4456 results about "Harmonics" patented technology

A method for conditioning and maintaining power with predictive load compensation using an uninterruptible power supply system is disclosed. The method includes measuring an electrical input from a primary power supply using analog sensors and transmitting the input through an impedance to introduce a controlled delay. During the delay, input parameters and downstream system effects are determined based on telemetry sensor data. Digital identities are generated for the electrical input and the downstream load and compared to a stored digital identity representing historical conditions. Using the comparison, a system simulation is performed with analog twinning to predict downstream system responses. The predicted response is used to adjust a power converter parameter, modifying the electrical input to an intermediate output that compensates for voltage fluctuations and harmonic distortions. A secondary power supply with a bidirectional high-discharge battery supplements or stores energy as needed, ensuring stable power delivery to the downstream load.

The invention relates to the technical field of power system fault monitoring, and discloses a 10kV voltage transformer ground fault real-time monitoring method and system, and the system comprises a ground fault data collection module, a waveform distortion analysis module, a transient signal detection module and the like. Three-phase current, zero-sequence current and voltage waveform data are collected, a current harmonic component proportion, a zero-sequence current high-frequency transient energy value and the like are analyzed, a fault type is determined by combining a phase difference, and a fault position is positioned according to topological parameters and line impedance. And the temperature of the grounding down lead can be monitored, and the fault probability is evaluated and the threshold value is dynamically adjusted by machine learning. According to the invention, real-time accurate monitoring can be realized, fault types and positions can be accurately diagnosed, potential hidden dangers can be comprehensively monitored, the intelligence of a monitoring system is improved, the operation and maintenance cost and risks are effectively reduced, and safe and stable operation of the 10kV power distribution network is ensured.

The invention discloses a data anomaly detection system and method based on power equipment, and belongs to the technical field of power system data processing and fault monitoring, and the method comprises the steps: obtaining a multi-dimensional operation parameter sequence of voltage, current, temperature, harmonic waves, switching states, topological energy transfer vectors and the like; constructing a local disturbance response map, extracting a micro-disturbance driving factor, and generating a high-dimensional feature embedding matrix; constructing a multi-scale state density map on the basis of the embedded matrix, and mapping an equipment behavior evolution track; introducing a coupling evolution path tracking algorithm based on the density map, identifying an abnormal state set, and constructing a cross-time-period risk channel; matching the current monitoring data with the risk channel, and calculating a risk evolution value; when the value exceeds a set threshold value, abnormal early warning is triggered, and an evolution path model is output; the method has the advantages of high accuracy, strong trend identification capability and early warning, and is suitable for intelligent operation and maintenance of power equipment under complex working conditions.

The invention relates to the technical field of intelligent power grids, and provides an intelligent operation centralized control center intelligent scheduling interaction method and system, and the method comprises the steps: generating a heat distribution gradient through environment noise filtering, reflecting the temperature field change of equipment, obtaining a voltage amplitude envelope through fundamental wave and harmonic wave separation, and monitoring the power quality; a current fluctuation coefficient is extracted by combining segmented deviation analysis to evaluate a line load state, and frequency fluctuation parameters are captured by using time domain statistics to track system stability. By constructing a dynamic association map, heterogeneous data such as thermodynamics, electrical quantity, load characteristics and synchronous states are mapped to power grid topological nodes, and a cross-dimension association relationship is established to realize whole-network state coupling analysis. An overload risk, a voltage out-of-limit probability and a system instability threshold are quantified through a hierarchical evaluation mechanism, a multi-target optimization constraint condition is formed, and finally a scheduling strategy considering equipment safety, economy and power supply reliability is generated. When the power system operates, intelligent scheduling is carried out according to the operation state of the power grid.

The invention discloses an electrical fire monitoring method based on inherent residual current automatic compensation, and relates to the technical field of electrical safety monitoring, and the method comprises the following steps: S100, collecting a residual current signal, executing multi-component time-frequency deconstruction processing, extracting an energy distribution characteristic through wavelet packet transformation, and extracting a mutability index in combination with short-time spectrum entropy analysis, and constructing a preliminary distribution map of higher harmonic interference, and determining boundary features of interference signals in a time domain and a frequency domain. According to the method, high-frequency interference signals are accurately positioned through time-frequency deconstruction, wavelet packet analysis and spectral entropy indexes, non-fault harmonic components are effectively eliminated in combination with amplitude-frequency coupling recognition and a recursive rejection strategy, closed-loop control is constructed by introducing an adaptive compensation and stability backtracking mechanism, accurate recognition and dynamic correction of real electric leakage risks are achieved, and the method is suitable for large-scale popularization and application. The identification precision and the safety reliability of the monitoring system in a complex industrial environment are obviously improved, and the method has good engineering adaptability.

The invention provides a permanent magnet motor and a variable-frequency scroll compressor, and relates to the technical field of scroll compressor design and manufacturing, and the permanent magnet motor comprises a stator iron core and a rotor iron core; the stator iron core comprises stator slots which are uniformly distributed along the circumference, copper windings are embedded in the slots, stator yokes which are uniformly distributed are arranged outside the bottom of each slot, each stator yoke is provided with an arc-shaped long slot, stator teeth are arranged between every two adjacent stator slots, and the tops of the stator teeth are sunken to form through-flow slots; the rotor core is internally provided with magnetic steel grooves which are uniformly distributed, two same first magnetic isolation grooves are arranged between two adjacent magnetic steel grooves, magnetic steel is arranged in the magnetic steel grooves, and the top of each magnetic steel is provided with two second magnetic isolation grooves which are symmetrically distributed. The outer side radius Rs1 of the stator core, the inner side radius Rs2 of the stator core and the axial length Lis of the stator core meet the following conditions: 1.282 < = Lis / (Rs1-Rs2) < = 2.778, and 34 < = Rs1-Rs2 < = 39 mm. The power density of the motor can be increased, the cost is reduced, the efficiency is improved, and the harmonic content is reduced so as to suppress torque ripple.

The invention discloses an emergency power supply quick access method based on scene recognition, which relates to the technical field of emergency power supplies, and comprises the following steps: in an emergency power supply system, firstly obtaining electrical input parameter information through a preset detection frequency; by introducing a load change evaluation mechanism based on machine learning, the system can identify load fluctuation in real time and dynamically adjust the detection frequency, and the response speed to the rapid change of the load is improved. Compared with a traditional detection method, the load state is intelligently evaluated and accurately divided, it is ensured that the power factor is adjusted in time when the load fluctuates violently, and power loss and waste are reduced. Correction is carried out according to the traditional frequency during stable load fluctuation, the frequency is dynamically adjusted during rapid fluctuation, the electric energy use is optimized, the electric power quality is improved, and harmonic distortion and overload risks are reduced.

The present invention relates to the technical field of secondary device monitoring. Disclosed are an online monitoring method for an operating state of a secondary current loop neutral line, and a system. The method comprises: by using a high-precision sensor for collection and a composite filtering algorithm for processing, obtaining a secondary current fundamental component of each neutral line of a transformer substation which is not influenced by harmonic waves and transient states, and uploading the secondary current fundamental component to a protection information master station; retrieving originally configured access protection information master station information to obtain three-phase secondary current loop information of each bay of the transformer substation, summarizing secondary current information of all monitoring ranges, and performing grouping and classification marking on said information by transformer substation, bay and winding; and using the collection information for operation analysis, automatically identifying and confirming an operating state of the line, and on the basis of the operating state, calculating the outlier deviation linearity and the continuous dynamic trend deviation degree of each winding of each bay. The present invention solves the problem that intermittent faults in secondary current loop neutral lines are concealed and are not easily found, realizes comprehensive monitoring for the whole system, and can quickly and accurately position a specific winding and issue an abnormal early warning.

The invention discloses a virtual synchronous generator grid-connected current harmonic suppression method and system, and relates to the technical field of power systems, and the method comprises the steps: S1, carrying out the digital sampling of intermittent high-frequency disturbance through a wind power plant grid-connected current signal in a power grid through an analog-to-digital converter, and obtaining an original digital current sequence; s2, according to the original digital current sequence, analyzing a wind load frequency component by adopting a fast Fourier transform algorithm, and determining amplitude and phase characteristics of a high-frequency harmonic component; s3, if the amplitude of the high-frequency harmonic component exceeds a preset threshold value, extracting an intermittent disturbance harmonic sequence from the frequency component to obtain a to-be-suppressed harmonic subset; according to the virtual synchronous generator grid-connected current harmonic suppression method and system, the stability of a remote wind power plant power grid is remarkably improved, continuous monitoring and real-time suppression of intermittent disturbance are achieved, and high efficiency and reliability of power grid operation are guaranteed.

The invention discloses a power transmission channel risk early warning evaluation method and system, and relates to the technical field of power transmission channel abnormal condition early warning, and the method comprises the steps: analyzing the current waveform distortion degree caused by a nonlinear load in a power transmission line through monitoring the voltage harmonic distortion rate, and evaluating the influence of harmonic waves on the insulation aging and heating loss of the line and equipment; the real-time gradient of the temperature of the wire is analyzed, abnormal heating conditions of different sections of the wire are judged, and the abnormal rising degree of the temperature of the wire and potential thermal damage accumulation caused by overload and poor contact factors are evaluated; by monitoring and analyzing multi-dimensional indexes such as the voltage harmonic distortion rate, the lead temperature real-time gradient, the sag dynamic deviation rate and the corona discharge intensity, the defect of a traditional monitoring means in the aspect of abnormal heating risk assessment is overcome.

The invention discloses a sampling implementation method and system suitable for motor protection quick response, belongs to the technical field of motor protection, and can increase the sampling frequency and improve the quick response of motor fault protection. Comprising the steps that motor phase current and bus voltage are collected, after anti-aliasing filtering is conducted, parallel sampling is conducted through a main ADC module and a redundant ADC module which are independently configured, and the following operations are synchronously executed based on a double-buffer-area framework: in a first buffer area, a compensation coefficient updating period is dynamically adjusted, and convergence is restrained; in the second buffer area, generating a voltage gradient prediction sequence, and compensating data abrupt change; when the harmonic frequency spectrum amplitude or the voltage gradient prediction sequence exceeds the limit, an oversampling mode is triggered, a redundant ADC module is allocated to load a multi-order digital filter, and an independent hardware acceleration unit is started to process harmonic compensation and gradient prediction in parallel; and generating a dynamic safety envelope, and if the gradient extreme value in the preset continuous window breaks through the safety envelope, generating an overvoltage fault signal.

The invention discloses a direct-current arc fault diagnosis method and device with adaptive capacity. The method comprises the following steps: 1) collecting a current alternating-current component when a current direct-current system normally works; 2) extracting time-frequency domain characteristics of a current AC component, wherein the time-frequency domain characteristics comprise a current peak-to-peak value, a standard deviation and an amplitude reconstruction harmonic power sum; 3) performing multi-time-frequency-domain feature fusion based on mahalanobis distance to obtain arc detection features; 4) calculating an arc fault judgment threshold value based on a box plot method; 5) collecting a current AC component in real time to calculate a Mahalanobis distance, comparing the Mahalanobis distance with an arc fault determination threshold, and recording an arc event; the method has the advantages that the system adaptability is high, the detection rate is high, the false alarm rate is low, and the method can be widely applied to high-voltage and low-voltage direct-current power distribution systems such as airplanes, vehicles and ships.

The invention relates to the technical field of electrical monitoring, provides a general generator electrical monitoring system with a fault self-diagnosis function, and aims to deeply excavate potential correlation between electrical and mechanical parameters by judging a coherence coefficient and a phase difference between a current harmonic component and a bearing vibration frequency band and marking a fault coupling identifier by using a coupling mode library. Electrical and mechanical coupling faults can be accurately identified, and the identification capability of complex faults can be greatly improved; meanwhile, the diagnosis threshold is dynamically adjusted in combination with the load rate and the winding temperature, so that the system can better adapt to different operation conditions of the generator, and the diagnosis accuracy and reliability are improved; the fault causal chain is analyzed through the causal inference algorithm, and the fault source is positioned, so that compared with the existing fault tracing mode lacking systematicness, the fault generation reason and process can be analyzed more comprehensively and deeply, the fault source can be positioned quickly and accurately, operation and maintenance personnel can take targeted measures in time, and the fault tracing efficiency is improved. And the operation safety and reliability of the generator are improved.

The invention relates to the technical field of circuit control, in particular to a control method and system of a bidirectional charging and discharging circuit. The method comprises the following steps: collecting current monitoring data and voltage monitoring data of a bidirectional charging and discharging circuit in real time; performing arc characteristic analysis on the current monitoring data and the voltage monitoring data to obtain arc characteristic data; analyzing a high-frequency harmonic component and a current ripple fluctuation amplitude of the bidirectional charging and discharging circuit based on the arc characteristic data; performing direct-current arc detection on the bidirectional charging and discharging circuit according to the high-frequency harmonic component and the current ripple fluctuation amplitude to generate a direct-current arc fault judgment result; and calculating the instantaneous current change rate of the current monitoring data, and carrying out short-circuit detection on the bidirectional charging and discharging circuit through the instantaneous current change rate. By monitoring current and voltage data in real time, arc and short circuit characteristics are accurately analyzed, relay control is optimized, an accurate control instruction is generated, and the safety and reliability of the two-way charging and discharging circuit are improved.

The invention relates to the technical field of adaptive control, in particular to an electrical automation adjustment method and system, and the method comprises the following steps: obtaining a three-phase current signal, collecting single-cycle high-frequency sampling, extracting an instantaneous extreme point, recording a time coordinate and an amplitude value, calculating a time interval and a change rate, screening the distribution of the extreme point, and obtaining a harmonic distortion characteristic parameter. According to the method, on the basis of high-frequency sampling, instantaneous extreme point extraction, time interval and change rate calculation, harmonic distortion feature description enhancement, extreme value growth rate and phase drift rate are utilized, time periods with prominent fluctuation amplitude are screened, harmonic change trend prediction precision is improved, and the harmonic change trend prediction precision is improved through zero-sequence component and phase offset calculation in combination with periodic change features. The harmonic source is accurately separated, the harmonic cause identification capability is improved, the compensation current is calculated based on the harmonic source, the injection opportunity is optimized, the compensation parameter is adjusted before the harmonic peak value, and the compensation response speed and the matching precision are improved.

The invention relates to the technical field of electric power reactive power compensation, in particular to a novel static dynamic reactive power compensation device and a control method thereof, and the device comprises a power grid state monitoring module, a reactive power demand calculation module, a compensation control execution module, a harmonic suppression module and a dynamic energy storage support module. According to the method, through real-time extraction and segmented analysis of the dynamic operation parameters of the power grid, accurate perception of the state of the power grid is realized, the transient characteristics of operation are represented, an accurate basis is provided for subsequent compensation, decomposition and classified accumulation of reactive power requirements are realized, inductive and capacitive power differences are accurately identified, the calculation accuracy and efficiency are improved, and load adaptation is optimized; in harmonic suppression, resolution and response speed are enhanced through signal separation and frequency correction, energy storage and compensation linkage is improved through dynamic energy storage optimization, dynamic response capability is enhanced, loss is reduced, voltage stability and power factors are improved, stable guarantee is provided for complex fluctuation scenes, and electric energy is saved.

The invention provides a virtual synchronous generator adaptive control method based on line impedance identification, and relates to the technical field of power system control. The line impedance identification-based adaptive control method for the virtual synchronous generator comprises the steps of dynamically adjusting the virtual inertia J, the damping coefficient D and the droop coefficient K of the virtual synchronous generator through a multivariable constraint optimization algorithm according to the impedance-frequency coupling model, and realizing real-time matching between the output power of the virtual synchronous generator and the impedance of a power grid. By collecting power grid signals in real time and extracting impedance characteristics, the dynamic change of power grid impedance can be timely and accurately mastered, and a reliable basis is provided for subsequent control strategy adjustment, so that real-time matching of the output power of the virtual synchronous generator and the power grid impedance is realized, power fluctuation is effectively reduced, and the stability of a power grid is improved; according to the invention, a self-adaptive modulation strategy and a multi-resonant controller are adopted, harmonic oscillation can be effectively suppressed, and the quality of output electric energy of the inverter is improved.

The invention discloses an intelligent operation and maintenance fault early warning method for a rail transit variable-frequency power supply, and relates to the technical field of power electronics and intelligent operation and maintenance, and the method comprises the following steps: setting a multi-point synchronous collection device to carry out the high-precision real-time collection of voltage and current signals of a variable-frequency power supply system, and carrying out the digital coding processing of data; and performing frequency domain analysis on the acquired voltage and current signals by using a preset spectrum analysis algorithm, and extracting harmonic amplitudes and phase characteristic parameters of different orders. According to the invention, through high-precision synchronous acquisition and spectrum analysis, rapid and accurate identification of harmonic abnormity is realized; a machine learning model and dynamic threshold adjustment are fused, and the adaptability and intelligent recognition capability of the system to fault modes under multiple working conditions are enhanced; and a trend prediction and graphical early warning platform is introduced, so that the fault risk is pre-judged in advance and visually responded, and the operation and maintenance efficiency and the operation safety of the rail transit power supply system are remarkably improved.

The invention provides a converter station in-station equipment energy consumption analysis model and method. Belongs to the field of converter station equipment energy consumption analysis. According to the method, a three-dimensional data acquisition system covering equipment in the whole station is established, electrical measurement data of the equipment is obtained in real time through a monitoring system, and meanwhile, a converter valve trigger pulse, a cooling water pump rotating speed adjusting signal and a circuit breaker opening and closing state are captured through an equipment digital twin interface. And carrying out real-time feature extraction by means of an edge computing node, and triggering high-speed data recording for a commutation failure event. And correcting abnormal data by combining a sliding window dynamic cleaning mechanism with a wavelet threshold denoising algorithm, and extracting a current harmonic distortion rate, a voltage fluctuation coefficient and equipment vibration spectrum characteristics. And further establishing a multi-dimensional characteristic matrix containing equipment operation conditions, environmental parameters and power grid interaction characteristics, performing energy consumption prediction by using a hybrid model, and generating a dynamic energy efficiency evaluation index which is applied to energy saving strategy optimization.

The invention discloses a dual-electric brake boosting system, which belongs to the technical field of vehicle brake control and comprises the following steps: S1, dynamically calculating quadrature-axis inductance parameters, generating a synchronous magnetic field signal and inhibiting electromagnetic interference of dual motors; s2, extracting a harmonic-rotating speed mapping relation, and dynamically correcting an observation equation to control a parameter error; s3, reconstructing neutral point voltage to counteract high-frequency jitter, and reducing residual harmonic interference through adaptive filtering; s4, establishing a three-dimensional thermal field to predict copper and iron loss, dynamically adjusting current and generating an inverse time limit protection curve; s5, splitting the hot parameters into parity check frames, optimizing a communication protocol and compressing a refresh cycle to 10ms; s6, overlapping response of the white noise excitation system, and performing closed-loop calibration on the filtering weight to improve the observation precision; s7, triggering an audible and visual alarm and synthesizing a directional voiceprint and a tactile pulse to ensure safety regulations and perception intensity; the method has the beneficial effects that the method has remarkable advantages in a high-temperature and high-vibration severe environment, and the reliability and the safety of a system can be improved.

The invention relates to the technical field of inverter control, and discloses an inverter output power control method and device, equipment and a storage medium. The method comprises the following steps: performing power frequency fundamental wave extraction and multi-band band-pass filtering on acquired voltage and current sampling data; performing phase compensation, first coordinate transformation and positive and negative sequence decoupling operation on the filtered fundamental wave principal component data; on the basis of a synchronous phase angle and a power grid fundamental wave frequency obtained by positive and negative sequence decoupling operation, carrying out second coordinate transformation, moving average and harmonic power delay difference operation on three-phase current and voltage data of an alpha-beta coordinate system; performing multi-level power calculation, power capacity distribution, error characteristic evaluation and decoupling operation on the inversion fundamental component and the inversion harmonic component subjected to the difference operation; and performing output signal modulation on the inversion power control quantity of the decoupling operation based on the fundamental wave synchronization phase angle, and generating a power control result. According to the invention, the control performance of the inverter on the output power in actual operation is improved.

The invention relates to the technical field of electrical performance testing, in particular to a water supply equipment electrical performance detection system based on artificial intelligence, which comprises an electrical parameter acquisition module, an energy efficiency analysis module, an insulation performance evaluation module and a comprehensive diagnosis module. According to the invention, a three-phase voltage and current root-mean-square value is dynamically calculated through a broadband current transformer and a sliding window integration method, a 50Hz fundamental component amplitude is extracted to separate power frequency and high frequency harmonic waves, a continuous period energy efficiency ratio standard deviation triggers an insulation detection threshold value, and a parameter fluctuation and insulation degradation response mechanism is established. Harmonic interference correction synchronous processing energy efficiency ratio and leakage current integration, the detection error being lower than 5%, temperature rise rate linear regression and bearing current threshold value cooperative determination, winding aging cross validation, fault misjudgment rate reduction to 26%, closed-loop detection fusion transient capture, dynamic threshold value triggering and multi-parameter diagnosis, early warning success rate reaching 92%, and positioning response being reduced to 3 seconds.

The invention discloses an SLCC control method and system based on similar network type SVF assistance, and the method comprises the steps: generating a first SVF voltage instruction value through an active outer ring and a reactive outer ring, processing the first SVF voltage instruction value through a voltage ring, and obtaining a fundamental frequency reactive compensation current instruction value; processing the LCC output current by using a multi-synchronous rotation coordinate method to obtain a harmonic compensation current reference value; and superposing the fundamental frequency reactive compensation current instruction value and the harmonic compensation current reference value, obtaining a second SVF voltage instruction value in combination with a current inner loop controller, and processing the second SVF voltage instruction value by using a voltage-sharing control strategy and a carrier phase-shifting modulation strategy to obtain a switching signal for controlling the SVF. According to the method, the dependence of the SVF on an alternating current system is reduced, stable and independent operation of the SVF in the SLCC by virtue of the self regulation capability is favorably realized, and the operation reliability and stability of the SLCC are improved.

The invention provides an intelligent harmonic dynamic compensation method and system for a data center. According to the method, server heat source surface temperature field distribution is monitored in real time through a distributed optical fiber temperature measurement array, and a dynamic impedance spectrum is generated; when the temperature gradient exceeds the flash evaporation critical value of the fluorinated cooling liquid, an active filter is activated to carry out dynamic impedance matching compensation on high-frequency harmonic current in the liquid cooling tank cabinet, and a pulse width modulation control signal of a circulating pump is generated; the compensation power of the filter and the turbulence intensity of the cooling liquid are synchronously adjusted by analyzing the coupling relation between the flowing vortex intensity of the cooling liquid and the dielectric polarization loss; when phase mismatch of a temperature field is caused by heat dissipation of multiple heat sources, a multi-band compensation strategy is reconstructed by utilizing frequency domain characteristics of a pulse width modulation signal and a compensation power historical value, and a cooling liquid branch flow distribution ratio and a filter frequency response curve are cooperatively adjusted. According to the technical scheme, the thermal stability and the electrical safety of the data center cooling machine room are improved.

The invention discloses a multi-scene cooperative control method, device and equipment for a network construction type energy storage converter, and a storage medium, relates to the technical field of converter control, and discloses the multi-scene cooperative control method for the network construction type energy storage converter, and the method comprises the steps: obtaining the state data of a power grid, determining grid-connected point power, power grid frequency, power grid voltage and power grid harmonic frequency spectrum according to the power grid state data; establishing a multi-objective optimization function, an energy storage system charge state constraint and a converter output current constraint based on the grid-connected point power, the power grid frequency, the power grid voltage and the power grid harmonic spectrum; and performing multi-objective optimization solution based on the multi-objective optimization function, the charge state constraint of the energy storage system and the output current constraint of the converter to obtain a fundamental current reference value and a harmonic current limit value so as to control the output current of the grid-forming type energy storage converter. According to the scheme of the invention, the capacity conflict between network construction type control and harmonic suppression can be solved.

The invention relates to the technical field of power grid monitoring, and discloses a voltage sensor multi-parameter real-time monitoring method and device in an Internet of Things environment. According to the method, real-time voltage fluctuation data of a target area is acquired by deploying a multi-channel voltage sensor array and is transmitted to an edge computing node; dynamic feature extraction is executed in the edge nodes, and a multi-dimensional feature matrix containing voltage fluctuation ratio, harmonic distortion and phase deviation features is generated; identifying voltage sag, overvoltage and harmonic resonance event characteristics based on an anomaly detection model; spatial correlation modeling is carried out in combination with power grid topological structure parameters, the coupling strength of adjacent sensor node parameters is calculated, and a multi-parameter correlation map containing event propagation paths and influence ranges is generated; inputting the voltage into a diagnosis model to generate a power grid state diagnosis report, and dynamically adjusting the sampling frequency and filtering parameters of the voltage sensor according to the power grid state diagnosis report. According to the method, real-time monitoring and analysis of multiple parameters of the power grid can be realized, and comprehensive support is provided for power grid state evaluation.

The invention provides a real-time dynamic harmonic detection method and system for a traction power supply system, and relates to the technical field of harmonic detection, and the detection method comprises the following steps: collecting a voltage signal of the traction power supply system in real time, and dynamically tracking fundamental frequency fluctuation through a phase-locked loop technology; dynamically adjusting the data window length of FFT analysis; dynamically adjusting a frequency spectrum calculation kernel of the FFT; carrying out linear compensation on the detected harmonic phase; taking the preliminarily detected harmonic parameter as an initial value, and iteratively updating the harmonic parameter until convergence by minimizing a signal reconstruction error; dynamically adjusting a sampling interval according to the fundamental frequency fluctuation, and carrying out anti-aliasing processing by adopting a filter with a variable cut-off frequency; and constructing a matrix model containing a fundamental frequency fluctuation parameter, and calculating a real harmonic parameter through a least square method. According to the method, the detection defect of the fixed window FFT during frequency fluctuation can be systematically solved, and high-reliability real-time data support is provided for harmonic resonance suppression of the electrified railway.

The invention belongs to the technical field of electrical safety, and particularly relates to a human body electric shock protection method and system based on multi-parameter fusion, multi-dimensional characteristic parameters are formed by extracting a high-frequency harmonic component, a voltage abrupt change slope and a magnetic field intensity fluctuation value of a residual current waveform, and the weight is dynamically adjusted according to the instantaneous change rate of each characteristic, so that the human body electric shock protection is realized. Generating a weighted feature vector; and a comprehensive criterion value is calculated in combination with a preset rule base and is compared with a dynamic threshold value, so that whether the circuit breaker is triggered to act or not is determined. According to the method, through fusion analysis of a plurality of physical characteristics, the identification capability of the system in a complex electromagnetic environment is improved, the probability of misoperation caused by external interference is effectively reduced, the action accuracy and stability of the circuit breaker are improved, and the power utilization safety and the power supply continuity are guaranteed.

The invention provides a method and system for achieving elevator energy feedback data communication. The method comprises the steps that multi-modal data are collected, and fault features are extracted, encrypted and packaged; and after decryption, phase deviation of elevator operation and power grid voltage is calculated by utilizing an algorithm, a current phase is synchronously fed back, and a feedback instruction is generated. Uploading the harmonic suppression parameter to an energy center, calculating a demand, generating a region-level feedback strategy, dynamically distributing a feedback power upper limit, synchronizing the harmonic suppression parameter, and obtaining region-level feedback data. And aggregating feedback data, and setting a global optimization target, including cost minimization, feedback maximization and carbon emission reduction. And calculating feedback energy and carbon integral according to a target adjustment algorithm, automatically settling to an operator account, and adjusting the target of the next period. Through an algorithm and an optimization mechanism, the problem of energy waste of a brake resistor in a traditional feedback technology is solved, the feedback efficiency is improved, and energy waste is reduced.

The invention discloses a high-precision electric power measurement method based on an intelligent electric meter, and relates to the technical field of electric power measurement. According to the invention, a plurality of high-precision voltage and current sensors with temperature compensation are uniformly arranged in a circuit, a low-noise front-end conditioning and multi-channel high-resolution ADC synchronous sampling technology is adopted, and a digital phase-locked loop is introduced to realize accurate correction of a sampling clock. And performing multi-stage weighted fusion, time domain instantaneous power calculation and FFT frequency domain decomposition compensation on the acquired data, and finally accurately calculating the real power in a power grid period. According to the method, measurement errors caused by temperature excursion, phase deviation and harmonic interference in the prior art are effectively solved, the measurement precision and stability of the system are remarkably improved, and the method is suitable for high-precision power monitoring in a complex power grid environment.