67 results about "Current limiting reactor" patented technology

According to the device for reducing the temperature rise of the dry-type hollow high-capacity current-limiting reactor and the design method thereof, a double-layer rainproof device technology and a split type staggered ventilation structure are adopted to realize rainproof and heat dissipation decoupling; according to the invention, heat dissipation is carried out through annular grating ventilation holes in the vertical direction of a top-layer rainproof cap and a middle ventilation net between the top-layer rainproof cap and a bottom-layer rainproof cap, and a coupling simulation technology of a magnetic field-flow field-temperature field of a reactor is utilized to form a correlation between structural parameters of a double-layer rainproof device and a flow rate change rate of fluid in an air passage of an encapsulation chamber; a bidirectional coupling model of a flow field and a temperature field is established, and the synergistic effect of encapsulated radiation and convective heat transfer is solved through a finite element method. Through multi-field coupling simulation and parametric modeling, the problem of collaborative optimization of rainproof device design and electric reactor thermal performance is solved, the equivalent heat dissipation area is increased to 2-3 times that of a single-layer structure, the use amount of wires is reduced by 8-15%, the coil hot-spot temperature rise is reduced to 78K from 88K of a traditional structure, and the reduction amplitude reaches 11.4%.

A fault suppression control method based on a capacitive energy storage system comprises the steps that a DC / DC converter of the capacitive energy storage system is constructed, a voltage and current double-closed-loop control structure of the capacitive energy storage system in a charging mode and a discharging mode is constructed based on the DC / DC converter, and the voltage of an energy storage capacitor or a filter capacitor serves as an outer loop control variable; the current of the energy storage inductor is used as an inner loop control variable, turn-on and turn-off signals of a switching device are output through PWM modulation, and finally fault suppression control is achieved after current-limiting control parameter optimization. Energy absorption and release between the ship power system and the energy storage capacitor are realized by adopting the bidirectional DC / DC converter, fault current suppression during a fault is realized, meanwhile, the requirement on a current limiting reactor is reduced, the cost of system elements is reduced, and the influence of reactor installation on the system is avoided.

The invention discloses a multi-terminal flexible direct current transmission line protection method based on injection signals, and relates to the technical field of power distribution network line protection. After the bipolar short-circuit fault is detected, the modularized multi-level converter is controlled to enter an active current limiting mode, and the fault current is limited to be 1.1 times of rated current, so that the impact on equipment is reduced; a main control station injects current sinusoidal signals with different angular frequencies twice, current and voltage signals of a port of the main control station are extracted, the impedance amplitude difference under the two angular frequencies is obtained, and the fault section protection method based on the impedance amplitude difference is established. Through a cut-and-trial method, the number of current-limiting reactors through which fault current flows is calculated, a criterion for matching and detecting a fault line section is established, and the fault section is isolated by a protection action. According to the method, synchronous communication is not needed, fault line protection can be realized under high resistance and noise, and the protection reliability and the recovery efficiency of the complex topology multi-terminal flexible direct current power grid are remarkably improved.

The invention provides a zero-loss deep current limiting device and a current limiting device control method, and relates to the technical field of transformer fault current limiting, the device comprises a main switch branch, an energy absorption branch, an artificial zero-crossing branch and a current limiting reactor; the main switch branch comprises a vacuum type quick switch which is positioned between the bus and the main transformer high-voltage winding connecting end part; the artificial zero-crossing branch and the modulation inductor are connected in series and then are connected in parallel to the main switch branch; the artificial zero-crossing branch comprises a zero-crossing energy storage capacitor and a vacuum trigger switch, and the zero-crossing energy storage capacitor and the vacuum trigger switch are connected in series; the current limiting reactor is connected in parallel to the vacuum type quick switch; and a controller for controlling the vacuum trigger switch and the vacuum type quick switch to work is also arranged in the device. The energy absorption branch comprises a zinc oxide resistor which is connected in parallel with the artificial zero-crossing branch. The current limiting reactor is small in loss in the normal running state of the system and high in running reliability when the system breaks down.

The invention relates to the technical field of transformers, and discloses an on-load voltage regulation method and device based on an existing transformer and a storage medium, according to the method, a transient overvoltage suppression device is arranged on a switch, one end of the transient overvoltage suppression device is connected with an action end, the other end of the transient overvoltage suppression device is connected with a contact end corresponding to middle gear voltage, and the break-over voltage of the transient overvoltage suppression device is larger than the maximum voltage difference value between the action end and the contact end. And the action end is connected with a phase correction capacitor and then is connected with a primary side sleeve through the capacitor. Each contact end is correspondingly connected with a current-limiting reactor and is connected to taps with different turns of a primary side winding of the transformer through the current-limiting reactor, and the other tap of the winding is connected with another primary side sleeve. Detecting the secondary side voltage value of the transformer, and driving the action end to be connected with the contact end which is positively correlated with the secondary voltage value according to the secondary side voltage value; according to the method, the existing transformer can realize on-load voltage regulation, and the power supply voltage stability is effectively improved.

This invention relates to a method and system for protecting DC lines in a multi-terminal flexible DC system, belonging to the field of relay protection technology. It solves the problem in existing technologies where multi-terminal flexible DC system DC line protection struggles to accurately identify DC line faults under low communication requirements. The method includes collecting the voltage and current of the current-limiting reactors at both ends of the DC line to be protected in the multi-terminal flexible DC system before and after a fault occurs, thereby obtaining the high-frequency component frequency of the DC line to be protected at ω. f The voltage and current surges at both ends of the current-limiting reactor are used to determine the frequency of the DC line to be protected at a high-frequency component of ω. f The sudden energy change of the current-limiting reactors at both ends; according to the DC line to be protected at a high frequency component frequency of ω f The sudden energy change of the current-limiting reactors at both ends and the fault protection criteria are used to determine whether a fault has occurred in the DC line to be protected; if so, the protection action of the DC line to be protected is initiated.

The name of the present invention is an energy-saving electrostatic precipitator high-voltage power supply and its control method. It belongs to the technical field of electrostatic precipitator high-voltage power supply. It mainly solves the problems of the existing electrostatic precipitator composite pulse high-voltage power supply, which requires two sets of power supply systems, such as complex system, high failure rate and poor fault tolerance. Its main features are: it includes a current limiting reactor, a rectifier unit, a high-frequency inverter unit, a high-frequency transformer, a DC voltage superposition unit and a pulse voltage superposition unit electrically connected in sequence; the high-frequency transformer is a high-frequency single-phase transformer with a single winding on the primary side and multiple windings on the secondary side; the DC voltage superposition unit includes a plurality of DC voltage circuits connected in sequence, and the pulse voltage superposition unit includes a plurality of pulse voltage circuits connected in sequence. The present invention has the characteristics of small size, adjustable pulse width and amplitude, multiple output characteristics and dust removal body energy storage, improves the dust removal efficiency of the electrostatic precipitator system and reduces power consumption, and is mainly used for high-voltage power supply in the electrostatic precipitator system.

The invention provides a circuit breaker with a current-limiting reactor LR switching function. The circuit breaker comprises a mechanical switch K1, a first thyristor D1, a current-limiting reactor LR, a coupling inductor LO and a power supply VDD, the positive electrode of the mechanical switch K1 is respectively connected with the current limiting reactor LR, the first thyristor D1 and the power supply VDD; the negative electrode of the mechanical switch K1 is respectively connected with the current limiting reactor LR, the first thyristor D1 and the vacuum switch K2 through the primary side of the coupling inductor LO; the negative electrode of the vacuum switch K2 is connected with the negative electrode of the power supply VDD through the load R. When the circuit breaker is in rated operation, current only passes through the mechanical switch and the vacuum switch, so that the system loss is reduced, and the energy transmission efficiency of the circuit breaker is improved; in a fault state, the current limiting reactor is put into use, so that the effect of limiting the rising rate of the fault current of the system can be achieved, and favorable guarantee is provided for fault removal of the circuit breaker; and the speed of transferring the fault transient current from the mechanical switch to the current limiting reactor is improved.

1. Name of the product in this design: Current-limiting reactor. 2. Purpose of this design: To limit excessively rapid fault current. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: 3D view 1.

The invention belongs to the technical field of power system relay protection and power distribution network flexible interconnection, and discloses a flexible loop closing device body topological structure, which comprises a double-core symmetric phase-shifting transformer and a mode switching interface unit, and is characterized in that the double-core symmetric phase-shifting transformer comprises an exciting transformer bank and a series transformer bank; the mode switching interface unit is arranged on a low-voltage electric energy coupling loop between the secondary side output end of the exciting transformer bank and the secondary side input end of the series transformer bank, and the mode switching interface unit is arranged on a low-voltage electric energy coupling loop between the secondary side output end of the exciting transformer bank and the secondary side input end of the series transformer bank. And the current-limiting impedance of the secondary side is mapped to the primary side by the square times of the transformation ratio, so that on the premise of not increasing the volume and cost of the external current-limiting reactor, the self-protection and fault current suppression of the body are realized, and the organic unification of steady-state current regulation and transient current limiting is realized. The invention also discloses a virtual impedance identification-based adaptive protection method matched with the topological structure of the flexible loop closing device body.

The invention provides a transformer short-circuit fault current limiting device and a capacitor maintenance management method in the device. The transformer short-circuit fault current limiting device comprises a main branch, a current limiting branch, a modulation inductor, an artificial zero-crossing branch and an energy consumption detection branch. The main branch is provided with a vacuum quick switch which is connected in series between the bus and the primary side port of the transformer; the current-limiting branch is provided with a current-limiting reactor which is connected in parallel with the vacuum quick switch. The artificial zero-crossing branch is connected in series with the modulation inductor and then is connected in parallel with the current-limiting branch, and the artificial zero-crossing branch comprises an energy-storage capacitor bank module and a vacuum trigger switch which are connected in series. In the application, when the fault current on the main branch is detected, the vacuum quick switch is firstly controlled to be switched off, and then the vacuum trigger switch is controlled to be switched on, so that the vacuum quick switch can be switched on and off conveniently; furthermore, the vacuum trigger switch is controlled to be turned off, the current limiting reactor is connected between the power distribution system bus and the transformer, short-circuit fault current limiting is achieved, and damage to the transformer when the load is short-circuited is reduced.

The invention discloses a series diode rectification topological structure which comprises more than two six-pulse converter valves which are connected in series, each six-pulse converter valve is a three-phase bridge type rectification circuit formed by six diodes, the input end of each six-pulse converter valve is connected to an alternating current system, and after all the six-pulse converter valves are connected in series, the input end of each six-pulse converter valve is connected to the alternating current system. Positive and negative output ends are respectively connected to a DC line, and a current-limiting reactor is connected in series between every two six-pulse converter valves connected in series. A plurality of six-pulse converter valves are connected in series, and the reactor is adopted to ensure the normal operation of the system, so that the direct current side voltage is improved, the higher direct current side voltage is obtained by adopting the lower alternating current voltage, the volume and weight increase caused by the use of an alternating current transformer is avoided, and the equipment cost is also saved. The technical problem that a diode rectifier topological structure adopted by an existing offshore wind power sending scheme needs to be connected into a transformer, and consequently the size and the weight are too large is solved.

The invention discloses a fault current limiter system based on a novel liquid metal current limiter. The system is composed of a novel liquid metal current limiter, a quick switch and a current-limiting reactor. The novel liquid metal current limiter has the effects of shortening the initial current limiting time and quickly and accurately capturing short-circuit fault symptoms in the system. In the system, on one hand, the influence caused by the slowing of the self-contraction speed of the liquid metal is reduced through quick opening; on the other hand, the voltage at the two ends of the system is increased, the current transfer speed from the novel liquid metal current limiter branch to the current limiting reactor branch is increased, and the electric arc and ablation of the novel liquid metal current limiter are further weakened. The current limiting depth can be improved by adding the current limiting reactor, and the defect that the liquid metal current limiter only depends on electric arc current limiting is overcome through a current transfer mode, so that the novel liquid metal current limiter can be applied to the high-voltage field.

The present invention relates to a short-circuit-resistant core-column energy-extracting shunt reactor, which comprises a yoke, a main winding, an energy-extracting winding and a built-in current-limiting reactor. A core column is arranged inside the yoke, the main winding and the energy-extracting winding are both wound around the core column, and one end of the energy-extracting winding is connected in series with the built-in current-limiting reactor. In the present invention, both the main winding and the energy-extracting winding are wound around the core column of the shunt reactor, which not only meets the requirement of compensating high-voltage transmission lines and realizes the energy-extracting function, but also makes the winding and the casing more simple and convenient. Moreover, it is applicable to both single-phase energy-extracting shunt reactors and three-phase energy-extracting shunt reactors, with a wider range of applications.

The invention discloses a series current limiting reactor state monitoring system and method, and belongs to the technical field of power equipment state monitoring. The system comprises a data acquisition module, a historical database module, a data fusion processing module, a comprehensive diagnosis module and an early warning module. According to the method, real-time multi-source data is collected and preprocessed, real-time multi-source fusion, historical trend fusion and scene-fault feature fusion are executed, a health index judgment state is calculated, and early warning is output. According to the method, historical data and scene parameters are combined through a multi-dimensional data fusion algorithm, so that the problems of high misjudgment rate and off-line detection lag in traditional monitoring of a single parameter are solved, the accuracy and the real-time performance of reactor state monitoring are improved, and reliable support is provided for operation and maintenance decision making.

The application relates to the technical field of power distribution networks, and discloses a novel DC power distribution network hybrid current limiter and a polarity self-recovery control method, wherein the hybrid current limiter comprises: hybrid current limiters which are respectively arranged in series between current limiters and DC circuit breakers at two ends of a DC line, and each end hybrid current limiter comprises a current passing branch, a current limiting branch and a commutation branch; the current passing branch is used for providing a current passing path; the current limiting branch is used for limiting the increase of a fault current; and the commutation branch is used for performing current commutation of the current passing branch and the current limiting branch to block the passing of the fault current from the current passing branch; the application not only improves the fault current limiting capacity of the DC power distribution network, but also reduces the breaking stress of the DC circuit breaker and the investment cost of the DC power distribution network system, and realizes fast reclosing.

The application discloses a fault current limiter input method based on a voltage drop criterion and belongs to the technical field of power system fault protection, which comprises the following steps: collecting three-phase voltage instantaneous values of a fault current limiter installation point and calculating zero sequence voltage; synchronously calculating real-time voltage amplitude and voltage change rate; comparing the real-time voltage amplitude and the voltage change rate with preset criteria and combining zero sequence voltage auxiliary criteria to determine a ground fault; quickly opening a switch to input a current limiting reactor when the fault occurs; and closing the switch to exit the current limiting reactor after the fault is eliminated. The application adopts a comprehensive design of double main criteria of voltage amplitude and voltage change rate plus zero sequence voltage auxiliary criteria, can accurately distinguish a ground fault from normal fluctuations of a power grid, avoids misjudgment and missed judgment, has a quick sampling response, realizes quick input of current limiting by cooperating with a quick switch, can be self-adaptively adjusted according to actual power grid parameters and operating conditions, can effectively suppress a fault current peak value, prevents power equipment from being damaged, and practically improves the safe and stable operation level of a power system.

The present invention discloses a control method for a fast-switching fault current limiter. The fast switch and a current-limiting reactor are connected in parallel to form the fast-switching fault current limiter, which is then connected in series with a power grid circuit breaker. The fast switch is configured with two sets of switch drive units and two sets of switch drive units. The control method is implemented as follows: first, the power grid circuit breaker current, the fast switch current, and the fast switch position are collected. The fast switch then adopts a double-opening and double-closing control strategy, making a comprehensive judgment based on the short-circuit current tolerance and rated current tolerance of the current-limiting reactor. After an overload action, the power grid circuit breaker is controlled to open. The present invention overcomes the shortcoming of the current-limiting reactor in existing technical solutions, which can only operate for a long time, and improves the reliability and cost-effectiveness of the fast-switching fault current limiter.

The invention relates to a direct current transmission line single-ended traveling wave protection method based on a fault voltage first traveling wave area ratio. The method comprises the following steps: S1, determining an internal and external fault identification criterion of a forward region; s2, establishing a protection starting criterion; s3, establishing a fault direction criterion; s4, establishing a fault pole selection criterion; and S5, determining a protection scheme. According to the method, internal and external faults can be identified and accurately distinguished within 1ms, high sensitivity and reliability are still achieved under the high-resistance fault condition, and meanwhile good robustness is achieved under noise interference and parameter change of the current limiting reactor.

The present invention relates to the technical field of flexible DC power grids, and aims to provide an optimized configuration method for current-limiting reactors in flexible DC power grids. The method includes: dividing the flexible DC power grid into protection zones, establishing a fault approximate analytical model for a single protection zone, and solving the functional expression between the maximum breaking current of each DC circuit breaker and the values of each current-limiting reactor; selecting the optimization objective of the maximum breaking current of the DC circuit breaker and a reasonable value range of the current-limiting reactors; then solving the optimized value set that meets the requirements within a single protection zone; and combining the total value upper limit of the current-limiting reactors and the total breaking capacity of the DC circuit breakers, selecting the overall optimal configuration scheme from the optimized value sets in each protection zone. On the premise of ensuring that the total value of the current-limiting reactors does not exceed the upper limit, the present invention selects the configuration scheme with the minimum total capacity of the DC circuit breakers as the optimal configuration scheme, which can improve the operation reliability of the flexible DC power grid while reducing the cost of protection equipment.

The invention relates to a test circuit and a test method for a distributed static synchronous series compensator, and the test circuit enables the steady-state current of a test power supply, a rectification circuit, a controllable voltage source, a transformer and a current-limiting reactor simulation line to be continuous, accurate and adjustable through switching on or switching off a circuit breaker, a high-speed switch and a high-speed bypass switch, and the test power supply is low in capacity. The method has the advantages that different states of the distributed static synchronous series compensator can be tested, the sub-modules of the distributed static synchronous series compensator can be tested in batches at the same time, the test efficiency is high, the technical economy is prominent, a high-capacity test power supply is not needed, and the test cost is low. All sub-modules of the distributed static synchronous series compensator can be tested at the same time under the laboratory condition.

The invention provides a power supply connection device which is composed of a 1 # power supply incoming line circuit breaker QF1, a 2 # power supply incoming line circuit breaker QF2, a connection circuit breaker MCB, a connection isolation MDB and a current limiting reactor L. The power supply connection device is used for solving the problem of loop closing power regulation under the scene that the voltage amplitude and phase angle difference of a power grid bus is large. According to the device, by tracking the frequency difference and angle difference changes of two paths of power supply voltages in real time, loop closing operation is carried out when voltage vector phases coincide, and equipment overload and relay protection maloperation caused by overlarge loop closing current are avoided. The device further comprises a current limiting reactor which is used for stabilizing impact current in the loop closing transient process and limiting short-circuit current when a short-circuit fault occurs. The power supply reliability can be effectively improved, and risks in loop closing operation are reduced.

The utility model provides a wind generating set high voltage ride through test device comprising a test box body, two ends of the test box body are respectively connected with a connecting lead, and the tail end of the connecting lead is provided with a fixing assembly; a test circuit board and a super capacitor module are arranged in the test box body, a display screen is arranged at the top of the test box body, a protective shell is arranged on the outer side of the display screen, and the test circuit board can be connected between a tested wind turbine generator and a power grid through connecting wires at the two ends. The test circuit board is provided with a current limiting reactor group, a parallel capacitor group, a thyristor and a plurality of groups of circuit breakers, and the super capacitor module is connected with a direct current bus of the tested wind turbine generator. The test equipment can solve the problems of poor connection stability, inaccurate voltage simulation and low test automation degree in the prior art.

The utility model belongs to the technical field of power equipment, and discloses a vehicle-mounted reactive power compensation device. According to the vehicle-mounted reactive power compensation device, the design that the first-layer frame and the second-layer frame are stacked in the first direction is adopted, the first-layer three-phase capacitor module and the second-layer three-phase capacitor module are installed on the first-layer frame and the second-layer frame respectively, the space utilization rate of a trailer plate is greatly increased, and compared with traditional single-layer arrangement, the three-dimensional layout has the advantages that the space utilization rate is greatly increased; more devices can be accommodated in the same trailer area, and the reactive compensation requirement of larger capacity is met; the first-layer frame and the second-layer frame are detachably connected, so that the equipment is more convenient to mount, dismount and maintain, and the expansibility is improved; and at least part of busbars in the three-phase inlet wire busbar group are arranged in an L shape, so that the wiring complexity is reduced, the electrical connection between the capacitor bank and the current limiting reactor is facilitated, the wiring flexibility of the three-phase inlet wire busbar group can be improved, and the space utilization rate is further improved.

This invention discloses a short-circuit current limiting system and method, relating to the field of short-circuit current limiting, including a fast switch and a current-limiting reactor; the fast switch includes an arc-extinguishing chamber and a fast mechanism, the fast mechanism including an electromagnetic drive component and a trigger circuit; the method comprises: calculating and obtaining the peak value of the first half-wave short-circuit current and the time of the first zero-crossing point; determining whether the fast switch should trip based on the peak value of the first half-wave, thereby reducing the number of system trips; determining the tripping time of the fast switch based on the zero-crossing point, thereby reducing the arc-extinguishing chamber arcing time; calculating and obtaining the peak value of TRV, adjusting the charging voltage of the trigger circuit based on the peak value of TRV, reducing the stress on the fast mechanism, thereby improving the overall lifespan of the system.

The application discloses a zero-loss deep current-limiting protection device, and relates to the technical field of protection devices.The device comprises a base, a control cabinet is arranged on one side of the top end of the base, a plurality of protection devices are arranged on one side of the control cabinet, and a refrigeration mechanism is arranged in the control cabinet.The refrigeration mechanism comprises a gas feeding pipe, a refrigeration device, an arc-shaped pipe, a flow guide pipe, a guide plate and a partition plate, the refrigeration device is arranged at the bottom end in the control cabinet, and the gas feeding pipe is arranged at the bottom end of the refrigeration device.The protection device comprises a fixing seat, a quick circuit breaker, a cylinder-type converter and a current-limiting reactor, the bottom end of the fixing seat is in contact with the top end of the base, and the quick circuit breaker is fixedly connected to the top end of the fixing seat.The zero-loss deep current-limiting protection device can guarantee the cooling effect, reduce the influence of liquid water on internal elements, and can complete the closing and opening operations in a short time because the vortex disc force direction is coaxial with the moving contact movement direction.

The application provides a circuit breaker with a current limiting reactor LR switching function, comprising a mechanical switch K1, a first thyristor D1, a current limiting reactor LR, a coupling inductor LO and a power supply VDD; the positive pole of the mechanical switch K1 is connected with the current limiting reactor LR, the first thyristor D1 and the power supply VDD respectively; the negative pole of the mechanical switch K1 is connected with the current limiting reactor LR, the first thyristor D1 and a vacuum switch K2 through the primary side of the coupling inductor LO respectively; the negative pole of the vacuum switch K2 is connected with the negative pole of the power supply VDD through a load R. In the rated operation of the circuit breaker, the current only passes through the mechanical switch and the vacuum switch, so that the system loss is reduced and the energy transmission efficiency of the circuit breaker is improved; in the fault state, the current limiting reactor is put into operation, which can limit the rising rate of the system fault current, thereby providing favorable guarantee for the circuit breaker to remove the fault; and the rate of the fault transient current transferred from the mechanical switch to the current limiting reactor is improved.

The utility model discloses a star-shaped frame for a bridge arm reactor and a current-limiting reactor, and the star-shaped frame comprises a central shaft which comprises axial grooves which are uniformly distributed in the axial direction; the axial groove comprises a lifting insertion groove, a confluence insertion groove and a star-shaped arm insertion groove; the at least three lifting arms are inserted and welded with the central shaft through the lifting slots; the confluence arm is inserted and welded with the central shaft through the confluence slot; a terminal plate is fixed on the confluence arm along a central shaft; the confluence arm comprises a first aluminum bar, a confluence arm reinforcing steel plate, an insulating plate and a second aluminum bar which are stacked in sequence; the star-shaped arm is inserted and welded with the central shaft through the star-shaped arm slot; and the star-shaped frame reinforcing plate is used for sequentially fixing the hoisting arm, the converging arm and the star-shaped arm in the circumferential direction by taking the central shaft as the axis. The confluence arm is manufactured into two layers of aluminum bars, and the confluence arm reinforcing steel plate and the insulating plate are arranged between the two layers of aluminum bars, so that the effect of shunting current is achieved, the phenomenon of abnormal temperature rise is avoided under the condition that the conductive cross section is reduced, stable hoisting can be performed, and stable use of the star-shaped frame is ensured.

The invention provides a zero-loss current limiting device based on an artificial zero-crossing technology and a device monitoring and maintenance method, and relates to a transformer fault current limiting technology, the device comprises a main switch branch, an energy absorption branch and an artificial zero-crossing branch; the main switch branch comprises a vacuum fast switch, the vacuum fast switch is connected in series between a bus of the power distribution system and the input end of the main transformer, and the vacuum fast switch is connected in parallel with a current limiting reactor; a modulation inductor is connected in series between the main switch branch and the artificial zero-crossing branch, and the energy absorption branch is connected in parallel to the artificial zero-crossing branch; the energy absorption branch comprises a plurality of zinc oxide resistors, and a nonlinear resistor module is formed by the plurality of zinc oxide resistors; the artificial zero-crossing branch comprises an energy storage unit and a trigger switch, the energy storage unit at least comprises a zero-crossing energy storage capacitor, and the zero-crossing energy storage capacitor and the trigger switch are connected in series. The zero-crossing energy storage capacitor releases electric energy to artificially produce a zero-crossing point, so that rapid opening of the vacuum rapid switch is facilitated, and short-circuit fault current limiting is realized.