152 results about "Arc suppression" patented technology

The invention discloses a power distribution network grounding fault research and judgment analysis method, relates to the technical field of power distribution network fault analysis, and solves the technical problem that fault analysis is not accurate and deep enough due to the fact that fault features in a neutral point grounding complex fault scene cannot be comprehensively considered. According to the method, single-phase grounding fault models of a neutral point ungrounded system, an arc suppression coil grounded system and a small resistor grounded system are respectively constructed, grounding current, phase voltage and neutral point voltage expressions under the models are detailedly deduced, and characteristics of voltage and current before and after a fault point in the steady-state and transient-state processes are deeply analyzed; the method comprehensively considers various complex fault scenes, can more accurately grasp essential characteristics of faults in different grounding modes, and provides a more comprehensive and accurate basis for fault diagnosis and processing.

The invention discloses an arc suppression coil grounding fault positioning method based on a transformer substation line protection device, particularly relates to the technical field of system fault measurement, and is used for solving the problem of insufficient positioning precision caused by neglecting the nonlinear characteristic of a fault point arc channel in an existing fault positioning method. A specific frequency current signal is injected into a fault phase, the phase relation between fundamental wave and harmonic wave components in current collected by a line protection device is analyzed to obtain a phase coherence coefficient, a fault line distribution parameter model is established to obtain theoretical reference information, and a spatial gradient sequence is generated by calculating actual measurement and theoretical spatial entropy values. Identifying a line section corresponding to the abnormal abrupt change point, and finally determining a grounding fault point according to the spatial position of the line section with significant difference. The method can effectively overcome the influence of nonlinear attenuation and frequency dispersion effect on the positioning precision, and achieves the precise measurement and positioning of a single-phase grounding fault.

The embodiment of the invention provides a distribution network line fault positioning method and system, and the method comprises the steps: determining a fault phase, and calibrating a fault moment; dividing the multi-branch line into a line partition and a branch line partition based on the distribution network topology; screening a target fault phase, calculating a fault phase current difference of adjacent detection points, and calculating a current abrupt change rate based on the fault phase current difference of the adjacent detection points; according to the arc suppression coil type and the fault transition resistance value, performing fitting to generate a partition threshold value; a suspected fault section is obtained according to the section threshold initial judgment section; calling a current abrupt change rate time sequence curve of upstream and downstream nodes of the suspected fault section, and checking a current difference amplitude change trend before and after the fault; for multi-branch topology, interference is eliminated through relevance of current abrupt change rates of a main line and branch lines, and finally a target fault section is locked. According to the invention, the problems of weak fault characteristic quantity and poor positioning reliability in a small current grounding mode can be effectively solved.

The invention provides a power distribution network single-phase earth fault processing and fault rapid regional isolation system for solving the problems existing in power distribution network single-phase earth fault regional isolation at present. The system is composed of an improved compensation damping type active intervention arc extinguishing device installed on a transformer substation bus, primary and secondary fusion intelligent switches installed at all nodes of a distribution line, and a primary and secondary fusion intelligent switch intelligent control terminal. When a single-phase grounding fault occurs, a grounding switch of the compensation damping type active intervention arc extinguishing device is switched on, a primary and secondary fusion intelligent switch control terminal of each node of a power grid generates corresponding low-resistance, medium-resistance and high-resistance zero-sequence protection fixed values, and when the single-phase grounding fault occurs, zero-sequence current protection is started to realize rapid fault area isolation of the single-phase grounding fault.

The invention discloses an electric arc dynamic suppression method for hot plugging of an electric meter connector, relates to the technical field of electric energy metering equipment, and aims to solve the problems of electric arc generation, overproof metering error and the like caused by passive protection and lack of dynamic cooperative control in the prior art. The core of the method is that gap distance and power grid voltage phase signals are acquired in real time through a microcontroller, and the plugging speed, the signal injection and the position fine adjustment are dynamically regulated and controlled in three stages of pre-contact, low-current transition and full connection; and a machine learning model is combined to optimize a parameter threshold value, a redundancy safety mechanism and a multi-phase electric meter cooperative control strategy, so that double management and control of arc peak energy and metering errors are realized. The method can actively inhibit arc generation, avoid connector ablation and insulation deterioration, guarantee metering continuity and accuracy, adapt to complex power grid and environment working conditions, and meet the precision requirement of the intelligent electric meter.

The invention discloses a generator stator grounding fault active arc extinction method based on double-loop quasi-PR control, and the method comprises the following steps: S1, monitoring the fundamental wave zero-sequence voltage and third harmonic voltage of a neutral point and a generator end of a generator, and carrying out the fault phase selection and positioning when a single-phase stator grounding fault occurs; s2, according to a fault positioning result, calculating a fault winding potential Ef, and setting a negative value-Ef of the fault winding potential Ef as a neutral point target compensation voltage; s3, a cascaded H-bridge converter is adopted as a topological structure of the active regulation and control device, and a double-closed-loop control framework composed of a voltage outer loop and a current inner loop is established; s4, setting quasi-PR control units for the fundamental wave component and the third harmonic component in the voltage outer ring and the current inner ring respectively; and S5, controlling the cascaded H-bridge converter to output a compensation voltage consistent with the target compensation voltage-Ef, and injecting the compensation voltage into the neutral point of the generator. The voltage regulation and control precision and the arc suppression speed in the active arc suppression process of the generator can be improved, and the operation safety and reliability of the generator are improved.

The invention provides an arc suppression coil grounding system zero-sequence overcurrent protection method based on zero-sequence voltage verification. The protection reliability is improved through multi-criterion fusion. The method specifically comprises the following steps: S1, arc suppression coil system fault starting criterion: monitoring a zero sequence voltage in real time, and triggering a protection algorithm when the amplitude of the zero sequence voltage exceeds a preset threshold value; s2, fault time calculation: calculating the duration time of a grounding fault based on the duration characteristic of the zero-sequence voltage; s3, fault position discrimination: in combination with the amplitude characteristics of the zero-sequence current, distinguishing an internal fault from an external fault; and S4, intelligent comprehensive decision making: fusing the transient and steady state characteristic quantities of the zero-sequence voltage and the zero-sequence current, and generating a protection action signal. According to the invention, by dynamically checking the correlation characteristics of the zero-sequence voltage and current, the problems of insufficient sensitivity and high maloperation rate of the traditional zero-sequence overcurrent protection in the arc suppression coil grounding system are effectively solved.

The application belongs to the field of power system fault diagnosis, and discloses a single-phase grounding fault determination method for a small current grounding system based on Bi-LSTM, which comprises the following steps: analyzing a model of a power system and actual dispatching data, building a computer numerical simulation model through the analyzed data, labeling fault data and non-fault data in the simulation data and the actual dispatching data, normalizing simulation and real-time dispatching characteristic data, making a training set and a test set of a Bi-LSTM model, and designing a fault line selection model based on Bi-LSTM and training and testing of the model. In the case of single-phase grounding, the application can quickly determine a fault line according to discrete dispatching data; compared with existing zero sequence current identification methods, the application does not require zero sequence current data, and has a higher identification rate in the case of neutral point grounding through an arc suppression coil or a fault point with high transition resistance, thereby realizing simple and efficient small current grounding fault line selection.

The utility model discloses a cabinet combination connecting structure of an arc suppression coil, which comprises a supporting plate, a double-thread screw is rotatably connected to the side inner wall of the supporting plate, a sliding block is in threaded connection to the side surface of the double-thread screw, a first clamping block is fixedly connected to the lower surface of the sliding block, a bottom plate is fixedly connected to the surface of one side of the clamping block, and a second clamping block is fixedly connected to the upper surface of the sliding block. A first spring is fixedly connected to the lower bottom wall of the supporting plate, a telescopic rod is fixedly connected to the end, away from the supporting plate, of the first spring, a buckle is fixedly connected to the side surface of the telescopic rod, an extension plate is fixedly connected to the side surface of the buckle, and a second spring is fixedly connected to the side surface of the extension plate. A top plate is fixedly connected to one end of the spring II away from the extension plate. Through the components, the positions of the sliding blocks on the supporting plate and the length of the telescopic rod after being pulled up can be adjusted to be used for being matched with the length and the height of the arc suppression coil, the device can be adjusted according to the size of the arc suppression coil, the fixing effect is improved, and the types of the matched arc suppression coil are increased.

The invention provides an alternating current arc detection method and a related device, and the method comprises the steps: obtaining an external instruction through a controller of an arc detection system, and determining a circuit simulation model based on the external instruction; acquiring a first current signal from the signal detection circuit module in the detection period, and determining an arc feature vector based on the first current signal; determining an arc generation condition based on the arc time-frequency feature vector; generating an arc generation image based on the arc generation condition and the circuit simulation model; a multi-stage circuit regulation and control strategy is determined based on the arc generation condition, and a regulation and control circuit module is regulated and controlled based on the multi-stage circuit regulation and control strategy; acquiring a second current signal; determining an arc suppression effect image based on the second current signal and a circuit simulation model; therefore, the arc generation condition and the suppression effect can be visualized in real time, the arc suppression efficiency is improved, the arc analysis accuracy is improved, the arc extinguishing time is shortened, and then the alternating current arc detection efficiency, the detection precision and the arc suppression speed are improved.

The utility model discloses an active power distribution network fault simulation experiment platform which comprises a public network power supply module, a line switch module, a power distribution network line section module and a plug panel which are connected in sequence, and a wave recording detection and relay protection module, a fault simulation module, a distributed power supply module and a load module which are connected with the plug panel, the public network power supply module and the line switch module are connected with the plug panel. The public network power supply module comprises a switch control circuit, a power supply side circuit breaker, a control contactor, a transformer and a distribution network side circuit breaker which are connected in sequence; the transformer is connected with an arc suppression coil, and the arc suppression coil is connected with the plug panel. The device is novel and reasonable in design and convenient to operate, realizes simulation experiments of different normal operation modes and different fault types in the active power distribution network by setting different topological structures and adjusting the fault types, realizes acquisition of characteristic signals in faults for fault characteristic signal analysis, and is good in safety performance and high in reliability. And an experimenter can conveniently carry out a simulation experiment.

This invention provides an intelligent pressure relief device for power distribution cabinets based on arc suppression, belonging to the field of power distribution cabinet pressure relief devices. It includes a cabinet body and a cabinet door. The cabinet door is rotatably connected to the side wall of the cabinet body via multiple hinges. An outer shell is fixedly connected to the outer wall of the cabinet body, and a baffle is provided on the outer wall of the outer shell. A pressure relief port is provided on the side wall of the cabinet body, and a sealing plate is provided on the outer wall of the cabinet body. It also includes: an auxiliary component located inside the outer shell, used to prevent high pressure from forming inside the cabinet and to cool the cabinet; a trigger component located below the auxiliary component, used to prevent open flames from forming inside the cabinet; and a reinforcement component located inside the cabinet body, used to improve the stability of the cabinet door. This invention, through the pushing of the sealing plate, drives the fixed rod to move, causing the end of the lever to press against the push plate, allowing carbon dioxide to be injected into the interior of the cabinet, reducing the possibility of open flames.

The invention provides a heterogeneous hybrid interconnection device topology and strategy for high-quality power supply and fault regulation and control. The heterogeneous hybrid interconnection device topology comprises a first multiplexing module, a second multiplexing module and a sharing module, the first multiplexing module is composed of a first NPC half-bridge module and a first cascade H-bridge module. The second multiplexing module is composed of a second NPC half-bridge module and a second cascade H-bridge module. The sharing module comprises a third NPC half-bridge module, a first IGBT switch tube, a second IGBT switch tube, a third IGBT switch tube, a fourth IGBT switch tube and an arc extinction inductor, wherein the first IGBT switch tube, the second IGBT switch tube, the third IGBT switch tube, the fourth IGBT switch tube and the arc extinction inductor are sequentially and reversely connected in series. According to the heterogeneous hybrid interconnection device provided by the invention, power supply quality improvement and grounding fault regulation and control can be simultaneously carried out, the interconnection power distribution network can still realize the functions of power flow regulation and control, reactive compensation, harmonic current compensation and the like during a single-phase grounding fault period, and the power supply reliability of a user is ensured.

The invention discloses a two-point grounding fault model analysis method in a neutral point non-effective grounding mode, and aims to solve the problem that a unified accurate mathematical model suitable for a neutral point non-grounding and arc suppression coil grounding system under an in-phase two-point grounding fault is lacked in the prior art. According to the method, a fault network topology is reconstructed, a multivariate function equation set containing a fault position, ground capacitance, arc suppression coil parameters and a power supply initial phase angle is established, explicit analytical expressions of zero-sequence voltage current and phase voltage current are deduced, and a transient process is modeled in combination with a state space method. And accurate description of a fault characteristic quantity spatio-temporal evolution rule is realized. By adopting the above technical scheme, the method can provide a modeling basis which can be directly called for high-fidelity simulation platforms such as RTDS, and supports intelligent protection algorithm development and fault diagnosis system optimization.

The application discloses an arc-extinguishing coil insulation self-starting fire extinguishing device and a control method, and belongs to the technical field of arc-extinguishing coil insulation self-starting fire extinguishing devices. The device comprises an arc-extinguishing coil body, a fixing frame and a fire extinguishing mechanism. The arc-extinguishing coil body is arranged on the fixing frame. The fire extinguishing mechanism is installed on the fixing frame. The fire extinguishing mechanism is sleeved on the surface of the arc-extinguishing coil body. The device is used for solving the technical problem that the artificial fire extinguishing mode is used for extinguishing fire, human beings need to know the fire phenomenon in time, and human beings need to arrive at the fire site in time to extinguish the fire, thereby causing low fire extinguishing efficiency and easily leading to property loss. The device can realize real-time sensing of the surface temperature change of the arc-extinguishing coil body through the fire extinguishing mechanism. When the surface temperature of the arc-extinguishing coil body reaches a preset value, the fire extinguishing mechanism is used for cooling the surface of the arc-extinguishing coil body, so that the formation of combustion conditions is effectively reduced. When the arc-extinguishing coil body catches fire, the fire extinguishing mechanism is used for extinguishing the fire at the fire site of the arc-extinguishing coil body, so that the harm caused by the flame can be reduced, and the effect of extinguishing the fire can be achieved.

An electrical switch (1) for a load tap changer (2), the electrical switch (1) comprising: at least three electrical contacts (3a, 3b, 3c) connected to respective electrical conductors (4a, 4b, 4c); a switching device (5) configured to be movable between a plurality of positions (P1, P2), wherein the switching device (5) in each respective position (P1, P2) physically contacts a respective combination (C1, C2) of the electrical contacts (3a, 3b, 3c) to provide electrical contact between the electrical contacts in each respective combination (C1, C2) of electrical contacts (3a, 3b, 3c); a gas-tight sealed housing (6) providing an inner space (7) enclosing the electrical contacts (3a, 3b, 3c) and the switching device (5), the electrical conductors (4a, 4b, 4c) extending from the electrical contacts (3a, 3b, 3c) inside the inner space (7) of the housing (6) to outside the housing (6); and a control device (10) configured to control movement of the switching device (5). The inner space (7) is under vacuum or filled with arc suppressing gas. The control device (10) comprises an operating member (8) extending from outside the housing (6) into the inner space (7) of the housing (6), the operating member being operatively connected to the switching device (5) such that the operating member (8) is able to move the switching device (5) to the plurality of positions (P1, P2) depending on the position of the operating member (8). Further, the operating member (8) comprises an arm (9) rotatably attached to the housing (6) for rotation about an axis of rotation (11), wherein the switching device (5) is attached to an end portion of the arm such that the switching device (5) is movable along an arcuate path between the plurality of positions.

A voltage arc suppression control method for single-phase ground faults in distribution networks belongs to the field of active arc suppression technology for single-phase ground faults in distribution networks. Its features include the following steps: Step a, acquiring signals; Step b, determining whether a ground fault has occurred; Step c, applying compensation based on a step coefficient k; Step d, determining whether the arc has been extinguished; Step e, determining whether the step coefficient k equals 1; Step f, applying compensation based on a secondary coefficient p; Step g, determining whether the arc has been extinguished; Step h, determining whether the secondary step coefficient p equals 0.1; Step i, the active inverter is continuously engaged according to the current output voltage. In this voltage arc suppression control method for single-phase ground faults in distribution networks, the impedance angle of the faulted line is used to determine the phase angle of the voltage drop from the fault point to the busbar, solving the problem that existing voltage arc suppression methods cannot reliably extinguish the arc and cause the fault current to increase instead of decrease when the fault point is far from the busbar and the fault transition resistance is small.

The utility model discloses an arc extinguishing coil assembly and switch assembly, the outer ring of arc extinguishing coil assembly, upper insulating pad, lower insulating pad and coil cover are set in the outer circumference of inner ring, and the coil is set between the outer ring and inner ring, and the upper insulating pad is set in the outer ring and the top of coil, and the lower insulating pad is set in the outer ring and the bottom of coil, and the inner ring bottom is provided with lower flanging, and the inner ring top is provided with upper flanging, and lower flanging and upper flanging cooperate and compress the lower insulating pad and upper insulating pad to be fixed on the outer ring and coil, and upper flanging is integrally formed on the inner ring. The utility model discloses the inner ring by riveting pressure's mode integrally forms upper flanging, and upper flanging and lower flanging cooperate and compress the lower insulating pad and upper insulating pad to be fixed on the outer ring and coil, and the structure is more compact, eliminates the risk of falling off, and is more safe and reliable.

The application provides a small-current grounding system single-phase grounding fault line selection method, and relates to the technical field of power distribution network fault detection.The method calculates the capacitive current of the system according to the measured zero sequence current data, counts and sums the capacitive current of each line to obtain the total capacitive current of the system, calculates the compensation degree of the arc suppression coil, extracts the fault characteristics, identifies the fault line after data processing and correction, compares the corrected zero sequence current signals of the fault line and the non-fault line, determines the fault line according to the difference between the corrected zero sequence current signals, and has high practicability and wide application prospect.

The application provides an alternating current arc detection method and related device. The method comprises the following steps: a controller of an arc detection system acquires an external instruction, determines a circuit simulation model based on the external instruction; acquires a first current signal from a signal detection circuit module in a detection period, and determines an arc feature vector based on the first current signal; determines an arc generation condition based on the arc time-frequency feature vector; generates an arc generation image based on the arc generation condition and the circuit simulation model; determines a multi-stage circuit regulation strategy based on the arc generation condition, and regulates a regulation circuit module based on the multi-stage circuit regulation strategy; acquires a second current signal; determines an arc suppression effect image based on the second current signal and the circuit simulation model; thus, the arc generation condition and the suppression effect can be visualized in real time, the arc suppression efficiency is improved, the arc analysis accuracy is improved, the arc extinguishing time is shortened, and the alternating current arc detection efficiency, detection precision and arc suppression speed are improved.

The utility model provides a capacitance current measuring circuit of a grounding system through a phase-controlled arc suppression coil, which comprises a phase-controlled arc suppression coil and a voltage source circuit, and is characterized in that the voltage source circuit is connected in parallel with a filtering winding of the phase-controlled arc suppression coil and is used for injecting voltage into the phase-controlled arc suppression coil; the power supply circuit comprises a capacitor Xcx, a transformer T2, a solid-state switch and an alternating-current power supply; the capacitor Xcx is used for dividing voltage and limiting voltage applied to the two ends of the filter winding induction coil; the capacitor Xcx is connected in series to one side of the transformer T2, the other side of the transformer T2 is connected in series with the solid-state switch, and one side of the solid-state switch is externally connected with an alternating current power supply. The voltage source circuit is introduced to be connected with the filtering winding of the phase-controlled arc suppression coil in parallel, voltage is injected into the phase-controlled arc suppression coil, the capacitive current of a grounding system can be accurately measured, the capacitor Xcx not only plays a role in voltage division, but also effectively limits the voltage applied to the two ends of an induction coil of the filtering winding, and therefore the voltage of the grounding system can be accurately measured. And the safety and the stability of the circuit are improved.

The invention discloses a longitudinal differential protection method and system based on crossed and overlapped difference, and the method comprises the steps: obtaining the accumulated break variables of voltage and current at a fault moment through SOD calculation according to the original three-phase voltage and current signals at two ends by using the break variables of electrical quantities at two ends of a line during the line fault; the method comprises the following steps: multiplying a voltage accumulated break variable by a current accumulated break variable to obtain power accumulated break variables on two sides, constructing a logarithmic function about the power accumulated break variables on a distributed power supply side and a power grid side, then obtaining a quadratic coefficient through a probability value self-adaptive attenuation function, comparing the quadratic coefficient with a set threshold value, and finally obtaining a maximum value of the distributed power supply side and the power grid side. And internal and external faults are checked. According to the method, only three-phase voltage and current at two sides need to be acquired, data acquisition is convenient, weak fault information can be effectively highlighted through SOD, influence of a neutral point arc suppression coil is avoided, faults inside and outside a region can be reliably detected, weak fault information can be better utilized, and weak feedback influence of a distributed power supply is reduced.

The invention provides an overvoltage tuning method and system based on parallel cooperation of a resistor and an arc suppression coil. The method comprises the following steps: judging an event type according to a neutral point voltage; when the event type is that the operation mode is changed, performing first tuning based on a first preset rule, and judging whether the neutral point voltage after the first tuning is greater than a threshold value or not; if the neutral point voltage after the first tuning is greater than the threshold value, performing secondary tuning based on a second preset rule, and judging whether the neutral point voltage after the secondary tuning is less than the threshold value; if the voltage of the neutral point after secondary tuning is larger than or equal to the threshold value, a second preset rule continues to be executed until the voltage of the neutral point after secondary tuning is smaller than the threshold value, and if the voltage of the neutral point after secondary tuning is smaller than the threshold value, it is judged that damping succeeds, and the resistance grounding device is reset. According to the invention, a unified zero-sequence impedance regulation and control strategy is established through cooperation of arc suppression coil operation and damping, so that the probability of occurrence of tuning overvoltage is reduced.

The invention relates to the technical field of power protection, and discloses a dynamic compensation switching method based on a grounding transformer arc suppression coil. The method comprises the following steps: collecting zero-sequence voltage, zero-sequence current and line impedance of a photovoltaic system in real time through a multi-branch collector to obtain a power grid operation state parameter set; according to the phase relationship between the zero-sequence current and the zero-sequence voltage, identifying a photovoltaic internal fault through a fault direction discrimination algorithm; inputting the fault confirmation signal into an arc suppression coil inductance adjusting system, and dynamically calculating a compensation inductance parameter according to the capacitive current of the fault point; the inductance of the arc suppression coil is adjusted through the combination of the graded reactors controlled by the thyristors, so that the inductive current and the capacitive current are counteracted with each other, and the grounding arc is extinguished. The technical problems that a traditional arc suppression coil cannot distinguish photovoltaic internal and external faults, compensation parameters are fixed and the response speed is low are solved, and the accuracy of ground fault processing and the dynamic response capability of compensation switching are improved.

The utility model relates to the technical field of arc suppression coils, and discloses a high-capacity arc suppression coil structure, which comprises a protection plate, the bottom of the protection plate is slidably connected with a cabinet body fixing seat, one side of the outer wall of the fixing seat is provided with a winding group, the lower surface of the protection plate is fixedly connected with a connecting plate, and the connecting plate is fixedly connected with the cabinet body fixing seat. A buffering assembly is arranged on the lower surface of the outer wall of the connecting plate and used for buffering vibration, a rotating shaft is rotationally connected to the interior of the connecting plate, a connecting rod is fixedly connected to the outer wall of the rotating shaft, and a damping assembly is arranged at one end of the connecting rod and used for reducing vibration generated during buffering of the protective plate. According to the anti-collision device, the problems that the resistance to external force impact of the structure is poor, mechanical damage is prone to occurring in long-term operation, the buffering protection capacity of the device is affected, and potential safety hazards are increased are solved, stable buffering protection is achieved, the anti-collision effect is achieved, and then the service life of the whole device is prolonged.

This invention discloses a digital simulation system and method for arc suppression coils. The digital simulation system includes an arc suppression coil digital simulation device and a host computer. The host computer communicates with the arc suppression coil digital simulation device via a USB interface, and the arc suppression coil digital simulation device communicates with the arc suppression controller under test via a serial port. The arc suppression controller under test also communicates with the host computer via a serial port. This invention uses a single digital simulation system to simulate a target arc suppression coil test system, allowing for convenient and on-site testing of the arc suppression controller under test. This improves test safety and eliminates the need for complex and bulky arc suppression coil bodies or tooling, providing arc suppression coil manufacturers with a convenient and safe testing method to verify the various functions of the arc suppression controller.

The invention discloses an arc suppression coil power distribution network arc grounding fault distance measurement method based on line double-end data analysis. The method comprises the steps that 1, phase sequence currents and phase sequence voltages of the two sides of a fault section are acquired; step 2, calculating fault point equivalent arc current and fault point equivalent arc voltage, constructing a fault point arc volt-ampere characteristic curve, and solving an arc grounding fault transition resistance curve; step 3, intercepting a resistance curve, extracting a steady-state arcing time period and calculating the resistance of the steady-state arcing time period; step 4, solving the accurate fault distance measurement function by using the accurate fault distance measurement function to obtain suspected fault points, and constructing a suspected fault point array; step 5, based on the suspected fault point array, setting suspected fault intervals with different lengths, solving positions and center points; step 6, setting a suspected fault interval length, and repeating the step 5 to obtain a position and a suspected fault distance array x; and step 7, eliminating abnormal values by using a quartile method, and determining a fault distance of final positioning.

A method and apparatus for controlling an arc suppression device of a three-phase electric network, the arc suppression device having an adjustable admittance connected between a neutral point of the three-phase electric network and earth, the apparatus being configured to determine a resonant frequency of a zero-sequence system of the three-phase electric network and determine, based on the determined resonant frequency of the zero-sequence system of the three-phase electric network, whether to initiate a tuning of the arc suppression device of the three-phase electric network.

The invention discloses a capacitance current measurement method and system, and the method comprises the steps: carrying out N times of measurement on an arc suppression coil grounding circuit, obtaining N parameters, N being an integer greater than 1, N times of measurement being in one-to-one correspondence with N parameters, the arc suppression coil grounding circuit comprising a host arc suppression coil and a slave arc suppression coil, the host arc suppression coil and the slave arc suppression coil run in parallel, and the parameter is a system capacitive reactance value or a reactance value of the slave arc suppression coil or a system capacitive current; m parameters are determined from the N parameters, the M parameters are parameters located in a preset interval in the N parameters, the preset interval is a confidence interval determined by normal distribution statistical analysis based on the N parameters, and M is a positive integer smaller than or equal to N; performing first processing on the M parameters to obtain M data, wherein the first processing is used for suppressing high-frequency noise interference; a target capacitive current is determined based on the M data. The method can improve the measurement precision of the capacitive current of the system.

The invention discloses an arc extinguishing and fire suppression device for a ship power system, and relates to the technical field of power equipment, and the device comprises a moving assembly which is disposed in the power system; the fixed assembly is arranged corresponding to the movable assembly; the connecting joint is fixed at one end, opposite to the moving assembly, of the fixed assembly; the moving contact is fixed in the center of the interior of the moving assembly; the static contact is fixed in the fixing assembly and corresponds to the moving contact; and the arc extinguishing device is fixed in the connecting joint. The stop block is arranged, the distance between the contacts is rapidly increased, so that the electric arc is cooled and lengthened, the extinguishing of the electric arc is promoted, and the electric arc can be rapidly cooled, thermal dissociation is inhibited and the arcing time is shortened in cooperation with the arc extinguishing device.