A self-limiting hybrid circuit breaker and a control method thereof

Abstract

The application discloses a self-limiting hybrid circuit breaker and a control method thereof, and the circuit breaker comprises an IGBT switch tube, a first voltage detection circuit, a second voltage detection circuit, a thyristor, a reactor and a mechanical switch; the first voltage detection circuit is connected with the mechanical switch, the second voltage detection circuit is connected with the thyristor, and the thyristor is further connected with the reactor; when the system normally works, the thyristor is in a blocking state; when the system fails, the current of the IGBT switch tube rises and works in an active area; when the second voltage detection circuit detects that the voltage of the IGBT switch tube exceeds a second preset voltage threshold, the thyristor is triggered to be turned on, the reactor is put into the system, and the rising of the fault current is inhibited; when the first voltage detection circuit detects that the voltage of the IGBT switch tube exceeds a first preset voltage threshold, the mechanical switch is triggered to act, and the fault current is broken. The application can realize the current limiting of a short-circuit fault and the removal of the fault current without relying on external current detection.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, and in particular to a self-current-limiting hybrid circuit breaker and its control method. Background Technology

[0002] With the increasing grid-connected capacity of new energy power generation year by year, and the continuous expansion of high-voltage direct current transmission due to its ability to more effectively improve the utilization efficiency of renewable energy, short-circuit currents are constantly growing, leading to an increasing demand for circuit breakers with strong breaking capacity. Based on the different components of the breaking section, circuit breakers are mainly divided into three types: mechanical, solid-state, and hybrid. Mechanical circuit breakers have advantages such as large current capacity, stable and noiseless operation, and low loss and heat generation. However, because mechanical circuit breakers have a clear breaking point, they are prone to arcing during the breaking process, requiring time until the inductive energy is completely dissipated before extinguishing. This arcing is even more pronounced when isolating short-circuit faults, resulting in excessively long breaking times and easily damaging the mechanical contacts. This limits their use in applications with high capacity and high breaking requirements. Solid-state circuit breakers offer advantages such as being contactless, arc-free, compact, flexible, controllable, and fast-breaking. However, their extensive use of power electronic switches results in high costs, high conduction losses, and significant heat generation during normal operation, requiring additional cooling measures and limiting their practical application in power systems. Hybrid circuit breakers combine the advantages of both types, effectively integrating ultra-fast mechanical switches with fully controlled power electronic devices to fully leverage their respective strengths in interrupting fault currents. This represents the future development direction for high-voltage circuit breakers.

[0003] However, existing hybrid circuit breakers need to monitor the magnitude of the external circuit current. If there is a problem with the current sampling, the circuit breaker cannot be triggered, resulting in the circuit breaker failing to operate. Moreover, existing hybrid circuit breakers usually do not have current limiting capabilities. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a self-current-limiting hybrid circuit breaker and its control method, which can limit the current of short-circuit faults and cut off the fault current without relying on external current detection.

[0005] To achieve the above objectives, embodiments of the present invention provide a self-current-limiting hybrid circuit breaker, including an IGBT switch, a first voltage detection circuit, a second voltage detection circuit, a thyristor, a reactor, and a mechanical switch;

[0006] The collector of the IGBT switch is connected to the first terminal of the first voltage detection circuit, and the emitter of the IGBT switch is connected to the second terminal of the first voltage detection circuit; the collector of the IGBT switch is also connected to the first terminal of the second voltage detection circuit, and the emitter of the IGBT switch is also connected to the second terminal of the second voltage detection circuit; the mechanical switch is connected to the collector of the IGBT switch.

[0007] The third terminal of the first voltage detection circuit is connected to the mechanical switch, the third terminal of the second voltage detection circuit is connected to the cathode of the thyristor, and the anode of the thyristor is connected to the collector of the IGBT switch. The cathode of the thyristor is also connected to the first terminal of the reactor, and the second terminal of the reactor is connected to the emitter of the IGBT switch.

[0008] When the system is working normally, the thyristor is in the locked state, and the system current flows through the mechanical switch and the IGBT switching transistor;

[0009] When a system fault occurs, the current of the IGBT switch increases, causing the IGBT switch to operate in the active region. When the second voltage detection circuit detects that the voltage of the IGBT switch exceeds a second preset voltage threshold, it triggers the thyristor to conduct, causing the reactor to be connected to the system to suppress the rise of the fault current. When the first voltage detection circuit detects that the voltage of the IGBT switch exceeds a first preset voltage threshold, it triggers the mechanical switch to operate and interrupt the fault current.

[0010] As an improvement to the above scheme, the self-limiting hybrid circuit breaker also includes a diode, which is connected in parallel between the collector and emitter of the IGBT switch to provide a freewheeling circuit for the reactor.

[0011] As an improvement to the above solution, the first voltage detection circuit includes a first comparator;

[0012] The first input terminal of the first comparator is connected to the collector of the IGBT switch, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to the mechanical switch.

[0013] As an improvement to the above solution, the second voltage detection circuit includes a second comparator;

[0014] The first input terminal of the second comparator is connected to the collector of the IGBT switch, the second input terminal of the second comparator is connected to a second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor.

[0015] As an improvement to the above scheme, the first preset voltage threshold is greater than the second preset voltage threshold.

[0016] This invention also provides a control method for a self-current-limiting hybrid circuit breaker. The method is applied to a self-current-limiting hybrid circuit breaker including an IGBT switch, a first voltage detection circuit, a second voltage detection circuit, a thyristor, a reactor, and a mechanical switch. The control method for the self-current-limiting hybrid circuit breaker includes:

[0017] When the system is working normally, the thyristor is in the locked state, and the system current flows through the mechanical switch and the IGBT switching transistor;

[0018] When a system fault occurs, the current of the IGBT switch increases, causing the IGBT switch to operate in the active region. When the second voltage detection circuit detects that the voltage of the IGBT switch exceeds a second preset voltage threshold, it triggers the thyristor to conduct, causing the reactor to be connected to the system to suppress the rise of the fault current. When the first voltage detection circuit detects that the voltage of the IGBT switch exceeds a first preset voltage threshold, it triggers the mechanical switch to operate and interrupt the fault current.

[0019] Furthermore, the self-limiting hybrid circuit breaker also includes a diode connected in parallel between the collector and emitter of the IGBT switch to provide a freewheeling circuit for the reactor.

[0020] Furthermore, the first voltage detection circuit includes a first comparator;

[0021] The first input terminal of the first comparator is connected to the collector of the IGBT switch, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to the mechanical switch.

[0022] Furthermore, the second voltage detection circuit includes a second comparator;

[0023] The first input terminal of the second comparator is connected to the collector of the IGBT switch, the second input terminal of the second comparator is connected to a second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor.

[0024] Furthermore, the first preset voltage threshold is greater than the second preset voltage threshold.

[0025] Compared to existing technologies, the beneficial effects of the self-current-limiting hybrid circuit breaker and its control method provided by this invention are as follows: This invention eliminates the need for external current detection. Utilizing the inherent operating characteristics of the IGBT switch, it exhibits low conduction losses under normal system operation and avoids false triggering when the IGBT switch operates in its normal saturation region. Upon the occurrence of a short-circuit fault, the IGBT switch rapidly enters the active region, causing its voltage to rise quickly. This characteristic can be used as a basis for judging the increase in fault current. The voltage detection circuit can quickly detect the rise in IGBT switch voltage and rapidly trigger the thyristor to conduct, causing the reactor to be engaged in the system and suppressing the increase in fault current. Simultaneously, it triggers the mechanical switch to interrupt the fault current, achieving fault current clearance under low short-circuit current conditions. Attached Figure Description

[0026] Figure 1 This is a circuit topology diagram of a preferred embodiment of a self-current-limiting hybrid circuit breaker provided by the present invention;

[0027] Figure 2 This is a circuit topology diagram of another preferred embodiment of a self-current-limiting hybrid circuit breaker provided by the present invention;

[0028] Figure 3 This is a typical output characteristic diagram of IGBT switch T1 in a self-current-limiting hybrid circuit breaker provided by the present invention;

[0029] Figure 4 This is a typical operating waveform diagram of IGBT switch T1 in a self-current-limiting hybrid circuit breaker provided by the present invention;

[0030] Figure 5 This is a typical operating waveform diagram of reactor L1 in a self-current-limiting hybrid circuit breaker provided by the present invention;

[0031] Figure 6 This is a typical operating waveform diagram of the mechanical switch MC1 in a self-current-limiting hybrid circuit breaker provided by the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figure 1 , Figure 1This is a circuit topology diagram of a preferred embodiment of a self-current-limiting hybrid circuit breaker provided by the present invention. The self-current-limiting hybrid circuit breaker includes an IGBT switch T1, a first voltage detection circuit CC1, a second voltage detection circuit CC2, a thyristor T2, a reactor L1, and a mechanical switch MC1;

[0034] The collector of the IGBT switch T1 is connected to the first terminal of the first voltage detection circuit CC1, and the emitter of the IGBT switch T1 is connected to the second terminal of the first voltage detection circuit CC1; the collector of the IGBT switch T1 is also connected to the first terminal of the second voltage detection circuit CC2, and the emitter of the IGBT switch T1 is also connected to the second terminal of the second voltage detection circuit CC2; the mechanical switch MC1 is connected to the collector of the IGBT switch T1.

[0035] The third terminal of the first voltage detection circuit CC1 is connected to the mechanical switch MC1, the third terminal of the second voltage detection circuit CC2 is connected to the cathode of the thyristor T2, the anode of the thyristor T2 is connected to the collector of the IGBT switch T1, the cathode of the thyristor T2 is also connected to the first terminal of the reactor L1, and the second terminal of the reactor L1 is connected to the emitter of the IGBT switch T1.

[0036] When the system is working normally, the thyristor T2 is in the locked state, and the system current flows through the mechanical switch MC1 and the IGBT switch T1.

[0037] When a system fault occurs, the current of the IGBT switch T1 increases, causing the IGBT switch T1 to operate in the active region. When the second voltage detection circuit CC2 detects that the voltage of the IGBT switch T1 exceeds the second preset voltage threshold, it triggers the thyristor T2 to conduct, causing the reactor L1 to be connected to the system to suppress the rise of the fault current. When the first voltage detection circuit CC1 detects that the voltage of the IGBT switch T1 exceeds the first preset voltage threshold, it triggers the mechanical switch MC1 to operate and interrupt the fault current.

[0038] Specifically, the self-current-limiting hybrid circuit breaker provided in this embodiment of the invention includes an IGBT switch T1, a first voltage detection circuit CC1, a second voltage detection circuit CC2, a thyristor T2, a reactor L1, and a mechanical switch MC1. The IGBT switch T1 carries current under normal conditions and acts as a trigger element for the thyristor T2 and the mechanical switch MC1 during the fault current rise phase. The first voltage detection circuit CC1 detects the voltage across the IGBT switch T1 and automatically triggers the mechanical switch MC1 to open after reaching the trigger threshold voltage, thereby cutting off the system fault current. The second voltage detection circuit CC2 detects the voltage across the IGBT switch T1 and automatically triggers the thyristor T2 to conduct after reaching the trigger threshold voltage, causing the current-limiting reactor to be engaged in the system. The thyristor T2 triggers the auxiliary branch, engaging the current-limiting reactor L1 in the system to limit the short-circuit current. The current-limiting reactor L1 limits the system short-circuit fault current. The mechanical switch MC1 provides a low-resistance on-state loop under normal conditions and cuts off the short-circuit fault current when necessary after a fault occurs. In this circuit, the collector of IGBT switch T1 is connected to the first terminal of the first voltage detection circuit CC1, and the emitter of IGBT switch T1 is connected to the second terminal of the first voltage detection circuit CC1. The collector of IGBT switch T1 is also connected to the first terminal of the second voltage detection circuit CC2, and the emitter of IGBT switch T1 is also connected to the second terminal of the second voltage detection circuit CC2. Mechanical switch MC1 is connected to the collector of IGBT switch T1. The third terminal of the first voltage detection circuit CC1 is connected to mechanical switch MC1, and the third terminal of the second voltage detection circuit CC2 is connected to the cathode of thyristor T2. The anode of thyristor T2 is connected to the collector of IGBT switch T1. The cathode of thyristor T2 is also connected to the first terminal of reactor L1, and the second terminal of reactor L1 is connected to the emitter of IGBT switch T1. When the system is operating normally, thyristor T2 is in a locked state, and the system current flows through mechanical switch MC1 and IGBT switch T1. IGBT switch T1 will not be falsely triggered when it is operating in the normal saturation region. When a system fault occurs, the system current rises rapidly, increasing the current flowing through IGBT switch T1. When the current in IGBT switch T1 exceeds a preset current threshold, it causes the IGBT switch T1, which normally operates in the saturation region, to operate in the active region. The voltage of IGBT switch T1 operating in the active region rises rapidly. When the second voltage detection circuit CC2 detects that the voltage of IGBT switch T1 exceeds the second preset voltage threshold Uth2, it triggers thyristor T2 to conduct, causing reactor L1 to be connected to the system to suppress the rise of the fault current. After the system current rises further, when the first voltage detection circuit CC1 detects that the voltage of IGBT switch T1 exceeds the first preset voltage threshold Uth1, it triggers mechanical switch MC1 to operate, interrupting the fault current.

[0039] This invention eliminates the need for external current detection. Utilizing the inherent operating characteristics of the IGBT switch, it exhibits low conduction losses under normal system operation and avoids false triggering when operating in its saturation region. Upon a short-circuit fault, the IGBT switch rapidly enters the active region, causing its voltage to rise quickly. This characteristic can be used to determine the increase in fault current. The voltage detection circuit rapidly detects the IGBT voltage rise and quickly triggers the thyristor to conduct, energizing the reactor and suppressing the rise in fault current. Simultaneously, it triggers a mechanical switch to interrupt the fault current, achieving fault current isolation under low short-circuit current conditions.

[0040] In another preferred embodiment, the self-limiting hybrid circuit breaker further includes a diode connected in parallel between the collector and emitter of the IGBT switch to provide a freewheeling circuit for the reactor.

[0041] For details, please refer to Figure 2 , Figure 2 This is a circuit topology diagram of another preferred embodiment of a self-current-limiting hybrid circuit breaker provided by the present invention. In this embodiment, the self-current-limiting hybrid circuit breaker further includes a diode D1, which is connected in parallel between the collector and emitter of the IGBT switch T1 to provide a freewheeling circuit for the reactor L1, maintaining continuous current flow.

[0042] In yet another preferred embodiment, the first voltage detection circuit CC1 includes a first comparator;

[0043] The first input terminal of the first comparator is connected to the collector of the IGBT switch T1, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to the mechanical switch MC1.

[0044] Specifically, in this embodiment of the invention, the first voltage detection circuit CC1 preferably includes a first comparator. The first input terminal of the first comparator is connected to the collector of the IGBT switch T1, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to a mechanical switch MC1. When the voltage at the first input terminal is higher than the voltage at the second input terminal, the output terminal of the comparator outputs a high level and transmits the high level to the mechanical switch MC1 to trigger the mechanical switch MC1 to open.

[0045] In yet another preferred embodiment, the second voltage detection circuit CC2 includes a second comparator;

[0046] The first input terminal of the second comparator is connected to the collector of the IGBT switch T1, the second input terminal of the second comparator is connected to the second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor T2.

[0047] Specifically, in this embodiment of the invention, the second voltage detection circuit CC2 preferably includes a second comparator. The first input terminal of the second comparator is connected to the collector of the IGBT switch T1, the second input terminal of the second comparator is connected to a second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor T2. When the voltage at the first input terminal is higher than the voltage at the second input terminal, the output terminal of the comparator outputs a high level and transmits the high level to the thyristor T2 to trigger the thyristor T2 to conduct, thereby connecting the reactor L1 into the system to suppress the rise of fault current.

[0048] As a preferred embodiment, the first preset voltage threshold is greater than the second preset voltage threshold.

[0049] Specifically, in this embodiment of the invention, the first preset voltage threshold Uth1 is greater than the second preset voltage threshold Uth2. This is because when a system fault occurs, the voltage of the IGBT switch T1 operating in the active region rises rapidly. First, the second voltage detection circuit CC2 detects that the voltage of the IGBT switch T1 exceeds the second preset voltage threshold Uth2, triggering the thyristor T2 to conduct, thus connecting the reactor L1 to the system. Then, when the system current further increases, the first voltage detection circuit CC1 detects that the voltage of the IGBT switch T1 exceeds the first preset voltage threshold Uth1, triggering the mechanical switch MC1 to operate.

[0050] The following is combined with Figures 3 to 6 The working process of the self-current-limiting hybrid circuit breaker provided in the embodiments of the present invention will be described. Figure 3 This is a typical output characteristic diagram of IGBT switch T1 in a self-current-limiting hybrid circuit breaker provided by the present invention. Figure 4 This is a typical operating waveform diagram of the IGBT switch T1 in a self-current-limiting hybrid circuit breaker provided by the present invention. Figure 5 This is a typical operating waveform diagram of reactor L1 in a self-current-limiting hybrid circuit breaker provided by the present invention. Figure 6 This is a typical operating waveform diagram of the mechanical switch MC1 in a self-current-limiting hybrid circuit breaker provided by the present invention.

[0051] In this embodiment of the invention, when the system is operating normally, thyristor T2 is in a locked state, and system current flows through mechanical switch MC1 and IGBT switch T1. IGBT switch T1 operates in the saturation region of normal operation and will not be falsely triggered. When a system fault occurs (at time t0), the system current rises rapidly, and the current flowing through IGBT switch T1 increases. When the current in IGBT switch T1 exceeds a preset current threshold, IGBT switch T1, which was normally in the saturation region, operates in the active region. The voltage of IGBT switch T1 operating in the active region rises rapidly. When the second voltage detection circuit CC2 detects that the voltage of IGBT switch T1 exceeds the second preset voltage threshold Uth2 (at time t1), it triggers thyristor T2 to conduct, causing reactor L1 to be connected to the system to suppress the rise of fault current. After the system current further increases, when the first voltage detection circuit CC1 detects that the voltage of IGBT switch T1 exceeds the first preset voltage threshold Uth1 (at time t2), it triggers mechanical switch MC1 to operate, interrupting the fault current.

[0052] Accordingly, the present invention also provides a control method for a self-current-limiting hybrid circuit breaker, the method being applied to a self-current-limiting hybrid circuit breaker including an IGBT switch, a first voltage detection circuit, a second voltage detection circuit, a thyristor, a reactor, and a mechanical switch; the collector of the IGBT switch is connected to a first terminal of the first voltage detection circuit, and the emitter of the IGBT switch is connected to a second terminal of the first voltage detection circuit; the collector of the IGBT switch is also connected to a first terminal of the second voltage detection circuit, and the emitter of the IGBT switch is also connected to a second terminal of the second voltage detection circuit; the mechanical switch is connected to the collector of the IGBT switch; a third terminal of the first voltage detection circuit is connected to the mechanical switch, a third terminal of the second voltage detection circuit is connected to the cathode of the thyristor, and the anode of the thyristor is connected to the collector of the IGBT switch; the cathode of the thyristor is also connected to a first terminal of the reactor, and the second terminal of the reactor is connected to the emitter of the IGBT switch; the control method for the self-current-limiting hybrid circuit breaker includes:

[0053] When the system is working normally, the thyristor is in the locked state, and the system current flows through the mechanical switch and the IGBT switching transistor;

[0054] When a system fault occurs, the current of the IGBT switch increases, causing the IGBT switch to operate in the active region. When the second voltage detection circuit detects that the voltage of the IGBT switch exceeds a second preset voltage threshold, it triggers the thyristor to conduct, causing the reactor to be connected to the system to suppress the rise of the fault current. When the first voltage detection circuit detects that the voltage of the IGBT switch exceeds a first preset voltage threshold, it triggers the mechanical switch to operate and interrupt the fault current.

[0055] Preferably, the self-limiting hybrid circuit breaker further includes a diode connected in parallel between the collector and emitter of the IGBT switch to provide a freewheeling circuit for the reactor.

[0056] Preferably, the first voltage detection circuit includes a first comparator;

[0057] The first input terminal of the first comparator is connected to the collector of the IGBT switch, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to the mechanical switch.

[0058] Preferably, the second voltage detection circuit includes a second comparator;

[0059] The first input terminal of the second comparator is connected to the collector of the IGBT switch, the second input terminal of the second comparator is connected to a second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor.

[0060] Preferably, the first preset voltage threshold is greater than the second preset voltage threshold.

[0061] This invention provides a self-current-limiting hybrid circuit breaker and its control method. It requires no external current detection and utilizes the inherent operating characteristics of the IGBT switch. Under normal system operation, the conduction loss is low, and the IGBT switch will not be falsely triggered when operating in its normal saturation region. After a short-circuit fault occurs, the IGBT switch quickly enters the active region, and its voltage rises rapidly. This characteristic can be used as a basis for judging the rise in fault current. The voltage detection circuit can quickly detect the rise in IGBT switch voltage and rapidly trigger the thyristor to conduct, causing the reactor to be connected to the system and suppressing the rise in fault current. Simultaneously, it triggers the mechanical switch to operate, interrupting the fault current and achieving fault current clearance under low short-circuit current conditions.

[0062] It should be noted that the system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the system embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0063] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A self-current-limiting hybrid circuit breaker, characterized in that, It includes IGBT switching transistors, a first voltage detection circuit, a second voltage detection circuit, thyristors, reactors, and mechanical switches; The collector of the IGBT switch is connected to the first terminal of the first voltage detection circuit, and the emitter of the IGBT switch is connected to the second terminal of the first voltage detection circuit; the collector of the IGBT switch is also connected to the first terminal of the second voltage detection circuit, and the emitter of the IGBT switch is also connected to the second terminal of the second voltage detection circuit; the mechanical switch is connected to the collector of the IGBT switch. The third terminal of the first voltage detection circuit is connected to the mechanical switch, the third terminal of the second voltage detection circuit is connected to the cathode of the thyristor, and the anode of the thyristor is connected to the collector of the IGBT switch. The cathode of the thyristor is also connected to the first terminal of the reactor, and the second terminal of the reactor is connected to the emitter of the IGBT switch. When the system is working normally, the thyristor is in the locked state, and the system current flows through the mechanical switch and the IGBT switching transistor; When a system fault occurs, the current of the IGBT switch increases, causing the IGBT switch to operate in the active region. When the second voltage detection circuit detects that the voltage of the IGBT switch exceeds the second preset voltage threshold, it triggers the thyristor to conduct, causing the reactor to be connected to the system to suppress the rise of fault current; when the first voltage detection circuit detects that the voltage of the IGBT switch exceeds the first preset voltage threshold, it triggers the mechanical switch to operate and interrupt the fault current.

2. The self-current-limiting hybrid circuit breaker as described in claim 1, characterized in that, It also includes a diode connected in parallel between the collector and emitter of the IGBT switch to provide a freewheeling circuit for the reactor.

3. The self-current-limiting hybrid circuit breaker as described in claim 2, characterized in that, The first voltage detection circuit includes a first comparator; The first input terminal of the first comparator is connected to the collector of the IGBT switch, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to the mechanical switch.

4. The self-current-limiting hybrid circuit breaker as described in claim 3, characterized in that, The second voltage detection circuit includes a second comparator; The first input terminal of the second comparator is connected to the collector of the IGBT switch, the second input terminal of the second comparator is connected to a second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor.

5. The self-current-limiting hybrid circuit breaker as described in claim 4, characterized in that, The first preset voltage threshold is greater than the second preset voltage threshold.

6. A control method for a self-current-limiting hybrid circuit breaker, characterized in that, The method is applied to a self-current-limiting hybrid circuit breaker including an IGBT switch, a first voltage detection circuit, a second voltage detection circuit, a thyristor, a reactor, and a mechanical switch. The control method for the self-current-limiting hybrid circuit breaker includes: When the system is working normally, the thyristor is in the locked state, and the system current flows through the mechanical switch and the IGBT switching transistor; When a system fault occurs, the current of the IGBT switch increases, causing the IGBT switch to operate in the active region. When the second voltage detection circuit detects that the voltage of the IGBT switch exceeds a second preset voltage threshold, it triggers the thyristor to conduct, causing the reactor to be connected to the system to suppress the rise of the fault current. When the first voltage detection circuit detects that the voltage of the IGBT switch exceeds a first preset voltage threshold, it triggers the mechanical switch to operate and interrupt the fault current.

7. The control method for a self-current-limiting hybrid circuit breaker as described in claim 6, characterized in that, The self-limiting hybrid circuit breaker also includes a diode connected in parallel between the collector and emitter of the IGBT switch to provide a freewheeling circuit for the reactor.

8. The control method for a self-current-limiting hybrid circuit breaker as described in claim 7, characterized in that, The first voltage detection circuit includes a first comparator; The first input terminal of the first comparator is connected to the collector of the IGBT switch, the second input terminal of the first comparator is connected to a first preset voltage threshold, and the output terminal of the first comparator is connected to the mechanical switch.

9. The control method for a self-current-limiting hybrid circuit breaker as described in claim 8, characterized in that, The second voltage detection circuit includes a second comparator; The first input terminal of the second comparator is connected to the collector of the IGBT switch, the second input terminal of the second comparator is connected to a second preset voltage threshold, and the output terminal of the second comparator is connected to the thyristor.

10. The control method for a self-current-limiting hybrid circuit breaker as described in claim 9, characterized in that, The first preset voltage threshold is greater than the second preset voltage threshold.

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