A method and system for actively suppressing VFTO in 800kV GIS by regulating the opening and closing resistance.

Abstract

This invention relates to the field of insulation protection technology for high-voltage electrical equipment, and discloses a method and system for controlling the opening and closing resistance of an 800kV GIS to actively suppress VFTO. The method includes an offline preparation stage and an online execution stage. The offline preparation stage includes the following steps: A1, collecting the structural parameters, parasitic parameters, switching characteristics, and operating parameters of the target 800kV GIS to form a target GIS parameter data table; A2, based on the target GIS parameter data table, constructing an electromagnetic transient simulation model with a mapping relationship between operating conditions, resistance parameters, and VFTO characteristics. This invention, by constructing an electromagnetic transient simulation model, pre-setting a typical operating condition library, and using a multi-objective optimization algorithm, generates an optimal damping strategy lookup table covering all operating conditions. In actual operation, it can quickly query and dynamically fine-tune the strategy based on real-time operating condition data streams. The "prediction-optimization-control" closed-loop technology paradigm provides a brand-new solution for overvoltage protection of ultra-high voltage equipment.

Description

Technical Field

[0001] This invention relates to the field of insulation protection technology for high-voltage electrical equipment, specifically to a method and system for actively suppressing the opening and closing resistance regulation of VFTO in 800kV GIS. Background Technology

[0002] With the rapid development of my country's ultra-high voltage (UHV) power grid, 800kV GIS (Gas Insulator System) has been widely used in UHV substations due to its advantages such as small footprint, high reliability, and low maintenance. However, during the opening or closing of disconnecting switches in GIS, the relatively slow movement speed of the contacts makes it prone to repeated reignition and extinction of the electric arc under the influence of the power supply voltage, thereby generating ultra-fast transient overvoltages (VFTO). VFTOs are characterized by high amplitude (up to 2.0-3.0 pu), steepness (wavefront time on the order of nanoseconds), and high frequency (up to tens of megahertz). The extremely high transient electric field intensity generated by VFTOs seriously threatens the insulation safety of the GIS body's basin insulators, shell, and connected power transformers, reactors, and other critical equipment.

[0003] Current VFTO suppression in 800kV GIS mainly relies on a fixed-parameter opening and closing resistor connected in parallel at the switch break, achieving passive suppression through its damping effect. However, this method has significant limitations in practical applications. First, the resistor parameters are usually conservatively set based on the worst-case operating conditions, making it difficult to flexibly adapt to different operating conditions. Second, to simultaneously meet the requirements of opening and closing, parameter selection often involves a compromise, resulting in the inability to achieve optimal suppression under specific single operating conditions. Furthermore, existing control methods are relatively simple, relying solely on a fixed correlation with mechanical timing, failing to dynamically adjust based on the real-time system status, leading to unstable suppression effects and insufficient protection reliability. Therefore, this paper proposes an active VFTO suppression method and system for adjusting the opening and closing resistors in 800kV GIS. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for actively suppressing the opening and closing resistance regulation of VFTO in 800kV GIS, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for actively suppressing the opening and closing resistance regulation of VFTO in an 800kV GIS, the method comprising an offline preparation stage and an online execution stage; The offline preparation phase includes the following steps: A1. Collect the structural parameters, parasitic parameters, switching characteristics and operating parameters of the target 800kV GIS, and form a target GIS parameter data table; A2. Based on the target GIS parameter data table, construct an electromagnetic transient simulation model with the mapping relationship between operating conditions, resistance parameters and VFTO characteristics, and perform model calibration. A3. Pre-set typical operating condition library, which contains a variety of operating conditions formed by typical interval values ​​of three core variables: power supply voltage phase, residual voltage and contact movement speed. A4. Using a multi-objective optimization algorithm, with the objectives of minimizing VFTO peak value, satisfying the preset constraints on voltage steepness, and minimizing resistance energy consumption, calculations are performed on each working condition in the typical working condition library to generate an optimal damping strategy lookup table containing the optimal resistance value, optimal engagement time, and optimal disengagement time. A5. Calibrate the sensors, drive units, and resistor switching units in the system, and load the optimal damping strategy lookup table into the control unit to complete system initialization; The online execution phase includes the following steps: B6. Respond to the opening and closing commands and synchronously activate all units of the system; B7. Real-time acquisition of power supply voltage phase, residual voltage, switch contact position and movement speed to form a real-time operating condition data stream; B8. Perform a self-diagnosis of system faults. If there are no faults, proceed to the next step. If there are faults, activate the preset conservative damping strategy. B9. Based on the real-time operating condition data stream, query the optimal damping strategy lookup table, and obtain the personalized optimal strategy for the current operating condition by matching or interpolation calculation. B10. Transform the personalized optimal strategy into driving instructions and amplify them; B11. Control the bypass switch in the resistor unit to perform the switching on and off operations of the damping resistor according to the drive command; B12. During the opening and closing process, continuously collect data and dynamically update the strategy to perform closed-loop adjustments; B13. After the opening and closing operation is completed, disconnect the damping resistor, record and upload the operation data, and the system returns to standby mode.

[0006] Preferably, in A3, the typical range of the power supply voltage phase is 0° to 360°, with a gradient of 10°; The typical range of the residual voltage is from 0 kV to the rated voltage, with a gradient of 50 kV. The typical range of the contact movement speed is ±30% of the rated speed, with a gradient of 0.1 m / s.

[0007] Preferably, in A4, the multi-objective optimization algorithm is a genetic algorithm or a particle swarm optimization algorithm, and the number of iterations for each working condition is not less than 100. The adjustable range of the optimal resistance value is 10Ω to 1000Ω.

[0008] Preferably, in B8, the fault self-diagnosis includes the diagnosis of sensor signal integrity, control unit circuit status, drive unit communication status, and resistor unit status. The preset conservative damping strategy is to use a fixed resistance value, engage it at a preset fixed contact position, and disengage it at a preset fixed time or after the contact is in place.

[0009] The present invention also provides a system for actively suppressing the opening and closing resistance regulation of VFTO in 800kV GIS, comprising a measurement unit, a control unit, a drive unit and a resistor unit; The measuring unit is connected to the control unit, the control unit is connected to the driving unit, and the driving unit is connected to the resistance unit. The measurement unit is used to collect key state quantities during the GIS operation process in real time; The control unit is used to generate an optimal control strategy based on the collected data; The drive unit is used to convert control commands into high-power drive signals; The resistor unit is used to perform resistor switching operation according to the drive signal to achieve active suppression of VFTO.

[0010] Preferably, the measuring unit includes a voltage sensor, a displacement sensor, and a velocity sensor; The voltage sensor is used to monitor the instantaneous phase of the power supply voltage and the residual charge voltage in the GIS pipeline in real time. The displacement sensor and velocity sensor are used to monitor the position and movement speed of the switch contacts in real time.

[0011] Preferably, the voltage sensor, displacement sensor, and speed sensor are shielded, filtered, and opto-isolated.

[0012] Preferably, the control unit includes an offline modeling and optimization module and an online real-time control module; The offline modeling and optimization module is used to establish an electromagnetic transient simulation model that reflects the mapping relationship between key characteristics of VFTO and operating conditions and resistance parameters based on the structural parameters, parasitic capacitance, inductance and switching characteristics of GIS. The online real-time control module is used to receive real-time data from the high-precision measurement unit before and during actual operation, and to perform fault self-diagnosis.

[0013] Preferably, the online real-time control module has a built-in interpolation algorithm or a lightweight online correction model for dynamic fine-tuning.

[0014] Preferably, the resistor unit includes a resistor sheet, a high-speed bypass switch, an SF6 gas circulation heat dissipation assembly, and a status monitoring assembly; The resistor is used to connect to the main circuit during the opening and closing process to consume oscillation energy and suppress VFTO; The bypass switch is used to achieve millisecond-level switching of the resistor; The SF6 gas circulation heat dissipation component is used to ensure that the temperature rise of the resistor unit under short-term high-current pulses is within a safe range. The status monitoring component is used to monitor the working status of the resistor unit in real time.

[0015] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects: I. This invention constructs a comprehensive safety protection system by actively suppressing VFTO. Based on a closed-loop logic of offline predictive optimization and online real-time control, it can predict the generation pattern of VFTO in advance and intervene at its critical stage. By real-time acquisition of key state variables such as power supply voltage phase, residual voltage, switch contact position and movement speed, combined with personalized optimal strategies, the peak value of VFTO is strictly controlled below 80% of the GIS insulation withstand voltage, and the voltage steepness is limited to ≤1kV / ns. This effectively avoids local insulation breakdown, improves the operational safety of the 800kV GIS and the entire power grid, and provides a solid guarantee for the stable operation of the power system.

[0016] Second, this invention constructs an electromagnetic transient simulation model, presets a typical operating condition library, and uses a multi-objective optimization algorithm to generate an optimal damping strategy lookup table covering all operating conditions. In actual operation, it can quickly query and dynamically fine-tune the strategy based on real-time operating condition data streams to achieve personalized optimal suppression. The "prediction-optimization-control" closed-loop technology paradigm provides a brand-new solution for overvoltage protection of UHV equipment.

[0017] Third, this invention significantly reduces the energy load and thermal stress of the resistor itself by optimizing resistor parameters and activation strategies. Through personalized optimal strategies, the timing of resistor activation, deactivation, and resistance value are controlled, ensuring that the temperature rise of the resistor under short-duration high-current pulses remains within a safe range, thus extending the resistor's service life. Simultaneously, it reduces equipment downtime caused by resistor damage, lowers maintenance costs, and improves the economic efficiency of the power system.

[0018] Fourth, this invention covers all aspects of the offline preparation and online execution phases. Through modular integrated design, it organically integrates the measurement unit, control unit, drive unit, and resistor unit to form a compact and efficient integrated system. This facilitates the modification and application of existing GIS equipment without requiring large-scale equipment replacement, thus reducing the difficulty and cost of engineering implementation. Furthermore, the system has high promotional value and can be widely applied to various UHV GIS equipment, providing strong support for the intelligent upgrading of the power industry.

[0019] Fifth, the core advantage of this invention lies in its initiative and adaptability. Through the closed-loop logic of "prediction-optimization-control", it can dynamically adjust the strategy according to the real-time operating conditions, which is highly adaptable and performs personalized optimization for each operation, resulting in better VFTO suppression. It effectively avoids the problems of over-suppression or under-suppression that may be caused by the "one-size-fits-all" suppression method in traditional solutions. In addition, this invention integrates a complete technology chain from refined modeling and intelligent optimization algorithms to high-speed actuators, forming a systematic, complete, and highly efficient VFTO suppression system, providing comprehensive protection for the safe operation of UHV equipment. Attached Figure Description

[0020] Figure 1 This is a flowchart of the present invention. Detailed Implementation Example 1

[0021] Please see Figure 1 This invention provides a technical solution: a method for controlling the opening and closing resistance of VFTO in an 800kV GIS, the method includes an offline preparation stage and an online execution stage; the method is based on a closed-loop logic of offline prediction optimization and online real-time control, covering the entire process of preparation, perception, decision-making, execution and feedback; The offline preparation phase includes the following steps: A1. Collect the structural parameters, parasitic parameters, switching characteristics and operating parameters of the target 800kV GIS, and form a target GIS parameter data table; The GIS parameter data table includes physical structural dimensions such as GIS tank length, pipe diameter, number of compartments, and contact spacing; parasitic parameters include parasitic parameters such as equivalent capacitance, equivalent inductance, and loop resistance of the GIS measured by testing equipment; switching characteristics include the travel range of switch contacts, opening and closing time, rated movement speed, and arc reignition characteristic curve; operating parameters include GIS rated voltage, rated current, power supply voltage fluctuation range during normal operation, and typical residual voltage range, forming a "target GIS parameter data table" to provide accurate input for subsequent modeling.

[0022] A2. Based on the target GIS parameter data table, construct an electromagnetic transient simulation model with the mapping relationship between operating conditions, resistance parameters and VFTO characteristics, and perform model calibration. Based on the parameters collected by A1, a simulation model that can accurately reflect the generation law of VFTO is constructed. The logic bits of the model are mapped to the "operating conditions, resistance parameters, and VFTO characteristics" to restore the electromagnetic transient process during the opening and closing of GIS. The model is calibrated by comparing a small amount of actual GIS opening and closing test data and adjusting the model parameters to ensure that the simulation error is ≤5%. The final output is a VFTO electromagnetic transient simulation model that matches the actual equipment.

[0023] A3. A preset typical operating condition library is provided, which contains a variety of operating conditions formed by typical interval value combinations of three core variables: power supply voltage phase, residual voltage, and contact movement speed. It covers the entire operation scenario of 800kV GIS and presets typical operating condition combinations to avoid the situation of "no strategy to look up" during online control.

[0024] The typical range of the power supply voltage phase is 0° to 360° with a gradient of 10°; the typical range of the residual voltage is 0kV to the rated voltage with a gradient of 50kV; the typical range of the contact movement speed is ±30% of the rated speed with a gradient of 0.1m / s, ensuring coverage of all common and extreme scenarios, with a total of no less than 1000 combined operating conditions, and finally outputting an "800kV GIS typical operating condition library for opening and closing".

[0025] A4. A multi-objective optimization algorithm is adopted, with the objectives of minimizing VFTO peak value, satisfying the preset constraints on voltage steepness, and minimizing resistance energy consumption. Calculations are performed on each working condition in the typical working condition library to generate an optimal damping strategy lookup table containing the optimal resistance value, optimal activation time, and optimal deactivation time. The objective is to minimize the VFTO peak value, preferably below 80% of the GIS insulation withstand voltage. The constraint objective is a voltage steepness ≤1kV / ns to avoid local insulation breakdown. The auxiliary objective is to minimize resistance energy consumption and extend the resistor's service life. The multi-objective optimization algorithm is either a genetic algorithm or a particle swarm optimization algorithm, with at least 100 iterations for each operating condition. The adjustable range of the optimal resistance value is 10Ω to 1000Ω. The optimal engagement time is triggered based on the contact position, with a preferred contact travel of 10%. The optimal disengagement time is triggered based on the voltage peak, with a preferred VFTO 2ms after reaching its peak. A lookup table of the optimal damping strategy covering all operating conditions is stored in the local storage module of the control unit.

[0026] A5. Calibrate the sensors, drive units, and resistor switching units in the system, and load the optimal damping strategy lookup table into the control unit to complete system initialization; ensure the coordination of each unit and eliminate errors for online operation; The voltage sensor, displacement sensor, and speed sensor are calibrated to ensure that the measurement error meets the requirements. The preferred values ​​are voltage ±5kV, position ±0.1mm, and speed ±0.1m / s. The signal transmission delay of the drive unit is tested, recorded, and compensated. The drive delay is calibrated to a total delay ≤1ms. During switch switching calibration, the actual switching time of the high-speed bypass switch in the integrated intelligent damping resistor unit is compared with the theoretical command time to correct the deviation. The requirement is: switching error ≤ ±0.1ms. The "optimal damping strategy lookup table" is loaded into the control unit's running memory, and the system enters standby mode. The calibration is completed, and the closed-loop system can respond to opening and closing commands at any time.

[0027] The online execution phase includes the following steps: B6. Responding to the opening and closing commands, the system's various units are activated synchronously. The commands are transmitted synchronously to the system through the communication interface, and all units are activated from standby mode and enter the working mode. The measurement unit begins to warm up, the drive unit is powered on and ready, and the control unit starts the data receiving port. The time consumption is ≤1ms, ensuring synchronous startup with the GIS switch operation.

[0028] B7. Real-time acquisition of power supply voltage phase, residual voltage, switch contact position and movement speed to form a real-time operating condition data stream; continuous acquisition of key state quantities to provide real-time data support for decision-making; The voltage sensor preferably acquires the instantaneous phase of the power supply voltage and the residual charge voltage in the GIS pipeline every 10μs. The data is uploaded after being shielded, filtered, and photoelectrically isolated. The displacement sensor and velocity sensor preferably acquire the real-time position and movement speed of the switch contact every 10μs and upload them synchronously to the control unit. The data upload and acquisition are transmitted in real time in the form of "data packets" to ensure no loss and no delay. The output is a real-time updated operating condition data stream, including voltage phase, residual voltage, contact position / velocity, and operation type.

[0029] B8. Perform self-diagnosis of system faults. If no fault is found, proceed to the next step. If a fault is found, activate the preset conservative damping strategy. While receiving data, quickly diagnose the system's own status to avoid ineffective control under fault conditions. Set thresholds, and determine faults if sensor data exceeds a reasonable range or communication interruption exceeds 500μs. If no fault is found, proceed to the next step of strategy query and fine-tuning. If a fault is found, immediately switch to fault-safe mode and activate the preset conservative strategy. The preferred fixed resistor is 500Ω. The engagement time is 10% of the contact travel, and the disengagement time is after the circuit breaker is fully open or closed to ensure basic protection. The time consumption is ≤1ms, which does not affect the timeliness of subsequent control.

[0030] B9. Based on the real-time operating condition data stream, query the optimal damping strategy lookup table, and obtain the personalized optimal strategy for the current operating condition by matching or interpolation calculation; fault self-diagnosis includes diagnosis of sensor signal integrity, control unit circuit status, drive unit communication status and resistor unit status; the preset conservative damping strategy is to use a fixed resistance value and engage it at a preset fixed contact position, and disconnect it at a preset fixed time or after the contact is in place.

[0031] Based on real-time operating conditions, the optimal strategy is matched and dynamically corrected. During operating condition matching, the current operation type (opening / closing), power supply voltage phase, residual voltage, and contact position are extracted from real-time data. The closest typical operating condition is quickly retrieved from the optimal damping strategy lookup table. If the current operating condition is the median of the typical operating condition, the preferred voltage phase is 35°. If there is no perfect match, a linear interpolation algorithm or a lightweight online correction model is used to fine-tune the retrieved basic strategy to generate a "personalized optimal strategy" adapted to the current real-time operating condition, including precise resistance value and switching time. The rationality of the strategy is simply verified to ensure that the preferred resistance value is within the safe range and that the switching time is within the critical stage of contact movement, avoiding logical errors. The time consumption is ≤3ms, ensuring that the decision is completed before VFTO is formed.

[0032] B10. The personalized optimal strategy is transformed into drive commands and amplified; the decision is transformed into an executable drive signal. The control unit transforms the personalized optimal strategy into standardized control commands, including resistance value signals and on / off timing trigger signals. After receiving the low-voltage control commands, the drive unit amplifies them into high-power drive signals. The preferred output power is ≥100W to ensure bypass switch operation. The entire transmission delay is ≤1ms to ensure that the command and VFTO form a precise match at the critical stage, and output high-power, low-latency execution drive commands.

[0033] B11. The bypass switch in the control resistor unit performs the connection and disconnection operations of the damping resistor according to the drive command; responding to the drive command, it intervenes at the critical stage of VFTO formation; according to the command, the bypass switch closes at a precise moment when the optimal contact gap is reduced to 5mm, connecting the optimal resistance value to the parallel circuit of the GIS switch break, and starting damping energy dissipation. The status monitoring component monitors the resistor temperature, SF6 gas pressure, and switch status in real time, and synchronously feeds back to the control unit. When it is detected that the VFTO peak has passed or the contact is in place, the high-speed bypass switch is disconnected according to the command, the damping resistor is disconnected, and the suppression action ends; the connection and disconnection time error is ≤±0.1ms, and the resistor connection accuracy deviation from the command is ≤±5%.

[0034] B12. During the opening and closing process, data is continuously collected and the strategy is dynamically updated for closed-loop adjustment. During the operation, the optimal time is usually tens of milliseconds to optimize the suppression effect in real time. The measurement unit updates the status data every 10μs, and the control unit re-queries and fine-tunes the strategy every 2ms to correct deviations caused by contact speed fluctuations and residual voltage changes. The feedback correction is based on the temperature and pressure data fed back by the resistor unit. If the energy consumption is too high, it means that the temperature is close to the threshold. The resistance value can be fine-tuned or the circuit can be cut off in advance to balance the suppression effect and equipment safety, ensuring that VFTO is always controlled in the optimal suppression state throughout the opening and closing process.

[0035] B13. After the opening and closing operation is completed, the damping resistor is disconnected, the operation data is recorded and uploaded, the system returns to standby mode, the bypass switch is completely disconnected, the system exits the working mode and returns to standby mode, and the key data of this operation is recorded, including operating parameters, the strategy adopted, VFTO peak / steepness, resistance energy consumption, and system operating status. The recorded data is uploaded to the GIS main control system for maintenance personnel to trace and analyze. The VFTO suppression of a single opening and closing operation is completed, the system returns to standby mode, and waits for the next instruction.

[0036] This invention also provides a system for actively suppressing the opening and closing resistance regulation of VFTO in an 800kV GIS, comprising a measurement unit, a control unit, a drive unit, and a resistor unit; the measurement unit is connected to the control unit, the control unit is connected to the drive unit, and the drive unit is connected to the resistor unit; the system unit adopts an electric field homogenization structure design, and its interior is filled with SF6 gas at the same pressure as the GIS body as an insulation and heat dissipation medium. The SF6 gas circulating heat dissipation component ensures that the temperature rise of the resistor under short-term high-current pulses is within a safe range.

[0037] The measurement unit is used to collect key state quantities during GIS operation in real time; the measurement unit includes voltage sensors, displacement sensors, and velocity sensors. Voltage sensors are used to monitor the instantaneous phase of the power supply voltage and the residual charge voltage in GIS pipelines in real time. Displacement and velocity sensors are used to monitor the position and speed of the switch contacts in real time. The voltage, displacement, and velocity sensors undergo shielding, filtering, and opto-isolation to ensure interference resistance and measurement accuracy in strong VFTO electromagnetic environments.

[0038] The control unit is used to generate the optimal control strategy based on the collected data. The control unit includes an offline modeling and optimization module and an online real-time control module. By pre-setting typical operating conditions, with multiple objectives such as minimizing VFTO peak value, limiting voltage steepness, and controlling resistor energy consumption, an intelligent optimization algorithm is used to perform offline calculations to generate an optimal damping strategy lookup table covering all operating conditions.

[0039] The offline modeling and optimization module is used to establish an electromagnetic transient simulation model that reflects the mapping relationship between key characteristics of VFTO and operating conditions and resistance parameters based on the structural parameters, parasitic capacitance, inductance and switching characteristics of GIS. The online real-time control module receives real-time data from the high-precision measurement unit before and during actual operation to perform fault self-diagnosis. First, it performs fault self-diagnosis. If the system is normal, it quickly queries the optimal damping strategy lookup table based on the current operation type, instantaneous power supply voltage, instantaneous residual voltage on the load side, and contact position. Then, it dynamically fine-tunes the parameters using an interpolation algorithm or a lightweight online correction model to generate the optimal control command for the current moment. If the system detects a fault, it automatically switches to fail-safe mode, activating a set of preset, conservative fixed-parameter strategies to ensure basic protection functions. The online real-time control module has a built-in interpolation algorithm or lightweight online correction model for dynamic fine-tuning.

[0040] The drive unit is used to convert control commands into high-power drive signals, ensuring extremely low transmission delay.

[0041] The resistor unit is used to perform resistor switching operations according to the drive signal to actively suppress VFTO. The resistor unit is directly installed inside the GIS tank and is at the same potential as the main circuit. The resistor unit includes a resistor element, a high-speed bypass switch, an SF6 gas circulation heat dissipation assembly, and a status monitoring assembly; The resistor is used to connect to the main circuit during the opening and closing process to consume oscillation energy and suppress VFTO; Bypass switches are used to achieve millisecond-level resistor switching; preferably, they are ultra-fast vacuum switches or solid-state power electronic switches. When using vacuum switches, a specially designed ultra-fast operating mechanism is required; when using solid-state switches, the issues of high-voltage isolation and heat dissipation need to be addressed.

[0042] SF6 gas circulation heat dissipation components are used to ensure that the temperature rise of the resistor unit is within a safe range under short-term high-current pulses; A status monitoring component is used to monitor the operating status of the resistor unit in real time.

[0043] When the GIS switch receives a tripping or closing command, the system starts synchronously. The measurement unit captures and uploads the system status in real time, and the control unit completes status analysis, strategy query, and decision-making within milliseconds. It then sends commands to the integrated module via the drive unit. The high-speed bypass switch operates at precisely calculated moments, engaging or disengaging the damping resistor, thus intervening at the critical stage of VFTO formation to achieve optimal damping effect. The entire process constitutes a rapid closed-loop control. Example 2

[0044] This embodiment establishes a simulation model based on actual parameters of an 800kV GIS. The following are the basic simulation parameters:

[0045] The following is a summary of simulation data comparisons under multiple operating conditions, with three schemes set up: undamped resistor, traditional fixed resistor, and the active control scheme of this invention. The following data are under rated operating conditions: closing operation, voltage phase 90°, residual voltage 400kV, and contact speed 1.5m / s.

[0046]

[0047] The following data are for high residual voltage operation, closing operation, voltage phase 180°, residual voltage 750kV, contact speed 1.8m / s.

[0048]

[0049] The following data are for low contact speed operation, opening operation, voltage phase 30°, residual voltage 200kV, contact speed 1.0m / s.

[0050]

[0051] The following data represents the fault-safe operating conditions, including closing operation, voltage phase 60°, residual voltage 300kV, contact speed 1.3m / s, and voltage sensor failure.

[0052]

[0053] The switching resistor regulation method of the present invention can further reduce the VFTO peak value from 1200kV in the traditional scheme to 800kV. The peak value reduction ratio is improved and the number of oscillations is reduced, which verifies its superior suppression effect. As can be seen from the above data, the control unit can dynamically adjust the resistor input command with millisecond-level accuracy according to the real-time collected voltage phase and contact position signals. The response is fast and accurate, which verifies the real-time performance and effectiveness of the active regulation logic.

[0054] In summary, this invention constructs a comprehensive safety protection system by actively suppressing VFTO. Based on a closed-loop logic of offline predictive optimization and online real-time control, it can predict the generation pattern of VFTO in advance and intervene at its critical stages. By real-time acquisition of key state variables such as power supply voltage phase, residual voltage, switch contact position and movement speed, and combined with personalized optimal strategies, the peak value of VFTO is strictly controlled below 80% of the GIS insulation withstand voltage, and the voltage steepness is limited to ≤1kV / ns. This effectively avoids local insulation breakdown, improves the operational safety of the 800kV GIS and the entire power grid, and provides a solid guarantee for the stable operation of the power system.

[0055] This invention constructs an electromagnetic transient simulation model, pre-sets a typical operating condition library, and uses a multi-objective optimization algorithm to generate an optimal damping strategy lookup table covering all operating conditions. In actual operation, it can quickly query and dynamically fine-tune the strategy based on real-time operating condition data streams to achieve personalized optimal suppression. The "prediction-optimization-control" closed-loop technology paradigm provides a brand-new solution for overvoltage protection of UHV equipment.

[0056] This invention significantly reduces the energy load and thermal stress of the resistor itself by optimizing resistor parameters and activation strategies. Through personalized optimal strategies, it controls the timing of resistor activation, deactivation, and resistance value, keeping the temperature rise of the resistor within a safe range under short-duration high-current pulses and extending its service life. Simultaneously, it reduces equipment downtime caused by resistor damage, lowers maintenance costs, and improves the economic efficiency of the power system.

[0057] This invention covers all aspects of the offline preparation and online execution phases. Through modular integrated design, it organically integrates the measurement unit, control unit, drive unit, and resistor unit into a compact and efficient integrated system. This facilitates the retrofitting and application of existing GIS equipment without requiring large-scale equipment replacement, thus reducing the difficulty and cost of engineering implementation. Furthermore, the system has high promotional value and can be widely applied to various UHV GIS equipment, providing strong support for the intelligent upgrading of the power industry.

[0058] The core advantage of this invention lies in its initiative and adaptability. Through the closed-loop logic of "prediction-optimization-control", it can dynamically adjust the strategy according to the real-time operating conditions, which is highly adaptable and performs personalized optimization for each operation, resulting in better VFTO suppression. It effectively avoids the problems of over-suppression or under-suppression that may be caused by the "one-size-fits-all" suppression method in traditional solutions. In addition, this invention integrates a complete technology chain from refined modeling and intelligent optimization algorithms to high-speed actuators, forming a systematic, complete, and highly efficient VFTO suppression system, providing comprehensive protection for the safe operation of UHV equipment.

[0059] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. A method for actively suppressing VFTO in 800kV GIS by adjusting the opening and closing resistance, characterized in that, The method includes an offline preparation phase and an online execution phase; The offline preparation phase includes the following steps: A1. Collect the structural parameters, parasitic parameters, switching characteristics and operating parameters of the target 800kV GIS, and form a target GIS parameter data table; A2. Based on the target GIS parameter data table, construct an electromagnetic transient simulation model with the mapping relationship between operating conditions, resistance parameters and VFTO characteristics, and perform model calibration. A3. Pre-set typical operating condition library, which contains a variety of operating conditions formed by typical interval values ​​of three core variables: power supply voltage phase, residual voltage and contact movement speed. A4. Using a multi-objective optimization algorithm, with the objectives of minimizing VFTO peak value, satisfying preset constraints on voltage steepness, and minimizing resistance energy consumption, calculations are performed on each working condition in the typical working condition library to generate an optimal damping strategy lookup table containing the optimal resistance value, optimal engagement time, and optimal disengagement time. A5. Calibrate the sensors, drive units, and resistor switching units in the system, and load the optimal damping strategy lookup table into the control unit to complete system initialization; The online execution phase includes the following steps: B6. Respond to the opening and closing commands and synchronously activate all units of the system; B7. Real-time acquisition of power supply voltage phase, residual voltage, switch contact position and movement speed to form a real-time operating condition data stream; B8. Perform a self-diagnosis of system faults. If there are no faults, proceed to the next step. If there are faults, activate the preset conservative damping strategy. B9. Based on the real-time operating condition data stream, query the optimal damping strategy lookup table, and obtain the personalized optimal strategy for the current operating condition by matching or interpolation calculation. B10. Transform the personalized optimal strategy into driving instructions and amplify them; B11. Control the bypass switch in the resistor unit to perform the switching on and off operations of the damping resistor according to the drive command; B12. During the opening and closing process, continuously collect data and dynamically update the strategy to perform closed-loop adjustments; B13. After the opening and closing operation is completed, disconnect the damping resistor, record and upload the operation data, and the system returns to standby mode.

2. The method for controlling the opening and closing resistance of an 800kV GIS to actively suppress VFTO according to claim 1, characterized in that, In A3, the typical range of the power supply voltage phase is 0° to 360°, with a gradient of 10°; The typical range of the residual voltage is from 0 kV to the rated voltage, with a gradient of 50 kV. The typical range of the contact movement speed is ±30% of the rated speed, with a gradient of 0.1 m / s.

3. The method for controlling the opening and closing resistance of an 800kV GIS to actively suppress VFTO according to claim 1, characterized in that, In A4, the multi-objective optimization algorithm is a genetic algorithm or a particle swarm optimization algorithm, and the number of iterations for each working condition is no less than 100. The adjustable range of the optimal resistance value is 10Ω to 1000Ω.

4. The method for controlling the opening and closing resistance of an 800kV GIS to actively suppress VFTO according to claim 1, characterized in that, In B8, the fault self-diagnosis includes the diagnosis of sensor signal integrity, control unit circuit status, drive unit communication status, and resistor unit status. The preset conservative damping strategy is to use a fixed resistance value, engage it at a preset fixed contact position, and disengage it at a preset fixed time or after the contact is in place.

5. A system for controlling the opening and closing resistance of an 800kV GIS for actively suppressing VFTO according to any one of claims 1-4, characterized in that, It includes a measurement unit, a control unit, a drive unit, and a resistor unit; The measuring unit is connected to the control unit, the control unit is connected to the driving unit, and the driving unit is connected to the resistance unit. The measurement unit is used to collect key state quantities during the GIS operation process in real time; The control unit is used to generate an optimal control strategy based on the collected data; The drive unit is used to convert control commands into high-power drive signals; The resistor unit is used to perform resistor switching operation according to the drive signal to achieve active suppression of VFTO.

6. The system for actively suppressing VFTO in an 800kV GIS by adjusting the opening and closing resistance according to claim 5, characterized in that, The measurement unit includes a voltage sensor, a displacement sensor, and a velocity sensor; The voltage sensor is used to monitor the instantaneous phase of the power supply voltage and the residual charge voltage in the GIS pipeline in real time. The displacement sensor and velocity sensor are used to monitor the position and movement speed of the switch contacts in real time.

7. The system for actively suppressing VFTO in an 800kV GIS by adjusting the opening and closing resistance according to claim 6, characterized in that, The voltage sensor, displacement sensor, and speed sensor are shielded, filtered, and opto-isolated.

8. The system for actively suppressing VFTO in an 800kV GIS by adjusting the opening and closing resistance according to claim 5, characterized in that, The control unit includes an offline modeling and optimization module and an online real-time control module; The offline modeling and optimization module is used to establish an electromagnetic transient simulation model that reflects the mapping relationship between key characteristics of VFTO and operating conditions and resistance parameters based on the structural parameters, parasitic capacitance, inductance and switching characteristics of GIS. The online real-time control module is used to receive real-time data from the high-precision measurement unit before and during actual operation, and to perform fault self-diagnosis.

9. The system for actively suppressing VFTO in an 800kV GIS by adjusting the opening and closing resistance according to claim 8, characterized in that, The online real-time control module has a built-in interpolation algorithm or lightweight online correction model for dynamic fine-tuning.

10. The system for actively suppressing VFTO in an 800kV GIS by adjusting the opening and closing resistance according to claim 5, characterized in that, The resistor unit includes a resistor sheet, a high-speed bypass switch, an SF6 gas circulation heat dissipation assembly, and a status monitoring assembly. The resistor is used to connect to the main circuit during the opening and closing process to consume oscillation energy and suppress VFTO; The bypass switch is used to achieve millisecond-level switching of the resistor; The SF6 gas circulation heat dissipation component is used to ensure that the temperature rise of the resistor unit under short-term high-current pulses is within a safe range. The status monitoring component is used to monitor the working status of the resistor unit in real time.

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