Self-charging current-limited ac solid state circuit breaker

Abstract

The application relates to a self-charging current-limiting alternating-current solid-state circuit breaker, belonging to the technical field of circuit breakers, which comprises a forced commutation branch for injecting reverse current into a current-carrying branch or a current-limiting branch when a short-circuit fault occurs; an energy consumption branch for consuming current when the current of the current-carrying branch or the current-limiting branch drops to a safe shutdown range; and a self-charging branch for charging a capacitor in the forced commutation branch. The self-charging current-limiting alternating-current solid-state circuit breaker provided by the application can inject reverse current into the current-carrying branch or the current-limiting branch through the forced commutation branch when a short-circuit fault occurs, and can consume current through the energy consumption branch when the current of the current-carrying branch or the current-limiting branch drops to a safe shutdown range, so that the short-circuit fault breaking process is completed, the short-circuit shutdown capacity of the solid-state switch can be improved, the number of semiconductor devices in parallel connection can be reduced, and the breaking capacity is improved while the cost of the solid-state circuit breaker is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to a self-charging current-limiting AC solid-state circuit breaker. Background Art

[0002] Traditional circuit breakers are usually mechanical, consisting of moving contacts, static contacts and an actuating mechanism. The circuit is interrupted by separating the moving and static contacts to form a gap. However, circuit breakers with this structure usually have a long actuation time (in milliseconds), and the breaking process is accompanied by the generation of arcs, causing problems such as contact wear, accelerating equipment aging, and reducing mechanical life.

[0003] In recent years, the widespread use of power electronic devices has promoted the development of solid-state circuit breakers. Compared with traditional mechanical circuit breakers, solid-state circuit breakers are smaller, have faster breaking speeds, and experience arc-free operation, offering significant advantages in the medium and low voltage applications. However, due to the limited capacity of fully controlled devices such as insulated-gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs), improvements in the shutoff capability of solid-state circuit breakers are significantly limited. Furthermore, when multiple devices are connected in parallel to enhance the shutoff capability of solid-state circuit breakers, problems such as dynamic current imbalance and gate oscillation can occur, further limiting the device's shutoff capability in solid-state switching applications. Summary of the Invention

[0004] In view of this, it is necessary to provide a self-charging current-limiting AC solid-state circuit breaker to solve the problem of insufficient shutoff capability of existing solid-state switches.

[0005] In order to solve the above problems, the present invention provides a self-charging current-limiting AC solid-state circuit breaker, comprising:

[0006] Current-passing branch, forced commutation branch, self-charging branch, current-limiting branch and energy-consuming branch;

[0007] The forced commutation branch is used to inject reverse current into the current-passing branch or the current-limiting branch when a short-circuit fault occurs;

[0008] The energy consumption branch is used to consume the current when the current of the current-passing branch or the current-limiting branch drops to a safe shutdown range;

[0009] The self-charging branch is used to charge the capacitor in the forced commutation branch.

[0010] In a possible implementation, the flow branch includes:

[0011] a first diode, a second diode, a third diode, a fourth diode, and a first semiconductor switch;

[0012] The first diode is connected to the fourth diode via the first semiconductor switch;

[0013] The second diode is connected to the third diode via the first semiconductor switch;

[0014] The forced commutation branch, the self-charging branch, the current limiting branch, and the energy consumption branch are respectively connected in parallel with the first semiconductor switch.

[0015] In a possible implementation, the forced commutation branch includes:

[0016] The capacitor and the second semiconductor switch are connected in sequence.

[0017] In a possible implementation, the current limiting branch includes:

[0018] A first inductor and a third semiconductor switch are connected in sequence.

[0019] In one possible implementation, the self-charging branch includes:

[0020] The current limiting branch, the second inductor and the fifth diode;

[0021] The second inductor is connected to the fifth diode.

[0022] In a possible implementation, the energy consumption branch includes:

[0023] a metal oxide surge arrester, the first inductor, the second inductor, a resistor, and a fourth semiconductor switch;

[0024] The resistor is connected to the fourth semiconductor switch.

[0025] In a possible implementation, the first semiconductor switch, the second semiconductor switch, the third semiconductor switch, and the fourth semiconductor switch are all fully-controlled semiconductor switches with low conduction losses.

[0026] In a possible implementation manner, the first inductor and the second inductor are mutually coupled inductors.

[0027] In a possible implementation, when a short-circuit fault occurs, the second semiconductor switch is turned on, and the forced commutation branch injects a reverse current into the pass branch;

[0028] When the current in the conduction branch drops to a safe shutdown range, the first semiconductor switch is turned off to allow the current to dissipate in the energy consumption circuit.

[0029] In a possible implementation, when a short circuit fault occurs, the first semiconductor switch is turned off, the second semiconductor switch is turned on, the third semiconductor switch is turned on, and the forced commutation branch injects a reverse current into the current limiting branch;

[0030] When the current of the current limiting branch drops to a safe shutdown range, the third semiconductor switch is turned off, so that the current is dissipated in the energy consumption circuit.

[0031] The beneficial effects of the present invention are as follows: the self-charging current-limiting AC solid-state circuit breaker provided by the present invention includes a flow branch, a forced commutation branch, a self-charging branch, a current limiting branch and an energy consumption branch. When a short circuit fault occurs, the forced commutation branch can inject a reverse current into the flow branch or the current limiting branch, and when the current in the flow branch or the current limiting branch drops to a safe shutdown range, the current of the flow branch or the current limiting branch is consumed by the energy consumption branch. As the energy stored in the system is continuously dissipated, the current gradually drops to zero, completing the short circuit fault breaking process, and charging the capacitor in the forced commutation branch through the self-charging branch. The capacitor does not require an external circuit to charge it. The reverse current is injected by the capacitor to reduce the size of the current turned off by the semiconductor switch, which can achieve an improvement in the short-circuit shutdown capability of the solid-state switch, reduce the number of semiconductor devices in parallel, and reduce the cost of the solid-state circuit breaker while increasing the breaking capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A schematic structural diagram of an embodiment of a self-charging current-limiting AC solid-state circuit breaker provided by the present invention;

[0034] Figure 2 This is a schematic diagram of the breaking process of the circuit breaker provided by the present invention when it is generally shut down;

[0035] Figure 3 The second schematic diagram of the breaking process of the circuit breaker provided by the present invention during general shutdown;

[0036] Figure 4 The third schematic diagram of the breaking process of the circuit breaker provided by the present invention during general shutdown;

[0037] Figure 5 This is a schematic diagram of the breaking process of the circuit breaker provided by the present invention during current limiting shutdown;

[0038] Figure 6 The second schematic diagram of the breaking process of the circuit breaker provided by the present invention during current limiting shutdown;

[0039] Figure 7 The third schematic diagram of the breaking process of the circuit breaker provided by the present invention during current limiting shutdown;

[0040] Figure 8 This is a schematic diagram of the self-charging process of the circuit breaker capacitor provided by the present invention;

[0041] Figure 9 This is the second schematic diagram of the circuit breaker capacitor self-charging process provided by the present invention. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] In the description of the embodiments of the present invention, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0044] The terms "first," "second," and so on, used in the embodiments of the present invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, technical features designated as "first" or "second" may explicitly or implicitly include at least one such feature.

[0045] Figure 1 A structural diagram of an embodiment of a self-charging current-limiting AC solid-state circuit breaker provided by the present invention is shown in FIG. Figure 1 As shown, the self-charging current limiting AC solid-state circuit breaker includes:

[0046] Current-passing branch, forced commutation branch, self-charging branch, current-limiting branch and energy-consuming branch;

[0047] The forced commutation branch is used to inject reverse current into the current-passing branch or the current-limiting branch when a short-circuit fault occurs;

[0048] The energy consumption branch is used to consume the current when the current of the current-passing branch or the current-limiting branch drops to a safe shutdown range;

[0049] The self-charging branch is used for charging the capacitor in the forced commutation branch.

[0050] Compared with the prior art, the self-charging current-limiting AC solid-state circuit breaker provided by the embodiment of the application comprises a through-flow branch, a forced commutation branch, a self-charging branch, a current-limiting branch and an energy consumption branch. When a short-circuit fault occurs, the forced commutation branch can inject a reverse current into the through-flow branch or the current-limiting branch, and when the current of the through-flow branch or the current-limiting branch drops to a safe shutdown range, the energy consumption branch is used for consuming the current of the through-flow branch or the current-limiting branch. With the continuous dissipation of the system stored energy, the current gradually drops to zero, and the breaking process of the short-circuit fault is completed. The capacitor in the forced commutation branch is charged by the self-charging branch, and the capacitor does not need to be charged by an external circuit. The reverse current is injected by using the capacitor, so that the size of the current to be shut down by the semiconductor switch can be reduced, the short-circuit breaking capacity of the solid-state switch can be improved, the number of parallel semiconductor devices can be reduced, and the cost of the solid-state circuit breaker can be reduced while the breaking capacity is improved.

[0051] In some embodiments of the application, the through-flow branch comprises:

[0052] a first diode, a second diode, a third diode, a fourth diode and a first semiconductor switch;

[0053] The first diode is connected through the first semiconductor switch and the fourth diode;

[0054] The second diode is connected through the first semiconductor switch and the third diode;

[0055] The forced commutation branch, the self-charging branch, the current-limiting branch and the energy consumption branch are connected in parallel with the first semiconductor switch.

[0056] As shown in Figure 1 , the through-flow branch comprises a first diode D1, a second diode D2, a third diode D3, a fourth diode D4 and a first semiconductor switch S main .

[0057] The first diode D1 is connected through the first semiconductor switch S main and the fourth diode D4, and the second diode D2 is connected through the first semiconductor switch S main and the third diode D3.

[0058] When the system is normally through-flowing, the first semiconductor switch S main is kept in a triggered state, the positive half-cycle current of the alternating current source flows through the first diode D1, the first semiconductor switch S main and the fourth diode D4, and the negative half-cycle current flows through the second diode D2, the first semiconductor switch S mainand a third diode D3.

[0059] D1, D4 and D2, D3 are turned on alternately to maintain normal working current, at which time no current flows through other branches.

[0060] In some embodiments of the present application, the forced commutation branch comprises:

[0061] a capacitor and a second semiconductor switch connected in sequence.

[0062] As shown in Figure 1 , the forced commutation branch comprises a capacitor C and a second semiconductor switch S commutation . The forced commutation branch can inject a reverse current to the current-carrying branch and the current-limiting branch by using the commutation capacitor C.

[0063] The self-charging current-limiting AC solid-state circuit breaker provided by the embodiments of the present application can inject a reverse current to the semiconductor switch by using the commutation capacitor, so as to reduce the size of the current to be turned off by the semiconductor switch, and can improve the short-circuit turn-off capability of the solid-state switch, reduce the number of semiconductor devices in parallel, and reduce the cost of the solid-state circuit breaker while improving the breaking capacity.

[0064] In some embodiments of the present application, the current-limiting branch comprises:

[0065] a first inductor and a third semiconductor switch connected in sequence.

[0066] As shown in Figure 1 , the current-limiting branch comprises a first inductor N1 and a third semiconductor switch S charge . The first inductor N1 can limit the short-circuit fault current rise rate.

[0067] The self-charging current-limiting AC solid-state circuit breaker provided by the embodiments of the present application can break the rated current, limit the fault current rise rate by using the first inductor N1, improve the breaking capability of the semiconductor switch device by using the forced commutation branch, and break the short-circuit fault.

[0068] In some embodiments of the present application, the self-charging branch comprises:

[0069] the current-limiting branch, a second inductor and a fifth diode;

[0070] The second inductor and the fifth diode are connected.

[0071] In some embodiments of the present application, the first inductor and the second inductor are mutually coupled inductors.

[0072] As shown in Figure 1 , the self-charging branch comprises a current-limiting branch (a first inductor N1 and a third semiconductor switch S charge), the second inductor N2 and the fifth diode D5.

[0073] The first inductor N1 and the second inductor N2 are mutually coupled inductors. The first inductor N1 induces a current in the second inductor N2 to charge the capacitor C. The fifth diode D5 can prevent the capacitor C from injecting a reverse current into the second inductor N2.

[0074] When the capacitor C needs to be charged, the first semiconductor switch S is controlled at the same time. main Turn off, the third semiconductor switch S charge After a certain period of time, the first semiconductor switch S is controlled at the same time. main Open, the third semiconductor switch S charge If the first inductor N1 is turned off, a current can be induced in the second inductor N2 to charge the commutation capacitor C.

[0075] In the self-charging current-limiting AC solid-state circuit breaker provided in an embodiment of the present invention, capacitor C does not require an external circuit to charge it, but can draw energy from the circuit for self-charging. The commutation capacitor is then used to inject a reverse current into the semiconductor switch to reduce the magnitude of the current turned off by the semiconductor switch. This can improve the short-circuit shutdown capability of the solid-state switch, reduce the number of semiconductor devices connected in parallel, and reduce the cost of the solid-state circuit breaker while increasing the breaking capacity.

[0076] In some embodiments of the present invention, the energy consumption branch includes:

[0077] a metal oxide surge arrester, the first inductor, the second inductor, a resistor, and a fourth semiconductor switch;

[0078] The resistor is connected to the fourth semiconductor switch.

[0079] like Figure 1 As shown, the energy consumption branch includes a metal oxide surge arrester MOV, a first inductor N1, a second inductor N2, a resistor R and a fourth semiconductor switch S dissipation .

[0080] Resistor R and fourth semiconductor switch S dissipation Connect the metal oxide arrester MOV and the first semiconductor switch S main Connect in parallel.

[0081] When the current limiting branch is used for current limiting shutdown, the second inductor N2 and the fourth semiconductor switch S dissipation The loop formed by the resistor R can dissipate some energy.

[0082] The self-charging current-limiting AC solid-state circuit breaker provided in an embodiment of the present invention consumes the current of the current-carrying branch or the current-limiting branch through an energy-consuming branch. As the system's stored energy is continuously dissipated, the current gradually drops to zero, completing the short-circuit fault breaking process.

[0083] In some embodiments of the present invention, the first semiconductor switch, the second semiconductor switch, the third semiconductor switch, and the fourth semiconductor switch are all fully controllable semiconductor switches with low conduction loss.

[0084] The first semiconductor switch S main , the second semiconductor switch S commutation , the third semiconductor switch S charge and the fourth semiconductor switch S dissipation Both are fully controlled semiconductor switches with low conduction losses.

[0085] A fully controlled semiconductor switch is a semiconductor device whose conduction and cutoff can be completely controlled by a control signal. It has the characteristics of low conduction loss. In the on state, it can conduct current with low energy loss, thereby improving circuit efficiency and reducing energy consumption.

[0086] The first semiconductor switch, the second semiconductor switch, the third semiconductor switch, and the fourth semiconductor switch may be MOSFETs, IGBTs, or bipolar junction transistors (BJTs).

[0087] MOSFETs are typically used in low- and medium-voltage applications, offering fast switching speeds and low on-resistance. IGBTs are suitable for high-voltage and high-current applications, combining the high input impedance of MOSFETs with the low saturation voltage drop of BJTs. BJTs are often used in applications requiring high current amplification and low cost.

[0088] Because the first, second, third, and fourth semiconductor switches are all fully controllable semiconductor switches with low conduction losses, the flow of current in the circuit can be effectively controlled, enabling precise management of the circuit state. Furthermore, their low conduction loss characteristics help improve the energy efficiency of the entire system and reduce unnecessary heat generation.

[0089] In some embodiments of the present invention, when a short circuit fault occurs, the second semiconductor switch is turned on, and the forced commutation branch injects a reverse current into the pass branch;

[0090] When the current in the conduction branch drops to a safe shutdown range, the first semiconductor switch is turned off to allow the current to dissipate in the energy consumption circuit.

[0091] When a short circuit fault occurs in the system, the self-charging current-limiting AC solid-state circuit breaker provided by the present invention has two shutoff modes, namely general shutoff and current-limiting shutoff.

[0092] The general shutdown is as follows:

[0093] When a short circuit fault occurs, the second semiconductor switch S is controlled commutation is turned on, the capacitor C in the commutation branch is forced to turn on the first semiconductor switch S main The reverse current is injected into the current-carrying branch where it is located.

[0094] S main When the current of the branch (current-carrying branch) drops to the safe shutdown range, the first semiconductor switch S is controlled main When the short circuit is turned off, the current is transferred to the metal oxide surge arrester (MOV) in the energy consumption circuit for dissipation. As the energy stored in the system is continuously dissipated, the current gradually drops to zero, and the entire short circuit fault interruption process ends.

[0095] The self-charging current-limiting AC solid-state circuit breaker provided in the embodiment of the present invention can interrupt the rated current, utilize the forced commutation branch to improve the interruption capacity of the semiconductor switch device, and interrupt the short-circuit fault.

[0096] In some embodiments of the present invention, when a short circuit fault occurs, the first semiconductor switch is turned off, the second semiconductor switch is turned on, the third semiconductor switch is turned on, and the forced commutation branch injects a reverse current into the current limiting branch;

[0097] When the current of the current limiting branch drops to a safe shutdown range, the third semiconductor switch is turned off, so that the current is dissipated in the energy consumption circuit.

[0098] The current limit shutdown is as follows:

[0099] When a short circuit fault occurs, the first semiconductor switch S is controlled at the same time main Turn off and control the second semiconductor switch S commutation and the third semiconductor switch S charge is turned on, then the main current flows through the third semiconductor switch S charge .

[0100] The capacitor C in the forced commutation branch is connected to the third semiconductor switch S charge The current limiting branch injects reverse current, S charge When the current of the branch (current limiting shutdown branch) drops to the safe shutdown range, the third semiconductor switch S is controlled charge When turned off, the current is diverted to the energy dissipation circuit for dissipation.

[0101] Among them, part of the current is induced to N2 and the fourth semiconductor switch S through the coupled inductors N1 and N2.dissipation The current dissipates in the circuit with resistor R, and the other part is transferred to the metal oxide surge arrester (MOV) for dissipation. As the energy stored in the system is continuously dissipated, the current gradually drops to zero, and the entire short-circuit fault interruption process ends.

[0102] The self-charging current-limiting AC solid-state circuit breaker provided in an embodiment of the present invention can interrupt the rated current, use coupled inductance to limit the short-circuit fault current rise rate, and use forced commutation branches to improve the breaking capacity of semiconductor switching devices to interrupt short-circuit faults.

[0103] For example, Figure 2 This is one of the schematic diagrams of the breaking process of the circuit breaker provided by the present invention when it is generally shut down. Figure 3 This is the second schematic diagram of the breaking process of the circuit breaker provided by the present invention when it is generally shut down. Figure 4 The third schematic diagram of the breaking process of the circuit breaker provided by the present invention is generally shut down. Figures 2 to 4 The breaking process of the circuit breaker provided by the present invention when generally shutting down is described in detail.

[0104] like Figure 2 As shown, in the normal flow state of the system, the positive half-wave current of the AC power source flows through the first diode D1, the first semiconductor switch Smain and the fourth diode D4.

[0105] like Figure 3 As shown, after a short circuit fault is detected, the second semiconductor switch Scommutation is turned on, and the capacitor C injects a reverse current into the conduction branch where the first semiconductor switch Smain is located. When the current of the Smain branch (main branch) drops to a safe shutdown range, the first semiconductor switch Smain is controlled to be turned off.

[0106] like Figure 4 As shown, when the turn-off overvoltage at both ends of the first semiconductor switch Smain reaches the varistor of the metal oxide surge arrester MOV in the energy consumption branch, the metal oxide surge arrester MOV is actuated and the current is rapidly transferred to the energy consumption branch. As the stored energy of the system is continuously dissipated, the current gradually drops to zero, and the entire short-circuit fault interruption process ends.

[0107] For example, Figure 5 This is one of the schematic diagrams of the breaking process of the circuit breaker provided by the present invention when the circuit breaker is closed by current limiting. Figure 6 This is the second schematic diagram of the breaking process of the circuit breaker provided by the present invention when the circuit breaker is closed by current limiting. Figure 7 The third schematic diagram of the breaking process of the circuit breaker provided by the present invention when the current is limited and shut down, Figures 5 to 7 The breaking process of the circuit breaker provided by the present invention during current limiting shutdown is described in detail.

[0108] like Figure 5As shown, in the normal flow state of the system, the positive half-wave current of the AC power source flows through the first diode D1, the first semiconductor switch Smain and the fourth diode D4.

[0109] like Figure 6 As shown, after a short circuit fault is detected, the first semiconductor switch Smain is turned off, the second semiconductor switch Scommutation and the third semiconductor switch Scharge are turned on, and the capacitor C injects a reverse current into the third semiconductor switch Scharge branch. When the current of the third semiconductor switch Scharge branch (current limiting shutdown branch) drops to a safe shutdown range, the third semiconductor switch Scharge is controlled to be turned off.

[0110] like Figure 7 As shown, when the shutdown overvoltage across the first semiconductor switch Smain reaches the voltage-sensitive voltage of the metal oxide surge arrester (MOV) in the energy-dissipating branch, the MOV activates, rapidly transferring current to the energy-dissipating branch. After the third semiconductor switch Scharge turns off, a portion of the energy is dissipated through the coupled inductor N1N2, which induces the second inductor N2, the fourth semiconductor switch Sdissipation, and the resistor R. As the system's stored energy is continuously dissipated, the current gradually decreases to zero, completing the short-circuit fault interruption process.

[0111] For example, Figure 8 This is one of the schematic diagrams of the circuit breaker capacitor self-charging process provided by the present invention. Figure 9 This is the second schematic diagram of the circuit breaker capacitor self-charging process provided by the present invention. Figures 8 and 9 The self-charging process of the circuit breaker capacitor provided by the present invention is described in detail.

[0112] like Figure 8 As shown, in the normal flow state of the system, the first semiconductor switch Smain is turned off and the third semiconductor switch Scharge is turned on at the same time, and the positive half-wave current of the AC power supply flows through the first diode D1, the first inductor N1, the third semiconductor switch Scharge and the fourth diode D4.

[0113] like Figure 9 As shown, when sufficient energy is stored in the first inductor N1, the first semiconductor switch Smain is turned on and the third semiconductor switch Scharge is turned off. Then, a current is induced in the second inductor N2 through the first inductor N1 to charge the commutation capacitor C. The system returns to a normal current flow state.

[0114] That is, the present invention proposes a solution for improving the short-circuit shutdown capability of a solid-state switch by utilizing self-charging capacitor commutation. The capacitor does not require an external circuit to charge it, and can draw energy from the circuit for self-charging. The commutation capacitor is used to inject a reverse current into the semiconductor switch to reduce the magnitude of the current turned off by the semiconductor switch. This can improve the short-circuit shutdown capability of the solid-state switch, reduce the number of semiconductor devices connected in parallel, and reduce the cost of the solid-state circuit breaker while increasing the breaking capacity.

[0115] The above is a detailed introduction to the self-charging current-limiting AC solid-state circuit breaker provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the self-charging current-limiting AC solid-state circuit breaker of the present invention and its core idea; at the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A self-charging current-limiting AC solid-state circuit breaker, characterized in that: include: Current-passing branch, forced commutation branch, self-charging branch, current-limiting branch and energy-consuming branch; The forced commutation branch is used to inject reverse current into the current-passing branch or the current-limiting branch when a short-circuit fault occurs; The energy consumption branch is used to consume the current when the current of the current-passing branch or the current-limiting branch drops to a safe shutdown range; The self-charging branch is used to charge the capacitor in the forced commutation branch; The through-flow branch comprises: a first diode, a second diode, a third diode, a fourth diode, and a first semiconductor switch; The cathodes of the first diode and the second diode are connected, and the anodes of the third diode and the fourth diode are connected; The branch consisting of the first diode and the second diode is connected in parallel with the branch consisting of the third diode and the fourth diode; The connection node of the first diode and the second diode and the connection node of the third diode and the fourth diode are connected to the first semiconductor switch; the forced commutation branch, the self-charging branch, the current limiting branch, and the energy consumption branch are respectively connected in parallel with the first semiconductor switch; The forced commutation branch comprises: a capacitor and a second semiconductor switch connected in sequence; The current limiting branch includes: a first inductor and a third semiconductor switch connected in sequence; The self-charging branch includes: The current limiting branch, the second inductor and the fifth diode; The second inductor and the fifth diode are connected in parallel across the capacitor; The energy consumption branch includes: a metal oxide surge arrester, the first inductor, the second inductor, a resistor, and a fourth semiconductor switch; The resistor and the fourth semiconductor switch are connected in parallel at both ends of the second inductor; The metal oxide surge arrester and the first semiconductor switch are connected in parallel.

2. The self-charging current-limiting AC solid-state circuit breaker according to claim 1, characterized in that: The first semiconductor switch, the second semiconductor switch, the third semiconductor switch, and the fourth semiconductor switch are all fully controllable semiconductor switches with low conduction loss.

3. The self-charging current-limiting AC solid-state circuit breaker according to claim 2, characterized in that: The first inductor and the second inductor are mutually coupled inductors.

4. The self-charging current-limiting AC solid-state circuit breaker according to claim 3, characterized in that: When a short circuit fault occurs, the second semiconductor switch is turned on, and the forced commutation branch injects a reverse current into the pass branch; When the current in the conduction branch drops to a safe shutdown range, the first semiconductor switch is turned off to allow the current to be dissipated in the energy consumption branch.

5. The self-charging current-limiting AC solid-state circuit breaker according to claim 3, characterized in that: When a short circuit fault occurs, the first semiconductor switch is turned off, the second semiconductor switch is turned on, the third semiconductor switch is turned on, and the forced commutation branch injects a reverse current into the current limiting branch; When the current of the current limiting branch drops to a safe shutdown range, the third semiconductor switch is turned off, so that the current is dissipated in the energy consumption branch.

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