82 results about "Grounding Malfunction" patented technology

The present disclosure relates to electrical wiring devices, specifically ground fault circuit interrupters (GFCIs) with integrated self-test and miswire detection capabilities. The device comprises line and load hot terminals, line and load neutral terminals, a differential transformer with a sense coil, a circuit interrupter, and a controller. The controller is configured to periodically initiate a simulated fault self-test, allowing the fault condition to persist in a non-trip test state and triggering the circuit interrupter only if a fault is not detected within a predetermined period. The controller also detects miswire conditions by monitoring power at the line hot terminal during trip events and maintains a miswire state in memory if improper wiring is detected.

The application discloses a TN-C-S low-voltage power distribution system single-phase ground fault identification method, and belongs to the technical field of power system fault characteristics and relay protection. The single-phase ground fault identification method effectively solves the inadaptability problem of traditional single residual current protection by collecting residual current and zero sequence current and the fault current approximately separated by the algorithm of the application. The application collects residual current, zero sequence current data and three-phase power supply voltage data respectively, relies on the short-time invariability of the neutral point grounding resistance and the repeated grounding resistance, proposes to separate the fault current by using the residual current and the zero sequence current, then compares the fault current with the setting threshold to identify the single-phase high-resistance ground fault, and obtains the fault phase according to the matching of the phase of the separated fault current and the phase of the power supply voltage, so that the single-phase high-resistance fault identification and phase selection identification are realized.

Adjustable frequency drives (AFDs) and methods of operating the same are described. An AFD includes a plurality of inverters having first terminals that are coupled to respective phases of a motor and having AC output terminals connected to one another at an AC neutral node. A voltage at the AC neutral node is detected. A root-mean-squared (RMS) voltage measurement is generated from the detected voltage. A potential ground fault is identified responsive to the generated RMS measurement. The AFD is controlled responsive to identification of the ground fault. Identifying a potential ground fault responsive to the generated RMS voltage measurement may include comparing the RMS voltage measurement to a reference value.

The present application relates to the technical field of small current grounding line selection, and provides a small current grounding line selection auxiliary increment device and method, a grounding transformer module for providing a neutral point for a target power system; the target power system is a system without grounding of the neutral point; a neutral point voltage detection module for detecting the voltage of the neutral point when a grounding fault occurs; an auxiliary increment module for selecting a corresponding input resistor according to the size of the voltage of the neutral point when the grounding fault occurs, so as to obtain an increment current matched with the voltage of the neutral point; the input resistor is used for connecting the neutral point; and a zero sequence current detection module for judging the grounding fault according to the increment current matched with the voltage of the neutral point. Through the above technical solution, the problem that the grounding line selection cannot be accurately judged according to the zero sequence current in the related art is solved.

This invention discloses a cable aluminum sheath grounding fault location system, method, and terminal equipment, belonging to the field of electrical detection and fault diagnosis. The system includes a pulse source module and a contact sensor module. During fault detection and location: the cable segment to be tested is in a normally open grounding port state; the pulse source module emits a pulse current to the voltage-applied end of the cable segment; the contact sensor module detects the pulse signal of the cable segment and obtains the current signal detection result; when a sudden pulse change occurs in the current signal detection result, a fault point is determined in the cable segment, and the location of the sudden pulse change is identified as the fault point, thus achieving cable aluminum sheath grounding fault location. This invention solves the technical problems of inaccurate location and low efficiency of traditional detection methods, achieving efficient and accurate location of cable aluminum sheath grounding faults.

The utility model discloses a small current grounding line selection device with grounding fault early warning relates to electric power equipment technical field, including cabinet, power module, acquisition subassembly, early warning subassembly, the acquisition subassembly fixed mounting is in the cabinet inner wall side, the acquisition subassembly contains current sampling board and voltage sampling board, the current sampling board is set on the bus, the voltage sampling board is connected on the open triangle winding of bus, the current sampling board is connected inductance through data line, the inductance outer wall other end connects transistor, the transistor is connected analog -digital converter through data line, the analog -digital converter is connected processor through parallel interface. The utility model discloses through acquisition subassembly and early warning subassembly, has realized the grounding fault early warning function, solved the problem of lacking effective early warning mechanism before the fault occurs, and the advance warning operation and maintenance personnel possible grounding fault, is favorable to the prevention measures of taking in time.

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.

This invention relates to the field of transformer monitoring technology, specifically to an online monitoring device and handling system for grounding current of transformer core and clamps. The system includes a data acquisition module, a current analysis module, a linkage analysis module, an early warning determination module, and a fault determination module. First, it analyzes the current surge and relative stability of the current data to determine the linkage characteristic of the current surge; then, it removes background current to obtain the true fault current; it determines the synchronization of the linkage response time between current and temperature; combining the linkage characteristic of the current surge and the synchronization of the linkage response time, it determines the early warning value for a metallic grounding fault; when the early warning value for a metallic grounding fault exceeds the preset normal early warning range, it compares the characteristics of different fault locations at the current moment with those in the historical database to obtain the fault location corresponding to the current moment. This invention achieves intelligent fault location determination.

The method and system for identifying new energy power supply under asymmetric fault based on sequence impedance difference, the protection device collects three-phase current and three-phase voltage in real time, and calculates to obtain negative sequence current voltage, zero sequence current voltage and positive sequence current voltage; after the protection is started, the asymmetric fault type is judged; when the ground fault occurs, the modulus difference and impedance angle difference of the negative sequence impedance and the zero sequence impedance are compared to judge the fault characteristics of the power supply behind the protection; when the phase-to-phase fault occurs, the modulus difference of the negative sequence impedance and the positive sequence impedance is compared, and the impedance angle difference of the negative sequence impedance and the positive sequence impedance and the difference between the line positive sequence sensitive angle are combined to judge the fault characteristics of the power supply behind the protection; it is determined that the power supply behind the protection is a new energy power supply, the identification of the new energy power supply under asymmetric fault based on sequence impedance difference is realized, and the safety and reliability of the relay protection under the new energy access to the power system are improved.

The application discloses a kind of small resistance grounding system grounding fault detection method and device in the technical field of power distribution network, method includes: using sensor to collect the zero sequence current I0 and zero sequence voltage U0 of line;When the zero sequence voltage U0 of line U set , the waveform comparison coefficient K of zero sequence voltage U0 and zero sequence current I0 is calculated r , that is, the ratio of the point number of the sign opposite of zero sequence voltage U0 left shift quarter cycle and zero sequence current I0 sampling value with the sampling point number N of each power frequency cycle;When the zero sequence voltage U0 of line U set , line is normal line;The size of K r With protection starting value K set , when K r >K set , it is judged as grounding fault line, and sends out fault signal after the set delay value t set ;When K r ≤K set , line is normal line.The method is simple and easy to operate, improves the sensitivity of small resistance grounding system grounding fault detection, reduces the time consumption of judgment, improves efficiency.

The application discloses an online fault diagnosis method for a hydro-generator based on a potential interval distance of a through screw, relates to the technical field of generators, and is suitable for detecting a stator winding ground fault. Voltage collection devices are additionally arranged on a plurality of through screws of the hydro-generator, real-time induced potential is acquired, a historical data matrix is established, and a data buffer matrix is updated at interval time; the data buffer matrix is divided into a data evaluation matrix, a fundamental wave and an odd harmonic phase are extracted through Fourier decomposition, a harmonic phase matrix is constructed, a phase difference matrix is obtained by calculating normalized phase differences of adjacent columns, a quartile distance is solved after being converted into a column vector array, a dynamic quartile distance array is formed, abnormal limit values are determined by combining a box plot principle and an error level of the voltage collection device, and faults are determined by traversing the array. The method does not need additional sensing devices and traditional threshold setting, is convenient to operate, has low implementation difficulty, and can accurately and timely identify faults.

The application relates to a non-full-phase power supply line comprehensive protection method, system, device and medium, characterized in that: when it is determined that traction power supply line protection at a transformer substation side has started, current and voltage information of two phases at the transformer substation side is collected; a fault element starting moment is recorded, a plurality of maximum sampling values in the former half cycle and a plurality of maximum sampling values corresponding to the latter half cycle before the moment are extracted; whether the traction power supply line at the transformer substation side appears a ground fault or a phase-to-phase fault is judged according to the current and voltage information, the extracted maximum sampling values and a first criterion, a second criterion and a voltage auxiliary criterion which are constructed in advance, and whether protection export is determined, and the application can be widely applied in the field of power supply lines.

The application relates to a cable trench single-phase grounding arc ignition time simulation calculation method and system, wherein the method comprises the following steps: constructing a cable single-phase grounding fault arc simulation model; the cable single-phase grounding fault arc simulation model comprises a cable two-dimensional geometric model, material physical property parameter and physical field coupling boundary condition; extracting an arc current and voltage waveform in a half cycle under different working conditions, calculating the arc average energy in the half cycle and the average power in the arc duration through numerical integration; constructing a cable tunnel model and configuring material parameters of the cable and the optical cable, and arranging monitoring equipment; taking the average power in the arc duration under different working conditions as a fire source heat release rate to input the cable tunnel model for simulation, and recording monitoring data of the monitoring equipment. Through the technical scheme, precise simulation calculation of cable trench single-phase grounding arc ignition time and fire can be realized.

The application discloses a kind of generator rotor winding dynamic ground fault multi-modal diagnostic system and method, belong to generator state monitoring and fault diagnosis technical field, in system, leakage current sensing module can collect the transient waveform of rotor winding leakage current to ground;Multi-physical quantity can synchronous acquisition module collects rotor voltage ripple signal and shaft vibration acceleration signal;Ground capacitance online measurement module can be under the working condition of generator rotation, acquisition rotor dynamic ground capacitance value;Signal processing and diagnosis host computer can carry out time-frequency analysis and data fusion to the signal received, construct leakage current-shaft vibration-voltage ripple three-dimensional fault fingerprint matrix, and then realize early fault identification, fault location, fault nature evaluation and rotor winding insulation state classification.The application fuses multi-modal information, resists strong electromagnetic interference, realizes early warning of dynamic ground fault, early identification of dynamic ground fault and accurate positioning and nature identification of insulation deterioration point.

This invention discloses a method, apparatus, and computer program product for determining the nature of phase-to-phase grounding faults. The method first acquires power system fault recording files, extracts three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current data, and uses this data to determine phase-to-phase grounding faults and identify the faulty and non-faulty phases. Next, it determines the fault direction based on the phase relationship between the faulty phase, zero-sequence current, and the voltage / zero-sequence voltage of the non-faulty phase. Subsequently, it distinguishes between metallic and grounding faults via transition resistance based on the amplitude relationship between the faulty phase current and voltage, and the phase characteristics of the zero-sequence voltage and the non-faulty phase current. Finally, it determines the fault location by combining the amplitude and phase characteristics of the faulty phase voltage, faulty phase current, and zero-sequence current. This invention achieves systematic and precise diagnosis of phase-to-phase grounding faults, improves the accuracy and reliability of fault diagnosis, provides technical support for the optimization of relay protection strategies, and meets the fault diagnosis needs of modern smart grids.

This invention relates to a method for identifying successive grounding faults in a distribution network based on the characteristics of phase current mutations. Applied to multiple monitoring points along the line, the method includes the following steps: When any monitoring point identifies the first single-phase grounding fault, the remaining monitoring points enter the successive grounding fault identification stage and perform the following actions: extracting the mutation characteristics of the three-phase and zero-sequence currents; calculating the effective value of each phase mutation and the vector sum of the mutations of the two non-faulty phases; determining the line experiencing a successive single-phase grounding fault; when the first faulted line trips and is disconnected, supplementary judgment is made based on the change in the three-phase current mutation at the moment of disconnection; for the identified successive faulted lines, the effective value and duration of the zero-sequence current are continuously monitored; tripping is executed when the successive fault protection criteria are met; if the zero-sequence current returns to the normal range, the successive grounding fault identification stage is exited; thereby achieving local identification and distributed protection of cross-line single-phase grounding faults of the same and different phases.

This invention relates to the field of power system fault diagnosis technology, specifically a method for accurate location and isolation of ground fault sections based on multi-edge terminal data association. It includes collecting transient current and voltage signals from multiple edge terminals in the distribution network, extracting high-frequency transient feature values, and combining them with a distributed computing model to generate a transient feature dataset, a candidate set of fault branches, and fault section location results. Finally, it generates isolation commands to achieve closed-loop control. This invention, by fusing transient signal frequency domain features, zero-sequence current distribution patterns, and fault phase abrupt change information, constructs a dynamic fault discrimination model, significantly improving the identification accuracy of intermittent arc grounding faults and high-resistance grounding faults, enhancing the self-healing capability of the distribution network, and ensuring power supply reliability.

The application discloses a capacitor power-taking type feeder terminal based on Internet of Things and a self-adaptive fault processing method. The terminal comprises a control module, a capacitor power-taking module, a wide-range zero-sequence current sampling module and a fault processing module. The control module is used for receiving data of each module and generating a control instruction. The capacitor power-taking module is used for obtaining electric energy from a high-voltage line and monitoring a power-taking state in real time. The wide-range zero-sequence current sampling module is used for obtaining a zero-sequence current signal and calculating an actual value of the zero-sequence current. The fault processing module is used for identifying a fault position and a state. The application solves the problems of the existing FTU, such as unsafe power taking, low sampling precision, poor fault processing adaptability and low integration of Internet of Things, and realizes wide-range sampling linearity, fast phase-to-phase fault processing, high accuracy of ground fault positioning, and is suitable for 12kV outdoor pole-mounted switches, so that the reliability and operation and maintenance efficiency of a power distribution network can be improved.

This invention discloses an intelligent method for identifying distribution network fault types based on multi-parameter analysis, belonging to the field of distribution network fault identification technology. Addressing the problem that existing technologies struggle to accurately identify intermittent arcing ground faults, this invention collects voltage and current signals from key nodes in the distribution network using a fault recording device, marking signal abrupt change periods to form a fluctuation time series. It analyzes the dynamic changes in electrical signal frequency during each abrupt change period, calculating the overlap degree and frequency change rate in conjunction with inherent interference frequency bands to generate a discrimination marker value for arcing abrupt changes. Then, based on multi-dimensional indicators such as time interval and electrical signal frequency change rate, it separates the mixed signal and extracts fault feature components to generate fault feature marker values. Finally, it combines the two marker values ​​to determine whether the current abrupt change belongs to an intermittent arcing fault, and distinguishes it from other voltage disturbances or phase-to-phase short-circuit faults. This effectively reduces misjudgments of intermittent arcing faults and improves the accuracy and reliability of distribution network fault identification.

This invention discloses an intelligent zero-sequence current transformer and its leakage current detection and fault diagnosis method, belonging to the field of transformer technology. The transformer includes a toroidal magnetic core, a high-sensitivity leakage current detection circuit, and a microprocessor chip. The toroidal magnetic core is installed on the monitored three-phase four-wire cable, and the toroidal magnetic core is connected to the high-sensitivity leakage current detection circuit. The high-sensitivity leakage current detection circuit is connected to the microprocessor chip, which has a communication interface for sending alarm signals and waveform recording files. This invention accurately extracts weak leakage currents through high-sensitivity detection and three-stage cascaded adaptive filtering; it employs a multi-scale time-frequency attention fusion network to intelligently identify various fault types and achieve early warning; and it integrates fault waveform recording functionality to provide complete waveform data for accident analysis, significantly improving the sensitivity and accuracy of ground fault detection and diagnosis, and ensuring the safe operation of the power system.

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

The application discloses a kind of starting spare transformer phase failure detection methods, comprising: measuring the high voltage side three-phase current and three-phase voltage of starting spare transformer;Based on the three-phase current and three-phase voltage, the positive sequence current, zero sequence current, positive sequence voltage and zero sequence voltage are calculated using symmetric component method;Determine whether the amplitude of the zero sequence current exceeds the zero sequence current threshold, yes, determine that phase failure has occurred, otherwise determine that no phase failure has occurred;In response to determining that phase failure has occurred, further determine the phase of the phase failure according to the amplitude of the zero sequence current and the positive sequence current and the angle relationship between the zero sequence current and the positive sequence voltage.Due to the adoption of the technical scheme, phase failure and phase-to-ground fault can be effectively identified under the condition of transformer no-load and load.

To enable detection of a break in the ground fault detection circuit that occurs during the output operation of the output circuit. [Solution] A ground fault detection device connected to an output circuit insulated from the earth, comprising: a midpoint resistor provided between a pair of output lines of the output circuit; a ground fault detection resistor provided between the midpoint resistor and the earth; an amplifier having a + input terminal connected to one end of the ground fault detection resistor and a - input terminal connected to the other end of the ground fault detection resistor; a pull-up resistor provided between one end of the ground fault detection resistor and the + input terminal of the amplifier and connected to a positive power supply voltage; a pull-down resistor provided between the other end of the ground fault detection resistor and the - input terminal of the amplifier and connected to a negative power supply voltage; and a disconnection detection unit that detects the disconnection of the ground fault detection resistor by detecting that the ground fault detection resistor is disconnected and that the positive power supply voltage and the negative power supply voltage are input to the input terminal of the amplifier via the pull-up resistor and the pull-down resistor.

The application provides a power distribution line ground fault monitoring method, a monitoring device and a fault indicator. The method comprises the following steps: acquiring a plurality of historical fault transient signals; calculating a plurality of first change trends by using the Prony algorithm according to the historical fault transient signals, wherein the first change trend comprises the change trend of the main harmonic frequency and the attenuation factor of the power distribution line in a historical time period; acquiring a current fault transient signal, wherein the current fault transient signal is a current signal recorded by the fault indicator in a target time period; calculating a second change trend by using the Prony algorithm according to the current fault transient signal, wherein the second change trend comprises the change trend of the main harmonic frequency and the attenuation factor of the power distribution line in the target time period; and determining the ground fault type of the power distribution line according to the first change trend and the second change trend. The method solves the problems of insufficient accuracy and poor anti-interference performance of the ground fault monitoring method in the prior art.

This invention discloses a method and apparatus for detecting grounding faults in substation battery banks based on square wave injection, belonging to the field of DC power system fault diagnosis technology. The method includes: real-time measurement and calculation of the total voltage across the series-connected battery bank; when the insulation resistance to ground of the positive and negative busbars is lower than a preset insulation threshold, a low-frequency square wave voltage signal is simultaneously injected into the positive and negative terminals of the DC busbars via an injection resistor network; the response voltage across the measuring resistor is simultaneously acquired; based on the voltage difference of the response voltage, the difference between the positive and negative half-waves of the injected square wave voltage, and the known resistance value, the grounding resistance and the relative location of the grounding fault are calculated; and the specific battery number where the grounding fault occurred is determined according to the total number of battery cells in the battery bank and the calculated relative location of the grounding fault. This invention achieves accurate measurement of battery grounding resistance and automatic location of faulty batteries through square wave injection, significantly improving the operational reliability of the DC system.

Systems, methods, and apparatus are provided for electrically shielding a heated component, more specifically, in a manner compatible with a circuit protected by a GFCI (Ground Fault Circuit Interrupter). An example is a heated component that is electrically shielded, comprising: a conductor which is a heating element connected between a power line and the neutral line of the circuit from a GFCI; and a shield adjacent to the conductor and connected to the GFCI, the shield receiving a portion of the current from the conductor and returning a portion of the received current to the GFCI.

The present disclosure provides a method for efficiently locating a ground fault in an electrical circuit. To implement the method, a transmitter device ("transmitter") is electrically coupled to a first connection location of the electrical circuit. The transmitter is capable of transmitting a tracking signal into the electrical circuit. The tracking signal can be followed to identify the location of a ground fault within the circuit.

A tester for a frequency-dependent ground fault interrupt wiring device, including: a tester circuit, including: a switch disposed between a first terminal and a second terminal, wherein a leakage current flows through a leakage path between the first terminal and the second terminal when a voltage is applied across the first terminal and the second terminal, a magnitude of the leakage current being determined, at least in part, by a conductivity of the switch; and a waveform generator configured to generate a periodic output signal having a frequency, wherein the switch is driven to modulate the magnitude of the leakage current such that the leakage current has a frequency substantially equal to a frequency of the waveform generator.

This invention discloses a method and apparatus for identifying stator winding grounding faults in hydro-generators, relating to the field of hydro-generator fault identification technology. The method includes acquiring the zero-sequence current signal during a single-phase grounding fault in the hydro-generator; using the minimization of envelope entropy as the fitness function, the IDBO algorithm is used to adaptively optimize the number of modes and penalty factor in variational mode decomposition (VMD) to obtain the optimal parameter combination; wherein the IDBO algorithm is obtained by fusing Logistic-Tent chaotic mapping, exponential decay convergence factor, and random perturbation mechanism; based on the zero-sequence current signal and the optimal parameter combination, signal decomposition processing is performed to obtain multiple intrinsic mode functions (IMF) components; the three components with the highest correlation coefficients are selected as effective fault features, their sample entropy is calculated, and the sample entropies are combined into a feature vector representing the fault state; the feature vector is used as an input layer variable and imported into a support vector machine for fault identification.