39 results about "Power system harmonics" patented technology

The invention discloses an electric power system harmonic propagation analysis method and device and a storage medium, and belongs to the technical field of electric power system harmonic analysis, and the method comprises the steps: inputting a to-be-predicted operation condition parameter and a harmonic voltage parameter into a trained regression prediction model, obtaining a corresponding prediction cross admittance matrix, and obtaining a prediction cross admittance matrix; the predicted cross admittance matrix is applied to harmonic propagation analysis of the power system; wherein the regression prediction model is integrated with Bagging based on a decision tree; according to the method, by improving the data set quality and optimizing the model hyper-parameters, the harmonic source cross admittance matrix which is self-adaptive to the operation condition and is established by adopting the decision tree-based regression device and the Bagging element regression device can meet the harmonic analysis precision requirements under different operation conditions, and harmonic propagation of the power system can be analyzed more accurately; the analysis efficiency is improved, and a feasible technical path is provided for online monitoring or rapid evaluation.

The invention discloses a harmonic analysis method based on double buffer window function optimization, and relates to the technical field of harmonic analysis and signal processing of a power system, and the method comprises the steps of hardware initialization, double buffer initialization, FFT module parameter configuration, data acquisition, buffer switching, data extraction and windowing and FFT processing. Parallel data acquisition and processing are realized through a double-buffer ping-pong mechanism, spectrum leakage is suppressed by applying a Hanning window function, and FFT calculation is performed after signal amplitude is recovered through a compensation factor; according to the method, the data acquisition continuity and real-time performance are improved, the harmonic amplitude error is controlled within + / -0.5%, the hardware resource utilization rate is optimized, and the method is suitable for power grid electric energy quality monitoring.

The invention discloses a harmonic monitoring system and method for a wall bushing of a flexible direct current converter station, and relates to the technical field of harmonic monitoring of a power system, and the system comprises a capacitor voltage dividing part which is connected in series with a main capacitor of the wall bushing for voltage division; the broadband current sensing component is annularly arranged on the outer wall of the bushing between the bushing tap and the capacitance voltage dividing component and is connected with the data acquisition component; the data acquisition part is connected with the capacitance voltage division part and the broadband current sensing part, executes synchronous sampling, filtering, wavelet transformation, harmonic modeling and feature extraction, and uploads a result to a data analysis background; the data analysis background is in communication connection with the data acquisition component and is used for receiving the uploaded data frame and cooperatively displaying harmonic monitoring information with the interactive interface; according to the system, structure coupling modeling and high-frequency signal synchronous acquisition linkage are realized, a multi-channel harmonic monitoring closed-loop path is constructed, and the monitoring integrity and the system collaboration are improved.

The invention discloses a harmonic stability evaluation method, device and equipment applied to a renewable energy power system and a medium, the method is applied to the technical field of power system harmonic, and the method comprises the steps: carrying out the impedance aggregation processing of topological structure data, and obtaining a harmonic impedance model; processing the renewable energy equipment data based on a Nyquist stability criterion to obtain a stability boundary condition of the power system; constructing a node admittance matrix based on the harmonic impedance model and the stability boundary condition; processing the node admittance matrix by using a Fourier technology to obtain impedance spectrum data, and processing the impedance spectrum data based on a modal impedance maximum value analysis method to obtain resonance modal characteristics; processing the resonance mode characteristics and the real-time operation condition to obtain a time domain verification result; and carrying out harmonic stability evaluation based on a time domain verification result. According to the method provided by the invention, the technical problem of harmonic stability evaluation distortion caused by incomplete measurement data can be solved.

The invention discloses a large power grid harmonic calculation method and system considering conventional direct current and flexible direct current, and belongs to the technical field of power system harmonic simulation. The method comprises the following steps: acquiring power grid operation mode data of a power grid, and constructing harmonic models of various elements of the power grid based on the power grid operation mode data; judging whether the current power grid operation mode comprises conventional direct current and flexible direct current or not, if so, acquiring operation data of the conventional direct current and the flexible direct current from the operation mode, and calculating harmonic source values of the conventional direct current and the flexible direct current at an alternating current side node based on the operation data; and inputting the harmonic source numerical value on the one or more nodes, carrying out load flow calculation based on the harmonic model and the operation data, and generating a calculation result of each harmonic. According to the method, the influence of harmonic waves generated by conventional direct current and flexible direct current in a normal operation state on the power grid can be considered, and the accuracy of large power grid harmonic wave calculation can be improved.

The invention discloses an electric power system harmonic detection method based on a neural network, and relates to the field of electric power system harmonic detection, and the method comprises the steps: sampling an electric power system signal to obtain an actual observation signal, and constructing to obtain a constructed observation signal; constructing a linear hybrid matrix by using the actual observation signal and the constructed observation signal, and preprocessing the linear hybrid matrix; performing independent component separation processing on the preprocessed linear hybrid matrix by using a Newton iteration formula introducing a convergence factor based on a Fast-ICA algorithm to obtain an independent component estimation value and extract an independent component coefficient; and inputting the independent component coefficient into a power system harmonic detection model obtained based on BP neural network training to obtain a fundamental wave source signal and each harmonic source signal. According to the method, the advantages of the Fast-ICA algorithm and the BP neural network algorithm on power system signal processing are fully combined, and the accuracy of a harmonic detection result is effectively improved.

The invention discloses a capacitor voltage transformer harmonic error prediction method based on NRBO-BP, and belongs to the technical field of modeling prediction. The method comprises the steps of analyzing harmonic transmission characteristics, adjusting stray capacitance numerical values to simulate different operating environments, performing simulation to obtain harmonic error data, optimizing initial weight and bias of a BP neural network by using an NRBO algorithm, constructing a harmonic error prediction model, and finally predicting 2-60 times of harmonic errors by taking typical harmonic errors as characteristic parameters. The performance of the model is evaluated by adopting a mean absolute error, a root-mean-square error and a decision coefficient, wherein the NRBO algorithm comprises the steps of population initialization, Newton-Raphson search and TAO trap avoidance; the method solves the problems of low model precision and susceptibility to environmental interference in the existing CVT harmonic error prediction, effectively improves the measurement precision of the CVT in the harmonic frequency band, and provides reliable technical support for harmonic analysis of a power system.

The present invention discloses a low-voltage intelligent broadband harmonic detection method and a detection device, belonging to the technical field of harmonic detection in power systems, including: denoising an input signal to obtain an initial signal; performing discrete wavelet transform based on the obtained number of transformation times to separate the initial signal into a low-frequency signal and a high-frequency signal; weighting the low-frequency signal based on a Hanning window to obtain a weighted signal, performing fast Fourier transform on the weighted signal to obtain a first harmonic spectrum, and performing feature extraction and spectrum correction on the first harmonic spectrum to obtain a first detection result; performing frequency reduction processing on the high-frequency signal through an orthogonal digital mixing function to obtain a frequency-reduced signal, performing band-selective fast Fourier transform on the frequency-reduced signal to obtain a second harmonic spectrum, and performing feature extraction on the second harmonic spectrum to obtain a second detection result. It overcomes the technical problem in the prior art that it is difficult to improve the real-time performance while improving the detection accuracy, and significantly improves the accuracy and real-time performance of harmonic detection.

The application provides an online identification method for harmonic resonance of a power system, comprising the following steps: collecting voltage waveform data and current waveform data at a preset common coupling point in the power system, pre-processing to obtain waveform difference degree, performing multiple transformations on the collected voltage waveform data and current waveform data to obtain current complex matrix and voltage complex matrix of a fundamental wave and each harmonic; determining a fundamental wave and a total harmonic impedance amplitude array of the common coupling point according to an equivalent model of the power system; calculating power factors of the fundamental wave and each harmonic, and obtaining a power factor array after screening; and determining that harmonic resonance occurs in the power system when the waveform difference degree, the harmonic number array and the power factor array simultaneously satisfy a preset resonance condition. The application combines the similarity of the collected waveforms, harmonic impedance and power factors of multiple parameters, and only needs voltage and current waveform data at the PCC point to identify the harmonic resonance in the power system.

The invention provides a filtering control device and a filtering control method based on a controllable reactor, and relates to the technical field of harmonic suppression of a power system. According to the technical scheme provided by the invention, the basic harmonic current and power are measured near the resonance point, and the task contribution proportion of each harmonic source can be quantified in combination with the calculation of the target harmonic power of the harmonic sources at the two sides of the line. According to the distribution mode based on the contribution proportion, distribution of the filtering tasks is more reasonable, and resource waste possibly occurring in a traditional method is avoided. And according to the determined task contribution proportion and the basic harmonic current, a controllable reactor filtering target and a filtering current required by each harmonic source can be accurately calculated, so that accurate treatment of harmonic waves is realized. Compared with a filtering mode in the related technology, the technical scheme provided by the invention can flexibly filter harmonics of different times for different harmonic sources, so that the filtering effect of the line can be improved.

The invention relates to the technical field of harmonic suppression and reactive compensation of a power system, in particular to a harmonic and reactive compensation system and method, and the system comprises a detection and analysis module, a control decision module, a compensation execution module, a man-machine interaction and communication module, and a fault pre-judgment and protection diagnosis module. Through an H-bridge cascade topology and microsecond-level response optimization mechanism, accurate and rapid generation and injection of compensation current are realized, the precision and efficiency of harmonic suppression and reactive compensation are effectively improved, meanwhile, the switching loss under a low-load working condition is reduced, and through multi-parameter real-time monitoring, hierarchical risk pre-judgment and multi-level accurate diagnosis, the real-time performance of the system is improved. Early warning and grading protection of power electronic device fault premonition are achieved, the fault position is accurately positioned, a standardized maintenance report is generated, and the safety, reliability and operation and maintenance convenience of system operation are greatly improved.

The invention relates to the technical field of power systems, and discloses a power system harmonic impedance partitioning method based on a Leiden community partitioning algorithm, which comprises the following steps: obtaining harmonic impedance data; performing feature extraction on the harmonic impedance data to generate a multi-dimensional feature matrix; outputting harmonic impedance characteristics after dimension reduction; calculating the Euclidean distance between the buses based on the harmonic impedance characteristics after dimension reduction, and constructing a harmonic impedance difference edge weight matrix; combining the power grid topology adjacency matrix and the harmonic impedance difference edge weight matrix, and utilizing a Leiden community division algorithm to carry out clustering partition; and outputting the partition label of each bus to form a power grid harmonic impedance partition result. According to the power system harmonic impedance partitioning method based on the Leiden community partitioning algorithm, a power grid is divided into a plurality of regions with similar dynamic characteristics according to impedance similarity, basic data support is provided for grid-side impedance regulation and oscillation risk management, and cross-band dynamic stability analysis and regional collaborative management are achieved.

This invention proposes a method for determining the impact of harmonic source types on monitoring points in power grids, belonging to the field of harmonic source tracing technology in power systems. The method involves acquiring various harmonic source currents and constructing harmonic source feature vectors; acquiring harmonic data for a specified time period T at monitoring point M, setting n sampling points, and constructing a normalized vector for each sampling point; multiplying the normalized vector of each sampling point with the feature vector of each harmonic source to determine the dominant harmonic source type for each sampling point; statistically analyzing the number of sources to determine the main harmonic sources at each monitoring point; if the number of sources is equal, it is determined that multiple sources are jointly affecting the source. This solution aims to solve the problems of difficult unified processing of harmonic sources and difficulty in extracting effective information from massive amounts of data, achieving accurate attribution determination.

The present application relates to a kind of wide frequency power grid harmonic fast extraction method based on multiscale collaborative measurement, belong to the field of power system harmonic analysis, including: construct multi-window parallel data buffer, utilize smooth transition function dynamically calculate the confidence weight of each window;Adopt adaptive window function strategy to load rectangular window and Blackman window respectively, and preliminary obtain full-band spectrum parameter in combination with zero padding FFT, introduce phase alignment algorithm based on time zero point to eliminate the phase drift caused by non-synchronous sampling;For random interference, use stability filtering mechanism to carry out effectiveness check.The present application realizes the unity of wide frequency harmonic transient fast locking and steady-state high-precision measurement by organically combining multi-window parallel processing with S-shaped smooth transition mechanism, significantly improves the dynamic adaptability and anti-noise reliability of measurement, and provides reliable technical foundation for new type power system wide frequency oscillation monitoring and control.

The application discloses a ship shaft generator system and battery coordination harmonic suppression method and system, and belongs to the technical field of ship power system harmonic suppression; the method comprises the following steps: synchronously collecting three-phase current signals of the shaft generator system and charging and discharging current signals of the battery system, and generating a harmonic characteristic data set; extracting a harmonic phase offset characteristic vector between the shaft generator system and the battery system based on the data set; determining the harmonic phase reversal direction that needs to be compensated by the battery system according to the offset characteristic vector; generating a phase reversal compensation logic matrix based on the harmonic phase reversal direction; generating a dynamic harmonic compensation instruction for driving the battery system according to the matrix; and executing the instruction through a bidirectional converter, so that the battery system outputs an active compensation current opposite to the harmonic phase of the shaft generator system. The system comprises corresponding function modules. The application can track the dynamic drift of the harmonic phase caused by the ship swing in real time, adaptively generate an optimal compensation strategy, and significantly improve the harmonic suppression efficiency and the power grid stability.

The application discloses a harmonic signal processing method and device and electronic equipment, and relates to the technical field of power system harmonic monitoring. The method comprises the following steps: obtaining a harmonic signal generated in a power system, and initializing parameters of an original search algorithm according to the harmonic signal to obtain a target search algorithm; performing initial estimation on the amplitude and phase of the harmonic signal to obtain an initial estimated value of the harmonic signal, and obtaining an actual amplitude and an actual phase value of the harmonic signal to obtain an actual value of the harmonic signal; calculating the error between the initial estimated value of the harmonic signal and the actual value of the harmonic signal, and determining the fitness function of the target search algorithm according to the error between the initial estimated value and the actual value; and performing iterative calculation on the initial estimated value of the harmonic signal based on the fitness function to obtain a final estimated value of the harmonic signal. Through the application, the problem that the effect of estimating the amplitude and phase of the harmonic signal generated in the power system is poor in the related art is solved.

The invention relates to a harmonic and inter-harmonic time domain detection method in a noise environment, and belongs to the technical field of power system harmonic measurement. The method comprises the following steps of: firstly, acquiring a harmonic sampling signal of a power system, performing variational mode decomposition on the acquired signal, and performing parameter optimization by adopting an optimization algorithm according to the number of modes and a penalty factor of variational mode decomposition; then, according to the correlation coefficient of each modal component and an original signal, selecting a proper modal component to carry out signal reconstruction, and carrying out parameter identification on the reconstructed signal by adopting a Prony algorithm to obtain information such as amplitude and frequency of each modal component. The detection method provided by the invention has good noise immunity, and can obtain the time domain information of the collected signal under the condition of strong noise.

The application discloses a kind of wide dynamic range signal measurement error calibration method and system, the present application includes on harmonic signal measurement experimental platform for specified harmonic different amplitude, different temperature is tested multiple times and the amplitude data of harmonic signal measurement device output is collected;Nonlinear parametrization function about amplitude correction parameter vector L is constructed and fitting error function;Combining the amplitude data collected and nonlinear parametrization function and fitting error function, amplitude correction parameter vector L is iteratively solved based on gradient descent method and substituted into nonlinear parametrization function to obtain temperature correction function, whether continue to iteratively solve amplitude correction parameter vector L according to the correction result of temperature correction function is judged.The present application aims to solve the error problem influenced by temperature change in power system harmonic signal measurement, and improve the accuracy and reliability of harmonic signal measurement in power system by effective error correction.

The invention relates to a broadband power grid harmonic rapid extraction method based on multi-scale cooperative measurement, and belongs to the field of power system harmonic analysis, and the method comprises the steps: constructing a multi-window parallel data buffer, and dynamically calculating the confidence coefficient weight of each window through a smooth transition function; respectively loading a rectangular window and a Blackman window by adopting a self-adaptive window function strategy, preliminarily acquiring full-band spectrum parameters by combining zero-padding FFT (Fast Fourier Transform), and introducing a phase alignment algorithm based on a time zero point to eliminate phase drift caused by asynchronous sampling; for random interference, a stability filtering mechanism is adopted to carry out validity verification. According to the method, multi-window parallel processing and an S-shaped smooth transition mechanism are organically combined, so that the unification of broadband harmonic transient fast locking and steady-state high-precision metering is realized, the dynamic adaptability and anti-noise reliability of measurement are remarkably improved, and a reliable technical basis is provided for broadband oscillation monitoring and control of a novel power system.

The application discloses a harmonic suppression method based on frequency adaptive resonance control and belongs to the field of power system harmonic suppression. In view of the problem that SVG under a traditional control strategy is difficult to effectively suppress harmonics, a resonance control strategy is designed based on an internal model theorem and is applied to a voltage control link of SVG. Meanwhile, in order to adapt to the uncertainty of harmonic frequency, a recursive least square method is introduced to identify the harmonic frequency, the resonance control parameter is dynamically adjusted, and the harmonic compensation bandwidth of the SVG device is widened. The simulation result shows that the suppression method provided by the application is simple in operation, can effectively eliminate the (intermediate) harmonic of the offshore wind power system without additionally adding electrical primary equipment, and has strong robustness and adaptability.

The invention relates to a power equipment technology, in particular to a transformer harmonic transfer characteristic analysis method and device based on phase sequence component decomposition, and the method comprises the steps: proposing a three-sequence equivalent model of a YNd11 three-phase double-winding transformer based on a classic T-type equivalent circuit of the transformer; according to an impedance star-delta transformation formula, equivalently obtaining a three-sequence equivalent model of the YNd11 three-phase double-winding transformer subjected to star-delta transformation by using the proposed three-sequence equivalent model, and then displacing the parallel branch to obtain a three-sequence equivalent model of the YNd11 transformer subjected to parallel branch equivalence; according to the equivalent YNd11 transformer three-sequence equivalent model after parallel branch displacement, a harmonic transfer relation under a sequence component is deduced; and deriving the harmonic transfer relationship under the phase component based on the harmonic transfer relationship under the sequence component. The method provides a theoretical basis for researching on-line harmonic monitoring, harmonic state estimation, harmonic responsibility division and harmonic pollution control of a power system.

The invention relates to the technical field of harmonic detection of a power system, in particular to a harmonic detection method combining dynamic window function optimization, fast Fourier transform (FFT), fractional Fourier transform (FRFT) and least square parameter correction, and is suitable for real-time monitoring and analysis of unsteady-state power signals. The method is especially suitable for inter-harmonic, sub-harmonic and frequency fluctuation problems in complex scenes such as new energy grid connection and industrial frequency conversion equipment. Through a hybrid algorithm, dynamic window optimization and a dual-core hardware architecture, the contradiction of a traditional method in precision, real-time performance and adaptability is solved, and the method is suitable for harmonic monitoring and treatment of an intelligent power grid, an industrial production line and a new energy system and has remarkable technical advancement and market application potential.

A filter impedance optimization method and apparatus based on harmonic current source control, and a device, relating to the technical field of power system harmonic control. The method comprises: acquiring first harmonic impedance imaginary part component data and electrical quantity parameters; on the basis of the electrical quantity parameters, calculating the maximum parallel impedance when a power alternating-current system and an alternating-current filter are connected in parallel; calculating second harmonic impedance imaginary part component data on the basis of the first harmonic impedance imaginary part component data and the maximum parallel impedance; and calculating filter impedance on the basis of imaginary part component data of system harmonic impedance and the second harmonic impedance imaginary part component data at a tuning point of the alternating-current filter. According to the method, the second harmonic impedance imaginary part component data is obtained by combining the maximum parallel impedance and the first harmonic impedance imaginary part component data, so as to determine a filter impedance range, thereby avoiding repeated trial calculation of the alternating-current filter and reducing the workload. The optimized impedance of the alternating-current filter is determined by calculating the filter impedance, and the optimal design of the alternating-current filter is realized on the basis of the filter impedance.

The application discloses an active damping virtual resistance adaptive method and system based on a linear assumption, and the method comprises the following steps: in the current iteration period, the harmonic voltage measured value at the common connection point of the active damping device is acquired, the absolute error between the harmonic voltage measured value and the harmonic voltage target value is calculated, if the error amount is less than or equal to the error threshold, it is determined that the system has converged, and the final setting value is output; if the error amount is greater than the error threshold, it is determined that the system has not converged, a theoretical straight line is formed by the connecting line of the coordinate origin and the current working point, based on the linear relationship corresponding to the straight line, the next iteration virtual resistance value that makes the harmonic voltage close to the target value is calculated through the variable step adjustment strategy, and the next iteration period is entered, and iteration is continuously carried out until the system converges; the application has the advantages that the application does not depend on the power grid impedance model, has the online adaptive capacity, can be quickly and accurately set, and effectively suppresses the power system harmonic resonance.

The present invention relates to the technical field of harmonic power metering, and specifically discloses a harmonic power metering control system based on artificial intelligence, including a harmonic data acquisition module, a harmonic data preprocessing module, a harmonic power data analysis module, a harmonic data error analysis module, a harmonic power comprehensive analysis module, a metering error evaluation module, and a management and warning module; by collecting harmonic data from the power grid and preprocessing it, the present invention analyzes and obtains harmonic voltage error indicators, harmonic current error indicators, and harmonic active power error indicators, and further analyzes and obtains a harmonic power metering error evaluation index. By introducing artificial intelligence technology, it realizes the precise detection and real-time error metering analysis of power system harmonics, evaluates the power metering error, controls the power metering error, improves the accuracy and reliability of power metering, and ensures the safe and stable operation of the power grid.

The invention discloses a power system harmonic detection method, system and device, a medium and a product, and relates to power harmonic detection, and the method comprises the steps: obtaining a power signal of a to-be-detected power system; constructing at least one sample patch, performing proximity search on the harmonic signal according to each sample patch to obtain a position set of similar blocks, and determining a data matrix of the blocks according to the position set; constructing a reduced-rank matrix and a Gaussian noise matrix based on the data matrix, and establishing an optimization function for solving the reduced-rank matrix; solving the optimization function to obtain a low-rank data matrix; according to the power signal, the under-sampling Fourier transform function and the low-rank data matrix, constructing an objective function for compressed sensing recovery of the harmonic signal; and carrying out iterative solution on the harmonic signal of the target function and the minimum low-rank data matrix to obtain a harmonic detection result of the to-be-detected power system. According to the invention, the problem of insufficient detection efficiency during harmonic signal detection by the existing compressed sensing technology is solved.

The application discloses a power harmonic and interharmonic analysis and detection method based on parameter optimization MSST and HT, and belongs to the technical field of power system harmonic detection. The application comprises the following steps: collecting original power signals and performing multiple synchronous compression transformation with different iteration numbers; calculating time-frequency entropy under different iteration numbers, and determining the optimal iteration number according to the change of the time-frequency entropy; performing multiple synchronous compression transformation and mode decomposition on the signals by using the optimal iteration number, and obtaining a series of inherent mode function components; and performing Hilbert transformation on each component, and extracting instantaneous frequency and instantaneous amplitude. The application realizes adaptive optimization of the iteration number of MSST by introducing information entropy as an evaluation index, solves the problem that the iteration number needs to be set according to experience in the traditional method, reduces the calculation cost while ensuring the time-frequency energy concentration degree, and improves the harmonic detection precision.

The application discloses a kind of power system harmonic impedance frequency characteristic measurement method, device, equipment and medium, for solving the technical problems of low efficiency, processing delay and simulation real-time insufficient of harmonic impedance measurement.It includes: when receiving the sweep starting instruction sent by user, generate the disturbance current signal of multiple frequency points using preset sweep parameter;The disturbance current signal is injected into the injection node of the electromagnetic transient simulation model of power system, and with preset simulation time step as sampling interval, the voltage time domain data of injection node and the current time domain data formed by disturbance current signal are continuously collected;The voltage time domain data is subjected to fast fourier transform, and the voltage complex spectrum is obtained, and the current time domain data is subjected to fast fourier transform, and the current complex spectrum is obtained;The equivalent impedance of multiple frequency points is calculated using voltage complex spectrum and current complex spectrum;Harmonic impedance frequency characteristic curve is generated using the equivalent impedance of multiple frequency points.

The invention discloses a coupled harmonic source positioning method and system based on SSA-VMD and a Spearman correlation coefficient, relates to the technical field of harmonic analysis and control of a power system, and solves the problems that it is difficult to construct an improved 0-1 planning algorithm and a double constraint design, and it is also difficult to construct a coupling harmonic source through an SSA-VMD optimal decomposition model in combination with a dynamic search space adjustment and double-index screening mechanism. And the technical problem of current signal reconstruction is solved. Comprising the following steps: firstly, optimizing PMU configuration through an improved 0-1 planning algorithm; constructing an optimal decomposition model, and screening effective modal components in combination with permutation entropy and symbol transfer entropy; then, extracting a harmonic current sequence of a matched frequency through fast Fourier transform, and introducing a time weight coefficient to construct an improved Spearman correlation coefficient to calculate the correlation between harmonic voltage and current; and finally, determining the position of the coupled harmonic source by combining the correlation sorting, the node load type, the historical harmonic data and the topology importance.

Signal processing methods based on compressed sensing (CS) theory, intended to solve storage space and communication limitations in a Nyquist sampling framework, have attracted increased attention in recent years. In conventional harmonic detection, sparse bases are typically represented by a discrete Fourier transform (DFT) matrix. Harmonic non-synchronous sampling inevitably leads to spectral leakage and fence effect. To address this issue, we present an improved CS model for harmonic detection in power systems. A windowing technique is introduced in the compression sampling process. The fixed-point continuation algorithm combined with interpolation technique is used to directly extract harmonic parameters from the sparse coefficients without reconstructing the original signal. The proposed harmonic detection method, using an improved CS model, can achieve an accuracy comparable to that of the windowed interpolation FFT algorithm.