221 results about "Phasor" patented technology

The invention discloses a current harmonic disturbance suppression method and suppression system for a permanent magnet synchronous motor. The method comprises the following steps: acquiring voltage and current signals of an electrical loop phasor test in the operation of the motor; an inductance identification algorithm based on high-frequency response is adopted, high-frequency excitation signals are injected, current response is monitored, and stator inductance parameters are calculated; constructing a multi-synchronous rotating coordinate system based on the parameter, and decomposing the current signal to obtain each harmonic current component; building a fuzzy full-order sliding mode observer, inputting an inductance parameter, voltage data and a harmonic current component, and dynamically adjusting a sliding mode surface parameter to observe the position and the rotating speed of a rotor; independently controlling each harmonic current adjusting channel under a multi-coordinate system in combination with observation information, and generating a compensation control signal; and the synthesized master control signal is output to the driving circuit. The system comprises six units, and the method and the system can accurately obtain parameters, efficiently decompose harmonic waves, accurately observe states, realize multi-frequency harmonic disturbance suppression, and improve motor operation stability and efficiency.

The invention discloses a broadband random power quality adaptive monitoring system, which relates to the field of power grid monitoring and comprises a broadband signal acquisition module, a synchronous phasor measurement module, an edge calculation module, a cloud edge collaborative analysis module and a local traceability module. The broadband signal acquisition module performs high-frequency sampling on a power grid signal and ensures integrity; the synchronous phasor measurement module is used for realizing time synchronization of multiple monitoring points and generating data with time marks; the edge calculation module is used for studying and judging disturbance and early warning through deep learning, and uploading data to the cloud; the cloud edge collaborative platform aggregates data, deduces regional power quality and issues an optimized AI model; the local traceability module quantifies harmonic responsibility and positions a broadband disturbance source. The system innovatively adopts an ensemble empirical mode decomposition and variational mode decomposition parallel strategy, combines a spectrum kurtosis maximization algorithm to determine the number of modes and accurately separate transient and steady components, solves the problem of feature confusion of a traditional method, and realizes the crossing from single analysis to multi-mode fusion research and judgment.

The invention discloses a broadband oscillation risk prediction method and system based on wide-area broadband measurement, and relates to the technical field of wide-area broadband measurement. The method comprises the following steps: firstly, collecting grid-connected point high-frequency synchronous phasor data by using a PMU device at a photovoltaic field station side, and performing filtering and time mark calibration processing to eliminate noise and ensure time consistency; performing spectrum correlation analysis on wide-area multi-station PMU data based on time mark synchronization, screening broadband oscillation candidate features, and transmitting the broadband oscillation candidate features to a scheduling master station prediction network; and finally, inputting the real-time operation parameters of the power grid and historical oscillation sample data into the network, carrying out risk assessment and trend prediction, and assisting broadband oscillation early warning and prevention and control decision. According to the method, efficient fusion of multi-area equipment data is realized, a full-system broadband dynamic monitoring view angle is formed, the oscillation dynamic state is captured in real time, the risk is pre-judged, the broadband oscillation risk caused by new energy power fluctuation and power electronic equipment transient response can be dealt with, and the dynamic monitoring requirement of a novel power system is met.

The invention discloses an energy storage rapid compensation method and system based on track overhead line system voltage fluctuation feature recognition, and relates to the technical field of track traffic traction power supply. The method comprises the following steps: synchronously acquiring voltage and current signals of the overhead line system, and extracting a composite feature vector containing disturbance root attributes and transient change rate; on the basis of the vector, a transient energy vacancy sequence covering the ultra-short-term future is output in real time through a prediction model fusing dynamic phasor analysis and a feedforward neural network; according to the sequence, a cooperative control strategy fusing overshoot and active damping is generated in combination with a proximity compensation principle and a voltage recovery state so as to drive an along-line energy storage unit; the strategy is executed in advance, compensation energy is injected, and finally double closed-loop correction is conducted based on the voltage residual error. According to the method, the problems of response lag, unclear disturbance identification, poor collaboration and lack of adaptive ability in the prior art are solved, and advanced, accurate, collaborative and self-optimized rapid suppression of the voltage fluctuation of the overhead line system is realized.

The invention discloses a reinforcement learning-based low-voltage power distribution network multi-target collaborative optimization method and system, and the method comprises the steps: S01, taking adjustable equipment of a low-voltage power distribution network as an intelligent agent, and obtaining the historical operation data of a plurality of intelligent agents to form a training data set; step S02, constructing a multi-objective optimization model, and defining a reward function in a phasor form and a multi-objective weight; step S03, performing centralized training on the deep reinforcement learning model, inputting a multi-target weight into a neural network in the training process, performing learning with a maximum accumulated reward according to a reward phasor, and fusing a multi-target weight vector and a Q value vector through a phasor fusion layer; and step S04, acquiring real-time operation data of a plurality of agents in the low-voltage power distribution network, and controlling each agent to act by using a strategy learned by training. According to the invention, multi-target collaborative optimization control can be realized in a distributed photovoltaic large-scale access scene.

The invention discloses a power grid switching operation anti-misoperation verification method and device based on real-time topology, and relates to the technical field of power grid anti-misoperation, and the method comprises the following steps: collecting the phasor data of target equipment and the real-time active power flow direction of a power grid, constructing a real-time directed topological graph, and extracting a to-be-reconstructed sub-graph associated with an operation instruction of the target equipment; converting the target equipment operation instruction into an impedance correction term, constructing an estimated impedance matrix based on the to-be-reconstructed sub-graph, and calculating a corresponding power flow transfer vector; performing double-layer constraint decoupling on the topological structure of the to-be-reconstructed sub-graph to generate a source flow path chain set; and generating a verification result based on the power flow transfer vector, the source flow path chain set and a preset anti-error rule. The method is used for solving the problems of electrical rehearsal real-time lagging and complex topology anti-error logic confusion in a complex power grid environment.

The invention relates to the technical field of power distribution network monitoring, in particular to a power distribution cabinet line intelligent detection method and system, and the method comprises the steps: collecting node voltage, phasor current and active / reactive power of each power distribution cabinet, attaching a sampling period and a quality identifier, and carrying out the arrangement according to a timestamp; carrying out edge calculation on harmonic waves, flicker, unbalance, missing measurement compensation and initial estimation, and generating a straight-through UDP stream and a storage stream; a real-time interface is aligned and fused with a topology version according to a unified time reference, state estimation is carried out, and a node initial value set is output; s4, according to the initial value and topological modeling node digital twinning (index recovery load), obtaining online parameters through four-stage sub-step discrete + UKF joint estimation; accessing a real-time simulation platform through HiL, and recharging in the same period; a variable damping impedance stable interface is adopted, and when consistency and a threshold value are met, a digital snapshot containing an online parameter, a steady-state quantity and a transient abstract is generated. According to the method, low time delay of measurement alignment, credible state estimation, digital twinborn self-adaption, hardware-in-loop stability and verifiable result release can be realized, so that the fault detection, positioning and evaluation capabilities of the power distribution network are improved.

The invention discloses a self-adaptive current-limiting control method and related device for a network construction type energy storage converter under a symmetric fault of a power grid, and belongs to the technical field of network construction type energy storage converter control, and the method comprises the steps: constructing a corresponding fault current dynamic response model based on the network construction type energy storage converter under the symmetric fault of the power grid; generating a self-adaptive current-limiting control strategy based on the voltage drop depth of the power grid; wherein the self-adaptive current-limiting control strategy comprises the steps of carrying out overcurrent steady-state component suppression based on a phasor current-limiting method and carrying out overcurrent transient-state component suppression based on a virtual impedance control method, and self-adaptively adjusting a power instruction to meet a system support requirement in a current-limiting process; a fault current dynamic response model is solved through a self-adaptive current-limiting control strategy, a current-limiting control scheme is obtained, it can be ensured that the converter maintains the networking characteristic in the fault period, steady-state and transient overcurrent is effectively restrained, output current is strictly limited within a safety threshold value, and transient stability of a system is maintained.

The invention relates to the technical field of power systems, in particular to a power grid fundamental harmonic and inter-harmonic detection method and device and a storage medium, and can collect power grid signals, arrange discrete samples into sample vectors, apply a Hanning window to the sample vectors for zero filling DFT, and obtain a frequency index of fundamental waves according to a peak value of frequency spectrum amplitude square; setting a harmonic wave search range according to the frequency index of the fundamental wave, and screening the harmonic waves according to the frequency related threshold to obtain a frequency index set of the fundamental wave and the harmonic waves; calculating a residual error between the power grid signal and the fundamental harmonic reconstruction signal, and calculating a residual error ratio; and performing secondary iteration on the residual error to obtain a TF coefficient corresponding to the inter-harmonic. According to the technical scheme, fundamental wave phasor measurement, harmonic detection and inter-harmonic detection can be completed at the same time, the precision is high, and the detection efficiency is high.

The invention discloses an interface method for a VSC direct current system mixed granularity model and an alternating current system electromechanical transient model. The method comprises the steps that a mixed granularity simulation framework is constructed, wherein an electromechanical transient phasor model is adopted on the alternating current side, and a simplified electromagnetic transient instantaneous value model considering electromagnetic characteristics is adopted on the direct current side; the VSC converter adopts a unified equivalent model, and various types of converters are adapted through parameter configuration; a low-voltage side bus of the converter transformer is arranged at the interface position of the simulation framework and the alternating current system; simulation and interaction rules are configured, wherein the simulation step length of each direct-current power grid is independently set; the alternating current system provides port voltage and alternating current control information for the simulation framework, the simulation framework is equivalent to the alternating current system as a power source, and power exchange is realized through the converter station; in one time step calculation of the electromechanical transient state, the simulation framework changes along with the alternating current side information, a historical simulation state is taken back, and direct current side simulation in the alternating current time step is carried out again until the power interaction deviation converges.

Disclosed are a method for distribution of PHASE to monitor the operating state of a power system by using heterogeneous data obtained from measurement of SCADA and a time synchronized PMU and a method for processing defect data in mixed DSE by using same. The method for distribution of PHASE to monitor the operating state of a large scale power system includes the steps of: defining an extended state variable and an extended state variable set for each region; performing a SCADA-based DSE by using a SCADA measurement value for each region and a covariance matrix thereof, and parallelly performing a PMU-based DSE by using a PMU measurement value for each region and a covariance matrix thereof; and mixing the estimation results of the SCADA-based and the PMU-based DSE algorithms so as to perform a phasor-aided normalized residual test and a general normalized residual test.

A WMU data analysis system and associated method are for monitoring an electrical power delivery system. The disclosed techniques entail processing synchro-waveform data to classify an event type and estimate, based on an impedance component and the event type, an event location so as to reduce a number of candidate inspection sites in the electrical power delivery system for inspection by a maintenance team.

The invention relates to the technical field of intelligent power distribution network safety detection and fault processing, in particular to a multi-source coupling leakage current accurate traceability and cooperative suppression method and system for a power distribution network, and the method comprises the steps: collecting leakage current, voltage phase and power fluctuation data through a synchronous phasor measurement device; based on the collected data, constructing a four-dimensional feature library, carrying out decoupling processing on leakage current signals, and then realizing accurate traceability positioning of the leakage current according to a matching result of the leakage current signals and the four-dimensional feature library and a time difference between sensors; data are uploaded to a distribution network dispatching center, leakage current is evaluated based on a dynamically adjusted safety threshold value, and then operation states of a photovoltaic inverter, an energy storage converter and a charging pile are cooperatively controlled to realize active suppression of the leakage current; and performing preliminary diagnosis on the leakage current at the edge side, uploading a result to a cloud end, and determining a final diagnosis conclusion. According to the invention, the accuracy of multi-source coupling leakage current tracing and the accuracy of cooperative suppression of the power distribution network are improved.

The invention relates to the technical field of power electronic application, in particular to a negative-sequence voltage compensation control method of a network-forming STATCOM (Static Synchronous Compensator). Comprising the steps of bridge arm current reference instruction unit phasor calculation, reactive voltage control, bridge arm positive sequence and negative sequence reactive current instruction calculation, bridge arm current reference instruction amplitude limiting logic, zero sequence voltage injection control and modulation wave instruction calculation. According to the method, the negative-sequence current output by the networking STATCOM in the asymmetric transient fault is always inductive, the proportion coefficient of the amplitude of the negative-sequence current instruction can be adjusted according to the requirements of an engineering project, and the cost is reduced; by dynamically solving a quadratic equation of unary of a reactive current amplitude limiting coefficient, an active current instruction is not limited by amplitude, balance control of direct current voltage is preferentially ensured, the reactive current is reasonably limited in amplitude, a total current reference instruction value is always in a maximum design value range of short-time overcurrent, and the stability and the safety of the device are improved.

The invention discloses a wide-area oscillation source positioning method and system based on physical feature embedding and a graph attention network, and the method comprises the steps: obtaining synchronous phasor data of a power system, carrying out the modal parameter identification of subsynchronous oscillation and / or super-synchronous oscillation based on the synchronous phasor data, constructing a topological graph of the power system, and carrying out the positioning of a wide-area oscillation source. And constructing the oscillation amplitude, the attenuation factor and the phase of each node obtained by identification into a feature vector of each node in a topological graph, inputting the topological graph and the feature vector into a graph attention network, and outputting an oscillation source positioning result, so that high-frequency recording data after an accident does not need to be waited, and the positioning accuracy of the oscillation source is improved only on the basis of synchronous phasor data. The identified modal parameters are used as physical characteristics to be embedded into the graph attention network, and the interpretability of a physical mechanism and the graph structure mining capability of deep learning are fused, so that subsynchronous oscillation and super-synchronous oscillation are accurately positioned.

The invention relates to the technical field of power electronic application, in particular to a control method of a star-chain network STATCOM (static synchronous compensator). Comprising positive sequence voltage unit phasor calculation, voltage feed-forward unit phasor calculation, bridge arm current reference instruction unit phasor calculation, reactive voltage control, bridge arm reactive non-limiting current reference instruction calculation, bridge arm reactive current reference instruction amplitude limiting logic, zero sequence voltage injection control and modulation wave instruction calculation. The bridge arm current reference instruction comprises a negative sequence component, and negative sequence compensation of the power grid voltage is realized; bridge arm current reference instruction amplitude limiting logic is designed, so that the safety of the device is effectively guaranteed; in the zero-sequence voltage injection control link, the phase with the functional quantity deviation adopts a current reference instruction phasor signal, and the dynamic adjustment efficiency is optimized; the equalization control effect of the inter-phase direct current voltage is enhanced, and the problem that overcurrent is easy to occur in transient faults of a network-forming STATCOM and the problem that a current instruction contains a direct current component are solved.

The invention discloses a short circuit parameter measurement and analysis method, system, equipment and medium, and relates to the technical field of power system detection, and the method comprises the steps: carrying out the synchronous sampling of a voltage signal and a current signal in a detected line, carrying out the conditioning and conversion of an obtained sampling signal, and generating an original digital quantity; calibrating the original digital quantity to obtain calibrated effective measurement data; short-circuit parameters are calculated based on the effective measurement data, the short-circuit parameters comprise short-circuit current, short-circuit impedance and short-circuit power, and the calculation process comprises fundamental wave extraction and phasor analysis; visually displaying the calculated short-circuit parameters, and generating report data containing a measurement result according to user operation; and in the measurement process, the running state is dynamically adjusted according to the current task type and the energy consumption state. According to the invention, the authenticity of measured data is improved through synchronous sampling and conditioning conversion of voltage and current signals in combination with a multi-dimensional calibration strategy.

The invention discloses a new energy box-type substation state abnormity diagnosis method and system, and relates to the technical field of power equipment monitoring. According to the method and the system, through event-triggered high sampling and cross-channel time base self-inspection, multi-source sequence synchronization is ensured, and a consistent time axis is provided for subsequent estimation, so that online analysis under the condition of no power outage is supported; introducing dual-path estimation of RL step fitting and voltage drop robust regression in a transient stage, cooperatively inhibiting a closing peak and outlier data, and obtaining a stable initial value of the contact resistance; in a steady-state stage, adopting Goertzel frequency selection to extract a fundamental wave phasor and performing ohmic purity judgment, and expanding to a resistance-inductance joint model when necessary to remove interference of parasitic inductive reactance on resistance estimation; and then mutual identification and residual constraint are carried out on the temperature and electric power coupling relationship by using a discrete heat RC model, and local write-back correction is carried out on the deviation, so that the consistent closed loop of the electric domain and the heat domain is realized.

A kind of single-phase grounding fault single-end impedance ranging method and system of DG-containing distribution line, method includes: input parameter and DG distribution to equipment, when single-phase grounding fault occurs in distribution network, the zero sequence voltage of equipment rises, it is judged that single-phase grounding fault occurs, and fault ranging calculation is started;Using symmetrical component method to obtain the sequence components of voltage and current at bus, DG access, load access and fault point;On the basis of the sequence components of voltage and current at fault point, the phase angle difference between line fault phase voltage and current is obtained, and the fault distance is calculated according to the phase angle difference.The ranging effect of the method of the application is very good, and it has practicality.

The application relates to a synthesis method of a rotating phasor, which is suitable for the technical field of electrical rotating phasor conversion and is particularly directed to the decomposition and synthesis of an electrical rotating phasor. The method adjusts the initial phase of two amplitude-constant sub-rotating phasors, and then synthesizes a target rotating phasor with adjustable amplitude and initial phase, and has the characteristics of easy generation of the sub-rotating phasor, good flexibility and high reliability. The application mainly utilizes the parallelogram rule of vector operation, reduces the generation difficulty of the sub-rotating phasor by reducing the generation problem of the target rotating phasor with adjustable amplitude and initial phase to the synthesis problem of the two sub-rotating phasors with constant amplitude and adjustable phase, and solves the problem of synthesizing a complex rotating phasor from a simple rotating phasor. The technical scheme provided by the application forms a simple sub-rotating phasor through electromagnetic conversion, and provides a new idea for the synthesis of a complex rotating phasor.

The application discloses a power distribution network fast protection method and device and a computer readable storage medium, wherein the method comprises the following steps: S1, sequentially calibrating branch lines of a radial power distribution network to determine the grades and numbers of the feeder branch lines; S2, constructing a starting criterion by using transformer low-voltage side currents to calibrate the moment of fault occurrence; S3, according to different fault types, selecting characteristic phases and calculating the amplitude and phase angle of the corresponding characteristic phase mutation current phasor; S4, taking the main transformer low-voltage side phasor as a reference phasor, calculating the inner product of the phasor calculated by other lines and the reference phasor respectively, and marking all the lines with inner product greater than the setting value; and S5, finding the line with the highest number and grade among all the marked lines and marking the line as a fault line. The application can solve the contradiction between the four properties of the traditional power distribution network three-section current protection, and well cope with many problems such as high resistance fault and slow backup protection action.

The invention relates to the technical field of intelligent power grid fault analysis, in particular to an intelligent power grid fault analysis method and system based on big data. Comprising the following steps: analyzing a power grid physical wiring diagram to construct a node admittance matrix, and extracting modal feature vectors through feature decomposition to generate a topological fingerprint database; synchronously collecting wide-area phasor data streams, dynamically intercepting a data time window, extracting resonance frequency band signals, and generating a fault feature data set through feature enhancement; a modal confidence factor is dynamically evaluated, when the dominant modal confidence coefficient is lower than a threshold value, redundant modals in the node-modal association map are activated, and fault feature vectors are fused and reconstructed; and matching the reconstruction vector with a fingerprint database, performing triple verification, and outputting a fault positioning coordinate or starting a safety protection instruction in combination with a confidence scoring decision. By introducing a dynamic confidence mechanism and a redundancy modal compensation strategy, the accuracy and fault-tolerant capability of fault identification in a new energy disturbance environment are improved.

The invention relates to a power distribution network harmonic analysis method and system, and the method comprises the steps: constructing a digital twinborn model of a power distribution network region, and selecting transformers in the region as analysis objects one by one; for each analysis object, various working conditions are simulated by changing the transformation ratio of the analysis object in a digital twin model, and voltage and current waveforms are collected and subjected to Fourier decomposition to obtain harmonic phasors; thirdly, performing phase reduction on the phasor data, separating a real part from an imaginary part to construct a matrix, and solving a harmonic coefficient matrix by using a least square method to realize error minimization; separating linear and nonlinear parts of the harmonic current, and calculating a harmonic emission capability parameter and a harmonic current risk parameter for quantitative evaluation; according to the method, all transformers are traversed and analyzed, and systematic harmonic evaluation of the whole power distribution network area is finally realized.

This invention relates to a single-end distributed parameter fault location method for ultra-high voltage (UHV) transmission lines, comprising: acquiring the line parameters of the UHV transmission line under test and determining whether a fault has occurred; acquiring the three-line voltage vector and three-phase current vector of the faulty end of the transmission line, establishing a distributed parameter model of the transmission line, and dividing the distributed parameter model of the transmission line into a fault-side segment model, a fault-opposite-side segment model, and a fault branch model according to the fault region; employing a single-end phasor domain centralized parameter fault location method to solve for the initial values ​​of the fault location and fault resistance; based on the fault-opposite-side segment model, constructing a fault location equation with the fault location and fault resistance as variables, and iteratively solving for the fault location and fault resistance as an optimization problem, as the fault location result. Compared with the prior art, this invention significantly improves the fault location accuracy of UHV long-distance transmission lines.

Certain aspects of the present disclosure provide techniques for determining a topology of an electric vehicle supply equipment (EVSE) network. An example method includes obtaining, for a first time period, for each of a plurality of pieces of equipment of the EVSE network, a respective magnitude of a respective current phasor, wherein for each of one or more pieces of equipment of the plurality of pieces of equipment, a respective phase angle of the respective current phasor is unknown; and determining, based on at least the respective magnitude of the respective current phasor for each of at least one piece of equipment of the one or more pieces of equipment, a respective subset of lines of the EVSE network to which the respective piece of equipment is coupled.

The invention relates to an asymmetric fault ride-through control method and system based on a three-phase four-leg virtual synchronous generator, and belongs to the technical field of power electronics and new energy power generation. The invention provides a solution for solving the problems of asymmetric output current, transient overcurrent, weakening of system supporting capability and the like under the asymmetric fault of a power grid in the prior art. The method comprises the following steps: detecting an asymmetric fault of a power grid; freezing a reactive power ring and retaining an active power ring when a fault occurs; determining a voltage drop coefficient and a phase jump angle according to the fault type; directly calculating a three-phase asymmetric excitation electromotive force reference value based on a system phasor geometrical relationship and a current amplitude limiting constraint; and giving the reference value to a voltage loop, and controlling the output of the inverter.

The invention discloses a pilot protection method and device based on instantaneous power total and incremental waveform similarity, and belongs to the technical field of power systems. According to the method, fault detection is started through voltage or current abrupt change, differential capacitance current compensation is carried out based on a full current sampling value, and a compensated voltage value is calculated by combining an electromagnetic wave transmission equation and a line Bergeron model so as to eliminate the influence of line parameters; and judging a passive load branch fault through a current amplitude and an integral value, otherwise, synchronously adopting an instantaneous power full-quantity waveform cosine similarity longitudinal main protection criterion and an instantaneous power increment waveform cosine similarity criterion to identify an internal fault, and overcoming a reliability'dead zone 'defect caused by near-zone fault voltage drop. The method does not need to depend on power frequency phasor calculation, and can improve the sensitivity and reliability of protection in scenes of a high-proportion new energy power grid, a micro-grid and the like.

The invention discloses a power distribution network fault accurate positioning method based on negative-sequence component characteristics and two-end quantities, and the method comprises the steps: collecting fault voltage and current information, and extracting voltage and current fundamental frequency components; performing phase-mode transformation on the fundamental frequency phasors of the three-phase voltage and the three-phase current to obtain negative-sequence components of the voltage and the current; the amplitudes of the current negative-sequence components at the outlets of all the lines are extracted and compared, and the line with the maximum current negative-sequence component amplitude at the outlet is judged as a fault line; establishing head-end quantity and tail-end quantity expressions of the negative-sequence voltage amplitude of the fault point; and solving and judging a fault point distance by using a simultaneous equation set of fault point negative sequence voltage amplitude expressions established by the head-end quantity and the tail-end quantity. According to the method, only the negative-sequence parameters at the two ends of the line and the negative-sequence impedance parameters of the fault line are needed, the cost is low, the practicability is good, a new thought is provided in the aspect of fault distance measurement, and technical support can be provided for reducing the manual line patrol range on site and improving the fault maintenance efficiency.

The application provides a harmonic source modeling method based on time-frequency feature extraction, first determines harmonic principal component frequencies of a harmonic source; then extracts harmonic voltage amplitude and phase angle corresponding to the harmonic principal component frequencies of the harmonic source, obtains a frequency domain feature set of the harmonic source, reconstructs the frequency domain feature set through IDFT to form a harmonic source frequency domain feature component matrix, and splices the frequency domain feature component matrix with an original voltage sequence collected by a synchronous phasor measurement device to obtain a time-frequency feature component matrix; the component matrix is converted into a gray scale image by using a matrix normalization method, and is converted into a three-channel time-frequency feature component color image by using a pseudo-color coding technology; finally, the collected harmonic source voltage data and the time-frequency feature component color image are taken as inputs of the model, the collected corresponding harmonic source current data are taken as outputs of the model, the network model is continuously trained through the measured data until accurate mapping of a relationship between harmonic voltage and harmonic current of the harmonic source is realized, and a harmonic source data-driven model is obtained.

This invention discloses a method, system, and apparatus for extracting the fundamental phasor of fault transient current, relating to the field of power system fault transient current analysis. The method involves acquiring N transient sampled currents and dividing them into M subsets according to a preset partitioning strategy. The discrete Fourier transform (DFT) output of each subset is then determined. Combining the DFT output expressions of each subset, the first DFT output corresponding to the first exponentially decaying DC offset component and the second DFT output corresponding to the second exponentially decaying DC offset component under the target subset are determined. Finally, the DFT output of the current fundamental phasor is determined by combining the DFT output expression and output results of the target subset, thus obtaining the fundamental phasor. This scheme pre-establishes a preset fault transient current discrete model and sets a preset partitioning strategy, achieving high-precision and rapid extraction of the fundamental phasor, which is beneficial for improving the reliability of power system relay protection.