Uninterruptible igbt antiparallel control device and method

Abstract

The present application relates to the technical field of power distribution line power supply guarantee, in particular to an IGBT anti-parallel control device and method for uninterrupted power supply, comprising a voltage detection module, a core control module, an IGBT anti-parallel driving module, a fault protection module, a circuit breaker linkage module and an isolated power supply module; the output end of the voltage detection module is electrically connected with the input end of the core control module, the output end of the fault protection module is electrically connected with the input end of the core control module, the output end of the core control module is respectively electrically connected with the input end of the IGBT anti-parallel driving module and the circuit breaker linkage module, and the output end of the isolated power supply module is electrically connected with the power input end of all the remaining modules, so as to realize the coordinated interaction of the power supply and signals of the whole device; the device adopts a full-control type topology of IGBT anti-parallel, cooperates with accurate time-sharing driving and voltage and current equalization design, realizes the fast, no-inrush and uninterrupted power supply of 10kV lines, has perfect fault protection function at the same time, and improves the power supply reliability and safety.

Description

Technical Field

[0001] This invention relates to the technical field of power supply protection for power distribution lines, and in particular to an IGBT anti-parallel control device and method for uninterrupted power supply. Background Technology

[0002] During the operation of 10kV distribution lines, switching operations are often required due to line maintenance, fault tripping, and other reasons. However, due to the large angle difference between many switching lines, loop closing operations cannot be performed, resulting in power outages for users on the switching lines and affecting normal production and life. To solve this problem, uninterruptible power supply equipment has emerged. Its core requirement is to quickly connect the power supply to the line after the circuit breaker of the switching line is disconnected, so as to achieve seamless power supply connection.

[0003] Currently, commonly used switching devices in uninterruptible power supply (UPS) equipment include mechanical switches and power electronic switches. Although mechanical switches are lower in cost, they have slow operating speeds, cannot achieve rapid switching, and are prone to arcing and inrush current, affecting power supply stability. Power electronic switches, such as IGBTs, have advantages such as fast switching speed, high control precision, and no arcing, and have gradually become the core components of UPS equipment. However, IGBTs are unidirectional conductors and cannot directly conduct AC current. Existing technologies often use a semi-controlled topology with IGBTs and fast recovery diodes in anti-parallel connection to achieve AC conduction. However, this topology has problems such as the inability to actively control reverse switching and the tendency to generate surges during freewheeling, making it unsuitable for the rapid switching requirements of 10kV lines. At the same time, in high-voltage scenarios, the withstand voltage of a single IGBT is insufficient, requiring the use of series-parallel topologies. How to ensure voltage equalization of series IGBTs, current equalization of parallel IGBTs, and synchronous drive and time-sharing control of anti-parallel IGBTs are the main challenges faced by existing technologies.

[0004] Therefore, developing an IGBT anti-parallel control device and method that can achieve uninterrupted power supply to the line, possess active control of AC conduction capability, and take into account voltage and current equalization and safety protection is of great practical significance. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an IGBT anti-parallel control device and method that employs a fully controlled topology with IGBT anti-parallel connection, combined with precise time-sharing drive and voltage and current equalization design, to achieve fast, inrush-free, and uninterrupted power supply to 10kV lines, while also possessing comprehensive fault protection functions, thereby improving the reliability and safety of power supply.

[0006] The uninterrupted power supply IGBT anti-parallel control device of the present invention includes a voltage detection module, a core control module, an IGBT anti-parallel drive module, a fault protection module, a circuit breaker linkage module, and an isolation power supply module. The output of the voltage detection module is electrically connected to the input of the core control module, the output of the fault protection module is electrically connected to the input of the core control module, the output of the core control module is electrically connected to the input of the IGBT anti-parallel drive module and the circuit breaker linkage module respectively, and the output of the isolation power supply module is electrically connected to the power input of all other modules, realizing the coordinated interaction of power supply and signal of the whole device.

[0007] Preferably, the voltage detection module includes multiple 10kV / 100V precision voltage transformers and a signal conditioning circuit. The multiple voltage transformers respectively collect the three-phase voltage at the incoming end and the three-phase voltage at the outgoing end of the circuit breaker. The signal conditioning circuit converts the 100V AC signal output by the voltage transformers into a low-voltage analog signal of 0~3.3V after rectification, filtering, voltage division, voltage following, amplitude limiting and linear optocoupler isolation, and then transmits it to the core control module.

[0008] Preferably, the core control module uses an STM32F407IGT6 chip to achieve voltage signal acquisition, AC phase detection, IGBT anti-parallel time-sharing drive logic operation, PWM signal generation, circuit breaker linkage control, and fault protection logic processing. The core control module is also equipped with an RS485 / CAN communication interface and a human-machine interface. The RS485 / CAN communication interface enables linkage with the power distribution automation system, and the human-machine interface includes a rotary encoder and a touch screen for setting voltage abnormality thresholds, IGBT soft start time, circuit breaker closing delay, and protection action values.

[0009] Preferably, the IGBT anti-parallel drive module adopts a three-phase bridge arm structure, with each phase bridge arm consisting of two sets of IGBT series units connected in anti-parallel. Each set of IGBT series units consists of several IGBT modules connected in series, and the number of series units is adapted to the 10kV high voltage withstand requirement. The gates of the IGBT modules in each set of IGBT series units are synchronously driven through a synchronous drive component. The two sets of anti-parallel IGBT series units are time-sharing driven through a core control module. Each set of IGBT modules is equipped with an independent drive circuit, which includes a drive chip, an isolation optocoupler, and an isolated drive power supply. The drive power supply provides the IGBT turn-on voltage and turn-off voltage. A voltage equalization component is connected in parallel across each IGBT module, and a protection component is connected in parallel between the gate and the emitter.

[0010] Preferably, the fault protection module includes an overcurrent protection unit, an overvoltage protection unit, and an overheat protection unit; Overcurrent protection unit: It adopts Hall current sensor in combination with high-speed comparator to realize hardware fast overcurrent protection, while the core control module collects current signal in real time to realize software overcurrent protection; Overvoltage protection unit: A voltage transformer is used to collect voltage signals, and a metal oxide varistor is connected in parallel with the IGBT bridge arm to achieve overvoltage protection; Overheat protection unit: It collects temperature signals through a temperature sensor installed on the IGBT heat sink to realize overheating load reduction and shutdown protection.

[0011] Preferably, the circuit breaker linkage module uses intermediate relays and contactors to achieve hard interlocking between the IGBT anti-parallel drive module and the circuit breaker. The core logic is as follows: after the IGBT anti-parallel drive module is switched on, the circuit breaker closing circuit is connected; after the circuit breaker is closed, the IGBT anti-parallel drive module turning-off circuit is connected; and when the IGBT fails, the circuit breaker closing circuit is disconnected.

[0012] Preferably, the isolated power supply module includes a main switching power supply and multiple isolated DC-DC modules, providing isolated and stable DC power to the core control module, IGBT anti-parallel drive module, voltage detection module, fault protection module, and circuit breaker linkage module. All power supply modules meet the preset isolation withstand voltage requirements. The 10kV high-voltage side and control side power supplies meet the high-voltage isolation withstand voltage requirements and are compatible with the 10kV power distribution equipment insulation standards. The main switching power supply is an AC220V / DC24V switching power supply, with the input taken from the backup power supply in the power distribution room. The core control module is powered by DC24V converted to DC5V via DC-DC, and then converted to DC3.3V. The IGBT drive unit is powered by DC24V converted to +15V / -15V via the isolated DC-DC module.

[0013] Preferably, the voltage equalization component of each IGBT series unit is a 100kΩ / 2W resistor with an accuracy of ±1%. The protection component includes a fast recovery freewheeling diode and an RC snubber circuit. In the RC snubber circuit, the resistance between the gate and emitter is 100Ω and the capacitance is 0.1μF / 630V. The resistance across the IGBT is 220Ω and the capacitance is 0.22μF / 2000V. The fast recovery freewheeling diode is model FR107, and the isolated drive power supply is model URA2415YMD-10WR3.

[0014] Preferably, the Hall current sensor is model ACS758, the high-speed comparator is model LM311, the temperature sensor is PT100 or DS18B20, and the metal oxide varistor is model 15kV / 20kA.

[0015] A preferred method for uninterrupted power supply IGBT anti-parallel control includes the following steps: S1: Equipment initialization: The core control module completes the initialization configuration of signal acquisition, PWM generation, GPIO and timers, sets the voltage abnormality threshold, IGBT soft start time, circuit breaker closing delay parameters, and initializes each status flag bit to the fault-free, off, and open states. S2: Voltage Status Monitoring: The voltage detection module collects the three-phase voltage signals of the circuit breaker's incoming and outgoing terminals in real time. After signal conditioning, the signals are transmitted to the core control module. The core control module calculates the effective voltage value and determines whether there is a voltage fault. If a fault exists, it proceeds to step S3; otherwise, it continues monitoring. S3: IGBT anti-parallel soft start: The core control module acquires the AC voltage phase signal, determines the voltage half-cycle state, and outputs PWM drive signals in a time-division manner according to the phase signal. During the positive half-cycle, it drives the positive direction IGBT series unit and turns off the reverse direction unit. During the negative half-cycle, it drives the reverse direction IGBT series unit and turns off the positive direction unit. A dead-time delay is set at the zero crossing time to avoid commutation overlap. Soft start is completed by linearly adjusting the PWM duty cycle. The IGBT switching status flag is set. The gate drive signal delay difference between the positive and reverse direction IGBT series units is <100ns. S4: Circuit breaker closing control: After the core control module confirms the IGBT bridge arm is stable under load after a preset delay time, it outputs a closing control signal, which controls the circuit breaker to close through the circuit breaker linkage module. S5: Closing status detection: The core control module detects whether the circuit breaker is closed through the auxiliary contacts. If it is closed, the circuit breaker closing status flag is set and the process proceeds to step S6. If it is not closed and the timeout occurs, the fault protection is triggered. S6: IGBT anti-parallel soft shutdown: The core control module linearly adjusts the PWM duty cycle of the two anti-parallel IGBT series units to the shutdown state, resets the IGBT status flag, and realizes the smooth exit of the bypass device. The soft shutdown process takes 10ms. S7: Full-process fault protection: The fault protection module monitors overcurrent, overvoltage and overheat faults in real time. If a fault is detected, the protection action is triggered immediately, forcibly shutting down the IGBT bridge arm, prohibiting the circuit breaker from closing, starting the alarm, and locking the fault status until the fault is cleared and manually reset. The priority of fault protection is as follows: IGBT overcurrent, overvoltage, overheating > line short circuit > circuit breaker linkage fault > voltage abnormality.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. It adopts a fully controlled topology with anti-parallel IGBTs to achieve active control of AC current. Compared with the traditional IGBT+diode semi-controlled topology, it can actively control the switching of AC positive and negative half-cycles. The soft start and soft turn-off processes are smooth and there is no follow current surge. It is suitable for the fast switching requirements of 10kV lines and ensures power supply continuity. 2. By designing a composite topology of IGBT series-parallel and anti-parallel connections, multiple IGBTs connected in series meet the 10kV high voltage withstand requirement, and IGBTs connected in parallel within each series unit meet the current carrying requirement. At the same time, through the design of voltage equalization resistors, current equalization inductors and synchronous drive, the problem of voltage and current equalization in IGBT series-parallel connections is solved, thereby improving the reliability and service life of the equipment. 3. Construct a dual hardware and software fault protection system. Overcurrent protection can quickly respond to various faults. The hard interlock design between IGBT and circuit breaker is not affected by software faults, avoiding the risk of short circuit caused by simultaneous switching of both, and ensuring the safe operation of equipment and lines. 4. The core control module supports both STM32 and FPGA solutions, adapting to scenarios with different scales and precision requirements. It is equipped with complete communication and human-machine interaction interfaces, enabling remote monitoring and on-site parameter tuning, thus meeting the development needs of intelligent power distribution systems. 5. The isolation power supply module adopts multiple independent isolation power supplies, with a high voltage and control side isolation withstand voltage ≥20kV, meeting the insulation standards of 10kV power distribution equipment, effectively suppressing high voltage interference, and ensuring the stable operation of the control circuit. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the topology of one phase bridge arm of the IGBT anti-parallel drive module; Figure 3 This is a schematic diagram of a single-channel IGBT drive circuit. Figure 4 This is a schematic diagram of the pin assignment of the core control module; Figure 5 This is a schematic diagram of the control method flow. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. Example 1

[0019] like Figures 1 to 4 As shown, the uninterrupted power supply IGBT anti-parallel control device of the present invention includes a voltage detection module, a core control module, an IGBT anti-parallel drive module, a fault protection module, a circuit breaker linkage module, and an isolation power supply module. The output of the voltage detection module is electrically connected to the input of the core control module, the output of the fault protection module is electrically connected to the input of the core control module, the output of the core control module is electrically connected to the input of the IGBT anti-parallel drive module and the circuit breaker linkage module respectively, and the output of the isolation power supply module is electrically connected to the power input of all other modules, so as to realize the power supply and signal coordination interaction of the whole device; Voltage detection module: includes multiple 10kV / 100V precision voltage transformers and signal conditioning circuit. The multiple voltage transformers respectively collect the three-phase voltage at the incoming end and the three-phase voltage at the outgoing end of the circuit breaker. The signal conditioning circuit converts the 100V AC signal output by the voltage transformer into a low-voltage analog signal of 0~3.3V after rectification, filtering, voltage division, voltage tracking, limiting and linear optocoupler isolation, and then transmits it to the core control module. In this embodiment, 1. A fully controlled topology with anti-parallel IGBTs is adopted to achieve active control of AC current. Compared with the traditional IGBT+diode semi-controlled topology, it can actively control the on / off of the positive and negative half-cycles of AC. The soft start and soft turn-off processes are smooth and there is no follow current surge, which is suitable for the fast switching requirements of 10kV lines and ensures power supply continuity. 2. By designing a composite topology of IGBT series-parallel and anti-parallel connections, multiple IGBTs connected in series meet the 10kV high voltage withstand requirement, and IGBTs connected in parallel within each series unit meet the current carrying requirement. At the same time, through the design of voltage equalization resistors, current equalization inductors and synchronous drive, the problem of voltage and current equalization in IGBT series-parallel connections is solved, thereby improving the reliability and service life of the equipment. 3. Construct a dual hardware and software fault protection system. Overcurrent protection can quickly respond to various faults. The hard interlock design between IGBT and circuit breaker is not affected by software faults, avoiding the risk of short circuit caused by simultaneous switching of both, and ensuring the safe operation of equipment and lines. 4. The core control module supports both STM32 and FPGA solutions, adapting to scenarios with different scales and precision requirements. It is equipped with complete communication and human-machine interaction interfaces, enabling remote monitoring and on-site parameter tuning, thus meeting the development needs of intelligent power distribution systems. 5. The isolation power supply module adopts multiple independent isolation power supplies, with a high voltage and control side isolation withstand voltage of ≥20kV, meeting the insulation standards of 10kV power distribution equipment, effectively suppressing high voltage interference, and ensuring the stable operation of the control circuit. Example 2

[0020] Based on Example 1, the uninterrupted power supply IGBT anti-parallel control device of the present invention has the following core control module: by using the STM32F407IGT6 chip, it realizes voltage signal acquisition, AC phase detection, IGBT anti-parallel time-sharing drive logic operation, PWM signal generation, circuit breaker linkage control and fault protection logic processing. The core control module is also equipped with an RS485 / CAN communication interface and a human-machine interface. The RS485 / CAN communication interface realizes linkage with the power distribution automation system. The human-machine interface includes a rotary encoder and a touch screen, which are used to set the voltage abnormality threshold, IGBT soft start time, circuit breaker closing delay and protection action value. IGBT anti-parallel drive module: It adopts a three-phase bridge arm structure. Each phase bridge arm consists of two sets of IGBT series units connected in anti-parallel. Each set of IGBT series units consists of several IGBT modules connected in series, and the number of series units is adapted to the 10kV high voltage withstand requirement. The gate of the IGBT module in each set of IGBT series units is synchronously driven through a synchronous drive component. The two sets of anti-parallel IGBT series units are driven in a time-sharing manner through a core control module. Each set of IGBT modules is equipped with an independent drive circuit. The drive circuit includes a drive chip, an isolation optocoupler, and an isolated drive power supply. The drive power supply provides the IGBT turn-on voltage and turn-off voltage. A voltage equalization component is connected in parallel across each IGBT module, and a protection component is connected in parallel between the gate and the emitter. Fault protection module: includes overcurrent protection unit, overvoltage protection unit and overheat protection unit; Overcurrent protection unit: It adopts Hall current sensor in combination with high-speed comparator to realize hardware fast overcurrent protection, while the core control module collects current signal in real time to realize software overcurrent protection; Overvoltage protection unit: A voltage transformer is used to collect voltage signals, and a metal oxide varistor is connected in parallel with the IGBT bridge arm to achieve overvoltage protection; Overheat protection unit: It collects temperature signals through a temperature sensor installed on the IGBT heatsink to realize overheating reduction and shutdown protection; Circuit breaker linkage module: It adopts intermediate relays and contactors to realize hard interlock between IGBT anti-parallel drive module and circuit breaker; the core logic is: after IGBT anti-parallel drive module is switched on, circuit breaker closing circuit is connected; after circuit breaker is closed, IGBT anti-parallel drive module turning off circuit is connected; when IGBT fails, circuit breaker closing circuit is disconnected. Isolated power supply module: Includes main switching power supply and multiple isolated DC-DC modules, providing isolated and stable DC power supply for core control module, IGBT anti-parallel drive module, voltage detection module, fault protection module and circuit breaker linkage module. All power supply modules meet the preset isolation withstand voltage requirements. The 10kV high voltage side and control side power supply meet the high voltage isolation withstand voltage requirements and are compatible with the 10kV power distribution equipment insulation standards. The main switching power supply is an AC220V / DC24V switching power supply, with the input taken from the backup power supply of the power distribution room. The core control module is powered by DC24V converted to DC5V via DC-DC, and then converted to DC3.3V. The IGBT drive unit is powered by DC24V converted to +15V / -15V via isolated DC-DC module. The voltage equalization component of each IGBT series unit is a 100kΩ / 2W resistor with an accuracy of ±1%. The protection components include a fast recovery freewheeling diode and an RC snubber circuit. In the RC snubber circuit, the resistance between the gate and emitter is 100Ω and the capacitance is 0.1μF / 630V. The resistance across the IGBT is 220Ω and the capacitance is 0.22μF / 2000V. The fast recovery freewheeling diode is model FR107, and the isolated drive power supply is model URA2415YMD-10WR3. The Hall current sensor is model ACS758, the high-speed comparator is model LM311, the temperature sensor is PT100 or DS18B20, and the metal oxide varistor is model 15kV / 20kA. Example 3

[0021] like Figure 5 As shown, the uninterrupted power supply IGBT anti-parallel control method of the present invention includes the following steps: S1: Equipment initialization: The core control module completes the initialization configuration of signal acquisition, PWM generation, GPIO and timers, sets the voltage abnormality threshold, IGBT soft start time, circuit breaker closing delay parameters, and initializes each status flag bit to the fault-free, off, and open states. S2: Voltage Status Monitoring: The voltage detection module collects the three-phase voltage signals of the circuit breaker's incoming and outgoing terminals in real time. After signal conditioning, the signals are transmitted to the core control module. The core control module calculates the effective voltage value and determines whether there is a voltage fault. If a fault exists, it proceeds to step S3; otherwise, it continues monitoring. S3: IGBT anti-parallel soft start: The core control module acquires the AC voltage phase signal, determines the voltage half-cycle state, and outputs PWM drive signals in a time-division manner according to the phase signal. During the positive half-cycle, it drives the positive direction IGBT series unit and turns off the reverse direction unit. During the negative half-cycle, it drives the reverse direction IGBT series unit and turns off the positive direction unit. A dead-time delay is set at the zero crossing time to avoid commutation overlap. Soft start is completed by linearly adjusting the PWM duty cycle. The IGBT switching status flag is set. The gate drive signal delay difference between the positive and reverse direction IGBT series units is <100ns. S4: Circuit breaker closing control: After the core control module confirms the IGBT bridge arm is stable under load after a preset delay time, it outputs a closing control signal, which controls the circuit breaker to close through the circuit breaker linkage module. S5: Closing status detection: The core control module detects whether the circuit breaker is closed through the auxiliary contacts. If it is closed, the circuit breaker closing status flag is set and the process proceeds to step S6. If it is not closed and the timeout occurs, the fault protection is triggered. S6: IGBT anti-parallel soft shutdown: The core control module linearly adjusts the PWM duty cycle of the two anti-parallel IGBT series units to the shutdown state, resets the IGBT status flag, and realizes the smooth exit of the bypass device. The soft shutdown process takes 10ms. S7: Full-process fault protection: The fault protection module monitors overcurrent, overvoltage and overheat faults in real time. If a fault is detected, the protection action is triggered immediately, forcibly shutting down the IGBT bridge arm, prohibiting the circuit breaker from closing, starting the alarm, and locking the fault status until the fault is cleared and manually reset. The priority of fault protection is as follows: IGBT overcurrent, overvoltage, overheating > line short circuit > circuit breaker linkage fault > voltage abnormality.

[0022] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An uninterrupted power supply IGBT anti-parallel control device, characterized in that, It includes a voltage detection module, a core control module, an IGBT anti-parallel drive module, a fault protection module, a circuit breaker linkage module, and an isolated power supply module; The output of the voltage detection module is electrically connected to the input of the core control module, the output of the fault protection module is electrically connected to the input of the core control module, the output of the core control module is electrically connected to the input of the IGBT anti-parallel drive module and the circuit breaker linkage module respectively, and the output of the isolation power supply module is electrically connected to the power input of all other modules, realizing the coordinated interaction of power supply and signal of the whole device.

2. The uninterrupted power supply IGBT anti-parallel control device as described in claim 1, characterized in that, Voltage detection module: includes multiple 10kV / 100V precision voltage transformers and signal conditioning circuit. The multiple voltage transformers respectively collect the three-phase voltage at the incoming end and the three-phase voltage at the outgoing end of the circuit breaker. The signal conditioning circuit converts the 100V AC signal output by the voltage transformer into a low-voltage analog signal of 0~3.3V after rectification, filtering, voltage division, voltage tracking, limiting and linear optocoupler isolation, and then transmits it to the core control module.

3. The uninterrupted power supply IGBT anti-parallel control device as described in claim 1, characterized in that, The core control module, using the STM32F407IGT6 chip, enables voltage signal acquisition, AC phase detection, IGBT anti-parallel time-sharing drive logic operation, PWM signal generation, circuit breaker linkage control, and fault protection logic processing. The core control module also features an RS485 / CAN communication interface and a human-machine interface. The RS485 / CAN communication interface enables linkage with the power distribution automation system, while the human-machine interface includes a rotary encoder and a touchscreen for setting voltage anomaly thresholds, IGBT soft-start time, circuit breaker closing delay, and protection action values.

4. The uninterrupted power supply IGBT anti-parallel control device as described in claim 1, characterized in that, IGBT anti-parallel drive module: It adopts a three-phase bridge arm structure. Each phase bridge arm consists of two sets of IGBT series units connected in anti-parallel. Each set of IGBT series units consists of several IGBT modules connected in series, and the number of series units is adapted to the 10kV high voltage withstand requirement. The gate of the IGBT module in each set of IGBT series units is synchronously driven by a synchronous drive component. The two sets of anti-parallel IGBT series units are driven in a time-sharing manner by a core control module. Each set of IGBT modules is equipped with an independent drive circuit, which includes a drive chip, an isolation optocoupler, and an isolated drive power supply. The drive power supply provides the IGBT turn-on voltage and turn-off voltage. A voltage equalization component is connected in parallel across each IGBT module, and a protection component is connected in parallel between the gate and the emitter.

5. The uninterrupted power supply IGBT anti-parallel control device as described in claim 1, characterized in that, Fault protection module: includes overcurrent protection unit, overvoltage protection unit and overheat protection unit; Overcurrent protection unit: It adopts Hall current sensor in combination with high-speed comparator to realize hardware fast overcurrent protection, while the core control module collects current signal in real time to realize software overcurrent protection; Overvoltage protection unit: A voltage transformer is used to collect voltage signals, and a metal oxide varistor is connected in parallel with the IGBT bridge arm to achieve overvoltage protection; Overheat protection unit: It collects temperature signals through a temperature sensor installed on the IGBT heat sink to realize overheating load reduction and shutdown protection.

6. The uninterrupted power supply IGBT anti-parallel control device as described in claim 1, characterized in that, Circuit breaker linkage module: It adopts intermediate relays and contactors to realize hard interlock between IGBT anti-parallel drive module and circuit breaker; the core logic is: after IGBT anti-parallel drive module is switched on, circuit breaker closing circuit is connected; after circuit breaker is closed, IGBT anti-parallel drive module turning off circuit is connected; when IGBT fails, circuit breaker closing circuit is disconnected.

7. The uninterrupted power supply IGBT anti-parallel control device as described in claim 1, characterized in that, Isolated power supply module: Includes main switching power supply and multiple isolated DC-DC modules, providing isolated and stable DC power supply for core control module, IGBT anti-parallel drive module, voltage detection module, fault protection module and circuit breaker linkage module. All power supply modules meet the preset isolation withstand voltage requirements. The 10kV high voltage side and control side power supply meet the high voltage isolation withstand voltage requirements and are compatible with the 10kV power distribution equipment insulation standards. The main switching power supply is an AC220V / DC24V switching power supply, with the input taken from the backup power supply in the power distribution room. The core control module is powered by DC24V converted to DC5V via DC-DC, and then converted to DC3.3V. The IGBT drive unit is powered by DC24V converted to +15V / -15V via isolated DC-DC modules.

8. The uninterrupted power supply IGBT anti-parallel control device as described in claim 4, characterized in that, The voltage equalization component of each IGBT series unit is a 100kΩ / 2W resistor with an accuracy of ±1%. The protection components include a fast recovery freewheeling diode and an RC snubber circuit. In the RC snubber circuit, the resistance between the gate and emitter is 100Ω and the capacitance is 0.1μF / 630V. The resistance across the IGBT is 220Ω and the capacitance is 0.22μF / 2000V. The fast recovery freewheeling diode is model FR107, and the isolated drive power supply is model URA2415YMD-10WR3.

9. The uninterrupted power supply IGBT anti-parallel control device as described in claim 5, characterized in that, The Hall current sensor is model ACS758, the high-speed comparator is model LM311, the temperature sensor is PT100 or DS18B20, and the metal oxide varistor is model 15kV / 20kA.

10. An uninterrupted power supply IGBT anti-parallel control method, characterized in that, Includes the following steps: S1: Equipment initialization: The core control module completes the initialization configuration of signal acquisition, PWM generation, GPIO and timers, sets the voltage abnormality threshold, IGBT soft start time, circuit breaker closing delay parameters, and initializes each status flag bit to the fault-free, off, and open states. S2: Voltage Status Monitoring: The voltage detection module collects the three-phase voltage signals of the circuit breaker's incoming and outgoing terminals in real time. After signal conditioning, the signals are transmitted to the core control module. The core control module calculates the effective voltage value and determines whether there is a voltage fault. If a fault exists, it proceeds to step S3; otherwise, it continues monitoring. S3: IGBT anti-parallel soft start: The core control module acquires the AC voltage phase signal, determines the voltage half-cycle state, and outputs PWM drive signals in a time-division manner according to the phase signal. During the positive half-cycle, it drives the positive direction IGBT series unit and turns off the reverse direction unit. During the negative half-cycle, it drives the reverse direction IGBT series unit and turns off the positive direction unit. A dead-time delay is set at the zero crossing time to avoid commutation overlap. Soft start is completed by linearly adjusting the PWM duty cycle. The IGBT switching status flag is set. The gate drive signal delay difference between the positive and reverse direction IGBT series units is <100ns. S4: Circuit breaker closing control: After the core control module confirms the IGBT bridge arm is stable under load after a preset delay time, it outputs a closing control signal, which controls the circuit breaker to close through the circuit breaker linkage module. S5: Closing status detection: The core control module detects whether the circuit breaker is closed through the auxiliary contacts. If it is closed, the circuit breaker closing status flag is set and the process proceeds to step S6. If it is not closed and the timeout occurs, the fault protection is triggered. S6: IGBT anti-parallel soft shutdown: The core control module linearly adjusts the PWM duty cycle of the two anti-parallel IGBT series units to the shutdown state, resets the IGBT status flag, and realizes the smooth exit of the bypass device. The soft shutdown process takes 10ms. S7: Full-process fault protection: The fault protection module monitors overcurrent, overvoltage and overheat faults in real time. If a fault is detected, the protection action is triggered immediately, forcibly shutting down the IGBT bridge arm, prohibiting the circuit breaker from closing, starting the alarm, and locking the fault status until the fault is cleared and manually reset. The priority of fault protection is as follows: IGBT overcurrent, overvoltage, overheating > line short circuit > circuit breaker linkage fault > voltage abnormality.

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