183results about "Effective value measurements" patented technology

The invention discloses an automatic anchor point searching and processing method for grid-connected test data of a photovoltaic inverter, and belongs to the technical field of automatic test of a power system. According to the method, a three-phase voltage and current signal output by a power grid simulator and an inverter power instruction signal are aligned through a high-precision time synchronization device; wavelet transform multi-scale noise reduction and moving average filtering combined preprocessing is adopted to improve the signal-to-noise ratio; identifying a voltage zero crossing point candidate set, a drop starting point candidate set and a recovery termination point candidate set based on a self-adaptive dynamic threshold value; transient energy characteristic verification is introduced for a voltage drop starting point; effective anchor points are confirmed through time window association of power instruction step changes. According to the method, the problems of low efficiency of manual key event point identification, misjudgment caused by noise interference, grid event and inverter response time sequence correlation missing and the like are solved, and the automation degree of test data analysis, anchor point positioning precision and control response time sequence analysis reliability are remarkably improved.

The invention discloses a bus voltage multi-dimensional real-time monitoring and analyzing method, system, equipment and medium, and belongs to the technical field of power system monitoring and fault prediction.The method comprises the steps that high-frequency synchronous sampling is conducted on bus voltage signals, discrete time sequence voltage signals are obtained and preprocessed, preprocessed voltage signals are obtained, and the discrete time sequence voltage signals are obtained; the method comprises the following steps: synchronously extracting multi-dimensional characteristic parameters of voltage, obtaining a characteristic parameter set, calculating a health degree index comprehensively representing a voltage state by utilizing a dynamic weighted fusion algorithm based on the characteristic parameter set, calculating an abnormal degree of a current value according to a historical data sequence of the health degree index, and performing fault grade judgment according to the abnormal degree. And performing trend extrapolation based on the health degree index and the historical data sequence of the key parameters in the characteristic parameter set, and generating predictive maintenance suggestions. According to the method, the crossing from passive alarm to predictive maintenance is realized, and the intelligent level and the operation and maintenance reliability of state monitoring of the power system are remarkably improved.

The invention discloses an electric energy quality comprehensive monitoring method and system based on real-time waveform analysis. The method comprises the following steps: S1, acquiring an analog voltage signal acquired by a mutual inductor; s2, preprocessing to obtain a voltage waveform data segment; s3, performing multi-dimensional feature extraction to obtain a voltage waveform multi-dimensional feature vector; s4, extracting a voltage RMS effective value, a total harmonic distortion rate and wavelet packet energy; s5, inputting the voltage RMS effective value, the total harmonic distortion rate and the wavelet packet energy into a grading event pre-detection model to obtain an event feature subset coding vector; and S6, enabling the event feature subset coding vector to pass through an intelligent event fine classification model to obtain an electric energy event accurate classification result. According to the electric energy quality comprehensive monitoring method and system based on real-time waveform analysis disclosed by the invention, the accuracy and efficiency of electric energy quality event monitoring are greatly improved.

The invention relates to the technical field of power equipment on-line monitoring and fault diagnosis, and discloses a converter transformer bushing end screen voltage abnormity detection device and early warning method.The method comprises the steps that voltage data are collected through a wireless intelligent sensor, soft synchronization and self-adaptive windowing are achieved through a commutation notch feature locking mechanism, and a preprocessing signal is output; topological correlation clustering is executed to construct a virtual health reference, a dynamic residual sequence is extracted through time domain difference, and system side and equipment side features are decoupled; constructing a variational mode decomposition model, and calculating a characteristic entropy value of the intrinsic mode function; and comparing the entropy value with a threshold value, triggering an active impedance disturbance verification mechanism, controlling a sensor to access a load and comparing an actual voltage drop rate with a theoretical voltage drop rate, and determining an insulation degradation or poor contact fault. High-precision synchronization can be achieved without a hardware clock, and the problems that weak fault features are difficult to extract and virtual connection and insulation faults are difficult to distinguish in a high-impedance loop are effectively solved.

Disclosed in the present invention are a feeder automation test method and apparatus, a device, and a storage medium. The method comprises: calculating a voltage effective value and a current effective value of each node in a distribution network framework under different fault handling section conditions of a feeder automation system; sending the voltage effective values and the current effective values to a corresponding tester, such that after receiving the voltage effective values and the current effective values, the tester converts the voltage effective values into an analog voltage waveform, converts the current effective values into an analog current waveform, outputs the analog voltage waveform and the analog current waveform to a corresponding field power distribution terminal, and returns switch position change information of the field power distribution terminal; and comparing the switch position change information with preset standard feeder automation action logic in a corresponding fault handling section condition and then, on the basis of a comparison result, obtaining a feeder automation test result. The present invention can improve the reliability of feeder automation tests.

The invention belongs to the technical field of electronic information, and relates to an online low-voltage load monitoring and abnormal tripping positioning method and a related device. According to the method, electrical parameters of all monitoring points are collected in real time, key parameters are calculated after analog-to-digital conversion and filtering denoising, and the key parameters are compared with a set threshold value to judge whether the monitoring points are in an abnormal state or not; once an abnormal state is found, an early warning is generated and uploaded to a remote platform; and continuously monitoring the state of the main switch or the total current at the same time, and when tripping occurs, backtracking an abnormal record within a preset time period before tripping, and positioning the last or the most serious abnormal monitoring point as an abnormal source. The system comprises a data acquisition module, an analog-to-digital conversion module, a preprocessing module, a calculation module, a judgment module, an early warning module, a trip monitoring module and a positioning module. According to the invention, early warning before a fault and rapid positioning after tripping are realized, and the intelligent level, the operation and maintenance efficiency and the power supply reliability of the power distribution network are improved.

The invention discloses a method for supporting high-frequency AC / DC component acquisition in core grounding current monitoring, which belongs to the technical field of transformers and comprises the steps of system initialization and communication establishment, continuous sample acquisition, period preprocessing and frequency spectrum and DC component calculation. The technical problem of accurately collecting and analyzing the high-frequency harmonic component and the direct-current component of the grounding current of the iron core at the same time is solved, the dual-channel sampling and digital signal processing technology is combined, on the basis of calculating the total current and the power frequency component, multi-dimensional monitoring and intelligent analysis of the running state of the transformer are achieved, and the fault diagnosis accuracy of the transformer is improved. According to the invention, various industrial scenes can be covered, missing detection of potential faults is avoided, and the fault early warning capability and the operation state judgment precision are improved.

The invention relates to an electric leakage alarm method and device for a resident end, equipment and a medium. The method comprises the following steps: acquiring a leakage current signal, performing low-pass filtering processing on the leakage current signal, and then calculating a leakage current effective value; dynamically calculating an alarm threshold according to the environment parameter information; the leakage current effective value is compared with an alarm threshold value, grading event judgment is carried out according to a comparison result and waveform characteristic parameters of the leakage current signal, and an alarm trigger mark is generated; according to the alarm triggering mark, generating an alarm instruction to execute at least one of the following response actions: driving a piezoelectric buzzer and an LED to generate a sound-light alarm signal; and generating alarm information according to the alarm triggering mark, and uploading the alarm information to a monitoring platform. According to the method, through leakage current signal filtering processing, dynamic alarm threshold calculation and a grading alarm mechanism, the accuracy and environmental adaptability of electric leakage detection in a residential electricity consumption scene are improved, and the intelligent level of electricity consumption safety monitoring is improved.

The invention discloses a state sensing and fault prediction system and method for a low-voltage switch cabinet, and relates to the technical field of power equipment monitoring, and the system comprises a multi-source feature fusion sensing module which is used for collecting multi-source data of the low-voltage switch cabinet to construct an original state data set, fusing credibility weighting and dynamic and static features, and constructing an enhanced state feature vector; the health assessment and fault prediction module is used for generating a health index and a state label through logistic regression mapping based on the enhanced state feature vector, performing health index prediction by adopting attention LSTM to calculate the remaining available life, and estimating the fault probability through structure perception k-NN; and the adaptive control optimization module is used for modulating the control advance based on the fault probability and generating a differential control instruction. According to the method, the accuracy of state sensing of the low-voltage switch cabinet and the credibility of fault prediction are remarkably improved, and the early warning capability and the operation and maintenance decision reliability are improved.

The invention provides a power grid interference monitoring and auxiliary diagnosis system. Based on a preset intelligent threshold value, when parameter fluctuation continuously exceeds 6dB, a data abnormity alarm is triggered, and hardware abnormity such as a sensor or a board card fault can be identified; calculating the total risk score of the power grid by quantitatively analyzing a plurality of parameters such as a voltage effective value, a frequency, a harmonic effective value, THD, low-frequency / radio-frequency conducted emission and a peak, and dividing the risk grades into'normal ', 'high risk' and'high risk '; the upper computer supports dynamic query, visual display and Excel export of historical data; an integrated interference auxiliary diagnosis function is combined with a typical database and a high-power equipment working condition information base, so that interference source equipment and abnormal frequency points can be automatically identified, and a diagnosis report is generated; the system is suitable for complex platforms such as ships and aircrafts, full-life-cycle electromagnetic compatibility management of a power grid is achieved, and the stability and safety of the system are improved.

The invention provides an electric energy quality regulation resource harmonic compensation capability evaluation method, which belongs to the field of electric energy regulation and comprises the following steps of: 1, measuring and calculating a real-time total effective value of phase voltage and phase current output by an electric energy quality regulation resource in real time according to a capacity calculation method; a real-time compensated output capacity Suse and a real-time residual adjustable capacity Ssurplus are obtained; and step 2, based on the real-time residual adjustable capacity Spurplus of the electric energy quality adjusting resource, considering four limiting factors, and evaluating the maximum value of each harmonic compensation current and the maximum value of the total harmonic compensation current which can be respectively sent by the electric energy quality adjusting resource in real time. The method assists in realizing optimal configuration of mass heterogeneous power quality regulation resources in a power grid.

The invention provides a mechanical characteristic monitoring method and system for a switch cabinet, and belongs to the field of power equipment detection, and the method comprises the steps: respectively obtaining the contact stroke of each phase of contact, the isolation knife current of each phase, the grounding knife current of each phase, and the motor current of each phase of a three-phase discrete switch of the switch cabinet in the switching-on and switching-off process; obtaining opening and closing time data of the circuit breaker in the opening and closing process; obtaining stroke characteristics of each phase of contact according to the contact stroke of each phase of contact; obtaining current characteristics of each phase according to the isolating knife current of each phase, the grounding knife current of each phase and the motor current of each phase; obtaining opening and closing characteristics according to the opening and closing time data; and monitoring the mechanical characteristics of the switch cabinet according to the contact stroke characteristics of each phase, the current characteristics of each phase and the opening and closing characteristics. The comprehensiveness and the accuracy of monitoring the mechanical characteristics of the switch cabinet and the effectiveness of fault identification can be improved.

A method and system for monitoring an insulation resistance (IR) of an electric machine, the system including a bridge circuit arrangement. A voltage on the bridge circuit arrangement is detected. The IR is calculated as a resistance in the bridge circuit arrangement associated with the detected voltage.

This invention discloses an intelligent data synchronization system and method for voltage monitoring instruments, relating to the field of intelligent data synchronization technology. The method includes the following steps: acquiring the original sampling sequence; constructing a preset step-size sliding window; generating filter coefficients based on the statistical characteristics of sampling points within each window and performing weighted calculations to obtain the filtered output value at the window center point, forming a preprocessed sequence; detecting the sign change of adjacent sampling points in the sequence; marking valid zero-crossing points; extracting an integer number of complete cycle sampling data as a cycle data block; calculating the theoretical number of sampling points based on the rated frequency and sampling rate and setting a tolerance range; comparing the actual number of points to preliminarily determine the synchronization effectiveness; calculating the actual frequency from the preliminarily valid data block; verifying the rated frequency deviation to confirm synchronization; simultaneously calculating its effective value; comparing it with a preset voltage threshold to determine whether the data is valid. This invention achieves intelligent synchronization of sampling data.

The utility model discloses a high-frequency current measuring circuit, and the circuit comprises a sampling circuit which receives a to-be-measured high-frequency current, converts the high-frequency current into a sampling signal, and outputs the sampling signal; the effective value conversion circuit is connected with the sampling circuit, receives the sampling signal, and performs multiplication operation on the sampling signal to output an effective value signal; the CPU is connected with the effective value conversion circuit, receives the effective value signal, processes the effective value signal into a digital signal and outputs the digital signal; and the display module is connected with the CPU and is used for receiving and displaying the digital signal. According to the utility model, an effective value conversion technology is adopted, an electronic circuit is adopted to replace a thermoelectric high-frequency ammeter, the structure is simplified, and the cost is reduced; and the measuring range is large and can reach several amperes, the precision is high, and the reading is visual.

This invention discloses a method and system for monitoring residual current of AC power supply in stations, relating to the field of electrical parameter measurement technology. The method includes: performing micro-amplitude reference self-check and acquisition deviation correction based on a time-scale aligned monitoring set; stitching together the spectral domains of low-frequency and high-frequency channels to generate a wideband calibrated residual current set; extracting frequency domain and transient features from the wideband calibrated residual current set; and using gated fusion to perform sparse inversion localization to obtain suspected abnormal feeders and target feature vectors; performing hierarchical cause discrimination based on the target feature vectors and suspected abnormal feeders; quantifying the deviation degree of the target feature vectors; and generating a handling judgment set. This invention generates self-check response records and forms acquisition deviation correction information through micro-amplitude reference self-check, achieving consistent calibration correction between low-frequency and high-frequency channel data to obtain a wideband calibrated residual current set, thereby stabilizing the wideband measurement reference.

A battery defect diagnosis apparatus according to an embodiment of the present invention can calculate a reaction amount of respective batteries stored for a predefined period at a reference temperature, generate a plurality of groups by grouping the batteries on the basis of the reaction amount of the respective batteries, obtain a representative value for each battery group on the basis of a voltage change of each of the batteries within the battery group, and determine, on the basis of the representative value, whether the battery group is defective.

The invention relates to a traction inverter IGBT junction temperature calculation method and device, equipment, a medium and a program. The method comprises the steps that the bus voltage, the output current effective value, the output current frequency, the modulation ratio and the power factor of a traction inverter are collected; based on the bus voltage, the output current effective value, the modulation ratio and the power factor, calculating the total average loss of all IGBT devices in the traction inverter in an output fundamental wave period; discretization equivalence is carried out on the average loss, pulse waveforms corresponding to multiple discrete periods are obtained, the loss value corresponding to each pulse waveform is calculated, and the size of the discrete periods is determined according to the set number of the discrete periods and the output current frequency; based on an electric heating model of the traction inverter IGBT device and the loss value corresponding to each pulse waveform, the IGBT junction temperature corresponding to each discrete period is calculated, and rapid and accurate calculation of the junction temperature of the traction inverter under the long-time mission profile is achieved.

The invention provides a circuit board service life prediction method and system based on line aging analysis, and relates to the technical field of circuit board fault prediction.The method comprises the steps that circuit board detection data are obtained through a sensor array arranged at the key position of a circuit board, and the circuit board detection data comprise temperature data and current data; circuit board operation environment data are obtained, and the circuit board operation environment data comprise circuit board operation environment humidity and a circuit board operation environment vibration acceleration effective value; obtaining circuit board operation time; determining a comprehensive aging coefficient according to the circuit board operation environment data, the circuit board operation time, the temperature data and the current data; determining a circuit board damage coefficient according to the comprehensive aging coefficient and the temperature data; and determining the predicted service life according to the comprehensive aging coefficient and the circuit board damage coefficient. According to the invention, the accuracy of predicting the service life of the circuit board can be improved.

The application provides a fault identification method and device of an excitation system based on phase voltage and phase current, and relates to the field of power systems. According to a cycle integral algorithm, three-phase phase current instantaneous values of a three-phase alternating current side current transformer of a small current test platform of a generator excitation system, three-phase phase voltage instantaneous values of a low voltage side of a synchronous transformer and rectifier output voltage instantaneous values are calculated to obtain three-phase phase current effective values, three-phase phase voltage effective values and rectifier output voltage effective values. An average value of the three-phase phase voltage effective values and the rectifier output voltage effective values are used to obtain a measured thyristor trigger angle during an open-loop load test. If a difference between the measured thyristor trigger angle and a given thyristor trigger angle is greater than a first preset threshold value, a fault phase is determined according to a first constraint relationship corresponding to the three-phase phase current effective values and a second constraint relationship corresponding to the three-phase phase voltage effective values after the thyristor is closed. The application has stronger anti-interference capability and strong engineering applicability.

The invention provides a method and device for predicting the service life of a generator, and the method comprises the steps: determining the reference voltage data of a target voltage feature of the generator at a preset time, and enabling the target voltage feature to represent the voltages of different parts of a generator winding; determining a voltage weight for the life prediction voltage data according to the difference between the actual voltage data and the reference voltage data of the target voltage feature in the predetermined time; according to the voltage weight, carrying out weight distribution on the life prediction voltage data to obtain weight distribution voltage data; and predicting the service life of the generator based on the weight distribution voltage data. The problem that the service life of the generator cannot be accurately predicted due to the fact that only the overall aging or insulation of the generator can be evaluated is solved, and the current states of different parts can be introduced into the service life prediction voltage data, so that the aging or insulation weak parts are considered during the service life prediction; therefore, the service life of the generator can be predicted more accurately.

The invention relates to the technical field of electric energy quality analysis and the technical field of artificial intelligence, and discloses a harmonic traceability method and device based on an electrified railway and a new energy inverter, and the method comprises the steps: obtaining the voltage spectrum amplitude of each harmonic of the new energy inverter through a trained deep belief network model, according to the voltage frequency spectrum amplitude of each harmonic wave of the electrified railway and the voltage frequency spectrum amplitude of each harmonic wave of the new energy inverter, generating a root-mean-square value of a harmonic voltage frequency spectrum of the electrified railway and a root-mean-square value of a harmonic voltage frequency spectrum of the new energy inverter; when the root-mean-square value of the harmonic voltage frequency spectrum of the electrified railway is greater than the harmonic threshold value of the electrified railway, marking the dominant equipment type of the harmonic source as the electrified railway, and when the root-mean-square value of the harmonic voltage frequency spectrum of the new energy inverter is greater than the harmonic threshold value of the new energy inverter, marking the dominant equipment type of the harmonic source as the electrified railway; and marking the dominant equipment type of the harmonic source as a new energy inverter. According to the invention, the acquisition efficiency of the dominant equipment type of the harmonic source can be improved.

This application relates to the field of single-phase asynchronous motor technology, and discloses a single-phase asynchronous motor starting control circuit with anomaly detection. The circuit includes an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit. The main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit. The MCU control unit executes control logic, which not only precisely controls the on and off timing of the main and secondary thyristors to optimize the motor starting process and reduce starting shock, but also judges abnormal states based on real-time current and voltage data provided by the electrical metering chip and quickly takes protective measures when an anomaly is detected. Furthermore, it records key operating parameters when an abnormal state occurs, providing a basis for subsequent fault analysis, greatly simplifying the fault diagnosis process and reducing maintenance costs.

Methods and systems for detecting and notifying power outages and power quality are described herein. A sensor coupled to a circuit transmits keep-alive packets to a server. The sensor detects an input signal generated by electrical activity. The sensor generates an output signal based on the input signal. The sensor monitors the output signal. During a clock cycle, the sensor determines whether a rising edge occurs and transmits a failure packet to the server if a rising edge occurs before a predetermined clock value or if no rising edge occurs. The server receives the failure packet from the sensor and listens for the keep-alive packets. When no keep-alive packets are received within at least a defined period of time after the failure packet is received, the server transmits a power outage notification. When one or more keep-alive packets are subsequently received, the server transmits a power restoration notification.

The invention belongs to the technical field of power system measurement and control, and relates to a fundamental wave zero-sequence current detection method based on a time domain CPT theory, which comprises the following steps: obtaining a time domain current signal and a voltage signal based on an actual power grid; based on the time domain current signal and the voltage signal, obtaining a physical quantity based on a CPT theory; the physical quantities based on the CPT theory comprise homologous voltage, active power, reactive power and basic apparent power; calculating the physical quantity based on the CPT theory to obtain a fundamental current effective value, a fundamental current voltage phase angle difference and a fundamental current phase; substituting the physical quantity, the voltage signal, the fundamental current effective value and the fundamental current phase based on the CPT theory into a zero-sequence current calculation formula to obtain fundamental zero-sequence current information; the fundamental wave zero-sequence current information comprises a fundamental wave zero-sequence current instantaneous value and a fundamental wave zero-sequence current effective value and amplitude; therefore, fundamental wave zero-sequence current detection which works stably under the conditions of harmonic distortion and three-phase imbalance is realized.

The invention is suitable for the technical field of power system detection, and provides a grounding detection method and device and terminal equipment, and the method comprises the steps: obtaining the starting recording data of two protection devices under the conditions that a grounding fault occurs in an electrical primary system and the two protection devices start a protection mechanism; and then, under the condition that the steady-state phase voltages of the two protection devices are determined to be in a normal state according to the initial three-phase voltage effective values and the initial synchronous voltage effective values of the two protection devices, if it is detected that at least one of the two protection devices has voltage abrupt change, transient analysis is started. And finally, according to the head wave voltage data after the transient analysis of the two protection devices is started, determining an abnormal protection device with neutral point offset in the two protection devices. According to the method, the abnormal protection device with neutral point offset can be accurately positioned from the two protection devices, so that the detection efficiency is improved.

The invention discloses a tunneling equipment high-speed sampling health diagnosis and protection method and an electric control system thereof, and relates to the field of tunneling equipment electric control systems, and the tunneling equipment high-speed sampling health diagnosis and protection method comprises a multi-loop three-phase current transformer, a common-bus three-phase voltage transformer, a high-speed sampler, a processing analyzer, a transmitter, an embedded industrial personal computer and an electric component formed by a controller. By high-speed acquisition and processing of original multi-electric-quantity signals, a traditional electric control system electric quantity sampling analysis mode is replaced, fault pre-warning, fault post-protection and original electric quantity information real-time storage are realized, online advanced pre-warning and protection are realized, offline analysis of high-speed sampled original large-capacity data is realized, functions of a small oscilloscope are integrated, and the system is simple in structure and convenient to use. The tunneling equipment electric control system is innovated, and the tunneling equipment electric control system has new functions of key transmission part degradation condition prediction, power supply network harmonic content analysis, ultra-high-speed original signal sampling, large-capacity data real-time transmission and storage and the like.

A contactless current sensing system and method for high power density power electronics systems are provided. The contactless current sensing system is a two current sensor system in which two current sensors having substantially the same sensitivity are positioned on opposite sides of a current-carrying conductor.

The invention relates to the technical field of electric energy quality, in particular to a system short-circuit capacity estimation method and system considering voltage fluctuation quantity and reactive correction. The method comprises the following steps: calculating a reactive power array of a power supply main incoming line of a concerned bus; identifying a reactive power abrupt change point corresponding to the maximum change of the adjacent extreme point in the monitored reactive power array, and obtaining the maximum reactive power value and the minimum reactive power value corresponding to the reactive power abrupt change point, and the fundamental wave voltage effective values of the concerned bus corresponding to the maximum reactive power value and the minimum reactive power value; correcting the maximum reactive power value and the minimum reactive power value corresponding to the reactive power abrupt change point to obtain a corrected reactive power value under the nominal voltage; calculating a voltage fluctuation quantity according to the fundamental wave voltage effective value of the concerned bus; and calculating the short-circuit capacity based on the voltage fluctuation quantity and the corrected reactive power value under the nominal voltage.