 stops outputting power.

[0053] Next, refer to Figures 8 - 9 to introduce another exemplary embodiment of the AC auxiliary power supply circuit 2.

[0054] As Figure 8As shown, in this embodiment, the AC input port 21 is also divided into three-phase AC ports GriD-R, GriD-S, and GriD-T, which are respectively powered by one of the three phases of the power grid. The AC auxiliary power supply 22 includes a rectifier bridge Z2 and a cascaded DC source J2. The rectifier bridge Z2 rectifies the alternating current into direct current, and then outputs the direct current through multiple ports of the cascaded DC source J2. Each phase of the AC input port is connected to the rectifier bridge Z2, and the rectifier bridge Z2 is then connected to the cascaded DC source J2. The second switch includes a DC switch K5 in this example, which is arranged at the rectified output end of the rectifier bridge Z2. That is to say, the rectified output end of the rectifier bridge Z2 is connected to the cascaded DC source J2 through the DC switch K5. In this example, the second switch can be a normally closed DC relay, or other switching devices suitable as DC switches such as IGBT (Insulate-Gate Bipolar Transistor) or MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET). The second DC output port can include n ports, which are respectively connected to each voltage interface VCC1…VCCn and the ground interface GND, so as to supply power to weak-current devices with different voltage specifications. The weak-current devices are, for example, MCU, fan, sampling circuit, and relay, etc. Figure 8 The control connection lines from the DC switch K5 and the second voltage sampler 25 to the MCU3 are omitted in the figure.

[0055] Figure 9 An example of the DC switch K5 is shown. In this example, the DC switch K5 is a normally closed DC relay, and the electromagnetic circuit of the relay includes a triode (or called transistor) N5. The control end of the triode N5 is connected to the MCU3. The electromagnetic circuit is connected to the voltage interface VCC1 or other voltage interfaces, and each voltage interface is connected to at least one of the first DC output port 13 and the second DC output port 23. Therefore, the electromagnetic circuit can be powered by the first DC output port 13 and / or the second DC output port 23.

[0056] When it is necessary for the AC auxiliary power supply 22 to output power, the MCU3 controls the triode N5 not to conduct, so the electromagnetic circuit of the relay does not pass current, and the electromagnet of the relay does not generate a magnetic field. The DC switch K5 is in the closed state, and the AC auxiliary power supply 22 continuously outputs power. When it is necessary to cut off the AC auxiliary power supply 22, the MCU3 controls the triode N5 to conduct, the electromagnetic circuit generates current, the electromagnet generates a magnetic field, and the moving contact of the DC switch K5 is attracted by the magnetic force to disconnect from the static contact. Therefore, the DC switch K5 is opened, and the AC auxiliary power supply 22 stops outputting power.

[0057] In the above two embodiments of the AC auxiliary power supply circuit 2, three-phase power supply is adopted, which can balance the power supply of the three-phase lines. In other embodiments, the AC auxiliary power supply 22 can also be powered by two-phase electricity or single-phase electricity. At this time, the second switch 24 can also be connected between the AC input port 21 and the rectifier input end of the rectifier bridge Z2, or between the AC input port 21 and the rectifier input end of the rectifier bridge Z2.

[0058] In the dual auxiliary power supply circuit for the energy storage converter provided in the embodiments of the present application, a first switch is provided in the DC auxiliary power supply circuit, and a second switch is provided in the AC auxiliary power supply circuit. The control ends of the first switch and the second switch are both connected to the MCU. Thus, the MCU can control the on and off of the first switch and the second switch according to the operating conditions. For example, one of them can be turned on while the other is turned off, so that the DC auxiliary power supply circuit and the AC auxiliary power supply circuit can be used alternately as backups according to time periods, providing reliable power supply for the weak current system of the energy storage converter. And since only one of the power supply circuits can be turned on at the same time, the power loss is reduced. At the same time, it can also prevent each auxiliary power supply from running continuously for a long time, prolonging its service life.

[0059] And by respectively arranging voltage samplers at the two DC output ports, the MCU can immediately know the voltage conditions of the two DC output ports, and then can judge whether there are operating faults in the DC auxiliary power supply circuit and the AC auxiliary power supply circuit according to the voltage conditions of the DC output ports. When a circuit has an operating fault, the switch of the other circuit can be turned on while the switch of this circuit is turned off, so as to actively switch after any problem occurs in either circuit of the dual power supply circuit, further improving the continuity and reliability of operation.

[0060] The embodiments of the present application also provide an energy storage converter, which has the dual auxiliary power supply circuit described above. The dual auxiliary power supply circuit can provide direct current for the weak current part of the energy storage converter.

[0061] The embodiments of the present application also provide an energy storage system, which includes the energy storage converter described above.

[0062] Since both the energy storage converter and the energy storage system include the dual auxiliary power supply circuit described above, the power loss can also be reduced, and it can prevent each auxiliary power supply from running continuously for a long time, prolonging its service life. Accordingly, the service lives of the energy storage converter and the energy storage system are improved, and the continuity and reliability of operation can be enhanced.

[0063] The above are only optional embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A dual auxiliary power supply circuit for an energy storage converter, characterized in that, The dual auxiliary power supply circuit includes a DC auxiliary power supply loop (1), an AC auxiliary power supply loop (2), and a microcontroller unit MCU (3); The DC auxiliary power supply loop (1) includes a DC input port (11), a DC auxiliary power supply (12), a first DC output port (13), and a first switch (14), where the first switch (14) is connected between the DC input port (11) and the DC auxiliary power supply (12); The AC auxiliary power supply loop (2) includes an AC input port (21), an AC auxiliary power supply (22), a second DC output port (23), and a second switch (24), where the second switch (24) is provided between the AC input port (21) and the AC auxiliary power supply (22) or in the AC auxiliary power supply (22); The DC input port (11) is adapted to be connected to a DC power supply, the AC input port (21) is adapted to be connected to an AC power supply, the first DC output port (13) and the second DC output port (23) are backup to each other, and the control ends of the first switch (14) and the second switch (24) are both connected to the MCU (3).

2. The dual auxiliary power supply circuit according to claim 1, characterized in that Both the first switch (14) and the second switch (24) are normally closed switches.

3. The dual auxiliary power supply circuit according to claim 1, characterized in that, The AC auxiliary power supply (22) includes a rectifier bridge (Z2); The second switch (24) is connected between the AC input port (21) and the rectifier input end of the rectifier bridge (Z2).

4. The dual auxiliary power supply circuit according to claim 3, characterized in that The second switch (24) is a normally closed AC relay.

5. The dual auxiliary power supply circuit according to claim 3, characterized in that, The AC input port (21) is a three-phase AC input port (GriD-R, GriD-S, GriD-T), and a second switch (24) is connected between each phase AC input port (GriD-R, GriD-S, GriD-T) and the corresponding phase rectifier input end of the rectifier bridge (Z2).

6. The dual auxiliary power supply circuit according to claim 1, wherein, The AC auxiliary power supply (22) includes a rectifier bridge (Z2), and the second switch (24) is provided at the rectifier output end of the rectifier bridge (Z2).

7. The dual auxiliary power supply circuit according to claim 6, characterized in that, The second switch (24) is a normally closed DC relay, IGBT, or MOSFET.

8. The dual auxiliary power supply circuit according to claim 1, wherein, At least one of the first switch (14) and / or the second switch (24) is a relay, and the electromagnetic circuit of the relay includes a triode, the control end of the triode is connected to the MCU (3), and the electromagnetic circuit is powered by the first DC output port (13) and / or the second DC output port (23).

9. The dual auxiliary power supply circuit according to any one of claims 1-8, characterized in that, The first DC output port (13) is provided with a first voltage sampler (15), the first voltage sampler (15) is used to sample the voltage of the first DC output port (13), and the output end of the first voltage sampler (15) is connected to the MCU (3); and / or, The second DC output port (23) is provided with a second voltage sampler (25), the second voltage sampler (25) is used to sample the voltage of the second DC output port (23), and the output end of the second voltage sampler (25) is connected to the MCU (3).

10. A energy storage converter, characterized in that, The energy storage converter has a dual auxiliary power supply circuit according to any one of claims 1-9.

11. An energy storage system, characterized in that, The energy storage system includes an energy storage converter according to claim 10.

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