A device and method for synchronization control and fault protection based on a GaAs photoconductive switch

Abstract

The application belongs to the field of power electronic drive and protection, and relates to a device and method for synchronous control and fault protection based on GaAs photoconductive switch, which comprises the following steps: optically coupling the light signal output end of a synchronous light trigger module and the photosensitive trigger end of a GaAs photoconductive switch load module; connecting the detection end of an electric parameter detection module and the main power loop of the GaAs photoconductive switch load module; connecting the signal output end of the electric parameter detection module and the signal input end of a threshold comparison control module; connecting the protection signal output end of the threshold comparison control module and the trigger control end of the synchronous light trigger module and the protection end of the GaAs photoconductive switch load module, respectively; and realizing accurate triggering and full-condition protection of the GaAs photoconductive switch and improving the working stability and reliability of the GaAs photoconductive switch under high-voltage and large-current working conditions.

Description

Technical Field

[0001] This invention relates to the field of power electronic drive and protection, and specifically discloses a device and method for synchronous control and fault protection based on GaAs photoconductive switches. Background Technology

[0002] GaAs photoconductive switches are optically controlled switching elements based on gallium arsenide semiconductor materials. They feature fast response speed, high voltage resistance, and strong current carrying capacity, and are widely used in high-end industrial fields such as pulse power, laser systems, and power system control. The switching of GaAs photoconductive switches is triggered by optical signals, and their semiconductor substrates are delicate. Under high voltage and high current conditions, asynchronous triggering optical signals or excessive operating voltage / current can easily lead to device breakdown and burnout, affecting the reliability of equipment operation.

[0003] In existing technologies, the supporting circuits for GaAs photoconductive switches are mostly single trigger circuits or simple overcurrent protection circuits, which have obvious technical defects: First, the trigger circuits are mostly single-channel optical signal outputs without synchronous design. When multiple GaAs photoconductive switches work together, timing deviations are prone to occur, leading to current distortion and damage to the switches. Second, there is a lack of real-time detection of the operating electrical parameters of GaAs photoconductive switches, making it impossible to predict faults in advance. Relying solely on downstream fuses for passive protection results in slow protection response. Third, there is no effective electrical isolation between the trigger circuit and the main power circuit. High-voltage interference can easily enter the low-voltage trigger circuit, causing trigger signal distortion.

[0004] In view of this, the present invention provides a device and method for synchronous control and fault protection based on GaAs photoconductive switches, which integrates modules such as synchronous optical triggering, real-time detection of electrical parameters and active fault protection, to achieve accurate triggering and full-condition protection of GaAs photoconductive switches, and improve their working stability and reliability under high voltage and high current conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for synchronous control and fault protection based on GaAs photoconductive switches, addressing the technical problems of asynchronous triggering, lack of real-time detection, and slow protection response in GaAs photoconductive switch circuits. The specific solution is as follows: A device for synchronous control and fault protection based on GaAs photoconductive switch includes a synchronous optical triggering module, an electrical parameter detection module, a threshold comparison control module, and a GaAs photoconductive switch load module. The optical signal output terminal of the synchronous optical triggering module is optically coupled to the photosensitive triggering terminal of the GaAs photoconductor switch load module, and is used to output synchronous optical pulses to trigger the GaAs photoconductor switch to turn on. The detection terminal of the electrical parameter detection module is connected to the main power circuit of the GaAs photoconductive switch load module, and is used to collect the working voltage and working current signals of the GaAs photoconductive switch and convert them into low-voltage detection signals; the signal output terminal of the electrical parameter detection module is connected to the signal input terminal of the threshold comparison control module. The protection signal output terminal of the threshold comparison control module is connected to the trigger control terminal of the synchronous light trigger module and the protection terminal of the GaAs photoconductive switch load module, respectively. It is used to compare the detection signal with the preset threshold, and output a protection signal and shut down the synchronous light trigger module when there is an abnormality.

[0006] Furthermore, the synchronous optical triggering module includes a trigger signal input interface, an NPN transistor Q1, a current-limiting resistor R1, a current-limiting resistor R2, a laser diode LD1, a filter capacitor C1, and a filter capacitor C2; The trigger signal input interface is connected to the base of NPN transistor Q1 via current-limiting resistor R1; The emitter of the NPN transistor Q1 is connected to the system signal ground GND_SIG, and the collector is connected to the negative terminal of the laser diode LD1 via the current limiting resistor R2. The positive terminal of the laser diode LD1 is connected to a DC power supply; The filter capacitor C1 is connected in parallel between the DC power supply and the system signal ground GND_SIG; The filter capacitor C2 is connected in parallel between the base and emitter of the NPN transistor Q1; The light-emitting end of the laser diode LD1 is optically coupled to the photosensitive surface of the GaAs photoconductive switch via an optical fiber.

[0007] Furthermore, the electrical parameter detection module includes a first operational amplifier U1, a second operational amplifier U2, a high-voltage divider resistor R3, a high-voltage divider resistor R4, a sampling resistor R_SENSE, an amplification resistor Rg, an amplification resistor Rf, a decoupling capacitor C3, and a decoupling capacitor C4. The power supply terminals of the first operational amplifier U1 and the second operational amplifier U2 are both connected to a DC power supply, and their ground terminals are both connected to the system signal ground GND_SIG. The inverting terminal and the output terminal of the first operational amplifier U1 are shorted to form a voltage follower, and the output terminal is the voltage detection signal terminal DET_V. The inverting terminal of the second operational amplifier U2 is connected to the system signal ground GND_SIG through an amplification resistor Rg, and the output terminal is connected to its inverting terminal through an amplification resistor Rf to form a differential amplifier circuit, and the output terminal is the current detection signal terminal DET_I. The high-voltage divider resistors R3 and R4 are connected in series and then in parallel across the two ends of the GaAs photoconductive switch, with the voltage divider node connected to the non-inverting input of the first operational amplifier U1. The sampling resistor R_SENSE is connected in series between the main power circuit of the GaAs photoconductive switch and the main power ground GND_PWR. One end is connected to the non-inverting input of the second operational amplifier U2, and the other end is connected to the inverting input of the second operational amplifier U2. The decoupling capacitors C3 and C4 are connected in parallel between the power supply terminal and the ground terminal of the first operational amplifier U1 and the second operational amplifier U2, respectively.

[0008] Furthermore, both the high-voltage divider resistor R3 and the high-voltage divider resistor R4 are 1MΩ metal film resistors; the sampling resistor R_SENSE is a 0.01Ω, 100W metal film resistor; the amplification resistor Rg is 1kΩ; the amplification resistor Rf is 10kΩ; and the amplification factor of the differential amplifier circuit is 11 times.

[0009] Furthermore, the threshold comparison control module includes a third operational amplifier U3, a precision potentiometer W1, a precision potentiometer W2, an NPN transistor Q2, a hysteresis feedback resistor R_UV, a hysteresis feedback resistor R_OC, a base limiting current resistor R_B, and a decoupling capacitor C5. The power supply terminal of the third operational amplifier U3 is connected to a DC power supply, and the ground terminal is connected to the system signal ground GND_SIG. The non-inverting terminal of the first channel of the third operational amplifier U3 is connected to the voltage detection signal terminal DET_V, and the output terminal of the first channel is connected to its inverting terminal via the hysteresis feedback resistor R_UV to form a voltage hysteresis comparator circuit. The non-inverting terminal of the second channel of the third operational amplifier U3 is connected to the current detection signal terminal DET_I, and the output terminal of the second channel is connected to its inverting terminal via the hysteresis feedback resistor R_OC to form a current hysteresis comparator circuit. The output terminals of the first and second channels of the third operational amplifier U3 are combined and connected to the base of the NPN transistor Q2 via the base limiting current resistor R_B. The decoupling capacitor C5 is connected in parallel between the power supply terminal and the ground terminal of the third operational amplifier U3; Both ends of the precision potentiometer W1 and the precision potentiometer W2 are connected to the DC power supply and the system signal ground GND_SIG, respectively; the middle tap of the precision potentiometer W1 is connected to the inverting input of the first channel of the third operational amplifier U3; the middle tap of the precision potentiometer W2 is connected to the inverting input of the second channel of the third operational amplifier U3. The emitter of the NPN transistor Q2 is connected to the system signal ground GND_SIG, and the collector is the protection signal output terminal TRIG_IN. The protection signal output terminal TRIG_IN is connected to the trigger signal input interface of the synchronous optical trigger module.

[0010] Furthermore, both the precision potentiometer W1 and the precision potentiometer W2 are 10kΩ through-hole potentiometers; both the hysteresis feedback resistor R_UV and the hysteresis feedback resistor R_OC are 1kΩ; the base limiting current resistor R_B is 100Ω; the NPN transistors Q1 and Q2 are S9013 transistors; and the laser diode LD1 is an 808nm laser diode.

[0011] Furthermore, the system signal ground GND_SIG and the main power ground GND_PWR are connected in a single-point common ground manner; the operating power supplies of the synchronous optical trigger module, the electrical parameter detection module and the threshold comparison control module are all DC power supplies, and are electrically isolated from the main power circuit of the GaAs photoconductive switch.

[0012] This invention also provides a method for synchronization control and fault protection based on GaAs photoconductive switches, applied to the aforementioned device for synchronization control and fault protection based on GaAs photoconductive switches, comprising: S1: The synchronous light triggering module receives an external pulse triggering signal and outputs a synchronous light pulse to the photosensitive triggering terminal of the GaAs photoconductor switch to trigger the GaAs photoconductor switch to conduct. S2: The electrical parameter detection module collects the working voltage and current signals of the GaAs photoconductive switch in real time, converts them into low-voltage detection signals, and outputs them to the threshold comparison control module. S3: The threshold comparison control module compares the received low-voltage detection signal with the preset overvoltage threshold and overcurrent threshold. If any detection signal exceeds the corresponding threshold, a protection signal is output to shut down the synchronous light trigger module, thereby turning off the GaAs photoconductor switch.

[0013] Furthermore, a single external pulse trigger signal drives multiple laser diodes to achieve zero-phase-difference synchronous triggering of multiple GaAs photoconductive switches; The optical signal output by the laser diode is transmitted to the GaAs photoconductive switch through an optical fiber to achieve electrical isolation between the low-voltage trigger circuit and the high-voltage main power circuit.

[0014] Furthermore, it also includes: using a hysteresis comparator circuit to perform threshold comparison to form a voltage hysteresis window; When the detection signal recovers to below the threshold, the protection signal is removed, and normal operation is restored.

[0015] The present invention has the following advantages and beneficial effects: This invention achieves precise synchronous optical triggering, real-time voltage / current detection, and active fault protection for GaAs photoconductive switches through modular circuit design. The circuit structure is simple, the components are universal, and the reliability is high.

[0016] This invention uses fiber optic coupling to transmit trigger signals, achieving electrical isolation between the low-voltage trigger circuit and the high-voltage main power circuit, avoiding high-voltage interference. Furthermore, a single trigger signal can drive multiple laser diodes, realizing zero-phase-difference synchronous triggering of multiple GaAs photoconductive switches and solving the current distortion problem caused by trigger timing deviation.

[0017] This invention achieves isolated and stepped-down detection of high-voltage signals from GaAs photoconductive switches using a voltage follower, and achieves accurate sampling and amplification of large currents using a differential amplifier circuit. The voltage and current detection signals are distortion-free and can reflect the working status of GaAs photoconductive switches in real time. This invention uses a hysteresis comparator circuit for threshold judgment, which can effectively avoid false triggering caused by signal fluctuations. When any electrical parameter exceeds the standard, a protection signal is immediately output and the triggering module is shut down, realizing active fault protection. Compared with traditional passive protection, the response speed is greatly improved. Attached Figure Description

[0018] Figure 1 This is an exemplary circuit schematic of the synchronous optical triggering module proposed in this invention; Figure 2 This is an exemplary circuit schematic diagram of the electrical parameter detection module proposed in this invention; Figure 3 This is an exemplary circuit schematic of the threshold comparison control module proposed in this invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] The present invention provides a device for synchronous control and fault protection based on GaAs photoconductive switch, comprising a synchronous optical triggering module, an electrical parameter detection module, a threshold comparison control module, and a GaAs photoconductive switch load module.

[0021] The optical signal output terminal of the synchronous optical trigger module is optically coupled to the photosensitive trigger terminal of the GaAs photoconductive switch load module, and is used to output synchronous optical pulses to trigger the GaAs photoconductive switch to conduct. The synchronous optical trigger module includes a trigger signal input interface, an NPN transistor Q1, current-limiting resistors R1 and R2, a laser diode LD1, filter capacitors C1 and C2.

[0022] The trigger signal input interface is connected to the base of NPN transistor Q1 via current-limiting resistor R1; the emitter of NPN transistor Q1 is connected to system signal ground GND_SIG, and the collector is connected to the negative terminal of laser diode LD1 via current-limiting resistor R2; the positive terminal of laser diode LD1 is connected to +5V DC power supply; filter capacitor C1 is connected in parallel between +5V DC power supply and system signal ground GND_SIG; filter capacitor C2 is connected in parallel between the base and emitter of NPN transistor Q1; the light-emitting end of laser diode LD1 is optically coupled to the photosensitive surface of GaAs photoconductive switch via optical fiber. Optical fiber transmission can achieve electrical isolation, avoiding high-voltage interference to the trigger circuit in the main power circuit, and a single trigger signal can drive multiple laser diodes, achieving zero-phase-difference synchronous triggering of multiple GaAs photoconductive switches. Figure 1 As shown, the working process of the synchronous optical trigger module is as follows: An external pulse trigger signal is connected to the trigger signal input interface. When the trigger signal is high, Q1 conducts, and the +5V power supply forms a conduction loop through LD1, R2, Q1 to GND_SIG. LD1 emits light, and the optical signal is coupled to the photosensitive surface of the GaAs photoconductive switch through the optical fiber, triggering the GaAs photoconductive switch to conduct. When the trigger signal is low, Q1 is cut off, LD1 is extinguished, and the GaAs photoconductive switch is turned off. The optical fiber provides electrical isolation, preventing high voltage from the main power circuit of the GaAs photoconductive switch from entering the trigger module. If multiple GaAs photoconductive switches need to work synchronously, the collector of Q1 can be connected to multiple current-limiting resistors and laser diodes to enable a single trigger signal to drive multiple LD1s, ensuring zero phase difference in the trigger optical signals of all GaAs photoconductive switches and achieving synchronous conduction.

[0023] The electrical parameter detection module includes a voltage detection branch and a current detection branch. The detection end of the electrical parameter detection module is connected to the main power circuit of the GaAs photoconductive switch load module, used to acquire the operating voltage and current signals of the GaAs photoconductive switch and convert them into a low-voltage detection signal. The signal output end of the electrical parameter detection module is connected to the signal input end of the threshold comparison control module. Figure 2 As shown, the electrical parameter detection module includes a first operational amplifier U1, a second operational amplifier U2, high-voltage divider resistors R3 and R4, a sampling resistor R_SENSE, an amplification resistor Rg, an amplification resistor Rf, a decoupling capacitor C3, and a decoupling capacitor C4. The high-voltage divider resistors R3 and R4 are both 1MΩ metal film resistors; the sampling resistor R_SENSE is a 0.01Ω, 100W metal film resistor; the amplification resistor Rg is 1kΩ; the amplification resistor Rf is 10kΩ; the differential amplifier circuit has an amplification factor of 11 times to amplify the weak current sampling voltage to a recognizable range; the decoupling capacitors C3 and C4 are 0.1μF decoupling capacitors; the first operational amplifier U1 and the second operational amplifier U2 are selected as LM358 operational amplifiers.

[0024] The power supply terminals of the first operational amplifier U1 and the second operational amplifier U2 are both connected to a +5V DC power supply, and their ground terminals are both connected to the system signal ground GND_SIG. The inverting terminal and the output terminal of the first operational amplifier U1 are shorted to form a voltage follower. The output terminal is the voltage detection signal terminal DET_V, and the output is a low-voltage detection signal that is proportional to the operating voltage of the GaAs photoconductive switch. The voltage follower has high input impedance and low output impedance to avoid the influence of the detection circuit on the main power circuit. The inverting input of the second operational amplifier U2 is connected to the system signal ground GND_SIG via an amplification resistor Rg, and its output is connected to its inverting input via an amplification resistor Rf, forming a differential amplifier circuit. The output is the current detection signal terminal DET_I. High-voltage divider resistors R3 and R4 are connected in series and then in parallel across the GaAs photoconductive switch to divide the high voltage of the GaAs photoconductive switch. The low-voltage signal after voltage division is connected to the non-inverting input of the first operational amplifier U1. The sampling resistor R_SENSE is connected in series between the main power circuit of the GaAs photoconductive switch and the main power ground GND_PWR. One end is connected to the non-inverting input of the second operational amplifier U2, and the other end is connected to the inverting input of the second operational amplifier U2. All the operating current of the GaAs photoconductive switch flows through R_SENSE. According to Ohm's law, a millivolt-level voltage difference proportional to the operating current is generated across R_SENSE. This voltage difference is connected to the non-inverting and inverting inputs of U2. U2, Rg, and Rf form a differential amplifier circuit with a gain of [missing value]. The millivolt-level sampling voltage is amplified to a volt-level low-voltage signal. The DET_I output of U2 is a detection signal proportional to the operating current of the GaAs photoconductive switch, achieving accurate sampling and amplification of large currents. Decoupling capacitors C3 and C4 are connected in parallel between the power supply terminals and ground terminals of the first operational amplifier U1 and the second operational amplifier U2, respectively, to filter out power supply noise and improve the stability of the detection signal.

[0025] The protection signal output terminal of the threshold comparison control module is connected to the trigger control terminal of the synchronous light trigger module and the protection terminal of the GaAs photoconductive switch load module, respectively. This is used to compare the detection signal with a preset threshold; in case of an anomaly, a protection signal is output and the synchronous light trigger module is shut down. For example... Figure 3 As shown, the threshold comparison control module includes a third operational amplifier U3, a precision potentiometer W1, a precision potentiometer W2, an NPN transistor Q2, a hysteresis feedback resistor R_UV, a hysteresis feedback resistor R_OC, a base limiting current resistor R_B, and a decoupling capacitor C5.

[0026] The power supply terminal of the third operational amplifier U3 is connected to a +5V DC power supply, and the ground terminal is connected to the system signal ground GND_SIG. The non-inverting input of the first channel of the third operational amplifier U3 is connected to the voltage detection signal terminal DET_V, and the output terminal of the first channel is connected to its inverting input via the hysteresis feedback resistor R_UV to form a voltage hysteresis comparator circuit. The non-inverting input of the second channel of the third operational amplifier U3 is connected to the current detection signal terminal DET_I, and the output terminal of the second channel is connected to its inverting input via the hysteresis feedback resistor R_OC to form a current hysteresis comparator circuit. The hysteresis comparator circuit effectively avoids false triggering caused by fluctuations in the detection signal near the threshold, improving the anti-interference capability of the control circuit. The output terminals of the first and second channels of the third operational amplifier U3 are combined and connected to the base of the NPN transistor Q2 via the base limiting current resistor R_B. The decoupling capacitor C5 is connected in parallel with the third operational amplifier. The power supply terminal and ground terminal of U3 are connected; both ends of the precision potentiometers W1 and W2 are respectively connected to the +5V DC power supply and the system signal ground GND_SIG; the middle tap of the precision potentiometer W1 is connected to the inverting input of the first channel of the third operational amplifier U3; the middle tap of the precision potentiometer W2 is connected to the inverting input of the second channel of the third operational amplifier U3. By adjusting the middle tap of the potentiometer, the overvoltage and overcurrent protection thresholds can be manually and accurately set; the emitter of the NPN transistor Q2 is connected to the system signal ground GND_SIG, and the collector is the protection signal output terminal TRIG_IN. The protection signal output terminal TRIG_IN is connected to the trigger signal input interface of the synchronous light trigger module. When any electrical parameter exceeds the standard, Q2 conducts and outputs a high-level protection signal, immediately shutting down the synchronous light trigger module to achieve active fault protection. Both precision potentiometers W1 and W2 are 10kΩ through-hole potentiometers; hysteresis feedback resistors R_UV and R_OC are both 1kΩ; the base limiting current resistor R_B is 100Ω; NPN transistors Q1 and Q2 are S9013 transistors; the laser diode LD1 is an 808nm laser diode, adapted to the photosensitive response wavelength of the GaAs photoconductive switch; the operational amplifier is an LM358, which compares the detection signal with a preset threshold; C5 is a 0.1μF decoupling capacitor, and the operating power supply is a +5V DC power supply.

[0027] The threshold comparison control module performs threshold setting, hysteresis comparison, and protection signal output. Threshold setting is as follows: W1 and W2 are connected to a +5V power supply and GND_SIG respectively. Rotating the adjustment knobs of W1 and W2 changes the output voltage of the center tap, setting the overvoltage and overcurrent protection thresholds of the GaAs photoconductive switch to suit different operating conditions. Hysteresis comparison is as follows: DET_V is connected to the non-inverting input of U3A and compared with the overvoltage threshold set by W1. The output of U3A is connected to the inverting input via R_UV to form a voltage hysteresis comparison circuit. DET_I is connected to the non-inverting input of U4A and compared with the overcurrent threshold set by W2. The output of U4A is connected to the inverting input via R_OC to form a current hysteresis comparison circuit. The hysteresis comparison circuit forms a voltage hysteresis window, effectively avoiding frequent switching of Q2 caused by fluctuations in the detection signal near the threshold, thus improving the circuit's anti-interference capability. The protection signal output is as follows: When the GaAs photoconductor switch is working normally, DET_V and DET_I are both below the preset threshold, U3A and U4A both output low level, Q2 is cut off, TRIG_IN is low level, and the synchronous light triggering module works normally; when the GaAs photoconductor switch has an overvoltage or overcurrent fault, the corresponding DET_V or DET_I exceeds the preset threshold, U3A or U4A outputs high level, which drives Q2 to conduct through R_B, and TRIG_IN outputs a high-level protection signal. This signal is transmitted to the trigger signal input interface of the synchronous light triggering module, immediately shutting off the trigger signal, LD1 is extinguished, and the GaAs photoconductor switch is turned off, realizing active fault protection and preventing the GaAs photoconductor switch from being broken down or burned due to overvoltage or overcurrent.

[0028] The system signal ground GND_SIG and the main power ground GND_PWR are connected in a single-point common ground manner to avoid ground loop interference; the synchronous optical trigger module, the electrical parameter detection module and the threshold comparison control module are all powered by +5V low-voltage DC power supply and are electrically isolated from the main power circuit of the GaAs photoconductive switch to improve the safety of circuit operation.

[0029] This invention also provides a method for synchronous control and fault protection based on GaAs photoconductive switches, comprising the following steps: S1: The synchronous optical trigger module receives an external pulse trigger signal and outputs a synchronous optical pulse to the photosensitive trigger terminal of the GaAs photoconductive switch, triggering the GaAs photoconductive switch to conduct. A single external pulse trigger signal drives multiple laser diodes to achieve zero-phase-difference synchronous triggering of multiple GaAs photoconductive switches; the optical signal output by the laser diode is transmitted to the GaAs photoconductive switch through optical fiber, achieving electrical isolation between the low-voltage trigger circuit and the high-voltage main power circuit.

[0030] S2: The electrical parameter detection module collects the working voltage and current signals of the GaAs photoconductive switch in real time, converts them into low-voltage detection signals, and outputs them to the threshold comparison control module.

[0031] S3: The threshold comparison control module compares the received low-voltage detection signal with the preset overvoltage and overcurrent thresholds. If either detection signal exceeds the corresponding threshold, a protection signal is output to shut down the synchronous optical trigger module, causing the GaAs photoconductor switch to turn off. A hysteresis comparison circuit is used for threshold comparison to form a voltage hysteresis window; when the detection signal recovers to below the threshold, the protection signal is canceled, and normal operation is restored.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for synchronous control and fault protection based on GaAs photoconductive switches, characterized in that, It includes a synchronous optical triggering module, an electrical parameter detection module, a threshold comparison and control module, and a GaAs photoconductor switch load module; The optical signal output terminal of the synchronous optical triggering module is optically coupled to the photosensitive triggering terminal of the GaAs photoconductor switch load module, and is used to output synchronous optical pulses to trigger the GaAs photoconductor switch to turn on. The detection terminal of the electrical parameter detection module is connected to the main power circuit of the GaAs photoconductive switch load module, and is used to collect the working voltage and working current signals of the GaAs photoconductive switch and convert them into low-voltage detection signals; the signal output terminal of the electrical parameter detection module is connected to the signal input terminal of the threshold comparison control module. The protection signal output terminal of the threshold comparison control module is connected to the trigger control terminal of the synchronous light trigger module and the protection terminal of the GaAs photoconductive switch load module, respectively. It is used to compare the detection signal with the preset threshold, and output a protection signal and shut down the synchronous light trigger module when there is an abnormality.

2. The device for synchronous control and fault protection based on GaAs photoconductive switches according to claim 1, characterized in that, The synchronous light triggering module includes a trigger signal input interface, an NPN transistor Q1, a current-limiting resistor R1, a current-limiting resistor R2, a laser diode LD1, a filter capacitor C1, and a filter capacitor C2. The trigger signal input interface is connected to the base of NPN transistor Q1 via current-limiting resistor R1; The emitter of the NPN transistor Q1 is connected to the system signal ground GND_SIG, and the collector is connected to the negative terminal of the laser diode LD1 via the current limiting resistor R2. The positive terminal of the laser diode LD1 is connected to a DC power supply; The filter capacitor C1 is connected in parallel between the DC power supply and the system signal ground GND_SIG; The filter capacitor C2 is connected in parallel between the base and emitter of the NPN transistor Q1; The light-emitting end of the laser diode LD1 is optically coupled to the photosensitive surface of the GaAs photoconductive switch via an optical fiber.

3. The device for synchronous control and fault protection based on GaAs photoconductive switches according to claim 1, characterized in that, The electrical parameter detection module includes a first operational amplifier U1, a second operational amplifier U2, a high-voltage divider resistor R3, a high-voltage divider resistor R4, a sampling resistor R_SENSE, an amplification resistor Rg, an amplification resistor Rf, a decoupling capacitor C3, and a decoupling capacitor C4. The power supply terminals of the first operational amplifier U1 and the second operational amplifier U2 are both connected to a DC power supply, and their ground terminals are both connected to the system signal ground GND_SIG. The inverting terminal and the output terminal of the first operational amplifier U1 are shorted to form a voltage follower, and the output terminal is the voltage detection signal terminal DET_V. The inverting terminal of the second operational amplifier U2 is connected to the system signal ground GND_SIG through an amplification resistor Rg, and the output terminal is connected to its inverting terminal through an amplification resistor Rf to form a differential amplifier circuit, and the output terminal is the current detection signal terminal DET_I. The high-voltage divider resistors R3 and R4 are connected in series and then in parallel across the two ends of the GaAs photoconductive switch, with the voltage divider node connected to the non-inverting input of the first operational amplifier U1. The sampling resistor R_SENSE is connected in series between the main power circuit of the GaAs photoconductive switch and the main power ground GND_PWR. One end is connected to the non-inverting input of the second operational amplifier U2, and the other end is connected to the inverting input of the second operational amplifier U2. The decoupling capacitors C3 and C4 are connected in parallel between the power supply terminal and the ground terminal of the first operational amplifier U1 and the second operational amplifier U2, respectively.

4. The device for synchronous control and fault protection based on GaAs photoconductive switches according to claim 3, characterized in that, The high-voltage divider resistors R3 and R4 are both 1MΩ metal film resistors; the sampling resistor R_SENSE is a 0.01Ω, 100W metal film resistor; the amplification resistor Rg is 1kΩ; the amplification resistor Rf is 10kΩ; and the amplification factor of the differential amplifier circuit is 11 times.

5. The device for synchronous control and fault protection based on GaAs photoconductive switches according to claim 2, characterized in that, The threshold comparison control module includes a third operational amplifier U3, a precision potentiometer W1, a precision potentiometer W2, an NPN transistor Q2, a hysteresis feedback resistor R_UV, a hysteresis feedback resistor R_OC, a base limiting current resistor R_B, and a decoupling capacitor C5. The power supply terminal of the third operational amplifier U3 is connected to a DC power supply, and the ground terminal is connected to the system signal ground GND_SIG. The non-inverting terminal of the first channel of the third operational amplifier U3 is connected to the voltage detection signal terminal DET_V, and the output terminal of the first channel is connected to its inverting terminal via the hysteresis feedback resistor R_UV to form a voltage hysteresis comparator circuit. The non-inverting terminal of the second channel of the third operational amplifier U3 is connected to the current detection signal terminal DET_I, and the output terminal of the second channel is connected to its inverting terminal via the hysteresis feedback resistor R_OC to form a current hysteresis comparator circuit. The output terminals of the first and second channels of the third operational amplifier U3 are combined and connected to the base of the NPN transistor Q2 via the base limiting current resistor R_B. The decoupling capacitor C5 is connected in parallel between the power supply terminal and the ground terminal of the third operational amplifier U3; Both ends of the precision potentiometer W1 and the precision potentiometer W2 are connected to the DC power supply and the system signal ground GND_SIG, respectively; the middle tap of the precision potentiometer W1 is connected to the inverting input of the first channel of the third operational amplifier U3; the middle tap of the precision potentiometer W2 is connected to the inverting input of the second channel of the third operational amplifier U3. The emitter of the NPN transistor Q2 is connected to the system signal ground GND_SIG, and the collector is the protection signal output terminal TRIG_IN. The protection signal output terminal TRIG_IN is connected to the trigger signal input interface of the synchronous optical trigger module.

6. The device for synchronous control and fault protection based on GaAs photoconductive switches according to claim 5, characterized in that, Both precision potentiometers W1 and W2 are 10kΩ through-hole potentiometers; both hysteresis feedback resistors R_UV and R_OC are 1kΩ; the base limiting current resistor R_B is 100Ω; both NPN transistors Q1 and Q2 are S9013 transistors; and the laser diode LD1 is an 808nm laser diode.

7. The device for synchronous control and fault protection based on GaAs photoconductive switches according to claim 1, characterized in that, The system signal ground GND_SIG and the main power ground GND_PWR are connected in a single-point common ground manner; the operating power supplies of the synchronous optical trigger module, the electrical parameter detection module and the threshold comparison control module are all DC power supplies, and are electrically isolated from the main power circuit of the GaAs photoconductive switch.

8. A method for synchronous control and fault protection based on GaAs photoconductive switches, characterized in that, The device for synchronous control and fault protection based on GaAs photoconductive switches as described in any one of claims 1-7, comprising: S1: The synchronous light triggering module receives an external pulse triggering signal and outputs a synchronous light pulse to the photosensitive triggering terminal of the GaAs photoconductor switch to trigger the GaAs photoconductor switch to conduct. S2: The electrical parameter detection module collects the working voltage and current signals of the GaAs photoconductive switch in real time, converts them into low-voltage detection signals, and outputs them to the threshold comparison control module. S3: The threshold comparison control module compares the received low-voltage detection signal with the preset overvoltage threshold and overcurrent threshold. If any detection signal exceeds the corresponding threshold, a protection signal is output to shut down the synchronous light trigger module, thereby turning off the GaAs photoconductor switch.

9. The method for synchronous control and fault protection based on GaAs photoconductive switches according to claim 8, characterized in that, A single external pulse trigger signal drives multiple laser diodes to achieve zero-phase-difference synchronous triggering of multiple GaAs photoconductive switches; The optical signal output by the laser diode is transmitted to the GaAs photoconductive switch through an optical fiber to achieve electrical isolation between the low-voltage trigger circuit and the high-voltage main power circuit.

10. The method for synchronous control and fault protection based on GaAs photoconductive switches according to claim 8, characterized in that, Also includes: A hysteresis comparator circuit is used to perform threshold comparison to form a voltage hysteresis window; When the detection signal recovers to below the threshold, the protection signal is removed, and normal operation is restored.

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