87 results about "Harmonic impedance" patented technology

The invention relates to the technical field of vehicle charging station operation and maintenance management, and particularly discloses a new energy vehicle charging station operation and maintenance management system and method based on the Internet of Things, and the method comprises the steps: collecting high-frequency harmonic characteristic data in a charging process in real time, and generating harmonic-impedance spectrum combined monitoring data; extracting dynamic attenuation gradient data of the line characteristic impedance; when the dynamic attenuation gradient data is lower than a preset critical safety threshold value, triggering a charging mode switching instruction; the charging piles are controlled to be switched into a charging mode, the phase difference parameters of the multiple charging piles are dynamically optimized, and a phase difference dynamic adjustment instruction set is generated; and finally, self-adaptive correction of the impedance compensation amount is carried out through the MEC equipment, and by self-adaptive correction of the impedance compensation amount, the system can maintain that the overall impedance is constantly greater than a critical safety threshold value, and power loss and equipment damage caused by impedance mismatch are avoided. The real-time feedback mechanism is helpful for improving the energy efficiency of the system, reducing the operation cost and ensuring the long-term reliability of the charging infrastructure.

The invention discloses a reclosing coordination control method and system based on electrical parameter measurement, particularly relates to the technical field of intelligent power grid fault processing and security defense, and is used for solving the problem that the reliability of fault judgment is reduced due to the fact that high-proportion distributed photovoltaic is connected to a power distribution network. A harmonic detection signal is injected during a reclosing waiting period, a response signal is measured, harmonic subspace energy distribution is extracted, an energy distribution matrix is constructed to calculate a nuclear norm change rate and form similarity, a system harmonic impedance stable state is judged through double verification, and finally a reclosing decision is executed according to a fault judgment parameter. The method can accurately identify the convergence characteristic of the dynamic process of the system, effectively distinguish the instantaneous fault from the permanent fault, and significantly improve the reclosing success rate and the power supply reliability of the distributed photovoltaic power distribution network.

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 provides a broadband high-efficiency filtering power amplifier and an output matching network design method thereof, and belongs to the technical field of wireless communication. The broadband high-efficiency filtering power amplifier comprises a power amplifier main body and an output matching network connected with the output end of the power amplifier main body; the output matching network structure is based on a three-mode transverse coupling filter; the output matching network comprises a plurality of transmission lines which are directly connected to form a first sub-network, a second sub-network, a third sub-network and a fourth sub-network; the structures of the first and second sub-networks are configured to be equivalent to a [lambda] / 4 transmission line having a harmonic impedance control function. Fundamental wave matching, harmonic control and filtering functions are integrated by adopting an output matching network structure: fundamental wave matching with a steep edge is realized by utilizing a three-mode transverse resonator, secondary harmonic impedance is controlled to a high-efficiency area by adopting an equivalent T-shaped lambda / 4 line, and while wide-bandwidth work is realized, the harmonic control and filtering functions are realized. And high efficiency and excellent harmonic suppression capability are realized.

The invention discloses a novel power grid harmonic compensation method and system based on harmonic responsibility division, and relates to the technical field of power grid harmonic compensation, and the method comprises the steps: collecting voltage and current signals at a common connection point of a power grid, and extracting each harmonic component from the voltage and current signals; based on each harmonic component, identifying harmonic impedance of a system side and a user side, and calculating a responsibility factor sequence corresponding to each harmonic; performing statistical analysis on the responsibility factor sequence in a preset time window to generate responsibility fluctuation entropy representing responsibility stability; dynamically correcting the compensation priority of each harmonic according to the responsibility factor and the responsibility fluctuation entropy corresponding to the responsibility factor; generating a harmonic compensation instruction of a non-user responsibility part according to the responsibility factor and the harmonic component after priority correction, and distributing available compensation capacity according to the priority when the capacity of a compensation device is limited; the method is applied to a system comprising a plurality of distributed power supplies with harmonic regulation and control capability.

The invention discloses a distributed photovoltaic power quality treatment method, system and device for multi-access point collaborative optimization and a storage medium, and relates to the field of distributed photovoltaic grid connection, and the method comprises the steps: carrying out the hierarchical division of a power distribution network, constructing a hierarchical collaborative management architecture, and implementing collaborative voltage support; photovoltaic output fluctuation and load demand data are combined to generate optimized topology and configure virtual impedance; in combination with the scene data, constructing and decomposing a multi-objective optimization model to obtain a reactive power distribution scheme; combining harmonic voltage and current data of each node to construct a harmonic impedance matrix to suppress harmonic waves; according to the invention, the voltage deviation can be controlled in a better range, and voltage shock is inhibited. The network loss is obviously reduced, and the economy is improved. The harmonic distortion rate is efficiently reduced, and interference is reduced. Parameters dynamically change along with scenes, the strategy switching success rate is improved, scene adaptability is enhanced, and powerful support is provided for safe, stable and economical operation of the power distribution network.

The invention discloses a box-type substation measurement and control system and method with a filter capacitor, and relates to the field of power monitoring. The objective of the invention is to solve the problems of poor filtering adaptability, single state monitoring dimension, high protection logic misjudgment rate, low service life prediction precision and low remote operation and maintenance efficiency in the prior art. The system comprises a self-adaptive filtering module, a multi-dimensional measurement and control module, an intelligent central control module, a hierarchical protection module, a dual-mode communication module and a local interaction module. According to the method, through multi-dimensional parameter acquisition, dynamic harmonic impedance matching and switching instruction generation, multi-sensor double-layer fusion diagnosis, multi-physics field aging prediction, three-level protection execution, data uploading and local interaction, organic fusion of dynamic harmonic treatment, multi-dimensional state perception, edge intelligent diagnosis and mechanism driving prediction is realized. The method is high in filtering adaptive capacity, comprehensive in monitoring, reliable in protection and efficient in operation and maintenance, the fault positioning precision reaches the branch level, conversion from passive response to active adaptation and early intervention can be achieved, and the method is suitable for a modern power distribution net box type transformer substation containing a distributed power supply.

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 embodiment of the application provides a power amplifier circuit, a radio frequency front end module and a communication device, relates to the technical field of electronics, and is used for improving the saturation power and saturation efficiency of the power amplifier circuit. The power amplifier circuit adopts an impedance matching network architecture of series connection of a capacitor and an inductor in at least one branch (which can be a main power amplifier branch or a peak power amplifier branch). Under the architecture, the fundamental wave impedance and the harmonic impedance of the branch are both adjusted by the series connection capacitor and inductor network. However, since the capacitance of the capacitor and / or the inductance of the inductor can be changed, the fundamental wave impedance is fixed, and the second harmonic impedance is changed. That is, when the second harmonic impedance is adjusted in a wideband range, the fundamental wave impedance can not be affected. Based on this, by reasonably selecting the capacitance of the capacitor or the inductance of the inductor, the fundamental wave impedance and the second harmonic impedance in the branch can meet the requirements respectively, so that the power amplifier circuit has relatively optimal saturation power and saturation efficiency.

This invention discloses a power system equivalent harmonic impedance identification strategy based on physical consistency constraints, comprising the following steps: First, voltage and current data at the common coupling point in the power system are collected, frequency domain analysis is performed on the data to obtain harmonic components, and the harmonic components are normalized and feature-processed to form a feature dataset for model training; then, a multilayer feedforward neural network (MLP) data-driven module and a physical information neural network (PINN) physical constraint module are designed, and a self-attention temporal convolution feature module is fused to construct a multilayer feedforward-attention physical information neural network (MLP-APINN) model; finally, the model is trained using a first-order gradient parameter iteration method, and the model parameters are updated using a learning rate adjustment strategy to obtain the identification result of the system-side equivalent harmonic impedance; this invention improves the stability and generalization performance of harmonic impedance identification by introducing physical consistency constraints, and is applicable to harmonic impedance identification at the common coupling point in the power system.

The invention relates to the technical field of power system protection, and discloses a direct-current line bipolar short-circuit fault protection method based on harmonic impedance, which comprises the following steps: measuring a voltage waveform signal and a current waveform signal of a direct-current line protection position in real time; processing the voltage waveform signal and the current waveform signal by adopting short-time Fourier transform, and extracting a high-frequency voltage component and a high-frequency current component of a specific harmonic order; calculating a module value and a phase angle of the high-frequency voltage component and a module value and a phase angle of the high-frequency current component, and obtaining harmonic impedance through voltage division calculation; the fault position is determined according to the harmonic impedance change of each line before and after the fault occurs; the fault position is determined through the harmonic impedance change of each line before and after the fault occurs, and a rapid, reliable and economical protection scheme is provided for the bipolar short-circuit fault of the direct-current line.

The invention provides a power distribution network harmonic instability critical damping dynamic early warning method and system. The method comprises the steps that harmonic voltage and harmonic current of key nodes of a target power distribution network are acquired every first preset time; identifying the harmonic voltage and the harmonic current according to a first preset rule so as to obtain equivalent harmonic impedance under a preset harmonic frequency according to an identification result; calculating a system damping ratio corresponding to a preset harmonic frequency according to the equivalent harmonic impedance; judging whether the system damping ratio is smaller than or equal to a preset damping ratio threshold value; and if the system damping ratio is smaller than or equal to the preset damping ratio threshold value, generating a harmonic instability early warning signal. According to the invention, the accuracy and practicability of early warning can be effectively improved.

The invention discloses a converter frequency coupling impedance test and calculation method and system. The method comprises the following steps: selecting a disturbance source form according to the type of a to-be-tested converter, and constructing an impedance test circuit of a steady-state working point; a steady-state working point of the converter is simulated by adjusting parameters of a controlled source for the impedance test circuit, and a positive-sequence harmonic disturbance signal and a negative-sequence harmonic disturbance signal are injected in a superposed manner, so that a response signal is obtained; performing spectral analysis on the positive-sequence harmonic disturbance signal, the negative-sequence harmonic disturbance signal and the response signal, and calculating phasors and phase differences of power frequency and harmonic components; based on the phase difference, performing phase correction on a coupling component in the response signal to obtain a correction result; and calculating equivalent harmonic impedance by using a correction result, and outputting a frequency coupling matrix of the harmonic impedance of the converter in the full frequency band. By implementing the method provided by the invention, the impedance measurement requirements of various converters are met, so that the limitations of unclear initial phase, lack of physical concept of coupling impedance, difficulty in four-quadrant impedance measurement and calculation and the like in the traditional technology are overcome.

The invention discloses an island detection method and system based on a Goertzel algorithm and quality factor entropy dispersion. The method comprises the following steps: acquiring three-phase voltage and current signals of a distributed power generation system; performing double-domain leakage suppression processing on the signal to obtain an accurate fundamental wave parameter; carrying out heavy fundamental wave construction and harmonic signal separation on the accurate fundamental wave parameter to obtain a residual harmonic signal; a Goertzel algorithm is adopted to carry out directional spectrum analysis on specific harmonics in the residual harmonic signals, and the voltage amplitude and the current amplitude of the specific harmonics are obtained; calculating a harmonic impedance amplitude according to the voltage amplitude and the current amplitude of the specific harmonic, and obtaining a quality factor entropy dispersion corresponding to the specific harmonic based on the harmonic impedance amplitude; and carrying out island detection according to the quality factor entropy dispersion corresponding to the specific harmonic wave to obtain a detection result. The load quality factor distribution consistency is quantified by using the information entropy theory, the detection blind area can be reduced, and the detection efficiency and accuracy are 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 discloses an ultrawide, high-efficiency inverse Class-F power amplifier based on an elliptic low-pass filter matching network. The gate DC bias network provides the gate bias voltage required for the power amplifier transistor to operate; the drain DC bias network provides the drain bias voltage required for the power amplifier transistor to operate; the input impedance matching network includes a microstrip line, a DC blocking capacitor, and an RC parallel circuit; the output impedance matching network includes a harmonic control network and an elliptic low-pass filter matching network. The harmonic control network selects two frequency points outside the passband for second harmonic control; the elliptic low-pass filter matching network is based on an improved sixth-order Chebyshev low-pass filter, generating two transmission zeros outside the operating frequency band to achieve the conversion from fundamental impedance to second harmonic impedance. This invention enables the power amplifier to achieve high efficiency and high gain within a bandwidth exceeding five harmonics.

The invention provides a method and a device for diagnosing abnormality of harmonic voltage measured values of high, medium and low voltage sides of a transformer, which can verify and identify the accuracy of phase measurement of the harmonic voltage at the three sides by using the phase and sequence characteristics of the harmonic voltage at the high, medium and low voltage sides of the transformer and the connection group data of the transformer. Furthermore, in combination with the three-side harmonic voltage and current phasors and the winding harmonic impedance reduced to the high-voltage side, on the basis of a transformer equivalent circuit model, the same-order harmonic sequence voltage theoretical values of the other two sides can be calculated by taking the harmonic sequence voltage passing verification on one side as the reference, and the theoretical values are compared with the actually measured values, so that the theoretical values of the same-order harmonic sequence voltage are obtained. And effective identification of three-side harmonic voltage amplitude measurement accuracy is realized. According to the method, the accuracy of the phase and amplitude data can be reliably discriminated even in a scene in which the multi-side measurement is possible to be abnormal, so that a solid and credible data basis is provided for subsequent harmonic traceability analysis and precise treatment measures.

The application discloses a small-size high-efficiency wideband class-F amplifier based on harmonic stretching, and solves the problem that the existing class-F amplifier is difficult to realize second harmonic impedance short circuit and third harmonic impedance open circuit at the current source end face in a wideband range. DS , a power amplifier tube V GS , a first microstrip TL1, a second microstrip TL2, one end of the first microstrip TL1 and one end of the second microstrip TL2 being connected to a first node A, the other end of the second microstrip TL2 being connected to a second node B, the other end of the first microstrip TL1 and the drain of the power amplifier tube V GS being connected to a third node C; the power supply V DS is connected to the second node B; and the first microstrip TL1 and / or the second microstrip TL2 is a variable cross-section microstrip.

The application discloses a wide-frequency monitoring method and system based on equivalent DC impedance of a converter, and aims at the defects of the existing monitoring technology based on positive sequence harmonic impedance, such as unresolvable parameters, incapability of covering negative sequence and coupled impedance, and high false alarm and missed alarm rates. The monitoring is realized through the following steps: collecting DC element voltage of a grid-connected converter DC side, rectification side DC current and inversion side DC current signals; performing harmonic decomposition on the signals and extracting the main harmonic component with the largest amplitude; calculating the real part of the equivalent DC impedance of the rectification side and the inversion side; comparing the impedance real part with a set threshold value, and judging whether wide-frequency oscillation occurs in the system.

The invention discloses a network construction type high-precision active power filter control method, an active power filter comprises a power outer loop control unit and a voltage and current inner loop control unit, and the power outer loop control unit comprises an active power outer loop and a reactive power outer loop. The voltage and current inner loop control unit comprises an AC voltage loop and an AC current loop, and the control method provides a control loop architecture for three-phase three-wire and three-phase four-wire high-precision active power filters, and comprises two-phase DQ closed-loop control and three-phase independent closed-loop control of grid-side harmonic current; through a mode of generating a harmonic voltage instruction through a harmonic current closed loop, the impedance of a harmonic current frequency band is remodeled while high-precision compensation of the harmonic current is realized; high-precision compensation of harmonic current is realized through a network construction control technology; while high-precision compensation is realized, port harmonic impedance is remodeled, so that the adaptability of a load and a power grid is higher.

The invention relates to a harmonic impedance value determination method and device and computer equipment. The method comprises the steps that the voltage fluctuation quantity of harmonic voltage of a common connection point between a power system side and a power utilization side and the current fluctuation quantity of harmonic current of the common connection point are acquired; determining a covariance function between the voltage fluctuation quantity of the harmonic voltage at the power system side and the voltage fluctuation quantity of the harmonic voltage at the power utilization side; constructing a covariance equation according to the established equivalent circuit model, the covariance function, the voltage fluctuation quantity of the harmonic voltage of the common connection point and the current fluctuation quantity of the harmonic current of the common connection point; and solving the covariance equation to obtain the harmonic impedance value of the power system side and the harmonic impedance value of the power utilization side. By adopting the method, the accuracy of the determined harmonic impedance value of the power system side and the harmonic impedance value of the power utilization side can be improved.

This invention provides a method and apparatus for selecting the location of an active harmonic mitigation device for radial distribution networks, belonging to the field of power quality management technology. The method includes: acquiring equipment parameters of each branch of the distribution network; determining the harmonic impedance of each branch based on the equipment parameters, and calculating the influence coefficient of each nonlinear load branch's harmonics on the distribution network's harmonic voltage; calculating the contribution rate of each nonlinear load branch's harmonics to the voltage distortion of the distribution network based on the influence coefficients of all nonlinear load branches; determining the numerical distribution characteristics of the voltage distortion contribution rate corresponding to all nonlinear load branches based on the coefficient of variation and a threshold; and determining the optimal location of the active harmonic mitigation device based on the numerical distribution characteristics, the expected minimum target for harmonic mitigation, and the voltage distortion contribution rate corresponding to each nonlinear load branch. This invention can solve the problem of difficult location selection for harmonic mitigation devices in radial distribution networks where harmonic sources are dispersed.

The application discloses an interface reaction kinetics parameter analysis method based on electrochemical impedance spectroscopy, and relates to the technical fields of electrochemical testing and data processing, and comprises the following steps: applying an alternating current signal with gradually increased amplitude to a to-be-tested interface, and extracting a fundamental frequency impedance vector and a harmonic impedance vector; performing anti-convolution calculation on the fundamental frequency impedance vector and the harmonic impedance vector respectively by using preset standard penalty weights, obtaining a fundamental frequency relaxation vector and a harmonic relaxation vector, and dividing the amplitudes of the two vectors by a node to obtain a response ratio; identifying an aliasing peak interval with an information entropy greater than an entropy value determination threshold in the fundamental frequency relaxation vector, wherein the aliasing peak interval contains an aliasing peak, and the aliasing peak only overlaps with an extreme value point of the response ratio; and the method has the beneficial effect that the evaluation error caused by improper selection of a human prior model is reduced, and the reliability of interface kinetics parameter analysis is ensured.

The invention discloses a distributed active filtering system improved by adopting a filtering algorithm, which relates to the technical field of edge computing, and comprises the following steps: acquiring harmonic impedance information of an access point to cooperatively generate a real-time harmonic impedance distribution diagram reflecting the harmonic voltage sensitivity of the whole network; constructing a local revenue function of each node according to the harmonic impedance distribution diagram and the local state information; on the basis of the revenue function, limited information interaction and iterative gaming are carried out between adjacent nodes; and executing an optimal compensation strategy determined by the game, and performing feedback correction on the harmonic impedance distribution diagram. According to the method, the real-time harmonic impedance distribution diagram is generated cooperatively, so that each node has global perception capability; a comprehensive optimal decision is realized by constructing a multi-target revenue function fusing a local effect, a capacity utilization rate and a system contribution degree; and online correction is carried out on the model through actual effect feedback, the adaptability of long-term operation is ensured, and the contradiction between local optimization and a global target is fundamentally solved.

The invention discloses a harmonic suppression method for impedance remodeling of a wide-range networking converter, the networking converter and a medium, and the method comprises the steps: collecting a voltage signal and an output current signal of a grid-connected point of the converter, separating a fundamental wave component and a harmonic wave component of the converter, and utilizing a harmonic wave voltage component, a harmonic wave current component, power grid harmonic wave impedance information and a harmonic wave impedance value in [0, 0]; synthesizing a harmonic voltage reference instruction according to a continuously adjustable single impedance adjustment coefficient in an interval 1]; and after the instruction is superposed with a fundamental wave voltage reference instruction, a converter switching device is controlled. By adjusting the coefficient, the equivalent harmonic impedance of the converter can be continuously and smoothly remolded, so that flexible and continuous regulation and control from complete suppression of the harmonic voltage of the grid-connected point to complete blocking of the harmonic current injected into the power grid are realized on the premise of not switching the control structure and not influencing the fundamental wave performance; the problems that voltage quality and current quality are difficult to consider and adjustment is not flexible in a traditional method are effectively solved.

This invention discloses a parameter design method and apparatus for an impedance correction device in a DC transmission system. The method includes: obtaining the voltage and harmonic parameters of the AC system based on the constructed target DC transmission system topology, and designing an amplitude-phase corrector parameter optimization model; obtaining the impedance characteristics of the AC and DC systems under different operating modes; simulating the component stress of the amplitude-phase corrector under corresponding fluctuation states using the amplitude-phase corrector parameter optimization model in response to the impedance characteristics; determining the parameters of the amplitude-phase corrector based on the voltage fluctuation rate of the AC system and the operating power range of the DC system in the corrector configuration stage, and optimizing the parameters based on the component stress to configure the amplitude-phase corrector; repeating the corrector configuration stage after configuring the amplitude-phase corrector until the equivalent harmonic impedance of the DC transmission system meets the preset system oscillation index. This method can effectively reduce harmonic oscillations in the DC transmission system by optimizing the parameters of the amplitude-phase corrector.

The present application relates to the technical field of electric variable detection, and in particular to a kind of active distribution network harmonic source positioning method and system, method includes: determining the probability characteristics of each substation in the current monitoring time period, in combination with the harmonic impedance attenuation characteristics of each substation, total harmonic current increment of substation is divided, the dynamic responsibility current distribution of each substation is obtained, in combination with historical harmonic responsibility index stock, obtain the latest harmonic responsibility index stock of each substation in the current monitoring time period, thereby screening substation, and the latest harmonic responsibility index stock and fundamental current effective value of target substation are fused, to obtain the electric-thermal comprehensive characteristic load of target substation, and then obtain the transformer insulation deterioration risk index of target substation, finally by transformer insulation deterioration risk index, the accurate positioning of distribution network harmonic source is realized, and the operation safety and operation efficiency of distribution network are significantly improved.

The invention relates to an isolation driving circuit and method for bidirectional signal power composite isolation transmission, and the circuit comprises an inversion unit, an isolation transformer, a rectification unit and an output unit which are connected in sequence, and a primary harmonic impedance regulation and control unit is arranged between the inversion unit and the isolation transformer. The primary side harmonic impedance regulation and control unit is connected with the main control unit through a primary side signal processing unit, a secondary side harmonic impedance regulation and control unit is arranged between the isolation transformer and the rectification unit, and the secondary side harmonic impedance regulation and control unit is respectively connected with the output unit and the power device through a secondary side signal processing unit. According to the circuit, different harmonic frequency components of voltages of a primary side detection end and a secondary side detection end are modulated through a primary side harmonic impedance regulation and control unit and a secondary side harmonic impedance regulation and control unit, so that a signal flow and a power flow are respectively transmitted under different frequencies, and a driving signal, a state monitoring signal and a power control signal are mutually independent in frequency; and high integration level and high control freedom degree of signal transmission are realized.

The application provides a distributed power balancing and voltage regulating method for a current control type converter cluster. The method belongs to the field of micro-grid control, and is based on reactive voltage droop and voltage amplitude control to generate a reference current amplitude of the parallel converter, so that each parallel converter outputs the same current amplitude; meanwhile, the phase of the current vector is determined by four-quadrant power factor control, so as to ensure that the output currents among the parallel converters are in the same phase state, and the load side currents are effectively superimposed and the maximum load current is obtained. In view of the harmonic problem caused by the access of a nonlinear load, the application further adopts harmonic virtual impedance control at a fundamental frequency and selected harmonic frequencies, and combines with the multi-resonance controller adjustment of the current loop to effectively reduce the amplitude of the equivalent harmonic impedance of the DG unit, so that the harmonic circulating current among the DGs is minimized, and the power quality at the point of common coupling (PCC) is improved.

The application discloses an islanding prevention rapid judgment method and system based on edge computing and HPLC, and belongs to the technical field of power system protection. The system adopts a layered edge computing architecture, including a terminal layer, an edge layer and a cloud platform layer: the terminal layer collects voltage and current waveforms through an HPLC communication module and extracts parameters such as frequency deviation and harmonic impedance; the edge layer runs a lightweight AI model containing a sliding window FFT module and a fuzzy logic decision engine, and judges islanding in combination with frequency deviation, harmonic impedance and load mutation rate; and the cloud platform layer updates edge end model parameters through a federated learning algorithm. The method adopts a multi-criterion fusion decision algorithm and a lightweight model compression technology, greatly improves the response rate and accuracy of islanding detection, and significantly reduces the misjudgment rate.