Short-circuit protection device of power generation system

Abstract

The utility model discloses a short circuit protection device of a power generation system, which relates to the technical field of power supplies, and comprises a rectifier bridge and a fuse, the rectifier bridge is connected with the power generation system, and the rectifier bridge outputs a direct current power supply through the fuse; the circuit break control circuit comprises a first relay, a first end of a first contactor of the first relay is connected with the direct current power supply, a second end of the first contactor of the first relay is connected with an input end of the inverter, and the first contactor of the first relay is in a normally closed state; the voltage detection circuit is connected with the direct-current power supply, and the control module is respectively connected with the coil end of the first relay and the voltage detection circuit. When the inverter or a circuit at the rear end of the inverter is short-circuited and the voltage is lower than a preset threshold value, the first contactor of the first relay is switched off; meanwhile, when the open circuit control circuit does not take effect, the fuse can be automatically fused, double insurance is achieved, and fault expansion is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply, in particular to a short circuit protection device for a power generation system. Background Art

[0002] In the turbine power generation system, the initial current is output in the form of AC, but its frequency does not meet the power supply requirements and needs to be adjusted. Therefore, the initial AC source needs to be rectified first and then inverted into AC with a frequency that meets the power supply requirements. However, in this process, if a short circuit occurs in the circuit and is not disconnected in time, it is very likely to cause a major safety hazard. The traditional solution uses series-connected fuses and frame circuit breakers to disconnect the fault circuit, but the fuses and frame circuit breakers have a certain delay and cannot be disconnected in time, which further expands the fault. Utility Model Content

[0003] The purpose of the utility model is to provide a short-circuit protection device for a power generation system, which is provided with a circuit breaker control circuit and a voltage detection circuit. When a short circuit occurs in the inverter or the circuit at the rear end of the inverter, causing the voltage to be lower than a preset threshold value, the circuit breaker control circuit controls the rectifier bridge and the inverter to disconnect. At the same time, a fuse is also provided. When the circuit breaker control circuit is ineffective, the fuse can automatically blow. The present application is provided with double insurance, which effectively prevents the expansion of faults.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] One aspect of the utility model provides a short-circuit protection device for a power generation system, the short-circuit protection device comprising: a rectifier bridge and a fuse, the input end of the rectifier bridge receiving the initial AC source output by the power generation system, the positive output end of the rectifier bridge connected to one end of the fuse, the other end of the fuse outputting a DC power supply, and the negative output end of the rectifier bridge serving as a circuit grounding point; a circuit breaker control circuit and an inverter, the circuit breaker control circuit comprising a first relay, the first end of a first contactor of the first relay connected to the DC power supply, the second end of the first contactor of the first relay connected to the input end of the inverter, and the first contactor of the first relay being in a normally closed state; a voltage detection circuit and a control module, the detection input end of the voltage detection circuit connected to the DC power supply, the control module respectively connected to the coil end of the first relay and the detection output end of the voltage detection circuit; when the control module detects through the voltage detection circuit that the voltage is lower than a preset threshold, the control module controls the coil end of the first relay to be energized, and the first contactor of the first relay is converted from a normally closed state to an open state.

[0006] Preferably, the circuit breaker control circuit also includes a second relay, a PNP transistor, a first resistor and a second resistor, the first end of the second contactor of the first relay and the first end of the contactor of the second relay are connected to the DC power supply, the second end of the second contactor of the first relay and the second end of the contactor of the second relay are connected to the first end of the coil end of the first relay, the second end of the coil end of the first relay is connected to one end of the second resistor, the other end of the second resistor is grounded, the first end of the coil end of the second relay is connected to the DC power supply, the second end of the coil end of the second relay is connected to the emitter of the PNP transistor, the base of the PNP transistor is connected to the control module, and the collector of the PNP transistor is grounded through the first resistor.

[0007] Preferably, the circuit breaker control circuit also includes a speaker, a third resistor and a fourth resistor, the positive electrode of the speaker is connected to the other end of the second resistor and one end of the fourth resistor through the third resistor, and the negative electrode of the speaker and the other end of the fourth resistor are grounded.

[0008] Preferably, the circuit breaker control circuit also includes a first diode, a second diode and a third diode, the positive electrode of the first diode is connected to the second end of the coil end of the first relay, the negative electrode of the first diode is connected to the first end of the coil end of the first relay, the positive electrode of the second diode is connected to the second end of the coil end of the second relay, the negative electrode of the second diode is connected to the first end of the coil end of the second relay, the negative electrode of the third diode is connected to the positive electrode of the speaker, and the positive electrode of the third diode is grounded.

[0009] Preferably, the voltage detection circuit includes a comparator, a voltage acquisition circuit and a voltage stabilizing circuit, the voltage acquisition circuit and the voltage stabilizing circuit are both connected to the DC power supply, the non-inverting input end of the comparator is connected to the voltage acquisition circuit, the inverting input end of the comparator is connected to the voltage stabilizing circuit, and the output end of the comparator is connected to the control module.

[0010] Preferably, the voltage acquisition circuit includes a fifth resistor, a sixth resistor and a seventh resistor, one end of the fifth resistor is connected to the non-inverting input terminal of the comparator, the other end of the fifth resistor is connected to one end of the sixth resistor and one end of the seventh resistor, the other end of the sixth resistor is connected to the DC power supply, and the other end of the seventh resistor is grounded.

[0011] Preferably, the voltage stabilizing circuit includes an NPN transistor, a voltage stabilizing diode, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor, one end of the ninth resistor is connected to the DC power supply, the other end of the ninth resistor is connected to the collector of the NPN transistor, one end of the eighth resistor and one end of the tenth resistor, the other end of the eighth resistor is connected to the base of the NPN transistor and the negative electrode of the voltage stabilizing diode, the positive electrode of the voltage stabilizing diode and the other end of the tenth resistor are grounded, the emitter of the NPN transistor is connected to one end of the twelfth resistor and the inverting input terminal of the comparator through the eleventh resistor, and the other end of the twelfth resistor is grounded.

[0012] Preferably, the voltage stabilizing circuit also includes a first capacitor and a second capacitor, the positive electrode of the first capacitor and the positive electrode of the second capacitor are both connected to the collector of the NPN transistor, the negative electrode of the first capacitor and the negative electrode of the second capacitor are both grounded, and the capacitance of the first capacitor is greater than the capacitance of the second capacitor.

[0013] Preferably, the short-circuit protection device also includes a third capacitor and a fourth capacitor, the positive electrode of the third capacitor and the positive electrode of the fourth capacitor are both connected to the DC power supply, the negative electrode of the third capacitor and the negative electrode of the fourth capacitor are both grounded, and the capacitance of the third capacitor is greater than the capacitance of the fourth capacitor.

[0014] Preferably, the short-circuit protection device further includes a first manual switch and a second manual switch, wherein the first manual switch is arranged between the rectifier bridge and the initial AC source, and the second manual switch is arranged between the first contactor of the first relay and the inverter.

[0015] According to a short-circuit protection device for a power generation system of the utility model, at least the following beneficial effects are achieved: the application is provided with a circuit breaker control circuit and a voltage detection circuit. When a short circuit occurs in the inverter or the circuit at the rear end of the inverter, resulting in a voltage lower than a preset threshold, the control module controls the coil end of the first relay to be energized, and the first contactor of the first relay is converted from a normally closed state to an open state, and the rectifier bridge and the inverter are disconnected; at the same time, the application is also provided with a fuse. When the circuit breaker control circuit is ineffective, the fuse can be automatically blown. The application is provided with double insurance, which effectively prevents the expansion of faults. The circuit breaker control circuit of the application is also provided with a speaker. When the voltage is lower than the preset threshold, the speaker works to remind the staff that a short circuit fault occurs and needs to be repaired in time.

[0016] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 4 is a circuit diagram of a short-circuit protection device according to an embodiment. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present disclosure will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0023] The technical solution of the embodiment of the present application is briefly described below:

[0024] According to some embodiments, Figure 1 As shown, the present application provides a short-circuit protection device for a power generation system, the short-circuit protection device comprising:

[0025] Rectifier bridge DB and fuse F, the input end of the rectifier bridge DB receives the initial AC source output by the power generation system, the positive output end of the rectifier bridge DB is connected to one end of the fuse F, the other end of the fuse F outputs a DC power supply, and the negative output end of the rectifier bridge DB serves as a circuit grounding point;

[0026] A circuit breaker control circuit and an inverter, wherein the circuit breaker control circuit comprises a first relay K1, wherein a first end of a first contactor of the first relay K1 is connected to a DC power supply, a second end of the first contactor of the first relay K1 is connected to an input end of the inverter, and the first contactor of the first relay K1 is in a normally closed state;

[0027] The voltage detection circuit and the control module, the detection input end of the voltage detection circuit is connected to the DC power supply, and the control module is respectively connected to the coil end of the first relay K1 and the detection output end of the voltage detection circuit.

[0028] Based on the working principle of the above embodiment, when a short circuit occurs in the inverter or the circuit at the back end of the inverter, the control module detects that the voltage is lower than the preset threshold through the voltage detection circuit. At this time, the control module controls the coil end of the first relay K1 to be energized, and the first contactor of the first relay K1 is converted from a normally closed state to an open state to prevent the short circuit fault of the inverter or the back end of the inverter from expanding. Among them, the preset threshold can be set according to actual needs.

[0029] The present application is provided with a circuit breaker control circuit and a voltage detection circuit. When the inverter or the circuit at the back end of the inverter is short-circuited, causing the voltage to be lower than the preset threshold, the control module controls the coil end of the first relay K1 to be energized, and the first contactor of the first relay K1 is converted from a normally closed state to an open state, and the rectifier bridge DB and the inverter are disconnected; at the same time, the present application is also provided with a fuse F. When the circuit breaker control circuit is ineffective, the fuse F can be automatically blown. The present application is provided with double insurance, which effectively prevents the expansion of faults.

[0030] The following is combined with the appendix of this manual Figure 1 , the preferred implementation modes of the present disclosure are further elaborated in detail.

[0031] According to some embodiments, Figure 1As shown, the circuit breaker control circuit also includes a second relay K2, a PNP transistor QP, a first resistor R1 and a second resistor R2, the first end of the second contactor of the first relay K1 and the first end of the contactor of the second relay K2 are connected to a DC power supply, the second end of the second contactor of the first relay K1 and the second end of the contactor of the second relay K2 are connected to the first end of the coil end of the first relay K1, the second end of the coil end of the first relay K1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is grounded, the first end of the coil end of the second relay K2 is connected to the DC power supply, the second end of the coil end of the second relay K2 is connected to the emitter of the PNP transistor QP, the base of the PNP transistor QP is connected to the control module, and the collector of the PNP transistor QP is grounded through the first resistor R1.

[0032] Based on the working principle of the above embodiment, when a short circuit occurs in the inverter or the circuit at the back end of the inverter, the control module outputs a low-level signal to the base of the PNP transistor QP, the PNP transistor QP is turned on, the coil end of the second relay K2 is energized, and the contactor of the second relay K2 is energized, causing the coil end of the first relay K1 to be energized, and the first contactor of the first relay K1 is converted from a normally closed state to an open state, and the second contactor of the first relay K1 is energized and self-locked, so that the first contactor of the first relay K1 is always in an open state.

[0033] According to some embodiments, Figure 1 As shown, the circuit breaker control circuit also includes a speaker LS, a third resistor R3 and a fourth resistor R4. The positive electrode of the speaker LS is connected to the other end of the second resistor R2 and one end of the fourth resistor R4 through the third resistor R3, and the negative electrode of the speaker LS and the other end of the fourth resistor R4 are grounded.

[0034] Based on the working principle of the above embodiment, when a short circuit occurs in the inverter or the circuit at the back end of the inverter, the PNP transistor QP is turned on, the second relay K2 is energized, the second contactor of the first relay K1 is energized and self-locked, and the speaker LS is energized to issue a short circuit alarm to remind the staff that a short circuit fault occurs and needs to be repaired in time.

[0035] According to some embodiments, Figure 1 As shown, the circuit breaker control circuit also includes a first diode D1, a second diode D2 and a third diode D3, the anode of the first diode D1 is connected to the second end of the coil end of the first relay K1, the cathode of the first diode D1 is connected to the first end of the coil end of the first relay K1, the anode of the second diode D2 is connected to the second end of the coil end of the second relay K2, the cathode of the second diode D2 is connected to the first end of the coil end of the second relay K2, the cathode of the third diode D3 is connected to the anode of the speaker LS, and the anode of the third diode D3 is grounded.

[0036] The first diode D1 is used for continuous current when the coil end of the first relay K1 is powered off, the second diode D2 is used for continuous current when the coil end of the second relay K2 is powered off, and the third diode D3 is used for continuous current when the speaker LS is powered off.

[0037] According to some embodiments, Figure 1 As shown, the voltage detection circuit includes a comparator U, a voltage acquisition circuit and a voltage stabilizing circuit. The voltage acquisition circuit and the voltage stabilizing circuit are both connected to a DC power supply. The non-inverting input terminal of the comparator U is connected to the voltage acquisition circuit, the inverting input terminal of the comparator U is connected to the voltage stabilizing circuit, and the output terminal of the comparator U is connected to the control module.

[0038] Further, such as Figure 1 As shown, the voltage acquisition circuit includes a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7, one end of the fifth resistor R5 is connected to the non-inverting input terminal of the comparator U, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6 and one end of the seventh resistor R7, the other end of the sixth resistor R6 is connected to a DC power supply, and the other end of the seventh resistor R7 is grounded.

[0039] The sixth resistor R6 and the seventh resistor R7 are used for voltage division, and the fifth resistor R5 is used for current limiting.

[0040] According to some embodiments, Figure 1 As shown, the voltage stabilizing circuit includes an NPN transistor QN, a voltage stabilizing diode DZ, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12, one end of the ninth resistor R9 is connected to a DC power supply, the other end of the ninth resistor R9 is connected to the collector of the NPN transistor QN, one end of the eighth resistor R8 and one end of the tenth resistor R10, the other end of the eighth resistor R8 is connected to the base of the NPN transistor QN and the negative electrode of the voltage stabilizing diode DZ, the positive electrode of the voltage stabilizing diode DZ and the other end of the tenth resistor R10 are grounded, the emitter of the NPN transistor QN is connected to one end of the twelfth resistor R12 and the inverting input end of the comparator U through the eleventh resistor R11, and the other end of the twelfth resistor R12 is grounded.

[0041] Further, such as Figure 1 As shown, the voltage stabilizing circuit also includes a first capacitor C1 and a second capacitor C2, the positive electrode of the first capacitor C1 and the positive electrode of the second capacitor C2 are both connected to the collector of the NPN transistor QN, the negative electrode of the first capacitor C1 and the negative electrode of the second capacitor C2 are both grounded, and the capacitance of the first capacitor C1 is greater than the capacitance of the second capacitor C2.

[0042] Based on the working principle of the above embodiment, when a short circuit occurs in the inverter or the circuit at the back end of the inverter, the voltage at the non-inverting input terminal of the comparator U is lower than the voltage at the inverting input terminal of the comparator U, and the comparator U outputs a low level to the control module. When the control module receives the voltage output by the comparator U as a low level, it determines that a short circuit occurs in the circuit, and then controls the PNP transistor QP to turn on.

[0043] According to some embodiments, Figure 1 As shown, the short-circuit protection device also includes a third capacitor C3 and a fourth capacitor C4, the positive electrode of the third capacitor C3 and the positive electrode of the fourth capacitor C4 are both connected to a DC power supply, the negative electrode of the third capacitor C3 and the negative electrode of the fourth capacitor C4 are both grounded, and the capacitance of the third capacitor C3 is greater than the capacitance of the fourth capacitor C4.

[0044] The third capacitor C3 and the fourth capacitor C4 are used for filtering, with a large capacitance at low frequencies and a small capacitance at high frequencies.

[0045] According to some embodiments, Figure 1 As shown, the short-circuit protection device further includes a first manual switch S1 and a second manual switch S2. The first manual switch S1 is arranged between the rectifier bridge DB and the initial AC source, and the second manual switch S2 is arranged between the first contactor of the first relay K1 and the inverter.

[0046] When a short circuit occurs in the inverter or the circuit at the back end of the inverter, the second contactor of the first relay K1 is self-locked, so that the first contactor of the first relay K1 is always in the disconnected state, and the speaker LS is powered and keeps issuing a short circuit alarm. When the staff is inspecting, they first manually turn off the first manual switch S1 and the second manual switch S2. When the first manual switch S1 is turned off, the coil end of the first relay K1 loses power, so that the first contactor of the first relay K1 returns to the normally closed state, the second contactor of the first relay K1 is disconnected, and the speaker LS also stops issuing a short circuit alarm. When the inverter and the circuit at the back end of the inverter are repaired and installed, the first manual switch S1 and the second manual switch S2 are manually closed, and the short circuit protection device resumes normal operation.

[0047] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0048] Although the present disclosure has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present disclosure can be implemented in a variety of forms without departing from the spirit or essence of the present application, it should be understood that the above-mentioned embodiments are not limited to any of the foregoing details, but should be widely interpreted within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A short-circuit protection device for a power generation system, characterized in that: The short circuit protection device comprises: A rectifier bridge and a fuse, wherein the input end of the rectifier bridge receives the initial AC source output by the power generation system, the positive output end of the rectifier bridge is connected to one end of the fuse, the other end of the fuse outputs a DC power supply, and the negative output end of the rectifier bridge serves as a circuit grounding point; A circuit breaker control circuit and an inverter, wherein the circuit breaker control circuit comprises a first relay, wherein a first end of a first contactor of the first relay is connected to the DC power supply, a second end of the first contactor of the first relay is connected to an input end of the inverter, and the first contactor of the first relay is in a normally closed state; A voltage detection circuit and a control module, wherein the detection input end of the voltage detection circuit is connected to the DC power supply, and the control module is respectively connected to the coil end of the first relay and the detection output end of the voltage detection circuit; When the control module detects through the voltage detection circuit that the voltage is lower than a preset threshold, the control module controls the coil end of the first relay to be energized, and the first contactor of the first relay is converted from a normally closed state to an open state.

2. The short circuit protection device according to claim 1, characterized in that: The circuit breaker control circuit also includes a second relay, a PNP transistor, a first resistor and a second resistor, wherein the first end of the second contactor of the first relay and the first end of the contactor of the second relay are connected to the DC power supply, the second end of the second contactor of the first relay and the second end of the contactor of the second relay are connected to the first end of the coil end of the first relay, the second end of the coil end of the first relay is connected to one end of the second resistor, the other end of the second resistor is grounded, the first end of the coil end of the second relay is connected to the DC power supply, the second end of the coil end of the second relay is connected to the emitter of the PNP transistor, the base of the PNP transistor is connected to the control module, and the collector of the PNP transistor is grounded through the first resistor.

3. The short circuit protection device according to claim 2, characterized in that: The circuit breaker control circuit also includes a speaker, a third resistor and a fourth resistor. The positive electrode of the speaker is connected to the other end of the second resistor and one end of the fourth resistor through the third resistor, and the negative electrode of the speaker and the other end of the fourth resistor are grounded.

4. The short circuit protection device according to claim 3, characterized in that: The circuit breaker control circuit also includes a first diode, a second diode and a third diode, the anode of the first diode is connected to the second end of the coil end of the first relay, the cathode of the first diode is connected to the first end of the coil end of the first relay, the anode of the second diode is connected to the second end of the coil end of the second relay, the cathode of the second diode is connected to the first end of the coil end of the second relay, the cathode of the third diode is connected to the anode of the speaker, and the anode of the third diode is grounded.

5. The short circuit protection device according to claim 1, characterized in that: The voltage detection circuit includes a comparator, a voltage acquisition circuit and a voltage stabilizing circuit. The voltage acquisition circuit and the voltage stabilizing circuit are both connected to the DC power supply. The non-inverting input end of the comparator is connected to the voltage acquisition circuit, the inverting input end of the comparator is connected to the voltage stabilizing circuit, and the output end of the comparator is connected to the control module.

6. The short circuit protection device according to claim 5, characterized in that: The voltage acquisition circuit includes a fifth resistor, a sixth resistor and a seventh resistor, one end of the fifth resistor is connected to the non-inverting input terminal of the comparator, the other end of the fifth resistor is connected to one end of the sixth resistor and one end of the seventh resistor, the other end of the sixth resistor is connected to the DC power supply, and the other end of the seventh resistor is grounded.

7. The short circuit protection device according to claim 5, characterized in that: The voltage stabilizing circuit includes an NPN transistor, a voltage stabilizing diode, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor, one end of the ninth resistor is connected to the DC power supply, the other end of the ninth resistor is connected to the collector of the NPN transistor, one end of the eighth resistor and one end of the tenth resistor, the other end of the eighth resistor is connected to the base of the NPN transistor and the negative electrode of the voltage stabilizing diode, the positive electrode of the voltage stabilizing diode and the other end of the tenth resistor are grounded, the emitter of the NPN transistor is connected to one end of the twelfth resistor and the inverting input end of the comparator through the eleventh resistor, and the other end of the twelfth resistor is grounded.

8. The short circuit protection device according to claim 7, characterized in that: The voltage stabilizing circuit also includes a first capacitor and a second capacitor, the positive electrode of the first capacitor and the positive electrode of the second capacitor are both connected to the collector of the NPN transistor, the negative electrode of the first capacitor and the negative electrode of the second capacitor are both grounded, and the capacitance of the first capacitor is greater than the capacitance of the second capacitor.

9. The short circuit protection device according to claim 1, characterized in that: The short-circuit protection device also includes a third capacitor and a fourth capacitor, wherein the positive electrode of the third capacitor and the positive electrode of the fourth capacitor are both connected to the DC power supply, the negative electrode of the third capacitor and the negative electrode of the fourth capacitor are both grounded, and the capacitance of the third capacitor is greater than the capacitance of the fourth capacitor.

10. The short circuit protection device according to claim 1, characterized in that: The short-circuit protection device further includes a first manual switch and a second manual switch, wherein the first manual switch is arranged between the rectifier bridge and the initial AC source, and the second manual switch is arranged between the first contactor of the first relay and the inverter.

Images