394results about "Harmonic reduction arrangement" patented technology

The utility model relates to the field of resonance eliminators, and discloses a protection element and a current limiting type resonance eliminator, the protection element comprises at least two groups of protection units, the two adjacent groups of protection units are connected in series, and each protection unit comprises a protection module; the current-limiting resonance eliminator based on the current-sensitive resistor made of the current-sensitive material is connected in series between the PT neutral point and the ground. Under the normal operation condition, the current-limiting resonance eliminator is in a low-resistance state, and system parameters and PT performance are not affected; when excitation energy is generated due to a system fault, the current-limiting resonance eliminator suddenly changes into a high resistance state, quickly absorbs resonance energy, destroys resonance parameters, suppresses PT excitation current below 200mA, and ensures that a voltage transformer is unsaturated and a PT fuse is not fused; and a built-in current sensor is connected, so that the running state of the current-limiting resonance eliminator can be monitored in real time.

The invention discloses a specific grid-connected current harmonic suppression method and device for an energy storage converter, and belongs to the technical field of power systems, and the method comprises the steps: obtaining a given current value of a fundamental current loop, and carrying out the dq / abc conversion to obtain a three-phase current reference value; acquiring a three-phase current value of a power grid side, and subtracting the three-phase current value from the three-phase current reference value to obtain a harmonic current value; converting the harmonic current value to a target subharmonic synchronous rotating coordinate system to obtain a target subharmonic current value; extracting the target sub-harmonic current value in a direct current form through a low-pass filter, and sending the target sub-harmonic current value to a PI regulator for regulation to obtain a harmonic voltage compensation amount; and injecting the harmonic voltage compensation amount into a modulation wave to realize suppression of the target subharmonic current. According to the invention, the grid-connected side current harmonic of the energy storage converter can be effectively suppressed, and the grid-side current quality is improved.

The invention provides a multi-harmonic source and grid-connected equipment modeling method based on a dynamic harmonic environment. The multi-harmonic source and grid-connected equipment modeling method comprises the steps that S1, dynamic harmonic environment parameters, multi-harmonic source basic data and grid-connected equipment basic data are collected; s2, multi-harmonic-source independent modeling is carried out; s3, independently modeling the grid-connected equipment; and S4, modeling a multi-harmonic source and grid-connected equipment topological structure. According to the invention, through multi-step collaborative modeling and algorithm optimization, high-precision and adaptive modeling of multiple harmonic sources and grid-connected equipment in a dynamic harmonic environment is realized.

The invention discloses a dynamic sliding window filtering method and device, and a medium. The method comprises the following steps: calculating and updating a sliding window length given value in real time based on a currently collected power grid frequency; comparing the obtained sliding window length given value with the current sliding window length; if the sliding window length given value is equal to the current sliding window length, the current sliding window length is kept unchanged; if the sliding window length given value is larger than the current sliding window length, the sliding window length is gradually increased according to a set mode; if the sliding window length given value is smaller than the current sliding window length, the sliding window length is gradually shortened according to a set mode. The device and the medium are both used for implementing the method. The beneficial effects of the application are that compared with a traditional fixed sliding window length, the technical scheme of the application can adaptively adjust the sliding window length according to the change of the power grid frequency, so that the data acquisition accuracy of the sliding window can be improved, and effective elimination of ripples can be realized.

The invention provides a grid-side current harmonic suppression method and device for a motor driving system without an electrolytic capacitor. The method comprises the following steps: determining first and second bus voltage harmonics based on bus voltage obtained by sampling and inverter switching frequency; correcting the bus voltage according to the first bus voltage harmonic wave and the second bus voltage harmonic wave so as to determine a reconstructed bus voltage; according to the second bus voltage harmonic, the reconstructed bus voltage, an inverter output three-phase duty ratio and a motor three-phase current, first and second network side current harmonic regulation and control voltages are determined based on a self-defined closed-loop controller; and adopting a motor alpha-axis correction voltage and a motor beta-axis correction voltage determined according to the first and second grid-side current harmonic regulation and control voltages to participate in motor SVPWM modulation to output the three-phase duty ratio of an inverter so as to suppress grid-side input current harmonics. According to the method and the device, factors such as motor operation conditions, bus voltage harmonic waves and digital control delay are comprehensively considered, the quality of grid-side input electric energy is improved, and disturbance to machine-side rotating speed and torque is reduced.

The invention provides a primary resonance elimination device of a power distribution network voltage transformer and a management and control method, and relates to the technical field of voltage transformer resonance elimination. The primary resonance elimination device comprises a primary resonance elimination resistor, a primary resonance elimination power electronic device, a standby resonance elimination resistor and a standby resonance elimination power electronic device; the primary resonance elimination resistor and the primary resonance elimination power electronic device are connected in series and then are connected in series between a neutral point of the power distribution network voltage transformer and a ground wire; the standby resonance elimination resistor and the standby resonance elimination power electronic device are connected in series, one end of the standby resonance elimination resistor and the standby resonance elimination power electronic device which are connected in series is connected with a neutral point of the power distribution network voltage transformer, and the other end is grounded; the primary resonance elimination device further comprises a current transformer and a temperature sensor; the temperature sensor is used for monitoring the temperature values of the primary resonance elimination resistor and the standby resonance elimination resistor; the current transformer is assembled on a line where the primary resonance elimination resistor and the standby resonance elimination resistor are grounded together and used for monitoring the value of current flowing through the primary resonance elimination device.

The invention provides a network construction type bidirectional low-harmonic energy storage converter based on virtual synchronous control and an intelligent load identification method thereof, and belongs to the field of power electronics. The converter comprises a power module and a control module, wherein the power module is used for bidirectional conversion and output of electric energy; the control module comprises a virtual synchronous control module and a harmonic suppression control module, and the virtual synchronous control module adopts a virtual synchronous generator technology to realize active / reactive power bidirectional adjustment during electric energy bidirectional conversion of the power module and network construction level voltage and frequency support during electric energy output; and the harmonic suppression module is provided with a parallel QPR controller group (comprising a first QPR controller, a second QPR controller and a third QPR controller) which are used for processing third-time, fifth-time and seventh-time characteristic harmonics respectively and suppressing the characteristic harmonics of the electric energy output side of the power module. According to the invention, the dual modules are arranged in the control module, so that the cooperation of a network construction function and low harmonic output is realized, and the electric energy quality and the system operation stability are effectively improved.

The invention discloses a harmonic suppression and dynamic reactive compensation control method for an energy router, which is suitable for a micro-grid and a distributed energy access system. According to the method, three-phase current and voltage signals of an alternating current port of the energy router are collected, five-time and seven-time main harmonic components are extracted through fast Fourier transform, harmonic compensation current instructions equal in amplitude and opposite in phase are generated and injected into an inverter to be output, and active counteracting of main harmonics is achieved. Meanwhile, the bus voltage deviation and the change rate thereof are detected, a reactive current instruction is adjusted on line by adopting a fuzzy self-adaptive PI controller, rapid and smooth dynamic reactive compensation is realized, and the bus voltage is stabilized. Decoupling control of active / reactive and harmonic components is realized in combination with Park conversion, and virtual impedance is introduced to enhance system damping and harmonic suppression capabilities. Compared with the prior art, harmonic suppression and voltage support can be simultaneously realized under a single control framework, the response speed is high, the stability is high, and the method is suitable for high-performance grid-connected operation of the multi-port energy router.

The invention relates to the technical field of transformer intelligent optimization compensation, in particular to an electric energy quality compensation method and equipment for new energy access to a power grid, and the method comprises the steps: connecting a dynamic voltage compensation converter in series at the low-voltage side of a transformer, and connecting a high-power bidirectional converter in parallel at the load side of a terminal, acquiring the voltage of the low-voltage side of the transformer at each moment in each period, and recording the voltage as transformer voltage; acquiring load current and load voltage at each moment in each period of the load side of the terminal; determining the influence weight of harmonic disturbance, the influence weight of reactive power disturbance and the influence weight of voltage out-of-limit in each period; constructing a target function; and obtaining an optimal power factor, each harmonic current component and each transformer voltage in the current period by utilizing an intelligent optimization algorithm and combining the objective function, and respectively performing transformer voltage compensation, reactive compensation and harmonic current compensation on the current period. Therefore, the overall stability of electric energy quality is 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 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 provides a power distribution network resonance key element identification method and device based on harmonic monitoring data, and the method comprises the steps: collecting the harmonic voltage and branch harmonic current data of a key node through the deployment of an online harmonic monitoring device, converting a time domain signal to a frequency domain through band-pass filtering for a preset harmonic number set, and extracting a complex amplitude value, carrying out normalization processing to obtain standardized data; secondly, constructing a node admittance matrix in a frequency domain in combination with the newest power grid topology and equipment static parameters, identifying a feature root closest to zero and a corresponding resonant frequency thereof through eigenvalue decomposition, and obtaining a modal vector; tiny disturbance is applied to inductive reactance / capacitive reactance element parameters, and the sensitivity of the inductive reactance / capacitive reactance element parameters to modal admittance is calculated and normalized into dimensionless indexes; and screening and sorting according to the sensitivity threshold, and outputting a group of resonance key elements. The method does not need off-line simulation, has the advantages of high real-time performance, high engineering adaptability, low implementation cost and the like, and provides efficient technical support for active treatment of harmonic waves of the power distribution network.

The invention discloses a frequency-locked loop of a self-adaptive delay signal elimination filter, which comprises a first filter, a second filter, a Park transformation module, a low-pass filter, an amplitude normalization module, an inverse Park transformation module, a frequency estimation module and a low-pass filter, and is characterized in that the first filter is used for eliminating higher harmonics, the second filter is used for eliminating low-order single harmonics, and the amplitude normalization module is used for normalizing the amplitude of the inverse Park transformation module. A signal passing through the filter is converted into a direct current component under a dq coordinate system through the Park conversion module, high-frequency clutter is filtered out through the low-pass filter, then the signal enters the amplitude normalization module, the signal amplitude is standardized to be 1, the signal is recovered into an alternating current signal through the reverse Park conversion module, the alternating current signal is input into the frequency estimation module, and the frequency estimation module estimates the frequency of the signal. And finally, a stable power grid frequency estimation value is obtained after processing by a low-pass filter. The invention aims to eliminate rounding errors and introduce a novel prefilter with relatively small time delay, so that the dynamic and steady-state performance of the first-order frequency-locked loop is improved.

The invention discloses a partial discharge harmonic online early warning method for a cable branch box, and particularly relates to the technical field of electrical measurement and power equipment state monitoring. And a unified time base is difficult to obtain through multi-point monitoring, harmonic distortion is easy to be misjudged as discharge, and stable positioning is difficult in a topological constraint. Harmonic scene fingerprints are constructed under a unified time base, version locking is carried out, power frequency phases are re-calibrated according to the fingerprints, gating compensation is set in a non-whole frequency band domain, and joint matching is carried out by combining arrival time difference with energy attenuation under the constraint of a topological equivalent transmission matrix. And dual-threshold interlocking trigger early warning is carried out by combining the separation degree with topological consistency, so that partial discharge pulses can still be stably displayed under the change of a harmonic working condition, false alarm and caliber drift caused by harmonic waves are inhibited, reviewable positioning and executable graded early warning of branch and joint levels are realized, and the reliability of the system is improved. And the stability, comparability and implementability of field judgment are improved.

The invention relates to the technical field of energy storage systems, and discloses a harmonic suppression method and system of an energy storage converter. According to the method, harmonic disturbance generated during switching of the switching state is analyzed based on the voltage modulation instruction and the switching characteristic parameters, so that prospective prediction of voltage harmonics caused by switching action time sequence deviation is realized, and the problem of detection and control delay existing in a traditional method is solved; carrying out credibility evaluation on the obtained prediction information of the voltage harmonic wave based on the real-time current harmonic component and the voltage harmonic wave disturbance prediction quantity, and fusing the real-time current harmonic component and the voltage harmonic wave disturbance prediction quantity based on the result to generate a harmonic wave suppression target with a quick response characteristic and high precision; and a safety voltage control instruction capable of effectively suppressing a harmonic suppression target is obtained through a closed-loop iterative optimization mechanism, so that the inherent contradiction that the harmonic suppression effect and the safety constraint are difficult to consider at the same time is solved, and the comprehensive performance of harmonic suppression is improved.

The invention discloses a coal mine high-voltage switch harmonic interference elimination method and a filtering monitoring protection device, and relates to the field of electrical variable measurement, in the method, an analog signal of a high-voltage switch is collected through a mutual inductor and converted into a digital signal, a zero-sequence current abrupt change slope is calculated, an auxiliary contact state signal is read, and three-phase voltage and zero-sequence voltage fundamental frequency are obtained. And constructing a basic reference vector based on the fundamental wave frequency, and judging an operation scene according to a switching value state and a zero-sequence current abrupt change slope. Superposing aperiodic direct current components in an operation transient scene to obtain a final interference reference vector, and adopting a relatively large step length coefficient; a basic reference vector is directly used in a non-operation transient scene, and a small step length coefficient is adopted. And finally, a purified electrical parameter signal is obtained through processing of an adaptive filtering algorithm. The method is used for reducing the influence of a transient distortion component on signal purification, so that the operation reliability of the high-voltage switch comprehensive protection device under a complex working condition is enhanced.

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 invention discloses a repetitive control-based circulating current suppression method between grid-forming type energy storage units, and relates to the technical field of power electronics and control, the method adopts three rings of power, voltage and current to regulate and control a grid-forming type multi-machine parallel inverter, a repetitive controller is introduced into a current inner ring, and the repetitive controller is introduced into a current outer ring to control the circulating current between the grid-forming type energy storage units. The method has the advantages that periodic harmonic current is accurately tracked and suppressed, meanwhile, a narrow-band resonance circuit and LC filter state feedback and pole assignment design are introduced into a current loop, LC filter resonance peaks are effectively eliminated through LC filter state feedback and pole assignment, typical harmonic circulation in a parallel system is further suppressed through the narrow-band resonance circuit, and the harmonic current suppression efficiency is improved. Efficient suppression of circulation among the units and uniform distribution of power are further realized; according to the technical scheme, the stable operation of the system can be guaranteed, the power sharing capability and the grid-connected adaptability of the energy storage unit are improved, a complex distributed communication structure is avoided, and the operation reliability of the network construction type energy storage system in a complex power grid environment is improved.

The invention discloses a method for improving electric energy metering precision in an electromagnetic harmonic environment, relates to the technical field of electric energy metering, and solves the problem of improving the electric energy metering precision in the electromagnetic harmonic environment. The method comprises the following steps: step 1, an electric energy metering device collects a power grid signal through a voltage sensor and a current sensor; 2, a harmonic wave sensing module collects a power grid electromagnetic field signal in real time; step 3, the quantum compensation unit changes the Bell curvature to be larger than or equal to 0.5 by regulating and controlling a vertical magnetic field, surface state transmission of harmonic current and physical isolation of fundamental current penetrating through a body material are achieved, and the harmonic isolation degree is larger than or equal to 60 dB; 4, the signal processing module adopts a fractional order tensor Fourier decomposition algorithm; and step 5, adopting a Monte Carlo dot quantum algorithm by a dynamic check unit. According to the invention, the electric energy metering precision in the electromagnetic harmonic environment is greatly improved.

The invention provides an off-line and on-line collaborative optimization MMC harmonic elimination method for harmonic constraint driving, and relates to the technical field of power electronics, S1, generating a switching angle training set and a parameter fluctuation label through clustering analysis and a differential evolution algorithm according to power grid parameters and MMC operation parameters; and S2, extracting harmonic characteristics by using a harmonic detection technology, predicting a switching angle through a neural network, and outputting a final switching angle in combination with a repetitive control link to realize harmonic suppression. According to the off-line and on-line collaborative optimization MMC harmonic elimination method based on harmonic constraint driving, an MMC under a low level number can always keep a low harmonic content level under the complex conditions of different modulation ratios and access to a new energy field station.

The invention provides a harmonic detection and treatment method and equipment used in an electric power system, and belongs to the technical field of electric power systems, and the method specifically comprises the steps: determining the harmonic influence type of a switch cabinet according to the temperature monitoring data of the switch cabinet in different harmonic current intervals, according to the method, the monitoring load interval is determined according to the switch cabinet data of different harmonic influence types, and when the switch cabinet is in the monitoring load interval of the active filter, whether harmonic detection processing is needed is determined according to the temperature detection data of the switch cabinets of different harmonic influence types, so that the working stability and reliability of the active filter are improved.

The invention discloses an integrated intelligent power management system and a harmonic control method. The method comprises the following steps: acquiring analog signals of voltage and current; digital signal sequences of voltages and currents in the N power distribution nodes are generated; obtaining a K-order frequency domain harmonic component of each power distribution node; judging abnormal harmonic nodes; if the abnormal harmonic nodes exist in the N power distribution nodes, constructing a harmonic description matrix for abnormal harmonic source positioning; inputting the harmonic description matrix into a pre-trained abnormal harmonic source positioning model, and outputting an abnormal node identifier where an abnormal harmonic source is located; according to the method, the judgment of the abnormal harmonic nodes is converted from single-index passive alarm to multi-feature driven active identification, and the management level of a power system is improved.

The invention discloses a lightning arrester leakage current measurement method and system based on harmonic decomposition, and relates to the technical field of electric quantity measurement, and the method comprises the steps: collecting a lightning arrester leakage current signal, carrying out the preprocessing of the signal, and obtaining a standardized time domain signal; executing harmonic decomposition, extracting amplitude and phase of each order, and generating harmonic characteristics and energy distribution; a harmonic topological sequence is constructed, nodes are based on order correlation, and edges are based on amplitude and phase changes; generating a double-order curvature matrix, extracting a curvature baseline, and calculating a capacitance path deformation degree parameter; constructing theoretical energy distribution, and comparing the theoretical energy distribution with actual energy to obtain a topology-energy dislocation quantity; and inverting the resistive leakage current based on the dislocation quantity, and outputting a measured value and a deformation degree parameter. According to the invention, through constructing the harmonic topological sequence and fusing curvature analysis and an energy inversion mechanism, accurate extraction of the resistive component in the leakage current of the lightning arrester and structured identification of the capacitance path state in a complex harmonic environment are realized.

The present application relates to the technical field of power system stability control simulation analysis, and provides a transient simulation analysis and decision method, device and equipment for power grid harmonic oscillation, which comprises the following steps: combining the model and model parameters of electromagnetic transient offline simulation with the topology of the power grid to be analyzed to obtain an electromagnetic transient example, and then describing the calculation process of electromagnetic transient with a hierarchical directed acyclic graph, and taking each calculation model with redistributed resources as the electromagnetic transient algorithm; performing risk analysis on the harmonic oscillation condition according to the simulation result, and making an optimized decision on the harmonic oscillation suppression measures; through example design and electromagnetic transient algorithm design, an electromagnetic online simulation model is constructed to meet the simulation requirements of large power grids and realize the analysis and suppression decision of harmonic oscillation.

The application belongs to the technical field of electromagnetic compatibility control design, and particularly relates to a marine low-ground-capacitance filter design method. The method specifically comprises the following steps: firstly, using an inductor as a main filter device, for a low-frequency band below 100 kHz, a magnetic core of the inductor uses an iron-based nanocrystalline material, for a low-frequency band from 100 kHz to 1 MHz, the magnetic core of the inductor uses MnZn magnetic material, and for a high-frequency band above 1 MHz, the magnetic core of the inductor uses NiZn magnetic material; secondly, based on the designed inductor, a multi-stage filter circuit combining low frequency and high frequency is designed; the filter circuit comprises: a plurality of common-mode inductors connected in series, a differential-mode capacitor Cx connected in parallel to both ends of the common-mode inductor, a common-mode capacitor Cy connected in parallel between a live wire and the ground, and a common-mode capacitor Cy connected in parallel between a zero wire and the ground; finally, modular packaging and glue filling are performed, so that the inductor of the filter circuit is parallel to the shell, the center position of the filter circuit is located at the center position of the shell, and overall insulation glue filling is not performed.

The invention discloses a power grid harmonic wave and inter-harmonic wave detection method and device based on distributed multi-frequency measurement data, equipment and a medium. A sine wave method comprises the following steps: detecting harmonic wave and inter-harmonic wave components existing at each sine wave measurement point based on a random matrix theory; determining the frequency and amplitude of each harmonic wave and inter-harmonic wave of each sine wave measurement point by using a rotation invariant technology; clustering the frequency of each harmonic wave and inter-harmonic wave on each measurement point by using a density-based noise application space clustering method to obtain the target frequency of each frequency cluster; and determining harmonics and inter-harmonics of the power grid according to the target frequency and the amplitude. Each harmonic and inter-harmonic component existing on a measurement point is detected through a random matrix theory and a rotation invariant technology, accurate frequencies and amplitudes of the harmonic and the inter-harmonic are obtained, and more accurate frequencies of the harmonic and the inter-harmonic of a power grid are obtained by fusing data of a plurality of distributed measurement points through a clustering method. Therefore, the detection capability of harmonic waves and inter-harmonic waves of a power grid is improved.

The utility model discloses a novel power saver, and particularly relates to the technical field of power savers, the bottom end of a power saver body is fixedly connected with a support frame plate, and a locking mechanism is arranged below the support frame plate; wherein the locking mechanism comprises a socket installed below the supporting frame plate, a locking screw rod is rotationally connected to the interior of the supporting frame plate, and a first thread sleeving extrusion block and a second thread sleeving extrusion block are sequentially arranged on the outer wall of the locking screw rod from left to right. Through the arrangement of the locking mechanism, the locking screw drives the second threaded sleeving extrusion block to move leftwards along the interior of the supporting frame plate under the action of the threads, and meanwhile the first threaded sleeving extrusion block moves rightwards along the interior of the supporting frame plate under the action of the threads; the two extrusion insulation pads are clamped at the two sides of the socket for extrusion locking, the power saver body can be directly fixed on the socket, and the installation of the power saver body is more time-saving and labor-saving.

The invention provides an energy router for an intelligent power distribution area, and relates to the technical field of power systems, and the energy router comprises a three-phase power supply, a high-voltage side main winding, a three-phase load, a low-voltage side main winding, a first voltage source converter, a second voltage source converter and a third voltage source converter. The high-voltage side main winding comprises a first high-voltage winding, a second high-voltage winding and a third high-voltage winding which are connected end to end; the low-voltage side main winding comprises a low-voltage small winding and a low-voltage winding; the low-voltage small windings comprise a first low-voltage small winding, a second low-voltage small winding and a third low-voltage small winding; the first low-voltage small winding, the second low-voltage small winding and the third low-voltage small winding are in star connection; the low-voltage winding comprises a first low-voltage winding, a second low-voltage winding and a third low-voltage winding which are connected end to end, and the low-voltage winding forms a three-phase series loop and is connected to the alternating current output terminal of the second voltage source converter.

The invention discloses a broadband random harmonic compression analysis method based on LSTM and multi-feature fusion, and belongs to the technical field of electric digital data processing. Comprising the following steps: collecting a broadband random harmonic signal for time domain analysis, and extracting a period; judging whether each period signal can be compressed or retained or not by using LSTM (Long Short Term Memory); carrying out down-sampling and coding compression on the compressible periodic section signal; decoding and reconstructing the signal through an LSTM decoder; the decoded and reconstructed signals are preprocessed, multi-dimensional features of the signals are extracted, and evaluation indexes are normalized; calculating the compression ratio of the dynamic fusion index and the signal; and dynamically displaying the evaluation index and the dynamic fusion index. According to the method, self-adaptive decision of compression or not is realized, the compression ratio is improved, and meanwhile, the spectrum fidelity and phase consistency are also kept; and parts which do not need to be compressed are reserved as original samples, so that real-time performance and error control are both considered.

The utility model provides a combined coupling network based on switch switching, comprising a resistor module used for voltage reduction and a capacitor module used for filtering, the resistor module is connected with the capacitor module through a first switch module; the resistor module comprises a plurality of resistor combinations of CN M2, CN M3 and CN M4, and the first switch module is used for controlling the type and number of the resistor combinations connected with the capacitor module in the resistor module. According to the utility model, a plurality of coupling networks can be combined into one, so that the production and later maintenance cost is saved.