332 results about "Recloser" patented technology

The invention discloses an intelligent reclosing circuit breaker modular protection system, which relates to the technical field of circuit breaker intelligent management, and comprises an acquisition module, a judgment module, a reclosing control module and an optimization module. Voltage holes caused by fault tripping and non-fault disturbance are effectively distinguished, and false triggering of reclosing operation is avoided; meanwhile, the optimization module introduces a machine learning algorithm to carry out continuous filing and strategy updating on misjudgment events, and self-adaptive discrimination logic optimization is realized, so that reclosing judgment accuracy and power supply stability of the power grid system under a complex load condition are remarkably improved, and system impact and equipment damage are effectively prevented.

The invention discloses a primary and secondary fusion pole-mounted intelligent circuit breaker. The primary and secondary fusion pole-mounted intelligent circuit breaker comprises a fault detection module, a protection action module, a reclosing module and an information reporting module, the fault detection module collects multi-dimensional electrical quantity through a current transformer and a voltage transformer, and judges a fault and identifies the type in combination with a dynamic normal range and a duration threshold. The protection action module calculates the fault distance based on the correction impedance, judges whether to act or not by combining the current flow direction and the protection range, and selects a protection level according to the fault severity; the reclosing module dynamically sets an observation time window, distinguishes instantaneous or permanent faults through a retest verification mechanism, and adaptively adjusts a reclosing strategy; and the information reporting module uploads fault related information. According to the method, the problems of high misjudgment rate, poor protection selectivity, rigid reclosing logic and the like of a traditional circuit breaker are solved, and the accuracy, quickness and self-healing capability of power distribution network fault processing are remarkably improved.

The invention discloses a modular reclosing circuit breaker protection system based on intelligent electrical cloud coordination, particularly relates to the technical field of intelligent power distribution network relay protection, and is used for solving the problems that fault diagnosis is delayed and a protection strategy cannot be generated in a fault clearing time window due to resource competition in a cloud coordination protection system. A dynamic preemption priority is generated based on power grid topology vulnerability and associated circuit breaker collaborative requirements by monitoring the load state of cloud computing node resources in real time; credibility attenuation control is carried out in combination with a fault current waveform distortion rate; when the resource preemption necessity exceeds a threshold value, freezing a periodic task thread and releasing computing resources, and opening up a high-priority communication channel at the same time; sending a fault recording compression instruction to a target circuit breaker terminal to obtain an edge preprocessing feature vector; and protection strategy optimization is executed in the released resources to generate reclosing parameters, and the reclosing parameters are issued and executed through a high-priority channel, so that quick response of a fault diagnosis task is realized.

The invention relates to the technical field of mechanical performance testing of power transformer winding materials, in particular to a method for evaluating the mechanical strength of a transformer winding under a reclosing working condition, and the method comprises the steps: obtaining and preprocessing historical operation data, finite element simulation data and laboratory simulation test data; deploying a micro foil strain gauge, an MEMS acceleration sensor and a flexible piezoresistive sensor based on the preprocessed data, and synchronously collecting radial strain, axial acceleration and cushion block pressure data; after noise filtering, time alignment and feature extraction, multi-directional deformation cooperative influence is analyzed through methods of Pearson's correlation coefficients, partial least square regression and the like; and in combination with a historical damage sample training evaluation model, outputting a mechanical strength degradation level in real time. According to the method, the problems of synchronous acquisition and correlation analysis of multi-direction deformation data under reclosing impact are solved, and accurate evaluation of overall mechanical strength change caused by accumulated deformation is realized.

The invention discloses a reclosing locking method and system based on winding hot-spot temperature fitting, and relates to the technical field of power transformer dynamic stability assessment, and the method comprises the steps: determining a target transformer, collecting parameters, building a winding current calculation model, calculating steady-state and short-circuit current waveforms, and carrying out the winding temperature rise test of the transformer, the method comprises the following steps: measuring a steady-state temperature rise value, constructing and correcting an electromagnetic heat flow coupling model, generating steady-state and transient-state temperature field data of a winding, constructing a target function of a winding hot-spot temperature, fitting simulation data by utilizing an optimization algorithm, obtaining a fitting function, calculating a winding stress value under a short-circuit working condition in real time, and comparing the winding stress value with a dynamically adjusted stress limit value, so as to obtain a winding stress value. Alarm and locking reclosing are triggered according to the result, and intelligent protection of the transformer is achieved. According to the invention, through accurate parameter acquisition, model establishment, temperature field simulation, hot-spot temperature fitting and stress calculation, real-time monitoring and intelligent protection of the transformer winding under the short-circuit working condition are realized.

The invention discloses a multi-stage collaborative protection simulation verification method for a subway power supply system, and the method comprises the steps: building an integrated simulation model which comprises an automatic reclosing switch, a spare power automatic switching switch and an automatic change-over switch based on an MATLAB / Simulink platform, and especially carrying out the precise modeling of an advanced compensation function of ATSE. The model is verified by a power-off test, a simulation result and actually measured data are highly consistent in voltage recovery time, an error of advanced compensation action time of ATSE is less than 2ms, and dynamic characteristics of an actual system are accurately reproduced. Model simulation shows that the advanced compensation strategy of the ATSE can effectively control the voltage sag amplitude within 15%, the power supply reliability of the system is remarkably improved, and through strict'simulation-actual measurement 'double-track verification, the model accurately reproduces the dynamic characteristics of the actual system, and shows remarkable advantages in the aspect of improving the power supply reliability.

The invention relates to the technical field of circuit breakers, in particular to a circuit breaker with a reclosing mechanism, which comprises a shell, a circuit breaker handle is rotationally arranged in the shell, an operating rod and at least three gears meshed in sequence are further rotationally arranged in the shell, and the tooth number of each gear is gradually increased in sequence. The two gears located on the two sides are a small gear and a large gear respectively, the number of teeth of the small gear is smaller than the number of teeth of the large gear, the operating rod is fixedly connected with the small gear, and the large gear is in transmission connection with a circuit breaker handle. Speed reduction and torque increase are realized through the gear train, so that the force required to be applied when a user manually operates the handle of the circuit breaker is remarkably reduced, the operation intensity is reduced, the convenience of manual reclosing is improved, and the manual reclosing device is particularly suitable for a large-current circuit breaker or an occasion requiring a relatively large operation torque.

The invention discloses a power distribution network power supply recovery method and system considering multi-type distributed power supply cooperation, and the method comprises the steps: enabling a fault section to be successfully isolated, and carrying out the non-voltage switching-on of a network-following type DG in an intertripping power-losing region; constructing a source-load balance island based on the network construction type DG, and preferentially recovering an important load; when there is no contact, the upstream switch of the fault point carries out non-voltage reclosing to process an instantaneous fault, and island grid connection is planned; when connection exists, an optimal connection switch is optimized according to the capacity of a connection line and the capacity of a power-losing load, closing is carried out after an unrecoverable section is cut off, and staged power restoration is achieved by circularly cutting off the unrecoverable load, grid connection of the grid-following type DG and updating the recoverable capacity by considering the capacity of the adjacent grid-following type DG. And when an island adjacent section is recovered, the connected switches are subjected to synchronization grid connection. According to the invention, through a multi-type DG cooperative control strategy, the maximum capacity safety recovery of a non-fault section load is realized, the active support capability of the DG is fully exerted, and the reliability of the power distribution system is remarkably improved.

The invention discloses a reclosing coordination control method and system based on electrical parameter measurement, particularly relates to the technical field of intelligent power grid fault processing and security defense, and is used for solving the problem that the reliability of fault judgment is reduced due to the fact that high-proportion distributed photovoltaic is connected to a power distribution network. A harmonic detection signal is injected during a reclosing waiting period, a response signal is measured, harmonic subspace energy distribution is extracted, an energy distribution matrix is constructed to calculate a nuclear norm change rate and form similarity, a system harmonic impedance stable state is judged through double verification, and finally a reclosing decision is executed according to a fault judgment parameter. The method can accurately identify the convergence characteristic of the dynamic process of the system, effectively distinguish the instantaneous fault from the permanent fault, and significantly improve the reclosing success rate and the power supply reliability of the distributed photovoltaic power distribution network.

The grid connection method is suitable for the field of connection of a low-voltage load independent power supply system into a medium-voltage power grid, and is an independent power supply system grid connection method which can give consideration to important load uninterrupted power supply and transformer starting inrush current suppression at the same time. Considering that the capacity of an energy storage battery is limited and power supply of all loads is difficult to support, the loads are divided into sensitive loads and general loads, and when a main network loses power, the energy storage battery supplies power to important loads through a hybrid transformer; in the reclosing grid connection process, the starting inrush current and time of the transformer are effectively reduced through voltage and current multi-control mode switching of a converter in the hybrid transformer device, and meanwhile uninterrupted power supply of an important load is guaranteed; and after the grid-connected starting of the passive transformer is completed, the medium-voltage power grid is switched to supply power, and a general load at a low-voltage side is put into use. According to the method, the problem that the sensitive load needs secondary power failure after the power grid loses power in a traditional power supply mode is solved, the service life of the passive transformer is effectively prolonged, and the working efficiency of the low-voltage important load is effectively improved.

The invention relates to the technical field of relay protection, in particular to a three-phase self-adaptive reclosing method and system for a wind power transmission line. The method comprises the following steps: when a fault is detected, collecting a secondary side voltage signal of a target fault phase of the wind power system; determining a fault phase voltage envelope value according to the peak value of the secondary side voltage signal; calculating energy in a plurality of time windows according to the fault phase voltage envelope value; sequentially calculating the energy ratio between the energy of the jth (j = 2, 3, 4,...) time window and the energy of the first time window; if the value of the energy ratio of at least three continuous time windows in the maximum discrimination time limit is greater than 1, determining a reclosing moment so as to output a circuit breaker closing signal after the reclosing moment is reached; otherwise, judging that the fault type is a permanent fault, and not outputting the circuit breaker closing signal. The objective of the invention is to solve the problem of how to identify the fault type of a wind power system before reclosing of a circuit breaker.

The invention discloses a photovoltaic power grid fault transient control method, device and equipment, and relates to the technical field of photovoltaic auxiliary equipment, and the method comprises the following steps: obtaining the operation data of a photovoltaic grid-connected point, constructing a three-phase coupling characteristic matrix, and generating a disturbance discrimination result according to the dynamic evolution of the three-phase coupling characteristic matrix; based on a disturbance judgment result, collecting three-phase output current of the photovoltaic inverter, calculating disturbance increment of each phase of current, extracting a stable current component during a fault period based on low-voltage ride-through control logic, and calculating equivalent support power of the stable current component at a fault point; the equivalent support power is compared with a preset arc extinguishing threshold value, and the dissociation condition of the fault point is dynamically evaluated; when the fault point is not free, the photovoltaic inverter is controlled to perform state conversion, so that the equivalent support power is lower than an arc extinguishing threshold value; and after detecting that the voltage of the fault point is recovered and the arc light is extinguished, dynamically adjusting the reclosing time sequence based on the voltage recovery rate. The problems that arc light is difficult to extinguish and the reclosing failure rate is high are solved.

The invention discloses a dual-stage distribution network fault recovery control method based on energy storage active variable power. In the first stage, energy storage maintains network construction type control, the sum of relative entropies of circuit breaker downstream positive sequence voltages in a reference time window and a detection time window is calculated in real time within the detection duration, if the sum of the relative entropies is larger than or equal to a voltage relative entropy threshold value, it is indicated that a fault is removed, and reclosing is delayed; if the sum of the relative entropies is continuously smaller than the voltage relative entropy threshold value, it is indicated that whether the fault is removed or not is not detected, and the second stage is started; in the second stage, variable power control is adopted for energy storage, the sum of relative entropies of the downstream positive sequence voltage of the circuit breaker in the reference time window and the detection time window is calculated in real time within the detection duration, and if the sum of the relative entropies is larger than or equal to the voltage relative entropy threshold value, time delay reclosing is conducted; and if the sum of the relative entropy is continuously smaller than the voltage relative entropy threshold value, the reclosing is locked. And rapid fault recovery can be realized, and secondary impact on the system possibly caused by blind switching of reclosure is avoided.

A three-phase adaptive reclosing method and system for wind farm transmission lines based on parallel reactor current is provided. When a phase to phase or three-phase fault occurs in the transmission line, the circuit breakers at both ends trip. The current transformer is used to sample the three-phase current signal of the parallel reactor, calculate the differential mode current of the parallel reactor, and perform zero crossing detection to construct a fault nature identification criterion. The fault nature is determined within the maximum discrimination time limit combined with the sliding time window. For permanent faults, the reclosing device is locked; for transient faults, calculate the time when the fault disappears and determine the reclosing time, and open the reclosing device. The method and system identifies the nature of faults by detecting whether the differential current of parallel reactors crosses the zero axis, with low sampling rate requirements, and small errors.

The invention discloses an intelligent opening and closing method and system for a reclosing circuit breaker based on an electromagnet, and relates to the field of intelligent control, and the method comprises the steps: monitoring a line current in real time, comparing the line current with a preset threshold value, and carrying out the opening after the overcurrent abnormality is detected. Entering a first time delay stage after opening, comprehensively evaluating the states of the circuit breaker and the circuit, and constructing a dynamic weight index system to calculate an evaluation score; if the score exceeds a threshold value, closing is carried out after time delay is finished, otherwise, an alarm is triggered. And entering a second delay stage after switching on, continuously monitoring the electric parameters and establishing an anomaly judgment mechanism, forming a closed-loop protection process of monitoring, switching off, evaluating, switching on and re-monitoring, and realizing intelligent linkage of overcurrent protection and state self-adaption. The method has the advantages that through real-time line electric parameter monitoring, multi-dimensional state evaluation and an intelligent decision-making mechanism, precise opening and closing of the circuit breaker are achieved, the power supply reliability is improved, the power failure time is shortened, and the misoperation risk is reduced.

The invention relates to the technical field of automatic control, and discloses a magnetic recloser adaptive control method and system for circuit design. The method comprises the steps of collecting multi-dimensional electrical parameters of a distribution line through an intelligent sensor array, constructing a mixed fault feature vector by utilizing a time-frequency domain fusion algorithm, separating instantaneous and permanent fault components by adopting three-stage fault recognition, obtaining fault severity level evaluation based on dynamic weight distribution, and performing fault severity level evaluation based on dynamic weight distribution. And generating a self-adaptive control instruction through grading reclosing strategy matching to execute the opening and closing operation of the magnetic recloser. According to the invention, the technical problem that the magnetic recloser cannot carry out accurate fault recognition and adaptive hierarchical control in a multi-transient fault and permanent fault mixed scene is solved.

The invention discloses a photovoltaic station island stability control and re-grid-connection method based on energy storage cooperative regulation and control, and the method comprises the steps: carrying out the island detection in real time in a normal grid-connection state, and switching a photovoltaic system from a first working mode to a second working mode if tie line protection trips, so as to reduce the output power of the photovoltaic system; detecting the state of a grid-connected point circuit breaker, if the connection line circuit breaker is changed from closing to opening, executing connection line current detection, and when the connection line current is judged to be smaller than a current threshold value, switching the energy storage system from the first working mode to a second working mode to provide voltage and frequency support for the photovoltaic system; grid-connected detection: judging whether the island voltage, frequency and phase meet grid-connected conditions or not, if not, continuing grid-connected detection, and if yes, reclosing grid connection; and then, firstly switching the energy storage system from the second working mode to the first working mode, then switching the photovoltaic system from the second working mode to the first working mode, and recovering normal operation of the station.

A high-efficiency power electronic voltage regulating device with a reclosing function is connected in series with a low-voltage line and comprises a silicon controlled bypass switch, a series power unit, a parallel power unit, an input filtering unit, an output filtering unit, a controller, a topology change-over switch, a mechanical bypass switch, an input switch, an output switch and the like. Under a normal working condition, power is supplied to a user through the silicon controlled bypass switch; through an AI pre-judgment technology, a power grid voltage drop or increase trend is pre-judged, and a series power unit is conducted in advance; a topology change-over switch is connected to form a boost or buck topology, and when the voltage of a power grid is too low or too high, the normal voltage of a user is ensured through PR closed-loop control; when the rear-end line / load breaks down, reclosing control is carried out; and voltage upper and lower limits are adjusted remotely. The device utilizes the AI pre-judgment technology, has the characteristics of stable voltage, no need of input / output commutation and the like, solves the problems of over-high and over-low voltage and automatic reclosing in fault, and improves the high power supply quality and the power supply reliability of users.

The invention relates to the technical field of circuit breakers, and discloses a switching-on and switching-off structure of a reclosing circuit breaker, which comprises a shell, a static contact, a moving contact, a switching-on and switching-off knife switch and a switching-on assembly, and the static contact and the moving contact are arranged in the shell. The closing assembly comprises a driving motor and a transmission part arranged between the opening and closing knife switch and an output shaft of the driving motor, the driving motor can drive the transmission part to act, and the transmission part can drive the opening and closing knife switch to act. When an instantaneous fault of a circuit where the circuit breaker is located disappears, the driving motor drives the transmission part to act and further drives the opening and closing knife switch to act, direct driving of a power source is achieved, the mechanical structure is simplified, the fault probability caused by complex mechanical interlocking and lock catch abrasion and jamming is reduced, the mechanical response time is shortened, and the service life of the circuit breaker is prolonged. And the execution speed of the automatic reclosing is improved, so that the intelligent power grid can recover power supply more quickly.

Provided are an adaptive reclosing method and apparatus for a distribution network, a medium, and a device, which relate to the technical field of automatic control for distribution networks. Firstly, a voltage threshold for reclosing start-up is set based on power of a load and a distributed renewable energy source that are connected in a downstream direction of a circuit breaker of a distribution network before the distribution network fails. Then, after a fault occurs in the distribution network, a positive sequence voltage amplitude and its change rate are calculated. Finally, disconnection and fault statuses of a distributed renewable energy source network are determined based on the positive sequence voltage amplitude and its change rate, and reclosing is performed based on a preset corresponding delay for different situations.

The invention discloses a power distribution network instantaneous fault recovery control method based on cooperation of energy storage and a circuit breaker. Firstly, a reclosing starting threshold value is set based on a power distribution network voltage after a fault is cleared; then, for a continuous arcing fault, after a circuit breaker trips, an energy storage converter is switched to arcing suppression control with the aim of reducing the voltage of an energy storage grid-connected point; and finally, after the fault arc is extinguished, acquiring the voltage at the downstream outlet of the circuit breaker, and if the voltage at the downstream outlet of the circuit breaker is greater than or equal to the reclosing starting threshold value within the fault detection time, indicating that the fault is eliminated, and reclosing after the first time delay; and if the voltage at the downstream outlet of the circuit breaker in the fault detection time is smaller than the reclosing starting threshold value, it is indicated that the fault is not cleared, and reclosing is carried out after second time delay. According to the method, the circuit breaker is combined with the energy storage power station, the energy storage power station adopts arcing suppression control and supplies power to the downstream load after the fault occurs, the downstream load does not need to operate off the grid, and the power supply reliability of the power grid is improved.

The invention discloses an overhead line fault diagnosis method, system and device based on space vector conversion and a storage medium, and relates to the technical field of intelligent power distribution, and the method comprises the steps: collecting the normal operation three-phase current data of an overhead power distribution line, and constructing a steady-state feature model; three-phase current data is collected in real time and converted into a space vector sequence, the Euclidean distance between a vector end point and a model center is calculated, and instantaneous offset is extracted. Integrating the offset in a sliding window, calculating a phase rotation rate, generating a multi-dimensional deviation tensor, inputting the multi-dimensional deviation tensor into a fusion function to obtain a misconstruction score, and normalizing the misconstruction score to obtain a misconstruction index; comparing the index with a threshold value, if the index exceeds the threshold value, determining that the disturbance is external transient disturbance, and adjusting the sampling frequency of the current sampling device; according to the method, interference can be effectively identified in a special electromagnetic environment, misjudgment of diagnosis is avoided, maloperation of a protection device is reduced, reclosing operation is guaranteed, and the fault diagnosis accuracy and robustness of a power distribution system are improved.

The invention relates to a coupled inductor current-limiting type hybrid direct-current circuit breaker topology and a working method. The coupled inductor current-limiting type hybrid direct-current circuit breaker comprises a current-carrying part and a breaking part, the current-carrying part is formed by connecting an ultra-fast mechanical switch UFD and a load change-over switch LCS in series, the breaking part comprises a bridge circuit, a first branch circuit, a second branch circuit, a third branch circuit, a fourth branch circuit, a fifth branch circuit and a sixth branch circuit, the fourth branch circuit is formed by connecting a thyristor, a coupling inductor and a primary side inductor in series to form a current-limiting branch circuit, and the fifth branch circuit is formed by connecting a secondary side inductor and a secondary side inductor. The sixth branch is formed by connecting a secondary side inductor of a coupling inductor with a thyristor in series and then connecting the secondary side inductor with a capacitor in parallel; the current limiting of the fault current is realized through the fourth branch, the fault breaking of the primary side inductor of the coupling inductor of the fourth branch is completed through the coupling effect of the secondary side inductor of the coupling inductor of the sixth branch, the peak value of the fault current is obviously reduced, and the breaking time is obviously shortened; the circuit breaker can quickly respond to faults of three working modes of current limiting breaking, reclosing and small current breaking; and the breaking part of the circuit breaker adopts the thyristors instead of the IGBTs, so that the cost of the circuit breaker is reduced.

The invention provides an automatic relay testing system and method based on parallel processing, and relates to the technical field of relay testing. The method comprises the following steps: recording a reference signal waveform, time sequence data, a baseline state index and an initial reclosing frequency increment of equipment in a normal operation state; equipment signal difference is monitored and collected in real time in the process of simulating power-off-reclosing, and signal changes are analyzed and sent to the next module; quantifying the system state change to obtain an equipment safety state value; creating a reclosing frequency adaptive algorithm, and judging whether to continue the test and decide the reclosing frequency of the next simulation according to the equipment safety state value and the initial reclosing frequency increment; and according to a test result, determining the maximum tolerable reclosing frequency to obtain a recovery robustness index. The problem that the fixed step length test cannot fit the actual state of the equipment is solved.

The invention provides an intelligent reclosing method and device for a new energy power distribution network. The method comprises the steps that after the power distribution network breaks down, an energy storage power station is connected into the power distribution network, and back electromotive force active arc extinction control is carried out; after it is detected that the fault arc is extinguished, the energy storage power station serves as a main power supply to continuously supply power to a downstream load of the power distribution network; and if the operation mode is a network construction type operation mode, determining a delay duration based on a first reclosing starting threshold value, and carrying out a delay reclosing operation, and if the operation mode is a current limiting operation mode, determining a delay duration based on a second reclosing starting threshold value, and carrying out a delay reclosing operation. According to the method, the fault state can be accurately identified in the complex environment of high-proportion distributed new energy and energy storage access, secondary impact caused by blind switching-on is avoided, meanwhile, rapid recovery of power supply and safety and stability of the system are considered, and efficient, safe and economical operation of the new energy power distribution network is effectively guaranteed.

The invention relates to the technical field of circuit breakers, in particular to a double-connecting-rod reclosing mechanism and a circuit breaker, and the double-connecting-rod reclosing mechanism comprises a driving assembly, a rotating part, a first connecting rod, a second connecting rod, a fixed plate and a sliding block, the driving assembly is used for driving the rotating part to rotate, and the first connecting rod comprises a connecting end and a transmission end; the connecting end is eccentrically and rotationally connected to the rotating piece, the transmission end is rotationally connected with the second connecting rod, the fixing plate and the sliding block are both located on one side of the rotating piece, the sliding block can slide in the direction close to or away from the rotating piece and is used for driving a circuit breaker handle to rotate, a chute is formed in the fixing plate, and the sliding block can slide in the chute in the direction close to or away from the rotating piece. The second connecting rod comprises a sliding end and a rotating end, the sliding end slides along the inclined groove, the rotating end is rotationally connected with the sliding block, and the transmission end is located between the sliding end and the rotating end.

The invention relates to the technical field of circuit breakers, and particularly discloses a recloser with a positioning structure and a circuit breaker. The recloser comprises a shell, an operating mechanism and a positioning mechanism. The operating mechanism achieves opening and closing control through left-right movement of the cross rod, the positioning mechanism is composed of a main body, an adjusting rod and a connecting plate, the main body is provided with a transverse groove and an inclined groove, and first protruding shafts at the two ends of the cross rod are embedded into the transverse groove and the inclined groove. The adjusting rod adjusts the relative position of the cross rod through up-and-down movement, and precise calibration of the working state is achieved. And the chute design can prevent the vacuum tube in the pole from being damaged due to false closing after the cross rod is dislocated. The cumbersome debugging steps of a traditional recloser are simplified through a pre-debugging mechanism, the opening stability is ensured through the friction force between the chute and the convex shaft, and manual and automatic dual-mode operation is supported. The positioning structure and the anti-misoperation design of the recloser and the circuit breaker remarkably improve the action reliability and the maintenance efficiency of the recloser and the circuit breaker, and are suitable for efficient operation and maintenance of a power system.

This invention relates to the field of DC circuit breakers, and discloses a thyristor-type DC circuit breaker and its control method. The DC circuit breaker structure is a thyristor T... m1 Anode-connected thyristor T m2 The cathode forms the A terminal of the circuit breaker, T m1 Cathode connection T m2 The anode of the thyristor forms the B terminal of the circuit breaker; the thyristor T p1 anode, thyristor T p2 The cathode is connected to terminal A; T p1 Cathode connection T p2 After anode, it passes through resistor R in sequence. g Switch RCB g Grounding; T p1 Cathode connection T p2 After the anode, it also passes through inductor L p Capacitor C is connected to terminal B; one end of the surge arrester MOV is connected to terminal T. p1 The cathode is connected to the first terminal, and the other end is connected to the B terminal. This invention has a simple structure and significant cost advantages; under normal operating conditions, only a single thyristor is conducting, resulting in extremely low losses and extremely high circuit breaker efficiency. Combined with control methods, it can actively and reliably connect or disconnect bidirectional operating current or bidirectional fault current; it can also achieve fast reclosing functionality.

A recloser pole convenient to overhaul is characterized in that the recloser pole comprises a packaging shell, a detachable upper wire inlet mechanism connected to the packaging shell, a detachable lower wire outlet mechanism connected to the packaging shell and electric display sensing parts embedded in the upper wire inlet mechanism and the lower wire outlet mechanism, and an upper connector and a lower connector are arranged on the packaging shell; clamping grooves are evenly distributed in the outer side wall of the upper connector and the outer side wall of the lower connector respectively, the upper wire inlet mechanism is matched with the upper connector, and the upper connector is sleeved with the upper wire inlet mechanism. The upper wire inlet mechanism comprises an upper wire inlet connector, an upper wire inlet connector base connected to the upper wire inlet connector, an outer ring wrapping the upper wire inlet connector base and an elastic clamping piece clamped between the upper wire inlet connector base and the outer ring, and the elastic clamping piece abuts against the clamping groove. The lower wire outlet mechanism is matched with the lower connector, and the lower wire outlet mechanism is arranged outside the lower connector in a sleeving mode, so that when the wiring end of the recloser has circuit problems such as virtual connection, the maintenance efficiency of workers is effectively improved, and the maintenance convenience is effectively improved.

The invention discloses a power distribution network protection method in the field of power system protection, and the method comprises the following steps: S101, collecting the multi-source data of a power distribution network in real time, collected multi-source information such as electrical quantity data, distributed energy output data, meteorological data, equipment state monitoring data, node voltage, current waveform, topological structure, distributed power output state and environmental parameters in a power distribution network is transmitted to a protection device or a control center through a communication network. Through application of multi-source information fusion and self-adaptive protection criteria, the protection device can judge faults more accurately, maloperation and refusal operation are reduced, the accuracy of power distribution network protection is improved, an intelligent reclosing strategy and implementation of distributed cooperative protection are adopted, and the safety of power distribution network protection is improved. The secondary impact and islanding effect of reclosing on the system are effectively avoided, the stability of the system is improved, and the safe operation of the power distribution network is guaranteed.