364 results about "Arc suppression" patented technology

This application presents an adaptive arc suppression method for ground faults in distribution networks, merging active and passive relay protection strategies. The method proceeds as follows: based on collected ground parameters, the fault phase is identified; compensation current is calculated from the fault's electromotive force, ground leakage resistance, and ground capacitance; current is injected at the neutral point according to the compensation current; finally, the arc suppression scheme is executed based on the zero-sequence voltage of the network's busbars. This approach incorporates both voltage- and current-based methods, addressing the limitation of fixed operation scenarios in traditional arc suppression methods. By quickly adapting to various fault situations, this method ensures an efficient and prompt response tailored to specific scenario requirements.

The invention discloses a stator winding grounding fault arc extinction method and system based on grounding transition resistance. The method comprises the following steps: S1, acquiring fundamental voltage of a neutral point and a machine end after normal operation and a grounding fault in real time; s2, calculating a fault phase potential EA1, and calculating a phase angle delta between the fault phase potential EA1 and the neutral point ground voltage UN1; s3, constructing a generator stator winding grounding fundamental wave fault analysis positioning equation, and substituting the measurement and calculation amount to complete fundamental wave fault positioning; s4, if multiple solutions occur in fundamental wave fault positioning, introducing a low-frequency injection quantity check criterion, and screening out a unique correct transition resistance value; and S5, carrying out arc extinction on the fault point of the neutral point of the generator in a high-resistance grounding mode. According to the method, the accuracy and reliability of fault positioning are remarkably improved, the possibility of misjudgment is eliminated, and an accurate compensation basis is provided for arc extinction.

The invention discloses a new energy medium-voltage switch intelligent control method based on multi-data interaction, and particularly relates to the field of switch intelligent control. According to the method, electrical, mechanical and temperature multi-dimensional operation data are collected in real time through a multi-source sensor, fault diagnosis is performed by adopting a hybrid reasoning architecture, features are extracted in combination with Hilbert-Huang transform and Mel cepstrum coefficient algorithms, and a three-level reasoning mechanism is constructed to realize accurate classification; based on a diagnosis result, a system dynamically optimizes a control strategy, the control strategy optimizes a switch-on and switch-off time sequence based on phase-space reconstruction and LSTM prediction, plasma impedance closed-loop adjustment and a quantum genetic algorithm are combined to realize arc suppression and mechanical compensation, and a six-dimensional compensation vector is introduced to correct mechanical operation deviation; the self-learning unit is based on a depth deterministic strategy gradient and an online knowledge distillation technology, verifies the validity of parameter update by using digital twin simulation, and forms a fault feature-control strategy-maintenance scheme triple knowledge base.

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 relates to relay protection technology, specifically a method, system, and medium for fault arc suppression in distribution networks using closed-loop self-healing control. When a fault is detected in the distribution network, transient changes in the measured and virtual phase currents of each phase are obtained. The Pearson correlation coefficient between these changes is calculated to identify the target fault phase. The neutral point-to-ground voltage value is retrieved, and the target fault phase's voltage is adjusted to zero based on this value. The current from the fault phase, when its voltage is zeroed, is acquired. An injected current is then compensated at the neutral point to match this value, ensuring both the ground fault current and the fault phase voltage are reduced to zero. This method enhances the applicability of arc suppression for grounding faults in distribution networks.

The invention provides a fault processing device and method compatible with arc suppression coil operation, and relates to the technical field of power supply equipment, the device comprises an arc suppression coil module and an intelligent grounding module, and the arc suppression coil module and the intelligent grounding module are connected in parallel; the arc suppression coil module comprises a first front circuit breaker, a first grounding transformer, an arc suppression coil and a first current limiting resistor, the wire inlet end of the first front circuit breaker is connected with a bus of the power distribution system, the output line of the first front circuit breaker is connected with the wire inlet end of the first grounding transformer, and the neutral point of the first grounding transformer is connected with one end of the arc suppression coil. The other end of the arc suppression coil is connected with a current-limiting resistor I, and the other end of the current-limiting resistor I is grounded; the intelligent grounding module comprises a front circuit breaker II, a fault phase selection sub-module and a fault line selection sub-module, a bus of the power distribution system is connected with a wire inlet end of the front circuit breaker II, the fault phase selection sub-module is connected with the front circuit breaker II in series and then is grounded, and the fault line selection sub-module is connected with the fault phase selection sub-module in parallel.

The invention discloses a power distribution network single-phase earth fault section positioning method based on multi-source data fusion, and the method comprises the steps: obtaining a power distribution cloud master station, dispatching remote signaling data, obtaining power distribution terminal grounding, bus grounding, small-current grounding line selection, arc suppression coil and bus voltage information through data cleaning, and carrying out the positioning of a single-phase earth fault section. Any information of a power distribution terminal grounding alarm signal, bus grounding and small current grounding line selection is used as a grounding research and judgment trigger condition; and after any information of a power distribution terminal grounding alarm signal, bus grounding and small current grounding line selection triggers grounding fault section research and judgment, the power distribution cloud master station respectively researches and judges a grounding fault section by adopting three kinds of information of grounding fault alarm information, a zero-sequence current remote measurement value and grounding fault recording. According to the method, the in-station line selection result, the relation between the neutral point grounding mode and the zero-sequence current, the terminal wave recording file and the terminal alarm information are considered at the same time, and the grounding fault section positioning method which is high in reliability, practicability and accuracy is comprehensively obtained.

The invention discloses a method for carrying out zero sequence loop impedance calculation by using a frequency conversion signal, the calculation method is applied to a power distribution network arc suppression coil grounding system, and the power distribution network arc suppression coil grounding system comprises a control device, a grounding transformer, an injection transformer and a variable signal source; according to the method, the signal source is adopted to inject signals with different frequencies to calculate the capacitive current, the impedance parameter of the arc suppression coil and the capacitive current of the system during parallel operation are calculated by establishing a loop equation according to different system zero sequence loop impedances under different frequencies, and then the capacitive current needing to be compensated by the system is accurately calculated. The method solves the problems of the calculation of the capacitance current of the system and the automatic tracking of the arc suppression coil during the parallel operation of the two machines, is not affected by the unbalance of the system, and provides a reliable basis for the precise control of the parallel operation of the two machines of the arc suppression coil.

The invention relates to a method for passive arc suppression in an electrical treatment of plants, comprising the step: (S400) Applying a pulse-width modulated direct electrical current (I) to the plants.

A method and system for measuring distribution network system parameters based on harmonic injection, for use in a low-current grounding system containing an arc suppression coil. The system injects currents of multiple frequencies into the neutral point of the low-current grounding system through an injection source and measures the neutral point voltage. The system uses formulas to calculate and obtain the line capacitance, arc suppression coil inductance, and damping resistance parameter values ​​in the distribution network system. This application can accurately measure line capacitance, arc suppression coil damping resistance, and reactance by injecting only two frequencies of current. This method has little impact on grid operation, high measurement accuracy, and broad application prospects.

The present invention relates to the technical field of disconnectors, and disclosed is a rotary disconnector. The rotary disconnector comprises an operating mechanism and several isolation units which are linearly coupled to each other and rotate to open or close. The operation mechanism comprises an operation rod assembly, a first spring, and a turntable assembly. The operation rod assembly comprises a first coupling and a guide member. The first coupling cooperates with the guide member, so that radial movement of the first coupling drives axial movement of the guide member. In the operating mechanism of the present invention, under the assistance of the first spring, the first coupling is rotated by 360°, and opening and closing of the operating mechanism are achieved by using radial-axial-radial movement. Compared with the existing method of using torsion springs, in one aspect, it is possible to avoid the phenomenon of contact bounce, so that service life may be prolonged; and in another aspect, stress concentration at a bending point of the torsion spring due to the torsion spring is avoided, thereby increasing the reliability of the operating mechanism. In addition, by means of shortening the on-off transient state of the disconnector and strengthening arc suppression, the service life of the disconnector is further improved.

The invention discloses an integrated preparation method of a large-thickness high-density electrical insulation-corrosion-resistant ceramic coating on the surface of a heat dissipation substrate for a high-power device, and relates to the technical field of surface treatment of aluminum alloys and composite materials thereof. The method comprises the following steps: placing a pretreated substrate as an anode and a stainless steel plate as a cathode in a basic arc suppression type electrolyte, and performing low-temperature soft plasma electrolytic oxidation on the surface of the pretreated substrate by using an asymmetric bipolar pulse micro-arc oxidation technology to grow a large-thickness high-density ceramic layer in situ; specifically, low-temperature soft spark discharge is induced by inserting additional negative pulse voltage, the plasma temperature and energy are stabilized, spark discharge is uniform, and the density is increased by an order of magnitude, so that continuous bombardment with no damage to the surface flatness as the plasma intensity upper limit is carried out on a passive film on the surface of a substrate; and the defects such as pores and cracks are continuously healed and repaired, and the densification of the coating is promoted, so that the aluminum oxide coating with large thickness, high density, high electrical insulation and corrosion resistance is obtained.

The invention relates to the technical field of intelligent electrical switches, and particularly discloses an intelligent reclosing air switch arc suppression method and device based on zero-crossing control, and the method comprises the following steps: detecting a voltage zero-crossing point and a current zero-crossing point of an AC loop, and marking an instruction issuing alignment point; the instruction issuing alignment points comprise a switching-on instruction voltage zero-crossing alignment point and a switching-off instruction current alignment point; and calculating a time window, issuing a switch-on and switch-off instruction at a corresponding window point so as to complete the switch-on operation at the voltage zero-crossing prediction point or complete the switch-off operation at the current zero-crossing prediction point, and achieving the purpose of arc suppression by approaching no current under the condition that the switch-on and switch-off completion time point is overlapped with the actual zero-crossing point. According to the intelligent reclosing air switch, the time of switching on and switching off is accurately controlled, generation of electric arcs is effectively reduced, the service life of the intelligent reclosing air switch is prolonged, and the intelligent reclosing air switch has remarkable technical advantages and market application prospects.

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 invention discloses a self-voltage-stabilizing system and method for a power distribution network active and passive integrated ground fault regulation and control device, and the system comprises a fault judgment module, the active and passive integrated ground fault regulation and control device, an arc extinction reactive energy output module and a fault elimination module based on the active and passive integrated ground fault regulation and control device. The method comprises the following steps: measuring resistance to ground and capacitance to ground of a line during normal operation of a system, and judging whether a single-phase ground fault occurs or not; if the grounding fault does not occur, measuring the three-phase voltage and current of the load and performing split-phase injection of reactive compensation current; after the system has a single-phase earth fault, controlling the active and passive integrated earth fault regulation and control device to output active energy to be 0, and outputting reactive energy required by arc extinction according to reactive compensation current injected into the power distribution network at present; and reducing the injected arc extinction current after the time period t, and observing whether the neutral point voltage changes proportionally.

The present invention provides a fault line selection method integrating functions of neutral point parallel resistance line selection and transient line selection (hereinafter referred to as integrated line selection), comprising: on the basis of capacitive current calculation and tap position control logic of an arc suppression coil, performing line selection determination logic by integrating a single-phase earth fault transient line selection determination basis with a neutral point parallel resistance line selection determination basis; and in the determination logic, determining, on the basis of a system voltage to earth, whether an earth fault disappears, inserting a parallel resistor for neutral point parallel resistance line selection, by combining results of transient line selection and neutral point parallel resistance line selection, correctly configuring the capacitive current calculation and tap position control logic of the arc suppression coil, a transient line selection function process and a neutral point parallel resistance line selection function process, so that the three functions do not influence each other, so as to obtain a final line selection result. When a single-phase earth fault occurs in an electric power system, the accuracy of line selection of a small-current earth-fault line selection device is improved while it is ensured that the arc suppression coil compensates for a system capacitive current in the line selection logic, effectively improving the power supply safety and reliability of a power distribution network.

The invention is suitable for the technical field of arc extinction of a power distribution network, and provides a self-adaptive composite arc extinction method based on a zero-sequence voltage threshold value of the power distribution network, which comprises the following steps: monitoring the neutral point voltage of the power distribution network, and judging whether the power distribution network has a single-phase earth fault or not; when the single-phase earth fault does not occur in the power distribution network, injecting a first current into the neutral point of the power distribution network, and calculating an earth parameter of the power distribution network and an earth capacitance current when the voltage of the neutral point of the power distribution network is zero; when a single-phase earth fault occurs in the power distribution network, injecting a second current into the neutral point of the power distribution network, and calculating a fault point offset voltage of the power distribution network; and calculating a voltage threshold value and a corrected current arc extinction reference value based on the ground parameter, the ground capacitance current and the fault point offset voltage, if the neutral point voltage of the power distribution network is smaller than the voltage threshold value when the single-phase ground fault occurs, adopting voltage arc extinction, otherwise, adopting the corrected current arc extinction reference value to implement current arc extinction. According to the invention, the reliability of single-phase earth fault arc extinction can be improved.

The invention belongs to the technical field of safety protection of large generators, and particularly discloses a slot potential-based ground fault arc extinction and TVS fault identification method and system. The fundamental wave slot potential and the third harmonic slot potential of each slot conductor are calculated by obtaining the fundamental wave and third harmonic voltage of the neutral point and the generator end of the generator. And furthermore, the real fault position is determined through matching with the ground fault potential, so that fault positioning at any position in a full winding range is realized, the limitation of a traditional method is broken through, and the coverage range of fault positioning is remarkably expanded. According to the invention, through the voltage and current low-frequency components of the neutral point of the generator, the grounding transition resistance during a grounding fault and the grounding transition resistance during stabilization after arc extinction are respectively calculated, and the fault property is judged by comparing the transition resistances in different states, so that an instantaneous fault and a permanent fault can be accurately distinguished; simple and effective fault identification is provided, engineering realization is easy, and fault properties can be rapidly and accurately judged.

The invention relates to the technical field of cable or wire installation, and provides a center-distance-adjustable top expansion bus connector, which comprises a shielding layer mechanism, a bus, wheelbase-adjustable modules, an arc suppression module and a heat dissipation module, and is characterized in that the wheelbase-adjustable modules are arranged at the two ends, close to the shielding layer mechanism, of the bus; the arc suppression module and the heat dissipation module are respectively arranged in the shielding layer mechanism and the bus; the wheelbase-adjustable module is used for adjusting the position of a bus connecting conductor so as to adjust the contact distance between the shielding layer mechanism and the connecting conductor in the bus, the heat dissipation module is used for dissipating heat in the shielding layer mechanism and the bus to the outside, and the arc suppression module is arranged at the connecting position of the shielding layer mechanism and the bus. According to the invention, through the cooperation of the adjustable wheelbase module and the arc suppression module, the center distance error between the bus and the joint is corrected, the phenomena of arc and partial discharge caused by poor contact are reduced, and the stability and reliability of electrical performance are improved.

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 intelligent arc extinguishing and current limiting method and system based on dynamic fault prediction, and relates to the technical field of power systems, and the method comprises the steps: collecting the data of a power distribution network, and carrying out the denoising and data smoothing processing; current trend prediction is carried out according to the power distribution network data, fault occurrence time and place are predicted, a fault prediction report is generated, a fault point is positioned, and a fault area is rapidly isolated; according to the power distribution network data and the fault prediction report, parameters of the arc suppression coil are dynamically adjusted, feedback control is performed on the parameters of the arc suppression coil according to the arc suppression effect monitored in real time, and rapid arc suppression and current limitation are realized. According to the method, the automation and intelligence level of fault processing is improved, the response time of fault processing is greatly shortened, and the operation reliability and stability of a power grid are improved.

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 relates to an automatic welding method and system for an air conditioner pipeline, and the method comprises the steps: arcing stage welding: determining arcing welding parameters according to first physical parameters and first environmental parameters, and carrying out arcing stage welding; the self-adjusting stage welding comprises the steps that an adjusting strategy is determined according to the second physical parameters, the welding parameters are adjusted in real time according to the adjusting strategy, and self-adjusting stage welding is conducted; the arc suppression stage welding comprises the steps that arc suppression welding parameters are determined according to the welding parameters of the self-adjusting stage, and arc suppression stage welding is carried out. In the welding process, relevant parameters are collected in real time, welding parameters of automatic welding are adjusted in real time according to the relevant parameters, heat conduction difference between copper and stainless steel can be effectively overcome by collecting relevant parameters of a molten pool, current, voltage and the like in real time and dynamically adjusting welding energy input, the probability of occurrence of defects such as air holes and cracks is reduced, and welding quality is improved. And the reliability of automatic welding is improved.

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 present invention relates to a complete set of automatic switching grounding mode equipment and an automatic switching grounding method thereof. It solves the problems of the existing single neutral node grounding mode. It comprises a controller, which is respectively connected in parallel with a resistor grounding structure, a gap grounding structure, a direct grounding structure and an arc extinguishing coil grounding structure. The resistor grounding structure comprises a controllable small resistor formed by a small resistor and a vacuum contactor in series. The direct grounding structure comprises an isolating switch for controlling the direct grounding of the neutral point of the power grid, and the isolating switch is connected with an electric operating mechanism. The advantages are: a grounding mode combining arc extinguishing coil grounding, small resistor grounding and non-grounding mode is adopted, which can be selected by users according to the operation conditions of the power grid, a small resistor is connected in parallel with the arc extinguishing coil, an isolating switch and the primary side of the gap, and the controller controls the adjustment of the arc extinguishing coil, the switching of the small resistor and the separation and combination of the isolating switch to realize the selection of several grounding modes.

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 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 power distribution network phase power supply feed-in type flexible grounding and voltage arc extinction complete equipment. The complete equipment comprises a transformer bank and a voltage arc extinction measurement and control cabinet. The transformer bank consists of a grounding transformer and an injection transformer; the voltage arc extinction measurement and control cabinet comprises a measurement and control unit, a phase selection control unit and an injection voltage adjusting unit. The signal input end of the measurement and control unit is connected with the power distribution network; the signal output end of the measurement and control unit is connected with the phase selection control unit and the injection voltage adjusting unit. A secondary coil leading-out terminal of the grounding transformer is connected with a primary coil of the injection transformer through the phase selection control unit, the injection regulation and control resistor Rx and the injection voltage regulation unit; the dotted terminal of the secondary coil of the injection transformer is connected with the neutral point of the grounding transformer, and the synonym terminal of the secondary coil of the injection transformer is grounded. According to the utility model, the active step-down arc-extinguishing function of the single-phase earth fault phase of the power distribution network can be realized, and the single-phase earth fault arc-extinguishing effect of the power distribution network is improved.