A circuit breaker with bidirectional breaking limiting short-circuit current

Abstract

A circuit breaker with bidirectional breaking and limiting short-circuit current is composed of a main current branch, a current limiting module and a breaking module. The current limiting module and the breaking module are connected in series, and the main current branch is connected in parallel with the two modules. A plurality of high-speed mechanical switches and superconducting current limiters are connected in series to form the main current branch, the high-speed mechanical switches and the superconducting current limiters are directly connected with outlet ends A1 and A2 of the circuit breaker respectively, the capacitor C1 and the fuse Fuse are connected in parallel to form the current limiting module, in the breaking module, two anti-parallel half-controlled power semiconductor devices form a power electronic branch, the transfer capacitor C2 with a certain pre-charge voltage, the oscillation inductor L and the half-controlled power semiconductor device Tr and four diodes together form a surge current module, the capacitor C2 and the resistor R are connected in series to form a buffer branch, and the MOV device forms an energy consumption branch. The hybrid DC circuit breaker has the ability of bidirectional conduction and limiting short-circuit current.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, and in particular to a circuit breaker with bidirectional breaking capacity to limit short-circuit current. Background Technology

[0002] Hybrid DC circuit breakers, with their advantages of high current-carrying capacity, fast breaking speed, and low on-state losses, have been a hot research topic in the industry in recent years. With the further development of DC power supply systems, new DC systems place higher demands on power supply reliability. Therefore, DC systems need to limit short-circuit current when a short-circuit fault occurs, which requires DC circuit breakers to be able to limit short-circuit current and interrupt bidirectional short-circuit currents. Unlike traditional DC circuit breakers, which only need to directly interrupt short-circuit currents, DC circuit breakers operating in such systems mostly achieve DC segmentation by generating an artificial zero-crossing point using an oscillating current opposite to the short-circuit current. In this application context, DC circuit breakers used in high-reliability DC power supply systems must have the ability to limit short-circuit currents when large short-circuit currents occur in the DC power supply system, thereby improving the circuit breaker's breaking capacity. Summary of the Invention

[0003] The purpose of this invention is to provide a circuit breaker with bidirectional breaking and short-circuit current limiting capabilities, which can be applied to bidirectional DC power supply systems.

[0004] Specifically, the present invention adopts the following technical solution:

[0005] A circuit breaker with bidirectional breaking capacity for limiting short-circuit current includes a main current branch, a current limiting module, and a breaking module. The two ends of the main current branch are directly connected to output terminals A1 and A2, respectively. The current limiting module is connected in series with the breaking module and then in parallel with the main current branch. Multiple high-speed mechanical switches are connected in series with a superconducting current limiter to form the main current branch. A capacitor C1 and a fuse are connected in parallel to form the current limiting module. The fuse does not operate when the circuit breaker interrupts the rated current, but operates when the circuit breaker interrupts the short-circuit current. The breaking module includes…

[0006] The power electronic branch includes power semiconductor devices IGCT1 and IGCT2 connected in anti-parallel;

[0007] A surge current module, which is connected in parallel to the power electronic branch, includes,

[0008] Four diodes, D1, D2, D3, and D4, are connected in a bridge configuration to accommodate bidirectional circuit breaker interruption.

[0009] Transfer capacitor C2, which contains a predetermined pre-charge voltage, has one end connected between diode D1 and diode D2;

[0010] An oscillating inductor L is connected to the other end of the transfer capacitor C2;

[0011] The semi-controlled power semiconductor device Tr has one end connected to the oscillating inductor L and the other end connected between diodes D3 and D4. The transfer capacitor C2 and the oscillating inductor L oscillate after the semi-controlled power semiconductor device Tr is turned on, so that the current in the power electronic branch is reduced to the turn-off range of power semiconductor device IGCT1 or power semiconductor device IGCT2 during the negative half-cycle of the oscillation.

[0012] A buffer branch, which is connected in parallel to the power electronic branch, the buffer branch including a capacitor C3 and a resistor R connected in series;

[0013] The power-consuming branch is connected in parallel with the power electronic branch, and the power-consuming branch includes MOV devices.

[0014] In the circuit breaker with bidirectional breaking and short-circuit current limiting, in the bridge structure, the cathodes of diodes VD1 and VD2 are connected, the anodes of diodes VD3 and VD4 are connected, the cathode of diode VD3 is connected to the anode of diode VD1, and the cathode of diode VD4 is connected to the anode of diode VD2.

[0015] In the circuit breaker with bidirectional breaking and short-circuit current limiting, both power semiconductor devices IGCT1 and IGCT2 are unidirectional power semiconductor devices.

[0016] In the circuit breaker with bidirectional breaking and short-circuit current limiting, under normal system current conditions, the system current flows through the main current branch. When a tripping command is received, the high-speed mechanical switch trips, and the power semiconductor device IGCT1 or the power semiconductor device IGCT2 of the tripping module is turned on. The current is transferred to the buffer branch in the tripping module to charge the capacitor C3. After the voltage of the buffer branch reaches the on-state voltage of the MOV device, the current is transferred to the energy-consuming branch to achieve the tripping.

[0017] When a short-circuit fault occurs, the control system issues a trip command, the high-speed mechanical switch trips, and the power semiconductor device IGCT1 or IGCT2 in the interrupting module turns on. The current is transferred to the buffer branch in the interrupting module, the fuse in the current limiting module trips, and the short-circuit current continuously charges the capacitor C1 in the current limiting module, thereby reducing the current and turning on the semi-controlled power semiconductor device Tr. The pre-charged capacitor C2 discharges through the semi-controlled power semiconductor device Tr, and an oscillating current is superimposed on the original short-circuit current. When the current in the power electronic branch decreases to the turn-off range of the power semiconductor device IGCT1 or IGCT2, the power semiconductor device IGCT1 or IGCT2 trips to turn off the current, thereby transferring the current to the buffer branch. After the current charges the capacitor C3 to the conduction voltage of the MOV device, the short-circuit current is transferred to the energy dissipation branch, thus completing the turn-off.

[0018] In the circuit breaker with bidirectional breaking and short-circuit current limiting, the high-speed mechanical switch is a high-speed mechanical switch based on electromagnetic repulsion, a mechanical switch driven by a high-speed motor, or a high-speed mechanical switch driven by explosion.

[0019] In the circuit breaker with bidirectional breaking and short-circuit current limiting, the semi-controlled power semiconductor device Tr is a unidirectional semi-controlled device, which is a single device or a combination of the following devices: GTO, thyristor, IGBT.

[0020] In the circuit breaker with bidirectional breaking and short-circuit current limiting, the energy-consuming branch includes a metal oxide surge arrester or a removable surge arrester.

[0021] In the circuit breaker with bidirectional breaking and short-circuit current limiting, the metal oxide surge arrester includes line-type metal oxide surge arrester, gapless line-type metal oxide surge arrester, and fully insulated composite jacket metal oxide surge arrester.

[0022] This circuit breaker, featuring bidirectional short-circuit current limiting, utilizes a current-limiting module. When a large short-circuit current is interrupted, the operation of the superconducting current limiter and fuse directs the large short-circuit current to the capacitor within the current-limiting module, thus limiting the short-circuit current. Bidirectional conduction and interruption are achieved through anti-parallel power semiconductor devices. When interrupting a large short-circuit current, the semi-controlled power semiconductor device Tr in the surge current module operates, and the pre-charge capacitor discharges via high-frequency oscillation, reducing the current in the power electronic branch to within the breaking capacity range of the IGCT power semiconductor device, allowing the IGCT to successfully transfer the short-circuit current. Attached Figure Description

[0023] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0024] Figure 1 This is a schematic diagram of a circuit breaker with bidirectional breaking capacity to limit short-circuit current.

[0025] Figures 2(a) to 2(e) This is a schematic diagram of the circuit breaker of the present invention with bidirectional breaking and short-circuit current limiting in positive operation and rated breaking condition.

[0026] Figures 3(a) to 3(f) This is a schematic diagram of the structure of the circuit breaker of the present invention with bidirectional breaking and short-circuit current limiting when it is operating in the forward direction and breaking the short-circuit current.

[0027] Figures 4(a) to 4(e) This is a schematic diagram of the structure of the circuit breaker of the present invention with bidirectional breaking and short-circuit current limiting when operating in reverse and rated breaking.

[0028] Figures 5(a) to 5(f) This is a schematic diagram of the structure of the circuit breaker of the present invention, which has bidirectional breaking and short-circuit current limiting, when operating in reverse and breaking the short-circuit current. Detailed Implementation

[0029] The following will refer to the appendix. Figures 1 to 5(f) Specific embodiments of this disclosure will be described in more detail below. While specific embodiments of this disclosure are shown in the accompanying drawings, it should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0030] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out this disclosure; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of this disclosure. The scope of protection of this disclosure is determined by the appended claims.

[0031] To facilitate understanding of the embodiments of this disclosure, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of this disclosure.

[0032] like Figures 1 to 5(f) As shown, a circuit breaker with bidirectional short-circuit current limiting includes a main current branch, a current limiting module, and a breaking module. The two ends of the main current branch are directly connected to output terminals A1 and A2, respectively. The current limiting module is connected in series with the breaking module and then in parallel with the main current branch. Multiple high-speed mechanical switches are connected in series with a superconducting current limiter to form the main current branch. A capacitor C1 and a fuse are connected in parallel to form the current limiting module. The fuse does not operate when the circuit breaker interrupts the rated current, but operates when the circuit breaker interrupts the short-circuit current. The breaking module includes…

[0033] The power electronic branch includes power semiconductor devices IGCT1 and IGCT2 connected in anti-parallel;

[0034] A surge current module, which is connected in parallel to the power electronic branch, includes,

[0035] Four diodes, D1, D2, D3, and D4, are connected in a bridge configuration to accommodate bidirectional circuit breaker interruption.

[0036] Transfer capacitor C2, which contains a predetermined pre-charge voltage, has one end connected between diode D1 and diode D2;

[0037] An oscillating inductor L is connected to the other end of the transfer capacitor C2;

[0038] The semi-controlled power semiconductor device Tr has one end connected to the oscillating inductor L and the other end connected between diodes D3 and D4. The transfer capacitor C2 and the oscillating inductor L oscillate after the semi-controlled power semiconductor device Tr is turned on, so that the current in the power electronic branch is reduced to the turn-off range of power semiconductor device IGCT1 or power semiconductor device IGCT2 during the negative half-cycle of the oscillation.

[0039] A buffer branch, which is connected in parallel to the power electronic branch, the buffer branch including a capacitor C3 and a resistor R connected in series;

[0040] The power-consuming branch is connected in parallel with the power electronic branch, and the power-consuming branch includes MOV devices.

[0041] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, in the bridge structure, the cathodes of diodes VD1 and VD2 are connected, the anodes of diodes VD3 and VD4 are connected, the cathode of diode VD3 is connected to the anode of diode VD1, and the cathode of diode VD4 is connected to the anode of diode VD2.

[0042] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, both power semiconductor devices IGCT1 and IGCT2 are unidirectional power semiconductor devices.

[0043] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, under normal system current conditions, the system current flows through the main current branch. When a tripping command is received, the high-speed mechanical switch trips, and the power semiconductor device IGCT1 or the power semiconductor device IGCT2 of the tripping module is turned on. The current is transferred to the buffer branch in the tripping module to charge the capacitor C3. After the voltage of the buffer branch reaches the turn-on voltage of the MOV device, the current is transferred to the energy-consuming branch to achieve the tripping.

[0044] When a short-circuit fault occurs, the control system issues a trip command, the high-speed mechanical switch trips, and the power semiconductor device IGCT1 or IGCT2 in the interrupting module turns on. The current is transferred to the buffer branch in the interrupting module, the fuse in the current limiting module trips, and the short-circuit current continuously charges the capacitor C1 in the current limiting module, thereby reducing the current and turning on the semi-controlled power semiconductor device Tr. The pre-charged capacitor C2 discharges through the semi-controlled power semiconductor device Tr, and an oscillating current is superimposed on the original short-circuit current. When the current in the power electronic branch decreases to the turn-off range of the power semiconductor device IGCT1 or IGCT2, the power semiconductor device IGCT1 or IGCT2 trips to turn off the current, thereby transferring the current to the buffer branch. After the current charges the capacitor C3 to the conduction voltage of the MOV device, the short-circuit current is transferred to the energy dissipation branch, thus completing the turn-off.

[0045] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, the high-speed mechanical switch is a high-speed mechanical switch based on electromagnetic repulsion, a mechanical switch driven by a high-speed motor, or a high-speed mechanical switch driven by explosion.

[0046] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, the semi-controlled power semiconductor device Tr is a unidirectional semi-controlled device, which is a single device or a combination of the following devices: GTO, thyristor, and IGBT.

[0047] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, the energy-consuming branch includes a metal oxide surge arrester or a removable surge arrester.

[0048] In a preferred embodiment of the circuit breaker with bidirectional breaking and short-circuit current limiting, the metal oxide surge arrester includes a line-type metal oxide surge arrester, a gapless line-type metal oxide surge arrester, and a fully insulated composite jacket metal oxide surge arrester.

[0049] In one embodiment, Figure 1 This is a schematic diagram of the circuit breaker body structure. A circuit breaker with bidirectional breaking and short-circuit current limiting includes a main current branch, a current limiting module, and a breaking module. Figures 2(a) to 2(e) , Figures 3(a) to 3(f) , Figures 4(a) to 4(e) , Figures 5(a) to 5(f) The process of current transfer during the specific breaking of a circuit breaker is given below. This will be discussed in conjunction with... Figures 2(a) to 2(e) , Figures 3(a) to 3(f) Explain the breaking process of the rated current and short-circuit current when the current flows to the right, combined with... Figures 4(a) to 4(e) , Figures 5(a) to 5(f) Explain the process of interrupting the rated current and short-circuit current when the current flows to the left.

[0050] 1. The process of interrupting the rated current when the current flows to the right:

[0051] (1) As shown in Figure 2(a) under normal current flow conditions, the system current flows in from the output terminal A1, and flows out from the output terminal A2 after passing through the high-speed mechanical switch and the superconducting current limiter.

[0052] (2) As shown in Figure 2(b), when the tripping command of the upper control system is received, the control system is notified and the control system issues a command. At the same time, the mechanical switch trips and IGCT1 is turned on. Under the action of the arc voltage, the current is transferred from the main current branch to the current limiting module and the breaking module.

[0053] (3) As shown in Figure 2(c), after the current is transferred, it passes through the fuse of the current limiting module and the power semiconductor device IGCT1 of the interrupting module. At this time, the fuse does not operate.

[0054] (4) As shown in Figure 2(d), when the power semiconductor device IGCT1 is turned off, the current is transferred from the power electronic branch to the buffer branch and charges the capacitor C3 of the buffer branch.

[0055] (5) As shown in Figure 2(e), when the voltage of the buffer branch in the interruption module reaches the conduction voltage of the MOV device in the energy dissipation branch, the current is transferred to the energy dissipation branch, and the interruption is completed.

[0056] 2. The process of interrupting the short-circuit current when the current flows to the right:

[0057] (1) As shown in Figure 3(a) under normal current flow conditions, the system current flows in from the output terminal A1, and flows out from the output terminal A2 after passing through the high-speed mechanical switch and the superconducting current limiter.

[0058] (2) As shown in Figure 3(b), when the detection system detects a short circuit fault in the system, it notifies the control system. The control system issues a command, the mechanical switch is opened and IGCT1 is turned on at the same time. The short circuit current triggers the superconducting current limiter to operate. Under the combined action of the arc voltage of the mechanical switch and the current limiting voltage of the superconducting current limiter, the current is transferred from the main current branch to the current limiting module and the breaking module.

[0059] (3) As shown in Figure 3(c), the rapidly rising short-circuit current triggers the fuse to trip. At this time, the current flows through the current-limiting capacitor C1 of the current-limiting module and the power semiconductor device IGCT1. The current charges the current-limiting capacitor C1 of the current-limiting module, limiting the short-circuit current;

[0060] (4) As shown in Figure 3(d), the semi-controlled power semiconductor device Tr is turned on, and the pre-charge capacitor C2 in the pulse current module is discharged through the semi-controlled power semiconductor device Tr. A high-frequency oscillating current wave is superimposed on the original current. At the peak of the negative half-cycle of the oscillating current, the current of the power semiconductor device IGCT1 is reduced to the turn-off capability range and turned off.

[0061] (5) As shown in Figure 3(e), when the power semiconductor device IGCT1 is turned off, the current is transferred from the power electronic branch to the buffer branch and charges the capacitor C3 of the buffer branch.

[0062] (6) As shown in Figure 3(f), when the voltage of the buffer branch in the interruption module reaches the conduction voltage of the MOV device in the energy dissipation branch, the current is transferred to the energy dissipation branch, and the interruption is completed.

[0063] 3. The process of interrupting the rated current when the current flows to the left:

[0064] (1) As shown in Figure 4(a) under normal current flow conditions, the system current flows in from the output terminal A2, and flows out from the output terminal A1 after passing through the mechanical switch and the superconducting current limiter.

[0065] (2) As shown in Figure 4(b), when the control system receives the tripping command from the upper control system, the control system issues a command, the mechanical switch trips and IGCT2 is turned on at the same time, and the current is transferred from the main current branch to the current limiting module and the breaking module under the action of the arc voltage.

[0066] (3) As shown in Figure 4(c), after the current is transferred, it passes through the fuse of the current limiting module and the power semiconductor device IGCT2 of the interrupting module. At this time, the fuse does not operate.

[0067] (4) As shown in Figure 4(d), when the power semiconductor device IGCT2 is turned off, the current is transferred from the power electronic branch to the buffer branch and charges the capacitor C3 of the buffer branch.

[0068] (5) As shown in Figure 4(e), when the voltage of the buffer branch in the interruption module reaches the conduction voltage of the MOV device in the energy dissipation branch, the current is transferred to the energy dissipation branch, and the interruption is completed.

[0069] 4. The process of interrupting the short-circuit current when the current flows to the left:

[0070] (1) As shown in Figure 5(a) under normal current flow conditions, the system current flows in from the output terminal A2, and flows out from the output terminal A1 after passing through the mechanical switch and the superconducting current limiter.

[0071] (2) As shown in Figure 5(b), when the detection system detects a short circuit fault in the system, it notifies the control system. The control system issues a tripping command. The mechanical switch trips and IGCT2 turns on at the same time. The short circuit current triggers the superconducting current limiter to operate. Under the combined action of the arc voltage of the mechanical switch and the current limiting voltage of the superconducting current limiter, the current is transferred from the main current branch to the current limiting module and the breaking module.

[0072] (3) As shown in Figure 5(c), the rapidly rising short-circuit current triggers the fuse to trip. At this time, the current flows through the current-limiting capacitor C1 of the current-limiting module and the power semiconductor device IGCT2. The current charges the current-limiting capacitor C1 of the current-limiting module, limiting the short-circuit current;

[0073] (4) As shown in Figure 5(d), when the semi-controlled power semiconductor device Tr is turned on, the pre-charge capacitor C2 in the pulse current module is discharged through Tr, and a high-frequency oscillating current wave is superimposed on the original current. At the peak of the negative half-cycle of the oscillating current, the current of the power semiconductor device IGCT2 is reduced to the turn-off capability range and turned off.

[0074] (5) As shown in Figure 5(e), when the power semiconductor device IGCT2 is turned off, the current is transferred from the power electronic branch to the buffer branch and charges the capacitor C3 of the buffer branch.

[0075] (6) As shown in Figure 5(f), when the voltage of the buffer branch in the interruption module reaches the conduction voltage of the MOV device in the energy dissipation branch, the current is transferred to the energy dissipation branch, and the interruption is completed.

[0076] Although the embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this disclosure is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of this disclosure, and all of these are within the scope of protection of this disclosure.

Claims

1. A circuit breaker with bidirectional breaking and short-circuit current limiting, comprising a main current branch, a current limiting module, and a breaking module, characterized in that: The two ends of the main current branch are directly connected to the output terminals A1 and A2, respectively. A current-limiting module is connected in series with a breaking module and then in parallel with the main current branch. Multiple high-speed mechanical switches are connected in series with a superconducting current limiter to form the main current branch. Capacitor C1 and fuse are connected in parallel to form the current-limiting module. The fuse does not operate when the circuit breaker interrupts the rated current, but operates when the circuit breaker interrupts the short-circuit current. The breaking module includes… The power electronic branch includes power semiconductor devices IGCT1 and IGCT2 connected in anti-parallel; A surge current module, which is connected in parallel to the power electronic branch, includes, Four diodes, D1, D2, D3, and D4, are connected in a bridge configuration to accommodate bidirectional circuit breaker interruption. Transfer capacitor C2, which contains a predetermined pre-charge voltage, has one end connected between diode D1 and diode D2; An oscillating inductor L is connected to the other end of the transfer capacitor C2; The semi-controlled power semiconductor device Tr has one end connected to the oscillating inductor L and the other end connected between diodes D3 and D4. The transfer capacitor C2 and the oscillating inductor L oscillate after the semi-controlled power semiconductor device Tr is turned on, so that the current in the power electronic branch is reduced to the turn-off range of power semiconductor device IGCT1 or power semiconductor device IGCT2 during the negative half-cycle of the oscillation. A buffer branch, which is connected in parallel with the power electronic branch, the buffer branch including a capacitor C3 and a resistor R connected in series; The power-consuming branch is connected in parallel with the power electronic branch, and the power-consuming branch includes MOV devices.

2. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 1, characterized in that: In the bridge structure, the cathodes of diodes D1 and D2 are connected, the anodes of diodes D3 and D4 are connected, the cathode of diode D3 is connected to the anode of diode D1, and the cathode of diode D4 is connected to the anode of diode D2.

3. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 1, characterized in that: Both power semiconductor devices IGCT1 and IGCT2 are unidirectional power semiconductor devices.

4. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 1, characterized in that: Under normal operating conditions, the system current flows through the main current branch. When a tripping command is received, the high-speed mechanical switch trips, and the power semiconductor device IGCT1 or IGCT2 of the tripping module is turned on. The current is transferred to the buffer branch in the tripping module to charge the capacitor C3. After the voltage of the buffer branch reaches the turn-on voltage of the MOV device, the current is transferred to the energy-consuming branch to achieve tripping. When a short-circuit fault occurs, the control system issues a trip command, the high-speed mechanical switch trips, and the power semiconductor device IGCT1 or IGCT2 in the interrupting module turns on. The current is transferred to the buffer branch in the interrupting module, the fuse in the current limiting module trips, and the short-circuit current continuously charges the capacitor C1 in the current limiting module, thereby reducing the current and turning on the semi-controlled power semiconductor device Tr. The pre-charged capacitor C2 discharges through the semi-controlled power semiconductor device Tr, and an oscillating current is superimposed on the original short-circuit current. When the current in the power electronic branch decreases to the turn-off range of the power semiconductor device IGCT1 or IGCT2, the power semiconductor device IGCT1 or IGCT2 trips to turn off the current, thereby transferring the current to the buffer branch. After the current charges the capacitor C3 to the conduction voltage of the MOV device, the short-circuit current is transferred to the energy dissipation branch, thus completing the turn-off.

5. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 1, characterized in that: The high-speed mechanical switch is a high-speed mechanical switch based on electromagnetic repulsion, a mechanical switch driven by a high-speed motor, or a high-speed mechanical switch driven by explosion.

6. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 1, characterized in that: The semi-controlled power semiconductor device Tr is a unidirectional semi-controlled device.

7. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 1, characterized in that: The energy-consuming branch includes a metal oxide surge arrester or a removable surge arrester.

8. The circuit breaker with bidirectional breaking and short-circuit current limiting according to claim 7, characterized in that: The metal oxide surge arresters include line-type metal oxide surge arresters, gapless line-type metal oxide surge arresters, and fully insulated composite-jacketed metal oxide surge arresters.

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