729 results about "Potential transformer" patented technology

The invention provides an intelligent monitoring and early warning method based on multi-source information fusion, and belongs to the technical field of intelligent diagnosis and early warning, and the method comprises the steps: synchronously collecting the multi-modal data of a voltage transformer, the multi-modal data comprising voltage / current waveform, partial discharge signal, temperature and vibration data; preprocessing the multi-modal data, wherein a preprocessing method comprises waveform segmentation, spectrogram generation and scalar normalization; constructing a dynamic weight distribution mechanism: calculating a weight matrix based on the relevance between the time sequence features and the spatial features, and dynamically adjusting scalar weights by combining the physical coupling relationship between the temperature and the vibration to generate feature fusion weights; iteratively updating the weight matrix according to the real-time prediction error; fusing the time sequence features, the spatial features and the scalar features through the dynamic weight distribution mechanism to generate a comprehensive feature vector; and synchronously outputting a fault type classification result and an equipment health score based on the comprehensive feature vector, and calculating a real-time prediction error.

The invention relates to the technical field of voltage transformers, in particular to a voltage transformer real-time monitoring system based on broadband and edge calculation, which comprises the steps of collecting multiple paths of voltage transformer data, extracting peak values and zero cross points, comparing jump rising edge time differences, unifying time sequences, extracting extreme values and slope identification disturbance sections, and monitoring the voltage transformers in real time. Measuring amplitude continuous change to judge the offset trend, analyzing trend direction classification waveform fragments, and combining the three indexes to generate an operation state label. According to the method, a unified time sequence is constructed by comparing cross-channel jump rising edge time differences, multi-channel jump process alignment is achieved, the synchronous anomaly recognition capability is improved, the number of extreme values and the slope direction are extracted to recognize a disturbance dense section, continuous anomaly is judged by combining statistics of overrun, and the fluctuation trend is judged by tracking the deviation trend between extreme values. And based on the three-index combination classification operation state, the anomaly identification precision is improved.

The invention discloses a fault diagnosis method and system for a metering error of a voltage transformer, and relates to the technical field of power equipment fault diagnosis, and the method comprises the steps: obtaining the historical electric quantity data of a secondary side under the normal operation of the voltage transformer, and carrying out the noise reduction and normalization preprocessing; establishing an initial principal component analysis model according to the preprocessed historical electric quantity data, and calculating to obtain a statistic control threshold value; updating a mean vector and a covariance matrix of the model by adopting a dynamic strategy based on real-time acquired new electric quantity data of the secondary side of the voltage transformer; and calculating a new statistic according to the updated mean vector and the covariance matrix, comparing the new statistic with a statistic control threshold value, and if the new statistic is greater than the statistic control threshold value, determining a metering error fault. According to the invention, the model parameters can be updated according to the real-time change data output by the voltage transformer, the adaptability to different metering error ranges of the voltage transformer is improved, and the detection precision is improved.

The utility model belongs to the technical field of medium-voltage power distribution systems, and discloses an isolating switch device and a switch cabinet, the isolating switch device comprises an insulating rod, a conductive block, a conductive sheet and an operating mechanism, the conductive block is sleeved on the insulating rod, the conductive sheet is fixedly connected with the conductive block, and the operating mechanism drives the conductive sheet and the conductive block to rotate through the insulating rod. Therefore, the conducting strip is selectively connected or disconnected with the circuit breaker connector bar, and the conducting block is electrically connected with the voltage transformer in the rotating process. An isolating switch device is additionally arranged between a circuit breaker and a voltage transformer in a switch cabinet, an operating mechanism is utilized to drive a conducting strip and a conducting block to rotate through an insulating rod, the conducting block and the voltage transformer keep electrical connection in the rotating process, the position of the conducting strip is changed in the rotating process, and then the conducting strip is selectively connected with or disconnected from a circuit breaker connector bar. The structure is simplified, the number of elements is reduced, flexible operation can be achieved, and the stability and reliability of the disconnecting switch device can be guaranteed.

A method, apparatus and system for state evaluation of metrological characteristics of a capacitor voltage transformer, relating to the technical field of voltage measurement. The method comprises the following steps: acquiring operation data of a capacitor voltage transformer, establishing a metrological performance evaluation model, and obtaining a statistical control threshold (S1); collecting in real time the operation data of the capacitor voltage transformer, and calculating a statistic of the operation data by means of the metrological performance evaluation model (S2); comparing the statistic of the operation data with the statistical control threshold to determine whether a fault occurs in the capacitor voltage transformer (S3); and detecting a change trend of a primary signal and a secondary signal of the tested capacitor voltage transformer to determine whether metrological characteristics are abnormal (S4). In the method, the concept of time is introduced, by providing a timestamp, the influence of newly obtained data on the metrological performance evaluation model is greater, and by means of real-time update, the metrological performance evaluation model can be updated, so that when in a stable state, the detection time is reduced, and the model calculation is reduced.

The invention discloses a voltage transformer metering error evaluation method, which relates to the technical field of voltage transformer metering and comprises the following steps of: constructing a synchronous acquisition system of multiple groups of voltage transformers in a transformer substation, acquiring original voltage data, constructing a virtual reference voltage generation model and outputting a reference voltage sequence; the method comprises the steps of establishing a virtual reference voltage model, calculating error statistical characteristics, marking the operating state grade of the voltage transformer, evaluating health scores according to the error characteristics, outputting a scoring result, receiving inspection feedback comparison differences, updating the model, generating an analysis chart, and uploading the analysis chart to a client display and linkage operation and maintenance system. On-line error evaluation is realized, multi-source data are fused, error features are dynamically extracted, an operation state is marked, a health scoring and early warning mechanism is established, a feedback closed loop is introduced to optimize model precision, an evaluation result is displayed in a chart form, operation and maintenance scheduling is assisted, and the real-time performance, the accuracy and the self-adaptive capability of evaluation are improved.

The utility model relates to the field of resonance eliminators, and discloses a protection element and a current limiting type resonance eliminator, the protection element comprises at least two groups of protection units, the two adjacent groups of protection units are connected in series, and each protection unit comprises a protection module; the current-limiting resonance eliminator based on the current-sensitive resistor made of the current-sensitive material is connected in series between the PT neutral point and the ground. Under the normal operation condition, the current-limiting resonance eliminator is in a low-resistance state, and system parameters and PT performance are not affected; when excitation energy is generated due to a system fault, the current-limiting resonance eliminator suddenly changes into a high resistance state, quickly absorbs resonance energy, destroys resonance parameters, suppresses PT excitation current below 200mA, and ensures that a voltage transformer is unsaturated and a PT fuse is not fused; and a built-in current sensor is connected, so that the running state of the current-limiting resonance eliminator can be monitored in real time.

The invention discloses a voltage transformer state influence factor analysis method, system and device and a medium, and belongs to the technical field of voltage fault analysis, and the method comprises the steps: collecting state parameters of a voltage transformer, carrying out the preprocessing of the state parameters, and constructing a nonlinear coupling relation between multidimensional feature tensor capture features; analyzing voltage fluctuation characteristics of the voltage transformer, and automatically correcting the insulation state evaluation model; and inputting abnormal feature vectors obtained by monitoring into a recursive attribution decision tree model, carrying out multi-dimensional abnormal clustering and causal analysis, generating a tracing report, and carrying out multi-dimensional evaluation and verification on an analysis result. According to the invention, continuous dynamic full-coverage monitoring of the equipment insulation health condition is realized, the accuracy and robustness of anomaly detection are improved, the phenomena of missing detection and false alarm are reduced, the scientificity of anomaly tracing analysis and the interpretation of early warning decision are improved, and the reliability of the system is improved. And the intelligent level of the monitoring and early warning system is improved by continuously adapting to new abnormal types and complex operation environments.

The invention discloses a self-adaptive transformation ratio adjustment electric quantity metering method and device, the device comprises a high-voltage metering device and a control center, and the high-voltage metering device is composed of a voltage transformer, a current transformer and an electric energy meter. The core innovation point is that the current transformer is provided with a plurality of secondary windings, each winding is respectively connected with a relay with a multi-gang switch contact, the output end of the relay is connected with the electric energy meter, and the relay and the control center realize linkage control. The control center drives a multi-gang switch contact of the relay to be automatically switched to a secondary winding adaptive to the current load by monitoring the current state of the load in real time; factors such as temperature, humidity and the year of a home-entry power grid are introduced to correct a current measured value, and the accuracy of electric quantity metering is improved. Meanwhile, the control center records transformation ratio switching data in real time, reliable support is provided for time-of-use electricity price execution, demand side response and electric quantity tracing, and the intelligence and refinement level of electric power metering is remarkably improved.

The invention provides a PT ferromagnetic resonance overvoltage suppression system and method based on graded damping. The system comprises a secondary resonance elimination module, the secondary resonance elimination module comprises a three-stage damping branch circuit which is connected in series with an open triangle of a voltage transformer, the three-stage damping branch circuit comprises a first current-sensitive resonance eliminator, a second current-sensitive resonance eliminator and a fixed resistor which are connected in parallel, and a branch circuit of the first current-sensitive resonance eliminator is connected in series with a first switch; a branch of the second flow-sensitive resonance eliminator is connected in series with a second switch, and a branch of the fixed resistor is connected in series with a third switch; the fan is used for carrying out air cooling on the first flow-sensitive resonance eliminator, the second flow-sensitive resonance eliminator and the fixed resistor; and the control module is used for controlling on or off of the first switch, the second switch and the third switch. Resonance early recognition is achieved through transient energy comprehensive criteria, three-level damping dynamic switching and fan intelligent temperature control are combined, and the three core problems of response lag, insufficient heat dissipation and weak self-adaption in ferromagnetic resonance suppression are solved.

The invention provides a new energy station high-voltage voltage transformer error evaluation method and system, and the method comprises the steps: collecting the voltage phasors of all measurement nodes in a preset time period at a transformer substation and a new energy station at the same time, obtaining the equipment parameters of a voltage transformer and the line parameters between the measurement nodes, and constructing a measurement data set; the method comprises the following steps: constructing a corresponding adjacency matrix and a node characteristic matrix by extracting line impedance and node working condition characteristics based on a power system line topological structure and data in a measurement data set, and obtaining a time sequence diagram structure data set according to the adjacency matrix and the node characteristic matrix; constructing a graph neural network, and training the graph neural network based on the time sequence graph structure data set; and inputting the voltage phasor of each measurement node, and based on the output result of the trained graph neural network, judging the state of the voltage transformer through a preset threshold value. According to the scheme, online evaluation of the error state of the voltage transformer can be realized, and the accuracy and interpretability of error evaluation are improved.

The invention relates to the field of electric power measurement, and provides a voltage transformer error evaluation method and device, electronic equipment and a storage medium, and the method comprises the steps: collecting the voltage phasor information of a measurement node in a preset time window, and obtaining the reference technical parameters of a voltage transformer corresponding to the measurement node; feature extraction based on a sliding window is carried out, sequence diagram structural features are obtained in combination with an adjacent matrix, and the adjacent matrix is constructed based on network topology and line electrical parameters of a power system; error estimation is carried out through a trained error estimation model based on the time sequence diagram structure features, an error estimation value is obtained, and the error estimation model is obtained by training a graph neural network model based on historical voltage phasor information and corresponding error labels; and performing error state evaluation based on the error estimation value. According to the method, the device, the electronic equipment and the storage medium provided by the invention, online continuous evaluation of the voltage transformer error is realized, and the limitations of long period and high cost of a traditional offline verification method are broken through.

The invention discloses a harmonic measurement error correction method and system for an electronic voltage transformer, and relates to the technical field of power electronics, and the method comprises the steps: obtaining the sparse sampling data of the electronic voltage transformer; constructing a harmonic reconstruction dictionary suitable for an asynchronous sampling condition according to the sparse sampling data and the set parameters of the sampling characteristics; extracting periodic characteristics of the sparse sampling data, performing frequency change analysis, and generating a frequency offset adaptive factor; and performing harmonic reconstruction on the sparse sampling data by adopting a multi-stage sparse reconstruction algorithm in combination with the harmonic reconstruction dictionary and the frequency offset adaptive factor to obtain a corrected harmonic component. The method can adapt to the change of dynamic frequency response of the electronic voltage transformer in different working states, considers the error formed by interweaving of the nonlinear frequency response characteristic and the frequency offset effect of the electronic voltage transformer, and improves the accuracy of harmonic measurement error correction.

The invention discloses a resonance elimination circuit, method and device, and relates to the technical field of circuits, and the circuit comprises a controller, a resonance elimination resistor and a switching circuit. Two ends of the resonance elimination resistor are respectively connected with the neutral point of the voltage transformer and the ground. The controller controls the switching circuit to be switched off when ferromagnetic resonance is detected, so that the resonance elimination resistor is connected to suppress resonance; after the fault disappears, the control switch is switched on, and the neutral point is directly grounded. The controller compares the neutral point current with a first threshold value to determine resonance generation, and determines fault disappearance when the current is smaller than a second threshold value. And when the resonance elimination resistor is a variable resistor, the controller adjusts the resistance value according to the current change rate and a pre-learned mapping relation. The switching circuit can adopt a switching tube or a relay, and the controller realizes switching by controlling the switching tube to be turned off or a relay coil to be powered off. The circuit can rapidly suppress ferromagnetic resonance, guarantee system stability and improve fault processing efficiency.

The invention relates to the technical field of electrical engineering, and discloses a voltage transformer, a design method and device thereof and a storage medium, and the method comprises the steps: determining the size of an iron core, and the electrical parameters of a primary side winding and a secondary side winding according to the electrical performance parameters and space limitation conditions of a target voltage transformer; calculating no-load loss, no-load magnetization and no-load current of the target voltage transformer based on the ferromagnetic material attribute parameters and the iron core size; determining a leakage reactance value reduced to a secondary side and total resistance of the winding according to the winding structure parameters; establishing an initial three-dimensional finite element simulation model of the voltage transformer based on the iron core size information and the winding parameters; determining a no-load error and a load error of the voltage transformer based on the no-load loss, the no-load magnetization, the leakage reactance value, the total winding resistance and the winding structure parameters; and performing feedback optimization on the initial simulation model based on the no-load error and the load error to obtain a target three-dimensional finite element simulation model, and manufacturing a target voltage transformer based on the simulation model.

The invention belongs to the technical field of nuclear power, and particularly relates to a ground capacitance measurement method based on series capacitance and high-frequency signal injection. In order to solve the problem that a traditional signal injection method cannot accurately calculate the ground capacitance level of a power distribution network, the invention provides a ground capacitance measurement method based on a series capacitor and high-frequency signal injection. The leakage inductance of the voltage transformer is accurately measured by injecting the high-frequency signal, so that a resonance point is convenient to find during frequency sweeping, and the resonance point measured during frequency sweeping is more accurate.

The invention discloses a high-voltage equipment fault judgment method based on voltage abnormity, and relates to the technical field of high-voltage equipment fault property judgment, and the method comprises the steps: determining whether an undervoltage or overvoltage condition occurs or not through monitoring the voltage level of each phase voltage of a voltage transformer; if the undervoltage or overvoltage condition occurs, determining voltage abnormity indication information corresponding to different conditions; and determining high-voltage equipment fault information according to the voltage abnormity indication information. The fault property can be quickly judged according to the voltage abnormal information in combination with other fault phenomena, so that the fault searching efficiency is improved, and the situation that fault downtime is prolonged due to misjudgment, even the fault range is expanded, and greater loss is caused to a user is prevented. And safe and stable operation of equipment power supply can be ensured.

The invention relates to the technical field of power system monitoring, discloses an anti-harmonic PT current monitoring system and method, and aims to solve the problem of secondary side current signal distortion of a voltage transformer caused by power grid harmonic pollution in the prior art. The method comprises the steps of electrifying and initializing a system, starting a high-speed analog-to-digital converter to acquire a voltage signal, executing fast Fourier transform to identify dominant harmonic waves, calculating and configuring a capacitance value of a tunable LC trap unit to suppress specific harmonic waves, and finally outputting a high-fidelity analog voltage signal in direct proportion to fundamental current. The system comprises a current-voltage conversion module, a tunable LC notch filter array, a high-speed analog-to-digital converter, a digital signal processing unit and a microcontroller. According to the technical scheme, dynamic self-adaptive suppression and precise selective harmonic wave blocking of power grid harmonic waves can be realized, low delay and high fidelity characteristics are guaranteed, and the engineering practicability and reliability of the system are improved.

The invention relates to a two-station operating mechanism for a PT (potential transformer) of a C-GIS (gas insulated switchgear), which comprises an operating mechanism box, a centering assembly is mounted in the operating mechanism box, the centering assembly comprises a quick-return crank arm, two sides of the quick-return crank arm are respectively connected with a reset spring guide rod, the other side of each reset spring guide rod extends out of the operating mechanism box, and the other side of each reset spring guide rod extends out of the operating mechanism box. The outer wall of the reset spring guide rod is further sleeved with a reset spring. The operating assembly comprises an operating handle, a mechanical operating transmission shaft and a sealing shaft, the sealing shaft penetrates through the operating mechanism box and then is connected with a bevel gear, the quick-return crank arm is sleeved on the sealing shaft, one side of the mechanical operating transmission shaft is connected with the sealing shaft, the other side of the mechanical operating transmission shaft is connected with the operating handle, and the operating handle drives the sealing shaft to rotate. And the position of the sealing shaft is kept through the cooperation of the centering assembly. According to the operating mechanism, the mechanical operating transmission shaft, the sealing shaft and the bevel gear are driven to rotate by rotating the operating handle, then the PT cabinet transmission mechanism is driven to rotate, and the operating mechanism is simple in structure, low in cost, small in occupied space, easy to operate, safe and reliable.

The invention discloses a voltage transformer intelligent inductance adjustment verification method and device based on a current inversion capacitor, and the method comprises the steps: obtaining a preset excitation voltage and an adjustable sweep frequency, and carrying out the sweep excitation of an inductance adjustment resonant circuit according to the preset excitation voltage and the adjustable sweep frequency; acquiring current sampling data of the inductance-adjusting resonance circuit; performing frequency domain analysis on the current sampling data, and calculating an equivalent capacitance value and a resonance state parameter of the inductance-adjusting resonance circuit according to a frequency domain analysis result; and the air gap length and the winding turns of the reactor are adaptively adjusted based on the resonance state parameters. The capacitance value and the resonance state parameter of the resonance circuit are calculated through inversion of the current frequency domain analysis result, dual-mode inductance adjustment closed-loop control is achieved based on the capacitance value and the resonance state parameter, the problems that an existing manual inductance adjustment mode depends on artificial experience and is tedious in operation and low in efficiency are solved, the method can adapt to a high-capacity mutual inductor, meanwhile, a resonance point is accurately locked, and the control precision is improved. And wide-range and high-precision inductance adjustment is realized.

The invention discloses a method for accurately measuring voltage, current and phase angles of a sectional intelligent electric energy meter, which relates to the technical field of electric energy meter metering and comprises the following steps of: S1, constructing a sectional load-mutual inductor angle difference correlation model, and dividing a plurality of load intervals according to an application scene of the sectional intelligent electric energy meter and working characteristics of a mutual inductor, acquiring current transformer angular difference data and voltage transformer impedance drift related data in different load intervals, and establishing and storing an association relationship between each load interval and a corresponding transformer angular difference compensation coefficient in combination with inherent parameters of the transformer; according to the invention, a segmented load-mutual inductor angle difference correlation model is constructed in advance, load voltage and current amplitude data are collected in real time to accurately determine a current load interval, and a corresponding mutual inductor angle difference compensation coefficient is automatically matched to carry out dynamic adaptive compensation on an initial phase angle. The problem of phase deviation caused by angular difference nonlinear change of a current transformer in different load intervals and impedance drift of a voltage transformer in the prior art is solved.

The invention discloses a voltage transformer current-sensitive intelligent resonance elimination device and a fault monitoring method thereof, belongs to the technical field of fault monitoring, and aims to solve the problems that a traditional current-sensitive resonance elimination device is unknowable in state, resonance and instantaneous disturbance are difficult to distinguish, the fault identification precision is low, and the operation and maintenance efficiency is poor. The device comprises a flow-sensitive response module and an intelligent monitoring assembly. The current-sensitive response module comprises a response body and a built-in current sensing element; the intelligent monitoring assembly constructs an associated time sequence data set by collecting a real-time electrical signal and a state signal of the current-sensitive response module so as to judge whether the power grid system enters a resonance state; response signal validity calibration and fault identification operations are executed on the flow sensitive response module by constructing a response feature set; the method comprises the following steps: constructing a monitoring data set, extracting evaluation dimensions to perform performance analysis on a flow-sensitive response module, and generating a performance score of the flow-sensitive response module; response monitoring accuracy and operation and maintenance intelligence are remarkably improved, and accurate research and judgment and intelligent operation and maintenance of the resonance state of the power grid are supported.

The invention discloses a capacitor voltage transformer on-line verification and state early warning method and system, and the method comprises the steps: synchronously collecting the secondary side time sequence data of a target CVT and other CVTs of the same bus with the target CVT through a power monitoring system; based on secondary side time sequence data of a plurality of CVTs on the same bus, screening out a CVT equipment group with consistent state through group consistency analysis, and generating a virtual standard reference value for error calculation; calculating a relative deviation between the secondary voltage measurement value of the target CVT and the virtual standard reference value as a first evaluation result; performing feature extraction on the secondary side time sequence data to obtain a feature vector representing the operation state of the target CVT, inputting the feature vector into a pre-trained intelligent evaluation model to obtain an error prediction value or a health state score of the target CVT, and taking the error prediction value or the health state score as a second evaluation result; and fusing the first evaluation result and the second evaluation result to obtain a comprehensive evaluation conclusion of the running state of the target CVT, and if the state level exceeds a normal range, generating early warning information.

The utility model discloses a mutual inductor detection and verification device which comprises a verification table, a first conveying belt is installed at the top end of the verification table, a limiting plate is installed on the verification table and located on one side of the first conveying belt, a rotating tray is movably installed in the center of the limiting plate, and a plurality of sets of rolling shafts are rotatably installed on the surface of the limiting plate. The output side of the verification bench is provided with a test bench in an attached manner, two sides of the test bench are fixedly provided with two groups of pressure test plates, and the interior of the test bench is provided with a detection plate. The lifting of the voltage transformer body is controlled through the arranged liftable rotating tray, and the rotation of the voltage transformer body is controlled through the cooperation of the electric driver in the rotating tray, thereby achieving the control of the testing positive and negative electrodes of the voltage transformer body in the testing process. And meanwhile, the purpose of rapidly moving the voltage transformer body to a test position is achieved through cooperation of the first conveying belt and the second conveying belt, participation of workers is reduced, and the detection quality is improved.

The invention discloses a traction power supply system voltage mutual fuse monitoring method, system and device, relates to the technical field of traction power supply systems, and solves the problems that the existing traction power supply integrated automation system cannot monitor the continuous fusing process of a fuse, resulting in that the PT voltage is lower than the actual operation voltage, and the safety is poor. According to the technical scheme, the method is characterized in that according to the power supply characteristics of a traction substation, the operation condition of a voltage transformer of the substation is automatically recognized, and a fuse monitoring method of the voltage transformer is automatically selected according to the operation condition of the voltage transformer; and monitoring and early warning of incomplete fusing of the voltage transformer fuse are realized.

The invention relates to the technical field of electromagnetic measurement and state monitoring, and discloses a global state sensing system and method for an electromagnetic voltage transformer. The technical problems that in the prior art, data robustness is insufficient and actual working condition changes of a power grid are difficult to adapt due to the fact that accurate resonance circuit parameters are depended and a single calculation path is adopted are solved. According to the method, ferromagnetic resonance phenomena under various faults are simulated based on electromagnetic transient simulation, phenomenon data are obtained, and influence factors are analyzed to obtain influence rule data. And taking the rule data as input, and adopting a comprehensive solving method combining programming calculation, system structure chart calculation and electromagnetic transient software simulation to obtain a high-reliability state quantity time sequence. Based on the time sequence, a nonlinear model which takes loss into account and does not depend on precise resonant circuit parameters is derived, and explicit mathematical functions of primary current and transient overvoltage of the voltage transformer are obtained.

The invention provides a non-effective grounding voltage transformer and a voltage mutual inductance state monitoring method, the non-effective grounding voltage transformer comprises a main voltage transformer and a zero sequence voltage transformer, the main voltage transformer comprises a primary high voltage winding, a secondary low voltage winding and a secondary protection winding, the zero-sequence voltage transformer comprises a zero-sequence primary winding, a zero-sequence secondary winding and a zero-sequence protection winding; a neutral point of the primary high-voltage winding is electrically connected with one end of the zero-sequence primary winding, a neutral point of the secondary low-voltage winding is electrically connected with one end of the zero-sequence secondary winding, and the other ends of the zero-sequence secondary winding and the zero-sequence primary winding are grounded; one end of the secondary protection winding and one end of the zero-sequence protection winding are grounded, the other end of the zero-sequence protection winding is grounded, and the other end of the secondary protection winding is grounded through the current-sensitive resonance elimination resistor; when a power distribution system is disturbed and attempts to cause resonance, the iron core of the zero sequence voltage transformer is rapidly saturated, which is equivalent to that a resistor is connected in series in a loop, so that a large amount of resonance energy is consumed and a resonance elimination effect is achieved.

The invention discloses an uninterruptible power protection device replacement system, and relates to the field of power protection devices. The sampling access module is used for connecting a current sampling loop of a temporary protection device to a secondary side of a current transformer in parallel through an isolation transmitter, and connecting a voltage sampling loop to a secondary side of a voltage transformer in parallel through a high-resistance isolation circuit; the parameter monitoring module is used for acquiring a temporary and old protection device homologous current phase difference and monitoring a common-mode interference voltage and an environment temperature change rate; the fusion calculation module is used for calculating a comprehensive protection coefficient; the locking control module is used for remotely locking an old protection device to enter a logic bypass when the comprehensive protection coefficient is stable and meets a preset condition; the safety monitoring module is used for monitoring residual leakage current and protection coefficient change in a logic bypass state; and the removal execution module is used for physically removing the old protection device and the wires when the conditions are met. The protection state is comprehensively evaluated by collecting operation parameters, the old protection device is remotely switched, the operation condition is continuously monitored, and the safety of the replacement process of the protection device is guaranteed.

The invention provides a current-sensitive resonance eliminator driven by grounding current, and belongs to the technical field of grounding protection. The current-sensitive resonance eliminator is used for being connected between a neutral point of a voltage transformer of a distribution network system and the ground, and is structurally characterized in that a high-voltage lead, a circuit board, an electromagnetic switch and a low-voltage connecting line are electrically connected in sequence from top to bottom and are arranged in an inner cavity of an insulating sheath, the low-voltage connecting wire is led out from the tail of the electromagnetic switch; the high-voltage lead is connected with a wiring terminal of a neutral point of the voltage transformer The low-voltage wire holder is sleeved at the bottom of the insulating sheath; the low-voltage connecting wire is connected with the grounding end through the low-voltage wire holder; a current-sensitive resistor is arranged in the circuit board; when the zero-sequence current of the neutral point of the system is increased suddenly, the resistance value of the current-sensitive resistor is increased suddenly to reduce the loop current; an electromagnetic coil in the electromagnetic switch is connected with a low-voltage connecting line, the electromagnetic switch is driven to be disconnected when grounding current large enough flows through the electromagnetic coil, and the normally-closed state is automatically recovered after a safe duration.

The invention discloses a voltage transformer reliability analysis method, which comprises the following steps of: acquiring a plurality of preset reliability index data of a voltage transformer, and performing standardization processing to eliminate dimensional difference and generate a standardized data matrix; on the basis of the standardized data matrix, objective weights of the indexes are calculated through information entropy, and a comprehensive weight is generated through fusion in combination with subjective structure weights determined by expert experience; constructing a membership function for each reliability index, and describing the degree of the index data belonging to different grades in a preset reliability grade set; according to the membership function and the comprehensive weight, calculating the comprehensive membership degree of the voltage transformer to each reliability level, determining the current reliability level according to the comprehensive membership degree, and triggering a corresponding maintenance decision; according to the method, the problem of boundary fuzziness in a traditional classification method is solved, reliability level description better conforms to practical application, and the accuracy and reliability of evaluation are remarkably improved.