1023 results about "Power frequency" patented technology

The invention provides a multi-dimensional electrical equipment insulation analysis and evaluation method, and relates to the technical field of electrical equipment insulation online detection and intelligent diagnosis. According to the method, an electrically isolated direct current detection channel is constructed in a neutral point small resistance grounding system, controllable direct current detection signals are injected, micro direct current leakage response signals are collected, and after zero drift correction, temperature compensation and power frequency ripple suppression are carried out, layered attribution is carried out in combination with primary system topology and an equipment ledger, and a multi-dimensional response matrix is formed. According to the method, environment and working condition normalization is realized through factor rejection and robust pull-back, a mechanism model containing leakage channel equivalent parameters and path constraints is established, multi-working-condition data is fused to calculate equivalent insulation parameters and credibility indication quantity, and a multi-dimensional insulation representation vector is generated. And performing time sequence analysis on the representation vector, extracting degradation and abrupt change characteristics, outputting a health index and a risk level, and realizing quantitative evaluation and intelligent early warning of the insulation state.

The invention discloses a high-voltage cable operation state on-line monitoring, intelligent early warning and fault positioning system, particularly relates to the technical field of power equipment insulation monitoring, and is used for solving the problems that transient discharge signals generated in the cable insulation degradation process are difficult to effectively capture and accurate fault positioning cannot be realized in the prior art. The method comprises the following steps: collecting transient leakage current signals and traveling wave propagation characteristic parameters, performing phase correlation analysis on leakage current pulses and power frequency voltage to identify discharge types, and performing variational mode decomposition and Hilbert-Huang transform on the signals to respectively extract complexity characteristics and energy distribution characteristics; signal logic conflicts are judged by analyzing similarity and statistical distance among characteristics of a plurality of monitoring points, and collaborative diagnosis is started or traveling wave distance measurement is directly utilized to carry out insulation state evaluation and fault location. And finally, differential early warning levels are generated according to the diagnosis result, and fault line selection and positioning information is output to realize real-time monitoring, intelligent early warning and accurate positioning of the operation state of the high-voltage cable.

The invention relates to the technical field of power system relay protection, and discloses a relay protection device mutual inductor adjustment system and method, and the system comprises a system connection initialization module, a data collection reference data generation module, a power frequency background signal offset module, a pilot frequency current injection error calibration module, and a calibration result verification output module. The method comprises the following steps: initializing sampling frequency of a to-be-calibrated mutual inductor and calibration source output precision of a calibration system, collecting amplitude and phase data of real-time power frequency current of the mutual inductor, generating offset current with equal amplitude and opposite directions through power electronic compensation based on reference data, optimizing offset current parameters through a closed-loop adjustment algorithm, and adjusting the offset current parameters through a closed-loop adjustment algorithm. Power frequency background signal offset is completed, pilot frequency calibration parameters are set, a difference value between a mutual inductor pilot frequency output signal and a calibration source standard signal is extracted by adopting a zero pointing technology, an optimal calibration coefficient is automatically calculated, verification of a calibration result is completed, and accuracy and reliability of the calibration result are ensured.

The invention relates to the technical field of ammeter fault detection, and provides an intelligent ammeter series arc fault detection method, system and device, a medium and equipment, and the method comprises the steps: firstly obtaining an ammeter data set of an intelligent ammeter, which comprises a pre-ammeter voltage, a post-ammeter voltage and a total loop current in a continuous power frequency period, and then carrying out the division through a sliding time window, obtaining a plurality of ammeter data windows; for each window, calculating a voltage difference sequence and a dynamic loss impedance sequence; when the absolute value of the total loop current is smaller than a preset threshold value, determining the current zero-break interval of each power frequency period and the current zero-break time corresponding to the window; determining an arc voltage estimation value according to a voltage difference between non-zero-break intervals in the zero-break interval; and finally, integrating the current zero break time, the arc voltage estimated value and the dynamic loss impedance of each window to judge whether a series arc fault exists, and if so, triggering a protection action. According to the embodiment of the invention, high-reliability identification of the series arc fault is realized.

The invention discloses a construction method and a modulation method of a three-port multi-frequency MMC topology based on bridge arm multiplexing, and relates to the technical field of power electronics. The construction method comprises the steps that sub-modules of a traditional double-bridge-arm MMC are integrated and optimized into a three-bridge-arm structure through a current conversion branch, independent energy interaction of three ports is achieved through an auxiliary bridge arm, multi-frequency operation modes of power frequency, frequency division, direct current and the like are supported at the same time, and therefore the utilization rate of the bridge arm sub-modules is increased, and the energy utilization rate of the MMC is increased. And the overall size and the manufacturing cost of the converter are reduced. Based on three-port multi-frequency coordination control and power balance requirements, a modulation method of the topological structure is provided, a multi-frequency coordination modulation strategy is adopted, frequency offset is performed through an auxiliary bridge arm to reduce cross interference of port frequency, and output waveform quality is improved through multi-objective optimized capacitor voltage balance control. And meanwhile, direct-current side faults are effectively eliminated by means of the auxiliary bridge arm.

The invention relates to the technical field of motor state monitoring, in particular to a motor state monitoring method and system based on data driving, and the method comprises the following steps: synchronously collecting a motor voltage signal amplitude time domain sample and a motor current signal amplitude time domain sample for a power frequency period in a motor operation state; and calculating an instantaneous phase difference between each corresponding sample point to obtain an instantaneous phase difference original data stream of the motor. The method comprises the following steps: synchronously acquiring voltage and current amplitudes during operation of a motor in real time, and calculating an instantaneous phase difference between the two amplitudes to obtain an electromagnetic state original data stream; further executing high-pass filtering and performing spectral analysis to filter interference signals and low-frequency trend influences, and improving the recognition precision and robustness of instantaneous phase difference jitter features; meanwhile, voltage pulses are actively injected into the winding, echo signals are collected, and rapid capturing and positioning of the abnormal state of the winding are achieved through propagation time delay calculation and impedance characteristic construction.

The invention specifically relates to a standardized fuse fault monitoring and diagnosis system, and relates to the technical field of power system protection equipment monitoring. A signal processing and impedance spectrum calculation module; an intelligent diagnosis and state evaluation module; and a benchmark management and personalized tracking module. According to the invention, controllable micro test signals are actively injected to obtain frequency domain impedance fingerprints, and accurate capture of microscopic degradation is realized; non-intrusive coupling and signal injection are adopted, the topology of a main loop does not need to be changed, the inherent protection characteristic of the fuse is guaranteed, and power frequency interference can be penetrated; the recognition amount of budding faults such as contact oxidation and melt corrosion is improved in advance, and power failure accidents caused by fault expansion are avoided.

The invention discloses a power frequency phase adaptive acquisition device, and relates to the technical field of electric power signal measurement, the device acquires electric field data at a gap through an electric field sensor integrated on an edge shell, calculates electric field intensity fluctuation, and generates interference diagnosis information in combination with a preset interference determination threshold value; when the interference diagnosis information shows that effective interference exists, the electric field intensity variable quantity is calculated, a mapping model is established based on a proportionality coefficient obtained through an experiment so as to obtain zero crossing point offset, and the sampling trigger moment of a zero crossing point detection module is corrected; the clock synchronization module calculates a phase difference by taking the corrected trigger moment as a reference, dynamically adjusts a calibration frequency by combining a phase difference threshold value, and outputs a synchronized system clock signal; and the control system takes the synchronized system clock signal as a trigger signal, collects power frequency phase data according to a power frequency period, and stores the power frequency phase data to a database through a transmission unit, thereby realizing high-precision power frequency phase collection.

The invention discloses an isolation type split-phase inverter circuit and a control method thereof. The isolation type split-phase inverter circuit comprises an isolation DC / DC module circuit and a power frequency rectification module circuit. The isolation DC / DC module circuit comprises an input-side full bridge, a three-end transformer and two output-side circuits, an input-side winding of the three-end transformer is connected with a midpoint of a bridge arm of the input-side full bridge, and the input-side full bridge is connected with a filter capacitor C1 in parallel; two output side windings of the three-end transformer are respectively connected with corresponding output circuits through a resonance network circuit, the two output circuits are connected to a power frequency rectification module circuit through filter capacitors C4 and C5, and the negative electrode of the first output circuit and the positive electrode of the second output circuit are connected to form an interface N; the power frequency rectification module circuit comprises a rectification full-bridge circuit, and an interface L1 and an interface L2 are obtained after rectification. Through cooperative control of direct transmission of integrated topology and voltage signals, a complex parameter matching algorithm is not needed, breakthrough in structure simplification, energy conversion efficiency, control convenience, cost control and safety is achieved, and the method is suitable for various power conversion scenes.

This invention relates to the field of radio frequency (RF) power supplies, specifically to an RF power supply frequency tuning dynamic tracking method and system. The method includes the following steps executed sequentially: S1: Generating a frequency-modulated signal based on an initial carrier frequency and the frequency of a preset modulation signal; S2: Coupled sampling of the RF signal output from the RF power supply after power amplification, filtering the sampled signal, extracting the corresponding signal components, and calculating the corresponding reflection coefficient amplitudes; S3: Comparing the corresponding reflection coefficient amplitudes and selecting the minimum reflection coefficient amplitude; S4: Using the frequency corresponding to the minimum reflection coefficient amplitude as the new carrier frequency, and obtaining a new first sideband frequency and a second sideband frequency based on the new carrier frequency; S5: Repeating steps S1 to S4 based on the updated frequencies. This solution, through iterative updates of the carrier frequency and sideband frequency, possesses the ability to detect and track the reflection coefficient amplitude in real time, and significantly shortens the tuning time.

The invention discloses a rectifier bridge arm fault identification method and system circuit based on multi-characteristic current waveform analysis, and relates to the technical field of rectifier bridge arm fault identification, and the method comprises the steps: collecting a current signal of an AC input side of a rectifier bridge through a current sensor, and obtaining an original current time domain waveform after filtering conditioning; performing period division on the original current time domain waveform based on a voltage synchronization signal, and outputting a positive half-cycle conduction interval and a negative half-cycle conduction interval in each power frequency period; in each power frequency period, performing square integral operation on the current waveforms of the positive half-cycle conduction interval and the negative half-cycle conduction interval to obtain a positive half-cycle energy value and a negative half-cycle energy value, and calculating an energy unbalance degree; and windowing fast Fourier transform is carried out on the original current time domain waveform, amplitudes and phases of third, fifth and seventh characteristic harmonics are extracted to form a harmonic characteristic vector, the vector is matched with a pre-stored bridge arm fault harmonic fingerprint template, and the matching degree of each fault type is obtained.

The invention relates to the field of radio frequency power supplies, in particular to a radio frequency power supply frequency tuning dynamic tracking method and system, and the method comprises the following steps: S1, generating a frequency modulation signal based on the initial carrier frequency and the frequency of a preset modulation signal; s2, carrying out coupling sampling on the radio frequency signal which is output by the radio frequency power supply and is subjected to power amplification, carrying out filtering processing on the sampled signal, extracting corresponding signal components, and respectively calculating corresponding reflection coefficient amplitudes; s3, the corresponding reflection coefficient amplitudes are compared, and the minimum reflection coefficient amplitude is selected; s4, taking the frequency corresponding to the minimum reflection coefficient amplitude as a new carrier frequency, and obtaining a new first sideband frequency and a second sideband frequency based on the new carrier frequency; and S5, repeatedly executing the steps S1 to S4 according to the updated frequency. According to the scheme, through loop iteration updating of the carrier frequency and the sideband frequency, the real-time detection and tracking capability of the reflection coefficient amplitude is achieved, and the tuning time is remarkably shortened.

The invention relates to the technical field of cable insulation detection, and discloses a power cable insulation state evaluation method and system based on multi-dimensional feature fusion, and the method comprises the steps: collecting a high-frequency current signal on a cable grounding wire, extracting a power frequency phase, a discharge amplitude and a pulse frequency band width, and carrying out the normalization processing, thereby obtaining a sample set; calculating a local sparseness adaptive factor of each sample point, and calculating an energy weighted local density of each sample point; calculating the relative distance of each sample point, constructing a decision value, and determining the sample point with the larger decision value as a clustering center; calculating the path transmission reliability of the non-clustering center sample points relative to each clustering center, distributing the sample points with the path transmission reliability meeting a preset condition to the corresponding clustering center, and if the preset condition is not met, marking the sample points as noise; and extracting statistical characteristics according to the separated discharge clusters, and evaluating the insulation state of the cable by using a preset fault diagnosis rule base. According to the invention, the accuracy of cable insulation state evaluation can be improved.

The invention provides a non-power-cut test method for mutual inductance parameters of a power transmission line under excitation of different-frequency signals and a related device, and solves the problems of difficulty in accompanying stop and high safety risk of adjacent lines. The method comprises the following steps: selecting one circuit in the same corridor for power failure, connecting the head end with an induced electricity suppression device, and performing three-phase short-circuit grounding at the tail end; injecting a different-frequency sinusoidal current of 45-55Hz into the power failure line; the synchronous measurement device collects head and tail voltage and current of a running line based on a satellite synchronous clock; extracting pilot frequency signals through two-stage notch filtering and Fourier transform; and different-frequency zero-sequence self-impedance and mutual impedance are calculated and converted into power-frequency impedance. According to the invention, accurate test without power failure can be realized, and safety and power supply reliability are guaranteed.

The invention discloses an intelligent diagnosis system for power utilization abnormal information acquisition, particularly relates to the technical field of power system monitoring, and is used for solving the problems of waveform distortion and broadening caused by transmission line distribution parameters in the long-distance wired transmission process of an existing system. The system collects abnormal characteristic waveform data through a distributed intelligent terminal, selects a characteristic harmonic component in the power frequency voltage of a power line to construct an inherent test signal, extracts the envelope form similarity of a response signal and the test signal through envelope analysis as a first distortion evaluation index, and obtains a second distortion evaluation index after statistical significance judgment. Performing instantaneous frequency stability analysis on the signal with significant distortion to obtain a second distortion evaluation index, and finally generating a corresponding waveform compensation parameter based on double indexes to realize real-time compensation correction; the integrity of the abnormal characteristic waveform in the transmission process is effectively maintained, and the accuracy and reliability of power consumption abnormity diagnosis are remarkably improved.

The invention discloses an electroencephalogram cap for meditation training and a control method thereof, and relates to the technical field of intelligent wearable equipment, the electroencephalogram cap comprises a cap body, an information acquisition module, a signal processing module, a wireless transmission module, a power supply module and a control host; the information acquisition module, the signal processing module, the wireless transmission module and the power supply module are respectively arranged on the helmet body, and the control host is respectively and electrically connected with the information acquisition module, the signal processing module, the wireless transmission module and the power supply module; the information acquisition module is used for acquiring microvolt-level electroencephalogram signals of a corresponding brain region and providing a data source for state recognition, the signal processing module is used for real-time denoising, power frequency interference suppression and artifact preliminary recognition, and the wireless transmission module is used for outputting processed electroencephalogram data streams in real time and transmitting the processed electroencephalogram data streams to the corresponding brain region. The power supply module supplies power to the information acquisition module, the signal processing module and the wireless transmission module. The electroencephalogram cap is convenient to wear, multi-dimensional analysis is achieved, feedback is timely, and the comfort level of mind calming training experience and the training effect can be improved.

The invention relates to the technical field of textile equipment testing, in particular to a yarn textile high-speed spindle operation stability testing method and system, and the method comprises the following steps: S1, testing element layout; s2, initializing the system; s3, carrying out transient test; s4, testing a steady state; s5, interference processing: carrying out spectrum analysis on the originally acquired data, identifying interference frequency characteristics, eliminating interference by adopting a notch filtering and Kalman filtering combined method, and verifying a filtering effect; s6, parameter correlation modeling: constructing a vibration-temperature-tension-rotating speed parameter correlation model by adopting a control variable method, solving model parameters through a fitting algorithm and verifying validity; s7, quality tracing; s8, stability judgment; and S9, performing real-time monitoring and regulation. According to the method, a combined filtering scheme of notch filtering and Kalman filtering is adopted, fixed interference and random interference such as power frequency and mechanical resonance are suppressed in a targeted manner, and through comparison of locally amplified signals, the filtered signals are smooth in waveform and thorough in noise removal, and the signal-to-noise ratio and reliability of vibration detection signals are improved.

The invention provides an eddy current sensor signal noise reduction method based on frequency division detection low-pass filtering and a monitoring system, belongs to the technical field of sensor signal processing, and can at least partially solve the problems of unstable signals and inaccurate measurement in the prior art. The signal noise reduction method for the eddy current sensor comprises the following steps: processing an original output signal of the eddy current sensor by adopting a synchronous detection module, demodulating a dynamic vibration alternating current component of the original output signal into a direct current voltage signal by utilizing a reference signal, and separating a static displacement direct current component signal; an independent dynamic signal channel and an independent static signal channel are formed; filtering high-frequency noise in the dynamic signal channel through a dynamic channel low-pass filter with a first preset cut-off frequency, and filtering power frequency interference in the static signal channel through a static channel low-pass filter with a second cut-off frequency; and reversely injecting compensation voltage at the output end of the static channel low-pass filter so as to eliminate the direct-current offset error of the static displacement component signal.

The invention belongs to the field of power distribution network traveling wave echo analysis, and particularly discloses a power distribution network traveling wave echo identification method based on time-frequency enhancement and multi-evidence fusion. The method comprises a closed-loop process of adaptive frequency band generalized S transformation, low-rank SVD time-frequency enhancement, double-threshold hysteresis starting point detection, physical template GLRT discrimination, double-peak fixed interval scanning and multi-band consistency rechecking. Firstly, a clear time-frequency energy diagram is obtained through preprocessing and self-adaptive frequency band S transformation, then power frequency and a slowly-changing background are suppressed through low-rank reconstruction, and then a candidate starting point is locked on a time energy track by adopting a hysteresis mechanism of'low-threshold triggering-high-threshold confirmation '; carrying out GLRT statistical discrimination in the candidate window by using single-peak / double-peak / damped ringing three types of physical templates, and quantifying time delay between peaks through fixed interval scanning when branch reflection exists; and finally, taking the energy consistency of the low / medium / high bands as cross-band physical evidence, and eliminating false detection only caused by high-frequency ringing.

The invention discloses a wireless charging pelvic floor muscle rehabilitation treatment system, method and equipment and a medium, and relates to the technical field of rehabilitation physiotherapy. A pelvic floor host is arranged to collect a first electromyographic signal of pelvic floor muscles, a first body surface electrode host synchronously collects a second electromyographic signal of abdominal muscles, power frequency notch processing is carried out on the two signals to improve signal quality, and then an abdominal muscle participation degree coefficient is calculated based on the processed signals. The coefficient can accurately quantify the compensation degree of abdominal muscles in pelvic floor muscle training. And the main controller adjusts the electrical stimulation parameters of the pelvic floor host in real time according to the abdominal muscle participation degree coefficient, and when the abdominal muscle compensation is detected to be obvious, the target electrical stimulation parameters are adjusted to inhibit the excessive participation of the abdominal muscle, so that the pelvic floor muscle can obtain more accurate training stimulation. Meanwhile, the system is further provided with a wireless charging storage box, a convenient wireless charging function can be provided for the treatment probe, and the use convenience of the equipment is improved.

The invention relates to the technical field of circuit fault processing, and discloses an automatic identification and remote isolation method for a fault section of a low-voltage distribution line, and the method comprises the steps: building a reference fingerprint database based on channel state information through a central coordination node; monitoring real-time channel frequency response and executing threshold comparison to judge suspected fault points; triggering an active impedance control unit of the terminal agent node to execute controlled perturbation; a transmission line network model is used for calculating a theoretical transmission function variable quantity, fitting analysis is carried out on the theoretical transmission function variable quantity and a measured value, and a physical fault is judged and load interference is stripped through a normalized residual coefficient; calculating a residual drift distance between adjacent nodes based on the topological mapping table to execute differential positioning so as to lock a fault physical interval; and issuing a tripping message, and driving the circuit breaker to execute physical isolation at the power frequency zero crossing point. According to the scheme, on-line fault identification and isolation are realized through active impedance perturbation and distributed residual analysis, and the robustness of fault judgment in a complex load environment is improved.

The invention discloses an energy storage cluster auxiliary thermal power frequency modulation and peak regulation collaborative optimization method considering dynamic balance, and belongs to the technical field of power system operation and control. Comprising the following steps: constructing a double-layer collaborative optimization control model; comprising the following steps: an energy storage cooperative thermal power frequency modulation and peak regulation power distribution layer introduces a frequency modulation demand in a peak regulation process, designs a power distribution and frequency modulation distribution strategy for peak regulation and peak regulation stages, and completes thermal power-storage frequency modulation and peak regulation power distribution by constructing a thermal power-storage frequency modulation and peak regulation power optimization distribution model; the multi-type energy storage power station power distribution layer constructs a multi-type energy storage power station power optimization distribution model by adopting a dynamic equilibrium coefficient; obtaining an energy storage power station power distribution value and an SOC state through a target function of the multi-type energy storage power station power optimization distribution model; and performing optimization scheduling on the new energy power system based on the power distribution value of the energy storage power station and the SOC state. According to the invention, the balance control of the calling degree and the SOC of the multi-type energy storage power station is realized.

The invention discloses a power frequency waveform classification method and device, a medium and equipment, and belongs to the field of waveform classification, and the method comprises the steps: obtaining preprocessed power frequency waveform data of a power transmission line, calculating various waveform features, and inputting the features into a preset cascade classifier model. The model is composed of a plurality of XGBoost binary classifiers which are cascaded in sequence, and each classifier is responsible for executing a specific binary classification task. The output result of the previous classifier is used for triggering the starting of the next classifier, or the final classification result is directly output. The cascade structure not only improves the accuracy and efficiency of classification, but also reduces the complexity of the model, and effectively solves the problem that the fault positioning power frequency of the power transmission line cannot be accurately and efficiently classified in the prior art.

The invention provides an online power supply switch mutual inductor fault detection method and system, a medium and a product, and relates to the technical field of online monitoring and fault diagnosis of power equipment, and the method comprises the steps: generating a synchronous triggering instruction at the zero crossing point moment of the power frequency current of a mutual inductor; in response to the instruction, injecting an excitation pulse into a secondary circuit of the mutual inductor and synchronously acquiring a feedback voltage to obtain a mixed transient signal; extracting a pure response waveform only containing a high-frequency component from the mixed transient signal to carry out multi-resolution time-frequency transformation, and calculating and outputting a multi-dimensional feature vector representing a winding state; inputting the multi-dimensional feature vector into a pre-trained neural network model for classification operation to obtain a fault classification probability of the current transformer state; and comparing the fault classification probability with a preset confidence threshold to generate a fault diagnosis result of the mutual inductor. By implementing the method, the recognition sensitivity of the system on early weak faults and high-frequency distribution parameter changes of the mutual inductor can be improved.

The invention provides an alternating-current weak current high-precision detection system and method, and the system comprises a copper-nickel alloy shielding cover which is used for inhibiting space power frequency radiation interference and power system broadband noise, and a magnetic sensitive element which is used for converting the detected magnetic field change into a corresponding initial current signal, the trans-impedance amplifier is used for converting the initial current signal into a voltage signal; the adaptive noise suppression module collects a power frequency fundamental wave reference signal and a harmonic wave reference signal, generates a harmonic wave anti-phase counteracting signal, and performs anti-phase counteracting on real noise of the initial current signal; the analog-to-digital converter is used for converting the voltage signal into a discretized digital signal, and the discretized digital signal comprises a target signal and a random noise signal; and the FPGA coherent demodulation module is used for carrying out cross-correlation operation and narrow-band filtering on the target signal and the random noise signal to separate out a micro-current signal. The technical problems that in the prior art, composite noise covering is limited, the frequency fluctuation adaptability is poor, and microvolt-level signals are difficult to capture are solved.

The invention relates to the technical field of power system state monitoring, and discloses an insulator defect detection method and device and a storage medium, and the method comprises the steps: collecting the leakage current of an insulator, and constructing a polarity conduction screening model through power frequency phase information, so as to generate a composite current sequence which highlights the polarization attribute of an interface; analyzing the nonlinear degree of the attenuation rate of the sequence drifting along with evolution time in a multi-stage diffusion evolution time domain, and generating an interface electrochemical mass transfer composite index; utilizing the index to invert and construct an interface polarization background reference and stripping the interface polarization background reference from the composite current sequence so as to extract an abnormal discharge pulse residual error; and finally, quantizing the pulse form distortion degree of the residual error, and performing suppression normalization operation on the distortion degree by using the index to output a judgment result. According to the invention, the interference of the interface mass transfer process is effectively eliminated, and the specific detection of the pollution flashover hidden danger is realized.

The invention relates to the technical field of power equipment state monitoring, and discloses a transformer oil paper insulation frequency domain response online monitoring system which comprises an interface protection module, a modulation control module, a servo balance module and a diagnosis reconstruction module. The interface protection module extracts end screen leakage current and provides overvoltage protection; the modulation control module tracks the bus voltage phase and generates broadband modulation excitation voltage; the servo balance module generates a reverse servo current through closed loop feedback, counteracts a power frequency component in a leakage current so as to maintain a virtual ground state of a measurement node, and injects broadband excitation in a superposed manner; and the diagnosis reconstruction module synchronously acquires signals, reconstructs data in combination with time sequence information, calculates equivalent complex admittance by utilizing cross-correlation demodulation, and outputs complex capacitance and a dielectric loss factor. According to the invention, the operating voltage is used as a carrier wave, strong power frequency interference is eliminated through hardware servo, and safe online excitation is realized by matching with phase chopping, so that the difficult problem of weak broadband signal extraction is effectively solved, and combined monitoring and diagnosis are realized.

The invention discloses an optimization method for supplying water to high and low reservoirs by a power / frequency conversion parallel pump set. The optimization method comprises the following steps: determining initial required flow of the high and low reservoirs; determining a theoretical relationship between the demand flows of the high and low reservoirs; adjusting the required flow of the high and low reservoirs by referring to the theoretical relationship; determining a total water head of the bifurcation point; determining a total water head of pump set parallel connection points; calculating the net lift of the water pump based on the total head of the parallel points; fitting a flow-lift curvilinear equation and a flow-shaft power curvilinear equation under a preset power frequency rotating speed; constructing a flow-lift curvilinear equation and a flow-shaft power curvilinear equation under the variable-frequency rotating speed based on a proportional law; calculating and solving a flow-net lift curve equation; a dynamic planning model is constructed, the optimal flow of the pump set is solved, and the optimal rotating speed is determined through inversion; and inverting the opening degree of the flow regulating valve so as to adjust the demand flow of the dominant branch and the non-dominant branch. According to the invention, the backflow risk is eliminated, the water supply energy consumption is reduced, and the flow control error is reduced.

The invention relates to the technical field of motor diagnosis, and discloses a motor eccentricity fault diagnosis method and system based on current harmonic analysis, and the method comprises the steps: carrying out the power frequency component extraction of a three-phase stator current signal, obtaining a residual current signal, carrying out the complex analysis envelope transformation of the residual current signal, and obtaining an envelope analysis signal; performing synchronous interpolation resampling on the envelope analysis signal to obtain a complex envelope signal; performing frequency spectrum estimation on the complex envelope signal to obtain a discrete frequency spectrum of a module value sequence; performing equalization processing on the order spectral line amplitude in the discrete spectrum to obtain a whitened spectrum, and performing inverse transformation on the whitened spectrum to reconstruct an angular domain amplitude signal of the target motor; performing cyclostationary analysis on the angular domain amplitude signal to obtain a third-order cyclic cumulant of the angular domain amplitude signal at a specific cyclic frequency; according to the third-order cycle cumulant, the type and severity level of the eccentric fault are judged; the accuracy of motor eccentricity fault diagnosis can be improved.

The invention discloses a wireless high-voltage current measurement method with a filtering anti-interference function, and belongs to the technical field of robot coordination control. The method comprises the following steps: obtaining an original discrete voltage signal sequence; calculating a discrete voltage signal sequence transient strength index; performing variational mode decomposition on the original discrete voltage signal sequence by using a mode number and a penalty parameter to obtain a group of intrinsic mode functions; respectively synthesizing the classified modes into corresponding interference reference signals; respectively inputting the orthogonal interference reference signals into a filter channel to estimate various interference components and carrying out dynamic adjustment; and a pure high-voltage wire current time domain signal is restored. According to the method, signal characteristics are sensed in real time by adopting the VMD, subsequent key parameters are dynamically adjusted, and the denoising performance is improved; a multi-feature modal intelligent classification method is adopted, mathematical modals with unknown physical meanings are mapped to four physical sets of useful signals, power frequency, high frequency and transient states, and decoupling of signals and noise in a time-frequency domain is achieved.