365results about How to "Improve power quality" patented technology

The invention discloses a full-effect electric energy optimization rapid detection system and method, and particularly relates to the technical field of electric energy detection. The method comprises the following steps: acquiring voltage, current, frequency, harmonic component and three-phase unbalance degree of a power grid in real time, calculating a power grid impedance value and a load dynamic characteristic ratio, drawing an impedance frequency characteristic curve, analyzing a harmonic amplification abnormal degree and a load dynamic response characteristic, and evaluating the accuracy of a detection instruction generated by the full-effect electric energy optimization device. The error correction is carried out on the inaccuracy detection instruction, the duty ratio is dynamically adjusted by utilizing the PWM technology, the accurate matching of the amplitude and the phase of the output current is realized, the error correction effect is evaluated by comparing the real-time detection value with the theoretical calculation value, and the detection model and the compensation strategy are automatically optimized. The problems of detection precision reduction and error compensation caused by complex power grid conditions in the prior art are solved, harmonic amplification, reactive power over-compensation and three-phase balance damage are avoided, and efficient and accurate electric energy optimization and power grid stability improvement are achieved.

The invention discloses a multi-dimensional time sequence photovoltaic grid-connected harmonic current prediction control method, and particularly relates to the technical field of power system control. Grid-connected original multi-dimensional electrical signals are collected and decomposed into multi-dimensional frequency signals through Fourier transform, the characteristic components of an independent harmonic source are separated through the blind source separation and non-negative matrix factorization technology, and the frequency and amplitude characteristics of the characteristic components are extracted; then, a multi-dimensional time sequence prediction model is constructed through a recurrent neural network, dynamic behaviors of multiple harmonic sources are predicted at the same time, and frequency domain data are reconstructed and frequency aliasing errors are corrected in combination with high-frequency compensation and multi-scale analysis; and finally, inputting a prediction result into a photovoltaic inverter control system, dynamically generating a compensation current opposite to a target harmonic wave, realizing effective offset of the harmonic wave, accurately processing the multi-source harmonic wave problem in a complex power grid environment, and greatly improving the harmonic wave suppression capability, the electric energy quality and the system operation stability of a photovoltaic grid-connected system.

The invention provides a power supply energy analysis method and system for a medium-voltage power distribution network. The method comprises the following steps: collecting multi-modal data of the medium-voltage power distribution network; constructing a health state evaluation model, and predicting a health score and a fault risk of the transformer of the medium-voltage power distribution network according to the fusion features after dimension reduction; constructing an optimization target of the power electronic equipment of the medium-voltage distribution network according to the health score and the fault probability of the transformer; constructing a multi-modal load prediction model to predict the load change of the power electronic equipment in the future; constructing a multi-objective optimization function, and generating an optimal scheduling strategy; and executing the optimal scheduling strategy to actually control the medium-voltage power distribution network equipment. According to the method, the defects of a traditional method in the aspects of equipment monitoring, load prediction and scheduling optimization are overcome, and the overall management level and coping capacity of a power grid are improved by introducing a leading-edge artificial intelligence algorithm and a data fusion technology.

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 invention discloses a special transformer state management method and system based on intelligent monitoring and remote diagnosis. The method comprises the steps that electrical parameters of a special transformer user are collected through monitoring equipment; the collected data parameters are analyzed in real time, and the operation state and the abnormal condition of the equipment are judged; monitoring data are transmitted through a communication network, and remote monitoring is achieved; and when an abnormality is detected, triggering an alarm mechanism, and providing fault diagnosis information. According to the invention, the safety and operation efficiency of the power system are improved. Key parameters such as voltage, current, power and frequency can be collected in real time, abnormal conditions such as overload and undervoltage can be rapidly detected through an intelligent algorithm, and an alarm is triggered in time. The system adopts AES encryption to guarantee data transmission security, supports 4G / 5G network to realize remote monitoring, and ensures that operation and maintenance personnel can quickly obtain fault diagnosis information and personalized processing suggestions. The fault response speed and the system stability are obviously improved, and the operation and maintenance cost is reduced.

The invention discloses a method for predicting and suppressing harmonic waves generated by photovoltaic grid connection, which relates to the technical field of harmonic wave prediction, and comprises the following steps: detecting a three-phase current signal of a photovoltaic grid connection circuit by using an ip-iq detection method, and decomposing the three-phase current into an active component and a reactive component through Clarke conversion and Park conversion; according to the method, high-precision detection and separation of harmonic waves in the photovoltaic grid-connected system are realized by combining an ip-iq method with Clarke and Park transformation, dynamic modeling and harmonic signal prediction are performed by using the LSTM model, the defect of poor adaptability of a traditional method to nonlinear loads is overcome, and the prediction error is as low as 0.1%. Through combination of LSTM prediction and APF dynamic compensation, the compensation current opposite to the harmonic current is generated in real time, the harmonic suppression efficiency and the power grid stability are significantly improved, the electric energy quality is optimized, and the dynamic change of a complex load is adapted.

The invention relates to the technical field of charging management, and discloses an intelligent charging management method, device and equipment for an electric scooter and a storage medium, and the method comprises the steps: carrying out the parameter collection and initialization setting of a single-phase bidirectional converter and a permanent magnet synchronous motor in the electric scooter, obtaining system basic parameters and communication data, and obtaining a network authentication identifier and a charging station operation parameter. And dynamic planning of a charging strategy is executed according to the parameters to generate a segmented charging control curve. And the data are input into the self-adaptive prediction controller to realize real-time adjustment in the charging process, and charging state data and power compensation parameters are obtained. And adopting a double-neural network model structure to obtain a battery safety feature matrix and a fault probability vector. And constructing a three-dimensional charging state space model to carry out optimization calculation on the power compensation parameters, inputting a deep reinforcement learning network to carry out iterative optimization, and generating charging control parameters of the next period, thereby improving the charging efficiency and the electric energy quality of the electric scooter.

The invention discloses a residual capacity harmonic compensation method for a household single-phase optical storage cooperative converter, and belongs to the technical field of converter control. The invention aims to provide a dynamic harmonic compensation method for household single-phase photovoltaic energy storage under limited power capacity and a residual capacity harmonic compensation method for a household single-phase photovoltaic energy storage cooperative converter based on an energy management harmonic priority compensation strategy. The household single-phase optical storage cooperative converter adopts a harmonic current priority compensation strategy, and the core of the harmonic current priority compensation strategy is to increase the residual current margin of a grid-connected inverter by utilizing photovoltaic load shedding and controlling the energy storage charging power, so that harmonic waves are completely compensated. Through a dynamic harmonic current compensation technology, when the output current of the grid-connected inverter exceeds a rated value, the harmonic current value is reduced through a harmonic current compensation factor, so that the output harmonic current value of the inverter is flexibly limited, and the harmonic current is compensated to the maximum extent while the grid-connected inverter works normally.

The invention discloses a photovoltaic coupling hydrogen production power supply device and system and a control method thereof.The device comprises a first power supply module and a second power supply module, the input end of the first power supply module is connected with a direct-current bus of a photovoltaic system, and the output end of the first power supply module is connected with a hydrogen production electrolytic bath; the input end of the first power module is further connected with an energy storage system or a power generation system through the second power module, and the first power module is used for being connected with direct current provided by a direct current bus of a photovoltaic system to conduct direct current conversion so as to supply energy to a hydrogen production electrolytic cell. And the second power supply module is used for converting the electric energy accessed to the energy storage system or the power generation system so as to provide supplementary direct current electric energy for the first power supply module, or returning the redundant electric energy output by the accessed photovoltaic system to the energy storage system or the power generation system. The system has the advantages of being simple in structure, low in cost, high in stability and efficiency, low in control complexity, high in flexibility and the like.

The invention provides a PWI modulation method for an inverter. Belongs to the technical field of power electronics, and comprises the following steps: setting basic working parameters of an inverter, initializing an initial value and a change range of a phase weighting factor, and presetting a PWF regulation strategy according to load characteristics and waveform quality requirements; loading and initializing a control algorithm of the inverter, and generating a standard sine wave as a reference wave according to a preset output voltage and frequency; calculating a PWF value of each phase point according to the current load state and a preset PWF adjustment strategy, and multiplying the PWF value by a standard sine wave to generate a target modulation waveform; and selecting a carrier signal, comparing the target modulation waveform with the carrier signal, and generating a PWM signal according to a comparison result. By presetting the PWF adjusting strategy and dynamically adjusting the PWF value, the waveform quality of the output voltage of the inverter can be effectively improved, and different load characteristics and waveform quality requirements are met.

The invention discloses a stability control method and device for an electric energy quality control system. The method is characterized by comprising the following steps: extracting characteristic parameters of acquired three-phase data of a power grid, and determining system state characteristic data; performing system compensation parameter estimation on the power quality compensation system according to the system state characteristic data and the power grid three-phase data, and determining system compensation parameter estimation data; determining an optimal control parameter according to the system state characteristic data and the system compensation parameter estimation data; performing system control prediction on the power quality compensation system according to the system compensation parameter estimation data, and determining a real-time control quantity of the power quality compensation system; performing control operation on the electric energy quality compensation system according to the real-time control quantity, and determining a control operation result; and optimizing the optimal control parameter based on the control operation result to obtain a target control parameter, and determining a target compensation current instruction according to the target control parameter. Efficient control is achieved, and economical efficiency, energy efficiency and reliability are met.

The invention relates to the technical field of big data analysis and data processing, and provides an intelligent power utilization load management method based on big data analysis, which constructs an accurate power utilization load prediction model by integrating historical power utilization data, climate data, a power grid equipment state and user behavior data. According to the method, the security and traceability of prediction data are improved by adopting a block chain technology, and automation of an electrical load management process is realized by means of an intelligent contract. The method comprises the specific steps of data acquisition and preprocessing, load prediction model construction and verification, prediction data storage and hash value generation, intelligent contract writing and execution, and process node data processing and evaluation. The method effectively solves the problems of load data abnormity and model errors, and improves the stability and management efficiency of a power grid system.

The invention discloses an industrial silicon intelligent power distribution and control system and method. The system comprises a data acquisition and processing module, a shared feature extraction module, an intelligent control module and a power distribution module which are connected in sequence. Multi-mode operation data is collected in real time, a shared feature extraction module is adopted to perform feature extraction on the operation data, data input is provided for subsystems of the intelligent control module, and information isolated island is avoided; through cooperative work of all the modules, global optimization control over the industrial silicon production process is achieved. The intelligent control module comprises an intelligent industrial silicon submerged arc furnace baking system, an automatic electrode lifting system, an automatic submerged arc furnace transformer gear adjusting system and an automatic electric energy quality adjusting system, and each system performs task prediction based on corresponding characteristics by adopting a pre-trained model and outputs optimized parameters; and the power distribution module generates a power distribution instruction based on the optimization parameters, so that intelligent distribution of power resources is realized, and dynamic adjustment and optimal distribution of energy consumption are realized.

The invention discloses a DAB-based two-stage DC-AC converter system, which is composed of a dual-active full-bridge DC-DC converter and a single-phase grid-connected inverter, and is characterized in that the dual-active full-bridge DC-DC converter is formed by connecting a primary side full bridge and a secondary side full bridge through a high-frequency transformer HFL and a resonance circuit composed of Cr and Lr; the single-phase grid-connected inverter comprises an inverter full bridge composed of switch tubes K1-K4 and an LCL type grid-connected filter circuit composed of inductors L1 and L2 and a capacitor C; the invention further discloses a secondary ripple suppression method and a control strategy, the pulse power of double frequency multiplication in the direct-current bus capacitor is transferred to the LC power decoupling branch through the LC passive branch connected to the middle point of the secondary side of the double active bridge, so that power decoupling is achieved, and the secondary ripple suppression in the direct-current bus voltage keeps the bus voltage stable.

The invention relates to the technical field of power grid impedance simulation control, and discloses a new energy grid-connected detection platform power grid impedance simulation control method which is based on a new energy grid-connected detection platform. Comprising the steps of output voltage and current sampling, phase voltage calculation, coordinate transformation, voltage regulation, modulation wave calculation, static coordinate system conversion, voltage calculation under simulation power grid impedance, SVPWM modulation and the like. According to the method, through accurate calculation and adjustment of each step, high-precision grid-connected performance evaluation can be realized, and reliable operation of new energy equipment under different conditions is ensured; performance testing can be carried out on different types of new energy equipment, by optimizing voltage regulation and SVPWM modulation, improvement of electric energy quality, reduction of harmonic waves and voltage fluctuation and guarantee of stability and high efficiency of a power system are facilitated, power grid impedance is simulated in a wide frequency domain, and engineering implementation is easy.

The embodiment of the invention provides a low-voltage electric energy quality problem monitoring terminal and a detection processing method, and belongs to the technical field of electric energy quality monitoring. The monitoring terminal comprises a central processor, a memory, a data acquisition module, a data preprocessing module, a feature extraction module, a problem identification module and an equipment positioning module. The data preprocessing module is used for preprocessing the collected data; the feature extraction module is used for extracting multi-dimensional features from the preprocessed data; the problem identification module is used for classifying and identifying the power quality problem by using a deep learning model and outputting an identification result; according to the monitoring terminal and the detection processing method, efficient, accurate and automatic monitoring and identification of the electric energy quality problem are realized, and powerful technical support is provided for detection of the electric energy quality problem of an electric power system.

The invention discloses a dynamic harmonic filtering control method and system, and relates to the technical field of electric power, and the method comprises the steps: collecting a voltage signal and a current signal of a power grid in real time; performing spectral analysis on the collected signals, and extracting harmonic characteristics; based on the harmonic characteristics, generating a compensation signal and optimizing the compensation signal; dynamically adjusting filtering parameters, and injecting an optimized compensation signal into a power grid through a filter module; uploading a system operation state in real time, and detecting and marking an abnormal state; according to the invention, rapid response and efficient suppression of power grid harmonics can be realized, the adaptability and filtering precision of multi-band harmonics are significantly improved, and the total distortion rate of the harmonics is greatly reduced, so that the quality of electric energy is optimized. The system operation efficiency and stability are improved, the anti-interference capability is strong, and the system is suitable for a complex power grid environment; the system can monitor the operation state in real time, automatically give an alarm and mark abnormity, the reliability and safety of power grid operation are improved, and the maintenance cost is reduced.

The invention relates to an electric energy quality comprehensive optimization method based on multi-resource cooperative control, and belongs to the field of electric energy quality comprehensive optimization. According to the method, operation of two kinds of differential regulation and control characteristic equipment of the SVG and the multifunctional grid-connected inverter is coordinated, and comprehensive treatment of three kinds of typical electric energy quality problems of harmonic distortion, voltage deviation and three-phase imbalance is considered. Wherein the SVG device is used as a common reactive compensation device and only participates in compensation of voltage / reactive power problems, and the multifunctional grid-connected inverter needs to meet active power output and also considers regulation and control of harmonic wave and reactive power problems. According to the invention, the problems of insufficient cooperative control and poor comprehensive treatment effect in the current electric energy quality regulation and control method can be solved.

The invention relates to the technical field of photovoltaic power generation, and discloses a phase-locked loop-free photovoltaic power generation system multi-power quality cooperative improvement method and system, and the method comprises the steps: processing a collected current signal of a three-phase grid-connected point of a photovoltaic power generation system to obtain a current fundamental component and a current harmonic component of the grid-connected point, and determining a fundamental reactive power; determining the capacity required by harmonic suppression and the capacity required by reactive compensation according to the current harmonic component of the grid-connected point and the fundamental reactive power; obtaining the residual capacity of the photovoltaic power generation system, and carrying out an optimization algorithm to determine the optimal compensation coefficient of harmonic suppression and reactive compensation; and transmitting the optimal compensation coefficient of harmonic suppression and reactive compensation to a photovoltaic inverter control algorithm to complete multi-power quality collaborative improvement of the photovoltaic power generation system. The technical problems of large delay, slow control response speed, need of a phase-locked loop and poor power quality management target collaboration in the prior art are solved.

The invention provides a three-phase SVPWM grid-connected inverter harmonic control method based on an improved particle swarm algorithm, and relates to the field of grid-connected control. On the basis of double closed-loop control of a three-phase SVPWM grid-connected inverter, a main circuit topological structure of the grid-connected inverter is firstly provided, and a mathematical model of the grid-connected inverter is determined; then determining a double-closed-loop control strategy based on space vector modulation according to the mathematical model; and aiming at a voltage outer loop and a current inner loop of the double-closed-loop control strategy, an improved particle swarm optimization algorithm is adopted to optimize PI parameters. According to the improved inertia weight, the minimum value, the maximum value and the fitness function of the inertia weight are comprehensively considered, a harmonic suppression performance index is added to the fitness function, and the improved particle swarm optimization algorithm enhances the global search capability and the accurate search capability, so that the probability of falling into a locally optimal solution is reduced. According to the control method, the grid-connected process of the grid-connected inverter can be more stable, the anti-interference capability is enhanced, the static error is reduced, and the electric energy quality is improved.

The invention discloses an energy storage converter control method, which relates to the technical field of energy storage converters and is a method for monitoring the running state of an energy storage converter in real time and executing fault protection and / or state machine switching. The energy storage converter fault protection method comprises the following steps: reading a GPIO state or collecting a measurement value of each protection point, and comparing the measurement value with a fault threshold parameter to determine whether a fault occurs; when a fault occurs, a fault bit corresponding to the fault code register is activated, and the state machine is switched to a fault state and executes a fault protection program; the energy storage converter state machine switching method comprises the following steps: detecting whether a master control word register jumps or not compared with a previous period and executing corresponding operation; and executing corresponding control logic according to the current state of the state machine, wherein the states comprise a shutdown state, an alternating current pre-charging starting state, a standby state, an operation state, a fault state and a synchronous phase pulse test state. According to the method, the fault can be quickly responded, and the operation stability and safety of the PCS are ensured.

The invention discloses a vehicle-mounted bidirectional power converter which comprises a pre-stage voltage stabilization module, a pre-stage driving circuit, a post-stage driving circuit, a post-stage filtering module and an electric vehicle battery module, the pre-stage voltage stabilization module is used for balancing circuit voltage and supporting reactive power, the pre-stage driving circuit is of a single-phase full-bridge AD-DC topological structure, and the post-stage filtering module is of a single-phase full-bridge AD-DC topological structure. The front-stage driving circuit is of a half-bridge type bidirectional DC-DC topological structure, the rear-stage driving circuit is of a half-bridge type bidirectional DC-DC topological structure, the front-stage driving circuit and the rear-stage driving circuit are connected together through a direct-current voltage-stabilizing bus, the size is small, the weight is light, a front stage and a rear stage do not interfere with each other, control is easy, the rear-stage filtering module is used for restraining direct-current side second harmonics, the harmonic quantity is prevented from influencing the stability of output direct-current voltage, and the output direct-current voltage is stable. According to the converter, a corresponding control method is designed, non-inductive decoupling control and a single-phase phase-locked loop of an improved loop filter are adopted, the phase of a power grid is accurately and efficiently obtained, and the converter works stably.

The invention relates to the technical field of power grids, in particular to a control method and system for an anti-resonance energy storage converter to be connected to a grid-connected system, a terminal and a medium. FFT Fourier transform is carried out on obtained current voltage and current of a grid-connected point, a complex time domain signal is decomposed into superposition of a plurality of simple sine and cosine functions, and the voltage and current of the grid-connected point are obtained; in a spectrogram, the frequency components and characteristics of the signal, including the amplitude and phase information of each frequency component, including harmonic parameters and characteristic sub-harmonics, can be clearly obtained. In the step S2, negation can be carried out on harmonic waves appearing in the grid-connected system through characteristic subharmonic waves, and deduction effect reduction is carried out on the harmonic waves. In the step S4, when the harmonic parameter still exceeds the preset standard value after the step S2 is carried out, it shows that harmonic oscillation causes a resonance phenomenon, and at the moment, the system impedance is changed by adjusting the virtual impedance of the energy storage converter, so that the harmonic oscillation can be weakened or even eliminated to a great extent.

The invention relates to the technical field of power transmission line detection, in particular to the technical field of active power distribution network power quality monitoring and management, and particularly relates to an active power distribution network power quality panoramic sensing and abnormity positioning management system. Comprising a monitoring terminal adaptation module, a monitoring point optimization configuration module, an electric energy quality sensing early warning module, a composite electric energy quality traceability module, an electric energy quality comprehensive treatment module and a power distribution network dispatching sensing module. According to the invention, full-process management and control from optimal configuration of the electric energy quality monitoring terminal, accurate perception, positioning and tracing of problems, comprehensive treatment and intelligent support of power distribution network dispatching are realized; various electric energy quality problems in the active power distribution network are effectively solved, safe and stable operation of the power grid is guaranteed, the power utilization quality and satisfaction degree of users are improved, and efficient and reliable development of the active power distribution network is promoted.

The invention discloses a method for determining a distributed photovoltaic access strategy of a power distribution network based on permeability. The method comprises the following steps: acquiring permeability information, network topology information and a distributed photovoltaic operation mode of a power distribution network in a preset power supply area; determining a distributed photovoltaic access mode based on the permeability information and the operation mode; based on the permeability information and the network topology information, determining access voltage grade information and access position information of the distributed photovoltaic; and determining a distributed photovoltaic access strategy based on the access mode, the access voltage level information and the access position information. According to the invention, the technical problem that the determination of the distributed photovoltaic access strategy lacks integrity and systematicness in the prior art is solved.

The invention provides a parameter correction method based on load prediction. The method comprises the following steps: acquiring electrical load information of a power distribution network area; an electrical load prediction model is constructed, the electrical load prediction model obtains electrical prediction data according to the electrical load information, and self-correction operation is carried out on input parameters of the electrical load prediction model; acquiring three-phase voltage information of the power distribution network area and a charge state of a battery, and calculating first reactive regulation power and first active regulation power of the power distribution network area by a preset area power regulation model according to the power utilization prediction data, the three-phase voltage information and the charge state; and adjusting the charging time period and the discharging time period of the power distribution network according to the first reactive adjustment power and the first active adjustment power. According to the technical scheme of the embodiment, the charging and discharging time period of the power distribution network is flexibly adjusted by dynamically calculating the reactive power adjusting power and the active power adjusting power of the PCS, so that the electric energy quality of the power distribution network is actively improved.

The invention provides a method and a system for calculating power grid impedance based on a sliding window. The method comprises the following steps: setting a signal category and a signal length of a disturbance signal to be injected into an access power grid by a new energy station; according to the signal category, the new energy field station injects orthogonal signals with the same amplitude and frequency into a d axis and a q axis of an access power grid at the same time as disturbance signals; acquiring three-phase current data and voltage data of the signal length at a grid connection point; and calculating the power grid impedance at the target frequency based on a sliding window according to the three-phase current data and the voltage data. According to the method and the system, the electric energy quality during the disturbance injection period is improved, the noise interference resistance of impedance calculation is improved, and it is well ensured that an impedance measurement result with rapidness and accuracy is obtained within a wide frequency range.

The invention discloses a power distribution network fault self-healing device and a self-healing method. The device comprises node equipment and an operation management platform, the operation management platform is used for analyzing operation parameters of the node equipment, positioning a fault area and sending a control instruction for power-off isolation and power supply recovery; the node equipment comprises power supply equipment, sensing equipment, a node control switch and electric energy quality treatment equipment; the sensing equipment is used for monitoring and collecting operation parameters of the node equipment; the node control switch is disconnected and isolates a fault area when detecting that an operation parameter exceeds a threshold value or the integrated fault detection model identifies an abnormal mode or receives a control instruction of the operation management platform, and is connected and recovers power supply of a non-fault area when receiving a power supply recovery control instruction of the operation management platform so as to realize fault self-recovery; the electric energy quality control equipment is used for reducing voltage fluctuation in the process of recovering power supply of a non-fault area and avoiding misoperation of a node control switch. The device is simple in structure and self-healing process, and quick response to faults is realized.

The invention relates to the technical field of load monitoring, and discloses a load monitoring method of a low-voltage transformer area and a line electric leakage detection method based on a low-voltage transformer area load detector device. Comprising the steps of current signal acquisition and processing, current-voltage conversion, signal processing, Fourier transform FFT processing, real-time current value calculation and output, data transmission, remote monitoring and the like. According to the load monitoring method and the line leakage detection method for the low-voltage transformer area, a real-time current signal is acquired through an open current transformer, and is processed by means of a Fourier transform FFT algorithm, so that the load distribution condition of the low-voltage transformer area can be accurately monitored; the problem of randomness of a traditional measurement method is solved, it is ensured that the collected load data accurately reflects the actual power consumption condition of each household, and reliable support is provided for follow-up three-phase load adjustment. The three-phase load condition of each branch line in the multiple branches of the low-voltage line can be accurately monitored by simultaneously monitoring the branch lines in the multiple branches of the low-voltage line.

The invention discloses a through traction power supply system based on two-phase-single-phase isolation and non-isolation hybrid topologies, and belongs to the technical field of power electronic transformers, the through traction power supply system comprises two single-phase isolation and non-isolation hybrid topologies, each single-phase isolation and non-isolation hybrid topologies comprises an isolation unit and a non-isolation unit which are cascaded, each isolation unit comprises one or more cascaded isolation modules, the isolation module comprises a first rectifier, an isolation type power electronic transformer and a first inverter which are in cascade connection in sequence; the non-isolation unit comprises one or more cascaded non-isolation modules, and each non-isolation module comprises a second rectifier and a second inverter which are cascaded in sequence. Compared with a system adopting transformer isolation, an industrial frequency transformer and part of high-frequency isolation transformers are omitted, a short-circuit path can be blocked based on the isolation module, the topological volume is effectively reduced, the cost is reduced, and compared with a completely non-isolated system, the available vector plane is widened, and the safety and reliability of the system are high.