A bilateral and bidirectional solid-state circuit breaker circuit

Abstract

The present invention discloses a bilateral bidirectional solid-state circuit breaker circuit, which includes a main switch device. The main switch device is connected to the main circuit and is controlled by a drive circuit. The drive circuit receives a control signal and controls the on / off of the main switch device. A power-side voltage clamping circuit is arranged on the power side of the main switch device, and a drive-side voltage clamping circuit is arranged on the drive side of the main switch device. The power-side voltage clamping circuit and the drive-side voltage clamping circuit cooperate with each other to clamp the overvoltage during the turn-off process of the main switch device to protect the main switch device. In the present invention, the use of a thyristor in series with a varistor on the power side of the main switch device greatly improves the voltage usage level of the solid-state circuit breaker, and the thyristor T1 is triggered by a bidirectional transient suppression diode, solving the deficiency in the traditional technology that only the voltage level of the power device can be increased to increase the ability to turn off the fault current. Therefore, both the cost and the volume are greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and particularly relates to a bilateral bidirectional solid-state circuit breaker circuit. Background Art

[0002] A solid-state circuit breaker is a new type of DC microgrid protection device. It uses digital sensors to monitor fault currents and quickly cuts off the fault currents through power semiconductors, and has advantages such as high speed (microsecond-level turn-off), no arc, and long service life. To protect the solid-state circuit breaker from overvoltage and excessive power loss during the turn-off process, an overvoltage protection circuit is generally required. The traditional solution generally uses the method of connecting a varistor and an RCD circuit in parallel on the power side to clamp and protect the power semiconductor to prevent it from being broken down by overvoltage. Among them, the RCD circuit is used to clamp the rising slope of the overvoltage, and the varistor is used to clamp the overvoltage and absorb the energy generated during the turn-off process.

[0003] However, the following problems exist in the traditional design:

[0004] 1) The varistor itself has parasitic inductance. When the fault current commutates into the varistor energy absorption circuit during the turn-off process, an overvoltage spike will be generated, and this overvoltage spike will continuously increase with the increase of the current. This will inevitably cause that when designing the solid-state circuit breaker, in order to increase the ability to turn off the fault current, only the voltage level of the power device can be increased. As the voltage level of the power device increases, its manufacturing and use costs are greatly improved; 2) When used in high-power applications, all kinds of devices in the clamping energy absorption circuit have high costs and large volumes. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies in the prior art and provide a bilateral bidirectional solid-state circuit breaker circuit.

[0006] The purpose of the present invention is achieved through the following technical solutions: A bilateral bidirectional solid-state circuit breaker circuit includes a main switch device. The main switch device is connected to the main circuit and is controlled by a drive circuit. The drive circuit receives a control signal and controls the on / off of the main switch device; a power-side voltage clamping circuit is arranged on the power side of the main switch device, and a drive-side voltage clamping circuit is arranged on the drive side of the main switch device; the power-side voltage clamping circuit and the drive-side voltage clamping circuit cooperate with each other to clamp the overvoltage during the turn-off process of the main switch device to protect the main switch device.

[0007] Preferably, the power-side voltage clamping circuit consists of a triac T1, a varistor MOV, a capacitor C1, a bidirectional transient voltage suppressor diode D1, a resistor R1, a resistor R2, a resistor R3, and a capacitor C2. The resistors R1, R2, and R3 are connected in series in sequence. One end of the resistor R1 is connected to the first anode of the triac T1 and is connected to the main circuit. One end of the second anode of the triac T1 is connected to one end of the varistor MOV. The gate of the triac T1 is connected to the other end of the resistor R1. The varistor MOV and the capacitor C1 are both connected in parallel with the resistor R3. One end of the resistor R3 is connected to the main circuit. The capacitor C2 is connected in parallel with the resistor R2. The capacitor C2 and the resistor R2 form a buffer circuit. The bidirectional transient voltage suppressor diode D1 is connected in parallel with the resistor R1.

[0008] Preferably, the resistance values of the resistor R1 and the resistor R3 satisfy the following formula:

[0009]

[0010] where, V DC is the static bus voltage; V RDM is the maximum withstand voltage of the triac.

[0011] Preferably, the bidirectional transient voltage suppressor diode D1 satisfies the following formula:

[0012] ;

[0013] where, V R1 is the voltage division of the resistor R1; V BR is the breakdown voltage of the bidirectional transient voltage suppressor diode D1.

[0014] Preferably, when selecting the varistor MOV, it should be satisfied that: at the maximum overvoltage, the maximum current flowing through it is greater than the bus current, and when the varistor MOV is at the bus voltage, its current value is less than the holding current of the triac T1.

[0015] Preferably, when in static operation, the resistors R1, R2, and R3 divide the voltage. At this time, the voltage division of the resistor R1 is less than the breakdown voltage of the bidirectional transient voltage suppressor diode D1, so that the current does not flow into the triac T1, thereby turning on the triac T1, and the varistor MOV does not absorb energy;

[0016] When dynamically turned off, the voltage on both sides of the main switch device rises rapidly. The voltage applied to the bidirectional transient voltage suppressor diode D1 reaches the breakdown voltage of the bidirectional transient voltage suppressor diode D1, causing the bidirectional transient voltage suppressor diode D1 to be broken down. At this time, the current flows through the gate of the triac T1 and turns on the triac T1. The fault current flows through the triac T1 into the capacitor C 1， The varistor MOV starts to clamp and absorb the fault current.

[0017] Preferably, the main switch device is composed of two series-connected insulated gate bipolar transistors, namely the first insulated gate bipolar transistor and the second insulated gate bipolar transistor; the emitter of the first insulated gate bipolar transistor is connected to the emitter of the second insulated gate bipolar transistor, and the collector of the first insulated gate bipolar transistor and the collector of the second insulated gate bipolar transistor are connected to the main circuit;

[0018] The drive circuit includes a first drive module and a second drive module, and the drive-side voltage clamping circuit includes capacitor C3, capacitor C4, bidirectional transient voltage suppressor diode D2, bidirectional transient voltage suppressor diode D3, bidirectional transient voltage suppressor diode D4, and bidirectional transient voltage suppressor diode D5;

[0019] The positive pole of the first drive module is simultaneously connected to one end of the bidirectional transient voltage suppressor diode D3 and the gate of the first insulated gate bipolar transistor, and the negative pole of the first drive module is connected to the emitter of the insulated gate bipolar transistor; the other end of the silicon-controlled driver D3 is connected to one end of the silicon-controlled driver D2, and the other end of the silicon-controlled driver D2 is connected to the collector of the first insulated gate bipolar transistor; the capacitor C3 is connected in parallel with the silicon-controlled driver D3;

[0020] The negative pole of the second drive module is simultaneously connected to one end of the bidirectional transient voltage suppressor diode D5 and the gate of the second insulated gate bipolar transistor, and the positive pole of the second drive module is connected to the emitter of the second insulated gate bipolar transistor; the other end of the silicon-controlled driver D5 is connected to one end of the silicon-controlled driver D4, and the other end of the silicon-controlled driver D4 is connected to the collector of the second insulated gate bipolar transistor; the capacitor C4 is connected in parallel with the silicon-controlled driver D4.

[0021] Preferably, the voltage of the transient voltage suppressor diode D2, the voltage of the transient voltage suppressor diode D3, the voltage of the transient voltage suppressor diode D4, the voltage of the transient voltage suppressor diode D5, and the rating selection should meet the following conditions:

[0022] The maximum clamping voltage after the bidirectional transient voltage suppressor diode D2 and the bidirectional transient voltage suppressor diode D3 are connected in series is less than the residual voltage of the varistor MOV;

[0023] The maximum clamping voltage after the bidirectional transient voltage suppressor diode D4 and the bidirectional transient voltage suppressor diode D5 are connected in series is less than the residual voltage of the varistor MOV.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention uses a method of connecting a triac in series with a varistor on the power side of the main switching device, which greatly improves the voltage utilization level of the solid-state circuit breaker. The triac T1 is triggered by a bidirectional transient suppression diode, which solves the deficiency in the traditional technology that only increasing the voltage level of the power device can enhance the ability to turn off the fault current. Therefore, both the cost and volume are greatly reduced.

[0026] 2. On the drive side of the main switching device, the transient suppression diode is used to actively clamp the overvoltage of the solid-state circuit breaker. Without increasing the cost significantly, it effectively prevents the power device from being broken down by overvoltage when the fault current is too large, ensuring the safety of the power device. Through the cooperation between the power-side voltage clamping circuit and the drive-side voltage clamping circuit, the deficiencies in the traditional design are effectively overcome, further avoiding the risk of the main switching device (IGBT) being broken down. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the overall schematic diagram of the bilateral bidirectional solid-state circuit breaker circuit of the present invention.

[0028] Figure 2 It is the schematic diagram of the power-side voltage clamping circuit.

[0029] Figure 3 It is the schematic diagram of the drive-side voltage clamping circuit.

[0030] Figure 4 It is the schematic diagram when the bilateral bidirectional solid-state circuit breaker circuit is connected to the power grid for governance.

[0031] Figure 5 It is the current-voltage waveform diagram when the bilateral voltage clamping circuit is turned off. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0033] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the present invention.

[0034] It is understood that the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple. The term "a" should not be understood as a limitation on the quantity.

[0035] As Figures 1 to 5 shown, a bilateral bidirectional solid-state circuit breaker circuit includes a main switch device. The main switch device is connected to the main circuit and controlled by a drive circuit. The drive circuit receives a control signal and controls the on / off of the main switch device. A power-side voltage clamping circuit is provided on the power side of the main switch device, and a drive-side voltage clamping circuit is provided on the drive side of the main switch device. The power-side voltage clamping circuit and the drive-side voltage clamping circuit cooperate with each other to clamp the overvoltage during the turn-off process of the main switch device to protect the main switch device.

[0036] Specifically, as Figure 2 shown, the power-side voltage clamping circuit is composed of a triac T1, a varistor MOV, a capacitor C1, a bidirectional transient voltage suppressor diode D1, a resistor R1, a resistor R2, a resistor R3, and a capacitor C2. The resistor R1, the resistor R2, and the resistor R3 are connected in series in sequence. The first anode of the triac T1 is connected to one end of the resistor R1 and is connected to the main circuit. The second anode of the triac T1 is connected to one end of the varistor MOV. The gate of the triac T1 is connected to the other end of the resistor R1. The varistor MOV and the capacitor C1 are both connected in parallel with the resistor R3. One end of the resistor R3 is connected to the main circuit. The capacitor C2 is connected in parallel with the resistor R2. The capacitor C2 and the resistor R2 form a buffer circuit. The bidirectional transient voltage suppressor diode D1 is connected in parallel with the resistor R1.

[0037] Among them, the resistance values of the resistor R1 and the resistor R3 satisfy the following formula:

[0038]

[0039] Among them, V DC is the static bus voltage; V RDM is the maximum withstand voltage value of the triac. R 1、 R 2、 R3 in the formula represent the resistance values of the resistor R1, the resistor R2, and the resistor R3 respectively.

[0040] In the present invention, when selecting the varistor MOV for energy absorption and clamping, it should be satisfied that: at the maximum overvoltage value, the maximum current flowing through it is greater than the bus current, and when the varistor MOV is at the bus voltage, its current value is less than the holding current of the triac T1.

[0041] The bidirectional transient voltage suppressor diode D1 satisfies the following formula:

[0042] ;

[0043] Wherein, V R1 is the voltage division of resistor R1; V BR is the breakdown voltage of bidirectional transient suppression diode D1.

[0044] When the power side voltage clamping circuit is in static operation, resistors R1, R2, and R3 divide the voltage. At this time, the voltage division of resistor R1 is less than the breakdown voltage of bidirectional transient suppression diode D1, so that current does not flow into triac T1, thereby turning on triac T1, and varistor MOV does not absorb energy;

[0045] When dynamically turning off, the voltage on both sides of the main switch device rises rapidly. Capacitor C1 is approximately in a short-circuit state when the voltage changes rapidly. Therefore, almost all the voltage is borne by bidirectional transient suppression diode D1. At this time, the voltage applied to bidirectional transient suppression diode D1 reaches the breakdown voltage of bidirectional transient suppression diode D1, causing bidirectional transient suppression diode D1 to break down. At this time, current flows through the gate of triac T1 and turns on triac T1. The fault current flows into capacitor C1 through triac T1. At this time, bidirectional transient suppression diode D1 is short-circuited and no longer bears voltage, and varistor MOV starts to clamp and absorb the fault current.

[0046] Wherein, assuming that the current is from Figure 2 the ① end to the ② end in is positive, the positive current flows from the ① end through bidirectional transient suppression diode D1, triac T1, and capacitor C1 in sequence and reaches the ② end. When flowing through the gate of triac T1, due to the unique characteristics of triac T1, current flowing through its gate in any direction can turn it on. Therefore, triac T1 is turned on at this time; conversely, assuming that the current is from Figure 2 the ② end to the ① end in is positive, then the current will start from the ② end and flow through capacitor C 1、 triac T1, bidirectional transient suppression diode D1 in sequence and then reach the ① end. When the current flows through the gate of triac T1, triac T1 is turned on.

[0047] As Figure 3 shown, the main switch device consists of two series-connected insulated gate bipolar transistors (IGBTs), namely the first insulated gate bipolar transistor and the second insulated gate bipolar transistor; the emitter of the first insulated gate bipolar transistor is connected to the emitter of the second insulated gate bipolar transistor, and the collector of the first insulated gate bipolar transistor and the collector of the second insulated gate bipolar transistor are connected to the main circuit.

[0048] The drive circuit includes a first drive module and a second drive module (corresponding to Figure 3 U in Driver1 and U Driver2 ).

[0049] The driving - side voltage clamping circuit includes capacitor C3, capacitor C4, bidirectional transient voltage suppressor diode D2, bidirectional transient voltage suppressor diode D3, bidirectional transient voltage suppressor diode D4, and bidirectional transient voltage suppressor diode D5; the positive pole of the first driving module is connected to one end of the bidirectional transient voltage suppressor diode D3 and the gate of the first insulated - gate bipolar transistor at the same time, and the negative pole of the first driving module is connected to the emitter of an insulated - gate bipolar transistor; the other end of the thyristor driver D3 is connected to one end of the thyristor driver D2, and the other end of the thyristor driver D2 is connected to the collector of the first insulated - gate bipolar transistor; the capacitor C3 is connected in parallel with the thyristor driver D3; the negative pole of the second driving module is connected to one end of the bidirectional transient voltage suppressor diode D5 and the gate of the second insulated - gate bipolar transistor at the same time, and the positive pole of the second driving module is connected to the emitter of the second insulated - gate bipolar transistor; the other end of the thyristor driver D5 is connected to one end of the thyristor driver D4, and the other end of the thyristor driver D4 is connected to the collector of the second insulated - gate bipolar transistor; the capacitor C4 is connected in parallel with the thyristor driver D4.

[0050] Among them, the transient - voltage - suppressor diode voltage D2, the transient - voltage - suppressor diode voltage D3, the transient - voltage - suppressor diode voltage D4, the transient - voltage - suppressor diode voltage D5, and the rating selection should meet the following conditions: the maximum clamping voltage after the bidirectional transient voltage suppressor diode D2 and the bidirectional transient voltage suppressor diode D3 are connected in series is less than the residual voltage of the metal - oxide varistor MOV; the maximum clamping voltage after the bidirectional transient voltage suppressor diode D4 and the bidirectional transient voltage suppressor diode D5 are connected in series is less than the residual voltage of the metal - oxide varistor MOV.

[0051] When dynamically turned off, the voltage rises rapidly. Although the varistor MOV will clamp the voltage and bear all fault currents after startup, due to the existence of the parasitic inductance of the varistor, the commutation process from the main switching device to the varistor circuit will not be completed instantaneously. If the fault current is too large at this time, it will break down the main switching device. Therefore, when the voltage rises to the startup point of the varistor MOV, the bidirectional transient suppression diode D2 starts to be broken down, and the current flows into the gate of the insulated gate bipolar transistor (IGBT) from the capacitor C3 and the bidirectional transient suppression diode D2, clamping the turn-off voltage slope of the IGBT. Since the turn-off voltage slope is limited, the voltage rises gradually but slowly at this time. Until the voltage is much greater than the residual voltage of the varistor MOV and the voltage is close to the rated voltage of the main switching device, the bidirectional transient suppression diode D3 is broken down, and the current flows into the gate of the insulated gate bipolar transistor (IGBT) through the bidirectional transient suppression diode D1 and the bidirectional transient suppression diode D3, making its turn-off voltage slope no longer change. At this time, the commutation process is not completely over, so part of the current is in the insulated gate bipolar transistor and the other part is in the varistor. However, the current in the insulated gate bipolar transistor (IGBT) is small and will not cause over-power to burn out the insulated gate bipolar transistor, thus playing a protective role for the insulated gate bipolar transistor.

[0052] As Figure 5 described, Figure 5 Figure 7 is the current-voltage waveform diagram when the bilateral voltage clamping circuit is turned off.

[0053] At time t0, the fault current starts to generate and rises rapidly;

[0054] At time t1, the fault current is detected, and the drive signal is sent out. The IGBT starts to receive the signal and turn off the fault current. At this time, due to the turn-off delay, the current will still increase for a period of time, but due to the characteristics of the IGBT device itself, the voltage rise will be ahead of the current drop.

[0055] At time t2, the current starts to decrease, and the IGBT device has entered the later stage of the Miller plateau. At this time, the voltage rises to the breakdown voltage of the bidirectional transient suppression diode D1, and the bidirectional transient suppression diode D1 is broken down. The pulse current flows into the gate of the triac T1, and the triac T1 is turned on. The voltage of the varistor MOV quickly becomes the same as the main circuit voltage. At this time, the current starts to flow from the triac T l into the capacitor C1, and the voltage rise slope starts to be clamped.

[0056] At time t3, the voltage reaches the first-stage clamping voltage value on the drive side, the bidirectional transient voltage suppression diode D2 is broken down, and the current starts to flow into the gate of the IGBT through the bidirectional transient voltage suppression diode D2 and the capacitor C3. At this time, the rising slope of the current is quickly clamped, and the current flowing into the capacitor C2 starts to decrease rapidly.

[0057] At time t4, the voltage reaches the second-stage clamping voltage value on the drive side, the bidirectional transient voltage suppression diode D3 is broken down, and the current flows into the gate of the IGBT through the bidirectional transient voltage suppression diode D2 and the bidirectional transient voltage suppression diode D3. At this time, the loop voltage will be quickly clamped and the voltage will no longer change. Since the clamping voltage value is greater than the residual voltage value of the metal oxide varistor MOV, the current starts to gradually commutate into the metal oxide varistor MOV at this time and the voltage does not change, resulting in no current flowing into the capacitor C1.

[0058] At time t5, the current has completely commutated into the metal oxide varistor, there is no current in the main circuit, the current energy will be quickly consumed by the metal oxide varistor MOV, and the voltage starts to drop.

[0059] At time t6, the current has basically dropped to about 100 mA. At this time, the current is less than the holding current of the triac T1. Therefore, the triac T1 will turn off, and the capacitor C1 starts to discharge the metal oxide varistor MOV. The voltage on the metal oxide varistor MOV keeps dropping, and the turn-off process is basically over.

[0060] At time t7, the voltage on the capacitor C1 is already the same as the voltage after being divided by the resistor R3, and the turn-off process is completely over.

[0061] The present invention has the following advantages:

[0062] 1. The present invention uses the method of connecting a triac in series with a metal oxide varistor on the power side of the main switching device, which greatly improves the voltage usage level of the solid-state circuit breaker. By triggering the triac T1 through the bidirectional transient voltage suppression diode, it solves the deficiency in the traditional technology that only the voltage level of the power device can be increased to increase the ability to turn off the fault current. Therefore, both the cost and the volume are greatly reduced.

[0063] 2. On the drive side of the main switching device, the transient voltage suppression diode is used to actively clamp the overvoltage of the solid-state circuit breaker. Without almost increasing the cost, it effectively prevents the power device from being broken down by overvoltage when the fault current is too large, ensuring the safety of the power device. Through the cooperation between the power-side voltage clamping circuit and the drive-side voltage clamping circuit, it effectively overcomes the deficiencies in the traditional design and further avoids the risk of the main switching device (IGBT) being broken down.

[0064] The present invention is not limited to the above-mentioned preferred embodiments. Any person can obtain other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, as long as it has a technical solution identical or similar to the present application, it falls within the protection scope of the present invention.

Claims

1. A double-sided bidirectional solid-state circuit breaker circuit, characterized in that: The main switch device includes a main switch device, which is connected to the main circuit and controlled by the drive circuit. The drive circuit receives the control signal and controls the on and off of the main switch device. The power side of the main switch device is provided with a power side voltage clamping circuit, and the drive side of the main switch device is provided with a drive side voltage clamping circuit. The power side voltage clamping circuit and the drive side voltage clamping circuit cooperate with each other and clamp the overvoltage during the shutdown process of the main switch device to protect the main switch device. The power side voltage clamping circuit is composed of a bidirectional thyristor T1, a varistor MOV, a capacitor C1, a bidirectional transient suppression diode D1, a resistor R1, a resistor R2, a resistor R3, and a capacitor C2. The resistors R1, R2, and R3 are connected in series in sequence. The first anode of the bidirectional thyristor T1 is connected to one end of the resistor R1 and connected to the main circuit. The second anode of the bidirectional thyristor T1 is connected to one end of the varistor MOV. The gate of the bidirectional thyristor T1 is connected to the other end of the resistor R1. The varistor MOV and the capacitor C1 are simultaneously connected in parallel with the resistor R3. One end of the resistor R3 is connected to the main circuit. The capacitor C2 is connected in parallel with the resistor R2. The capacitor C2 and the resistor R2 form a buffer circuit. The bidirectional transient suppression diode D1 is connected in parallel with the resistor R1.

2. A double-sided bidirectional solid-state circuit breaker circuit according to claim 1, characterized in that: The resistance values ​​of resistors R1 and R3 satisfy the following formula: Among them, V DC is the static bus voltage; V RDM It is the maximum withstand voltage of the bidirectional thyristor.

3. A double-sided bidirectional solid-state circuit breaker circuit according to claim 1, characterized in that: The bidirectional transient suppression diode D1 satisfies the following formula: ； Among them, V R1 is the voltage divided by resistor R1; V BR is the breakdown voltage of the bidirectional transient suppression diode D1.

4. A double-sided bidirectional solid-state circuit breaker circuit according to claim 1, characterized in that: The selection of the varistor MOV should meet the following requirements: when the overvoltage is at its maximum value, the maximum current flowing through it is greater than the bus current; when the varistor MOV is at the bus voltage, its current value is less than the holding current of the bidirectional thyristor T1.

5. A double-sided bidirectional solid-state circuit breaker circuit according to claim 1, characterized in that: When working statically, the resistors R1, R2 and R3 divide the voltage. At this time, the divided voltage of the resistor R1 is less than the breakdown voltage of the bidirectional transient suppression diode D1, so that the current does not flow into the bidirectional thyristor T1, thereby turning on the bidirectional thyristor T1 and the varistor MOV does not absorb energy. When dynamically turned off, the voltage on both sides of the main switch device rises rapidly, and the voltage applied to the bidirectional transient suppression diode D1 reaches the breakdown voltage of the bidirectional transient suppression diode D1, causing the bidirectional transient suppression diode D1 to break down. At this time, the current flows through the gate of the bidirectional thyristor T1 and turns on the bidirectional thyristor T1. The fault current flows into the capacitor C through the bidirectional thyristor T1. 1， The varistor MOV starts to clamp and absorb the fault current.

6. A double-sided bidirectional solid-state circuit breaker circuit according to claim 1, characterized in that: The main switch device is composed of two insulated gate bipolar transistors connected in series, namely a first insulated gate bipolar transistor and a second insulated gate bipolar transistor; the emitter of the first insulated gate bipolar transistor is connected to the emitter of the second insulated gate bipolar transistor, and the collector of the first insulated gate bipolar transistor and the collector of the second insulated gate bipolar transistor are connected to the main circuit; The driving circuit includes a first driving module and a second driving module, and the driving side voltage clamping circuit includes a capacitor C3, a capacitor C4, a bidirectional transient suppression diode D2, a bidirectional transient suppression diode D3, a bidirectional transient suppression diode D4, and a bidirectional transient suppression diode D5; The positive electrode of the first driving module is connected to one end of the bidirectional transient suppression diode D3 and the gate of the first insulated gate bipolar transistor at the same time, and the negative electrode of the first driving module is connected to the emitter of an insulated gate bipolar transistor; the other end of the silicon-controlled driver D3 is connected to one end of the silicon-controlled driver D2, and the other end of the silicon-controlled driver D2 is connected to the collector of the first insulated gate bipolar transistor; the capacitor C3 is connected in parallel with the silicon-controlled driver D3; The cathode of the second driving module is connected to one end of the bidirectional transient suppression diode D5 and the gate of the second insulated gate bipolar transistor at the same time, and the anode of the second driving module is connected to the emitter of the second insulated gate bipolar transistor; the other end of the thyristor driver D5 is connected to one end of the thyristor driver D4, and the other end of the thyristor driver D4 is connected to the collector of the second insulated gate bipolar transistor; the capacitor C4 is connected in parallel with the thyristor driver D4.

7. A double-sided bidirectional solid-state circuit breaker circuit according to claim 6, characterized in that: The level selection of transient suppression diode voltage D2, transient suppression diode voltage D3, transient suppression diode voltage D4, transient suppression diode voltage D5 should meet the following conditions: The maximum clamping voltage after the bidirectional transient suppression diode D2 and the bidirectional transient suppression diode D3 are connected in series is less than the residual voltage of the varistor MOV; After the bidirectional transient suppression diode D4 and the bidirectional transient suppression diode D5 are connected in series, the maximum clamping voltage is less than the residual voltage of the varistor MOV.

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