374 results about "Branch current" patented technology

The invention discloses an active power distribution network two-stage island division method and system considering flexible resource support. The method comprises the following steps: establishing a first resource allocation model considering energy storage and controllable load, the first resource allocation model comprises energy storage battery charging and discharging upper and lower limit constraints, an energy storage battery degradation cost model, a controllable load model and a controllable load related user protocol; obtaining parameter data of a target power distribution system, wherein the parameter data comprises a line parameter, a load level, a load level, a network topology connection relationship, a system operation voltage level and branch current limitation, a system fault position, a reference voltage and a reference power initial value; and according to the parameter data, establishing a mathematical model for two-stage island power supply recovery based on a first resource allocation model. The method for solving the island is simple and convenient, the island recovery amount can achieve the optimal recovery effect, meanwhile, the search time is greatly shortened, the solving efficiency is higher, and the rapid power supply recovery capacity of the power distribution network is improved.

The invention relates to the technical field of electric energy conversion control, and discloses a multi-source load auxiliary power supply power balance control system, which comprises a sampling module, a control module and a modulation module, the sampling module obtains parallel converter branch current and direct current bus voltage; the control module determines a weight by utilizing physical associated association of a bus voltage change gradient and branch current change polarity, corrects a dynamic slope factor determined by a current change rate according to the weight, and performs upper limit clamping on the dynamic slope factor according to a bus voltage margin; according to the invention, the rigid restriction of droop control logic is eliminated, the power deviation generated by asymmetry of feeder impedance is automatically offset while the bus voltage stabilization precision is maintained, and the convergence speed and the certainty of the system during violent load switching are improved.

The invention belongs to the technical field of DC power grid short-circuit current calculation, and particularly relates to a short-circuit current calculation method for a metal backflow four-terminal bipolar DC power grid, and the method comprises the steps: S1, building an MMC equivalent model; s2, constructing and processing an equivalent circuit of a Bergeron lossy transmission line of the DC line to obtain a Bergeron two-port equivalent model of a single-phase transmission line and a Bergeron equivalent model of a three-phase transmission line; s3, establishing an equivalent model of the metal backflow four-terminal bipolar direct current power grid; s4, establishing an accompanying circuit model of the metal backflow four-terminal bipolar direct current power grid; s5, constructing a conductance matrix G, and forming a node voltage equation; and S6, according to the fault type, modifying a node admittance matrix G in the node voltage equation into an equivalent conductance matrix G ', and then solving the modified node voltage equation to obtain the branch current and the node voltage after the fault. According to the method, the problem that the short-circuit current calculation method of the metal backflow four-terminal bipolar direct-current power grid is insufficient in accuracy can be solved.

The invention relates to a motor simulator current tracking control method and system, and the method comprises the steps: building a reference model of a motor simulator test system which comprises a tested motor drive module and a motor simulator connected with the tested motor drive module; performing simulation comparison on the branch current of each parallel branch and the model output reference current with single-phase total current feedback, setting a hysteresis coefficient of hysteresis comparison according to a hysteresis comparison principle, and generating a hysteresis comparison result; according to the branch states of the tested motor driving module and the motor simulator, current increase and decrease of a parallel branch on the inverter side of the motor simulator are controlled in combination with a hysteresis comparison result, commutation is carried out after current increase and decrease at a single time in each period, and multi-branch fixed-frequency phase-dislocation current control is achieved. By adopting a current hysteresis comparison control method with total current feedback compensation and a fixed-frequency phase-dislocation current control algorithm, the high-frequency and high-power working requirement of the motor simulator is met, and the current tracking precision and the dynamic response speed are improved.

The invention discloses a high-voltage discharge circuit suitable for a storage battery power supply and an electric flame stove. The high-voltage discharge circuit comprises an inversion driving module, a boosting transformer T1, at least three groups of active bridge rectifier modules and discharge modules corresponding to the active bridge rectifier modules. Through combination of driving of the active bridge rectifier module, voltage / current double-closed-loop feedback and real-time PWM signal output control of the control chip U1, current difference of each discharge branch is eliminated, the problem of uneven branch current is solved, and ring current and reactive power loss between branches are eliminated; a diode in a voltage doubling rectifying circuit and a bleeder resistor of a resonance circuit in the prior art are abandoned, an active bridge type rectifying module is adopted for driving, a PWM signal is dynamically adjusted through the low ESR characteristic of a capacitor C1 and closed-loop control, extra power loss is avoided, the working temperature of the circuit is controlled to be below 85 DEG C, and the service life of the circuit is prolonged. And the continuous service life of components in the circuit is prolonged.

The invention relates to the technical field of power systems, and provides a power transmission line lightning stroke fault positioning method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring transient voltage data after a power transmission line is directly struck by lightning; defining a set of possible fault locations based on the historical fault data; converting the transient voltage into a transient current; reversely injecting the transient current into a simulation model of the power transmission system from the same observation point, and simulating a transverse branch current at each possible fault position; and calculating the time domain similarity between the transient current and the transverse branch current at each possible fault position, and determining the fault position with the highest similarity as a lightning stroke fault position. According to the invention, high-precision positioning of the lightning stroke fault can be realized only by installing one measurement point in the main substation, and the reliability is high. The method is not only suitable for a lossless system, but also suitable for a lossy transmission line.

The invention discloses a reinforcement learning-based multi-target scheduling optimization method. The method comprises the following steps of obtaining historical voltage data of each node of a power system; randomly generating power supply and load disturbance, changing the voltage value of each node after solving through load flow calculation, and recording the current of each branch, the total network loss and the total reactive compensation capacity of the system; calculating the sensitivity vectors of each voltage node to the branch current, the total network loss of the system and the total reactive compensation amount by using a Monte Carlo method, and carrying out weight addition normalization to obtain a total weighted sensitivity vector which is the weight of each node; a node'weight 'is defined to be multiplied by a time sequence operation voltage deviation value of the node'weight' to be a node weighted voltage deviation value, and the node'weight 'is globally accumulated to be a system weighted voltage deviation value; introducing a system weighted voltage deviation value to train a near-end strategy to optimize a reinforcement learning agent; therefore, the voltage real-time optimization control strategy of the power system is realized. According to the invention, multi-target control of the power system can be effectively realized, and safe, reliable and economical operation of the power system is facilitated.

The invention relates to the technical field of electronic digital data processing, in particular to an operation fault diagnosis method and system for a PTC (Positive Temperature Coefficient) heating device. The change intensity of the branch current of the PTC aluminum pipe under the surface temperature data is determined, so that the thermal performance risk possibility of the PTC heating device is determined, the PTC fault performance degree at the current moment is obtained in combination with the in-vehicle temperature data and the initial temperature and the air inlet rate of the air of the PTC air inlet, and then the power-on current data input by the PTC total circuit are combined to determine the fault performance of the PTC heating device. And obtaining a PTC operation early warning index at the current moment for fault alarm. According to the invention, through the combined analysis of the resistance heat sensitive characteristics of the PTC electric heating element and the characteristics of the air entering the PTC device in an actual scene, the early warning diagnosis precision of the PTC operation fault of the automobile is improved.

The invention relates to a current switching-on and switching-off converter which comprises a shell barrel, a plurality of limiting rings and a plurality of wires, a shell cavity is formed in the shell barrel, the limiting rings are contained in the shell cavity, limiting holes and conductive springs are arranged in the limiting rings, the limiting holes are communicated with guide holes, the conductive springs surround the limiting holes, one ends of the wires are electrically connected with the conductive springs, and the other ends of the wires are electrically connected with the conductive springs. And the other end of the lead extends out of the shell cylinder. By adopting the technical scheme provided by the invention, when the number of branch currents is more, the wires are not limited to be arranged in the same plane any more, the reduction of the appearance size of the electric connector is facilitated, and the electric connector can be assembled and applied in a narrow space range; when the electric connector provided by the invention is plugged with other electric connectors, the rigid surfaces of the conductive parts are in contact with the flexible surfaces of the conductive springs, so that good electrical contact between the electric connectors can be ensured, and the reliability of electrical connection is ensured.

The invention discloses a fault current analysis method and system for a multi-terminal flexible DC circuit, and the method comprises the steps: analyzing fault current data when the DC side of a modular multilevel converter is short-circuited, and obtaining time sequence segmentation rule data; performing equivalent processing on the modular multilevel converter based on the segmentation rule data to obtain an equivalent circuit model comprising an RLC series circuit and a time-varying current source; constructing a second-order differential equation for describing the fault current according to the equivalent circuit model, and solving the second-order differential equation to obtain a fault current expression containing dynamic alternating current feed-in; constructing a fault equivalent network of the multi-terminal flexible DC circuit; and constructing a state-space equation of the fault equivalent network based on a branch current method and the fault current expression, and solving the state-space equation to obtain fault current data of the multi-terminal flexible DC circuit. According to the method, the accuracy of fault analysis is improved.

A converter station AC filter group circuit breaker abnormal arcing modeling analysis method comprises the following steps: firstly, carrying out time mark alignment, amplitude calibration and filtering de-noising on wave recording signals such as AC bus voltage and filter branch current to obtain high-quality input data; then, combining a primary wiring diagram, enabling an alternating current system to be equivalent to an ideal power supply and series impedance, enabling circuit breaker arcing to be equivalent to arc resistance changing along with time, and constructing an equivalent circuit model comprising the power supply, the impedance, a capacitor, an electric reactor and dynamic arc resistance; establishing a state space equation according to a voltage and current constraint relation, and performing time domain solution by adopting a two-step two-order or three-order diagonal implicit Runge-Kutta method to obtain voltage and current responses of the whole process of the fault; on this basis, the arc resistance change is inversed according to the ratio of arc voltage to current, the current zero passage is identified through the resistance symbol change at adjacent moments, and the zero passage section is smoothed; and finally, the inversion result is verified again by means of the simplified equivalent model.

The invention relates to the technical field of power grid safety evaluation, in particular to a power system short-circuit parameter prediction method, system and device based on time-space relevance and a storage medium. A multi-dimensional state vector including a node voltage vector, a branch current vector, a short-circuit impedance matrix, spatial position information and a time feature vector is constructed, and a space-time correlation feature vector including a time-dimensional feature, a spatial-dimensional feature, a space-time coupling feature and a state feature is extracted. Wavelet transform, Fourier analysis and graph theory analysis are adopted to identify a parameter change rule and a propagation effect. A multi-level prediction model of a statistical prediction layer, a deep learning layer and a fusion layer is constructed, and comprehensive description of dynamic characteristics of short-circuit parameters is realized through spatio-temporal feature fusion. A staged training strategy is adopted, and comprises the steps of establishing a basic model through offline training, updating parameters in real time through online learning, and quantifying uncertainty through a probability prediction framework. And a prediction correction mechanism and a reliability evaluation system are established, and a complete prediction-evaluation-correction closed loop is formed.

The invention relates to the field of capacitor monitoring, and provides a capacitor quasi-online state monitoring method and system for a wind power converter, and the method comprises the steps: extracting a data slice comprising DC bus voltage, capacitor branch current, housing temperature and output power from a data buffer area; furthermore, output power data is utilized, intelligent screening is carried out through a quasi-steady-state slice trigger, and only effective data with the power average value large enough and the fluctuation small enough are reserved. And for the screened effective data slices, extracting the DC bus voltage and the capacitance branch current, and accurately identifying the voltage, current amplitude and phase information of the main harmonic through fast Fourier transform. Based on the key harmonic data, the complex impedance of the capacitor is calculated, and then the original ESR and capacitance estimation value are calculated. And finally, in combination with the capacitor shell temperature extracted from the same data slice, performing temperature compensation on the original parameters, and outputting a final result capable of truly reflecting the aging state of the capacitor.

The invention discloses an electric power system wiring detection method based on block parallel processing, and relates to the field of current detection, and the method comprises the steps: collecting real-time operation data through a sensor disposed at a key node, and constructing a basic data set after Kalman filtering denoising and normalization processing; establishing a sub-block identification system based on topological structure blocks, and extracting electrical and topological feature vectors; a master-slave parallel computing architecture is adopted, a master node allocates tasks according to priorities, and an improved random forest model is utilized to perform sub-block level anomaly preliminary screening; cross-sub-block collaborative verification is realized by verifying the boundary interconnection switch state, the branch current and the bus voltage; and finally, constructing a global wiring state map to perform difference analysis, accurately positioning abnormal equipment and types, and verifying a result through high-precision retest. The method has the advantages that the efficiency is improved through scientific partitioning and distributed parallel computing, the accuracy is guaranteed in combination with multi-dimensional detection, boundary verification and a retest mechanism, wiring abnormity is efficiently positioned, and reliable support is provided.

The invention belongs to the technical field of power protection, and particularly relates to a station transformer grounding current synchronous synthesis method and system, and the method comprises the steps: carrying out the grouping according to the number of a station transformer, synchronously collecting the grounding branch current of each station transformer to obtain an original signal, carrying out the double identification, and carrying out the homologous copying; generating two paths of independent signals of frequency detection and phase calibration; frequency detection signals are grouped according to double identifications, the independent actual frequency of each station transformer is obtained after frequency detection processing, and a same-frequency sine dynamic reference signal is generated based on the independent actual frequency; performing phase alignment and compensation on the phase calibration signal and the corresponding reference signal according to the double identifiers to obtain a calibrated signal; according to the method, the phase calibration reference of each station transformer is completely matched with the actual frequency of the station transformer, the reason of phase reference dislocation caused by frequency fluctuation is eliminated from the source, and the accuracy of synthesizing the total grounding current in the station is improved.

The invention belongs to the technical field of energy storage and grid connection, and particularly relates to a non-linear modeling method for a network-building type energy storage converter based on a mixed potential function, which comprises the following steps of: in an analysis model of the mixed potential function, determining a group of complete mixed variables of branch current and voltage by a non-energy-storage element and a capacitor; the method comprises the following steps: calculating a product of a current potential function of a non-energy-storage element and a voltage and a current on a capacitor according to an energy relation of system elements according to an inductive current and a capacitor voltage in an energy storage grid-connected system, and further deriving a mixed potential function of the system; and constructing a nonlinear model of the energy storage grid-connected system according to the determined hybrid potential function of the energy storage system. According to the method, the transient stability behavior of a nonlinear circuit is considered from the perspective of energy, the Lyapunov function construction difficulty of a high-order nonlinear system is reduced, and the problem that the transient stability analysis difficulty of the nonlinear system is large under the condition that the system is subjected to large disturbance can be solved.

The invention discloses a synchronous generator rotor turn-to-turn fault online monitoring method and system, and the method comprises the steps: building a time-varying parameter mathematical model which comprises a stator branch, a normal excitation loop, an excitation fault additional loop, a damping loop and a load based on a multi-loop theory, and collecting the current signals and key-phase signals of all parallel branches of a stator in real time; the fractional harmonic characteristic quantity representing the fault is extracted through analysis, and whether turn-to-turn short circuit occurs or not is judged according to a preset criterion; and if the fault is determined, determining the position of the fault magnetic pole by adopting a phase matching algorithm in combination with the key-phase signal and the magnetic pole fault characteristic angle database. According to the method, the primary side of the generator does not need to be transformed, high-sensitivity online monitoring and accurate positioning of rotor turn-to-turn faults in operation can be achieved, and the method is suitable for safety guarantee of an active-service unit.

The invention relates to the technical field of display, and discloses an electronic paper display device and a driving method thereof.The electronic paper display device comprises a co-stage electrode module which is arranged on the color film substrate side of an electronic paper module and comprises N independent electrode blocks forming a whole-surface co-stage electrode, the area or resistance value of each independent electrode block is equal, and N is larger than or equal to 2; the current sharing circuit module is used for dynamically adjusting the charging and discharging current of each independent electrode block according to the dynamic adjusting instruction and controlling the current difference of each branch within a preset fluctuation range; the driving control module is used for receiving the balanced current signal output by the current sharing circuit module and sending a dynamic adjusting instruction to the current sharing circuit module through a control signal line; and the driving control module is also used for outputting charging and discharging pulses to each independent electrode block according to a preset time-sharing sequence. According to the device and the driving method thereof, the charging and discharging current difference is reduced, and the reliability of the electronic paper in a high-temperature environment is improved.

The invention discloses a transformer substation reactive power compensation equipment optimal configuration method cooperating with energy storage value, electronic equipment and a medium, and the method comprises the following steps: depicting the physical characteristics of an energy storage compensator and a reactive power compensator based on a Distflow equation; dividing power flow in the power distribution network considering factors including the type, the quantity, the output power, the access mode and the load of new energy power generation so as to coordinate active power and reactive power; based on the power flow, constructing a target function taking the minimization of the voltage deviation value and the load shedding cost as targets; and according to a preset photovoltaic energy storage capacity constraint, an energy storage charging and discharging constraint, a power flow constraint, a power distribution network branch current constraint, a power distribution network node voltage constraint, a second-order cone constraint and a target function, carrying out collaborative optimization of the energy storage and reactive power compensation device.

The invention discloses a method for establishing a small-signal mathematical model of a train network system during dynamic change of train operation, which comprises the following steps of: firstly, dividing the system into four sub-modules, namely a train, a traction network, a traction transformer and a power grid, and dividing an uplink traction network and a downlink traction network into n + 2 sections according to the maximum number n of trains operating on a power supply arm, the traction network is formed by cascading the impedance of each section of equivalent line of uplink and downlink, then establishing a small-signal mathematical model of each sub-module, and then forming a system small-signal mathematical model when the number of trains capable of running on a power supply arm is maximum through a relational expression between the voltage of each node and the current of each branch of the network according to the actual topology of the system. When the train operation number changes, state variables related to the trains and coefficient matrix elements related to the state variables are deleted, and when the train operation position changes, the specific value of the impedance of each section of the traction network is changed, so that dynamic modeling of the train network coupling system can be realized. According to the invention, the stability of the vehicle network system can be evaluated online.

The invention discloses a direct-current system ground fault real-time monitoring method and system, and relates to the field of intelligent power distribution, and the method comprises the steps: collecting the bus voltage, branch current and disturbance response signals of each branch, constructing a fusion abnormal factor in a fixed monitoring window, comprehensively reflecting the voltage change rate, disturbance amplitude response and current vector offset characteristics, and carrying out the real-time monitoring of the ground fault of a direct-current system. And inputting the factor and a disturbance parameter into a nonlinear scoring function together, and outputting a grounding probability confidence score. And for the branch with the scoring result exceeding a set threshold value, the system executes bypass closing and main branch opening operation, voltage and current derivative data are collected in a recovery window, the voltage drop recovery rate is calculated, and whether an actual grounding point is formed or not is judged. And if the fault is confirmed to be true, the isolation state is maintained, and branch reset operation is completed through a recovery criterion and a manual permission mechanism in a subsequent period. The method has better effects in real-time performance, accuracy and safety.

The invention belongs to the technical field of metallurgical equipment, and particularly relates to a method for transforming a direct-current submerged arc furnace based on a traditional three-phase alternating-current submerged arc furnace and the direct-current submerged arc furnace. The direct-current submerged arc furnace comprises a submerged arc furnace body, three cathodes, three anodes and a direct-current power source, the three cathodes are arranged on the furnace top at equal intervals of 120 degrees, and the three anodes and the three cathodes are arranged at the furnace bottom in an aligned mode; the three anodes are respectively connected with the positive electrode of a direct-current power supply, the three cathodes are respectively connected with the negative electrode of the power supply, direct current is respectively input into the furnace through the three anodes and forms three groups of stable electric arcs with the three corresponding cathodes, so that the magnetic induction force of an external magnetic field can be reduced, the problem of arc deflection is solved, and the energy consumption of metallurgy is reduced; the insulating layer can cut off branch currents distributed in the hearth of the direct-current submerged arc furnace, interference of the branch currents on electric arcs is avoided, the electric arcs are prevented from deviating, the length of the electric arcs is shortened, heat efficiency is improved, and energy consumption of metallurgy is reduced.

The invention provides a low-voltage distribution network node voltage prediction method based on user shared line impedance, which belongs to the technical field of intelligent power grids, and comprises the following steps: S1, carrying out load flow calculation based on a forward and backward substitution method, and calculating the voltage and branch current value of each node through forward and backward substitution processes; s2, a forward-backward substitution method is simplified, and the relation between node voltage and current and user shared line impedance is obtained; s3, based on a Newton-Raphson method, solving user shared line impedance; and S4, based on the obtained user shared line impedance, according to the estimated user load, obtaining the predicted voltage of each node of the low-voltage power distribution network. According to the method, the problem that the network topology structure of the low-voltage distribution network is difficult to obtain is effectively avoided, the difficulty of predicting the node voltage of the low-voltage distribution network is greatly reduced, the prediction process is simpler, more convenient and more practical, and the method is also suitable for the high-voltage distribution network.

The invention relates to the technical field of electromagnetic transient simulation, in particular to an electromagnetic transient simulation decoupling method, system and device based on a single-impedance branch and a medium, and the method comprises the steps: dividing a system to be simulated into two subsystems which are connected through the single-impedance branch, and carrying out the equivalent reconstruction to form a reconstructed branch model; establishing a discrete state space equation based on the reconstructed branch model; according to the main step length, the number of sub-steps meeting the stability condition is determined based on a small-step synthesis algorithm, and the main step length is equally divided into differential step lengths; in each main step length interval, performing iterative calculation on the state-space equation by using a differential step length to obtain a branch current and a capacitor voltage at the next moment; and injecting the calculated branch current serving as a known current source into an original network equation, solving in parallel to obtain the port voltage of the subsystem, and completing decoupling calculation and promoting simulation. According to the method, effective decoupling of the universal single-impedance branch can be realized, and the applicability, the numerical stability and the calculation efficiency of parallel simulation are improved.

Disclosed in the present application are a floor address automatic setting circuit and method, and an elevator. The floor address automatic setting circuit comprises a main control module, a plurality of cable modules, a plurality of hall-call panel modules, and a voltage measurement module, wherein each hall-call panel module comprises a branch unit and a load unit which are connected in parallel, and when the branch unit is connected, a branch current is superimposed on a load current of the load unit, such that an input current of the hall-call panel module increases, so as to increase the voltage drop of a front-end cable module, thus increasing the voltage difference between two adjacent hall-call panel modules; and the voltage measurement module measures input voltages of the plurality of hall-call panel modules, and the main control module determines, on the basis of the input voltages, floors where the hall-call panel modules are located, so as to perform floor address setting.

The invention relates to the technical field of fault detection, in particular to a generator stator winding turn-to-turn short circuit detection method and system, and the method comprises the steps: synchronously collecting stator branch current, an air-gap magnetic field and an engine base vibration signal; preprocessing the signal and standardizing the working condition; extracting and adaptively fusing three types of feature vectors of branch current circulation, magnetic field asymmetry and vibration feature spectrum correlation to generate a comprehensive fault feature vector; inputting the short-circuit fault into a trained turn-to-turn short-circuit intelligent classifier, and outputting a fault judgment result and a continuous short-circuit fault confidence coefficient index; and finally, combining a confidence index trend and a feature contribution degree backtracking analysis result to generate a comprehensive state evaluation report. According to the invention, high-sensitivity and high-reliability online detection and early warning of early weak turn-to-turn short circuit are realized.

The invention relates to the technical field of power management, and discloses a power grid resource visual display method for a business expansion scheme. According to the method, by collecting and processing the power grid operation data, the power grid topological data and the user power load historical data in real time, high-quality and more accurate fusion analysis of the data is guaranteed, static data is converted into dynamic information, the limitation that a traditional visualization tool can only provide outdated information is overcome, and the method is suitable for popularization and application. By means of calculation of short-term and long-term load prediction, the influence of a newly added load on the overall safety and stability of an existing power grid is effectively evaluated, and a user can visually observe voltage distribution of each node of the power grid, a branch current state and a real-time load condition through a visual display module, so that the user experience is improved. According to the comprehensive display scheme, the intelligence level of power resource configuration is improved, important support is provided for optimization management decision of power grid operation, and efficient utilization and further sustainable development of power grid resources can be achieved.

The invention discloses an open circuit diagnosis method, an open circuit diagnosis device, an energy storage system and a vehicle, and belongs to the technical field of energy storage. The open circuit diagnosis method comprises the following steps: judging whether an open circuit fault occurs in n branches or not; and when the open circuit fault occurs in the n branches, determining the shunt current in each branch, and if the shunt current is less than or equal to the first target current, judging that the corresponding branch is open circuit. According to the open circuit diagnosis method provided by the invention, the problems of fault false alarm and the like caused by circulation between the branches due to the differential pressure can be effectively solved, the open circuit state of each branch can be diagnosed, and the after-sales maintenance efficiency can be improved.

The invention discloses a distributed photovoltaic-containing power distribution network planning layer multi-objective optimization method, which comprises the following steps of: constructing a multi-objective optimization model taking investment cost, network loss and voltage deviation as sub-objectives, and integrating the sub-objectives into a unified optimization function through a weight coefficient method; multi-dimensional constraint conditions such as node voltage safety, power balance, capacity upper limit, branch current and whole network permeability are established in combination with load flow calculation, photovoltaic optimal point distribution and capacity configuration are solved by adopting an improved flower pollination algorithm, and the convergence speed and optimization precision are improved. The improved dynamic projection primal-dual distributed algorithm is adopted, and local information exchange and a self-adaptive step length mechanism are utilized, so that the real-time network loss minimization and voltage stability control of the high photovoltaic penetration power distribution network are realized, and the safety and economy of the system are ensured.

The invention provides a power distribution network node harmonic exceeding main cause identification method, device and system and a medium, and the method comprises the steps: building a node admittance matrix based on the node harmonic voltage and branch current monitoring data of a power distribution network, building a related equation of the harmonic voltage and an injection current, and employing a compressed sampling matching pursuit algorithm to identify the harmonic exceeding main cause of the power distribution network; solving a sparse harmonic injection current vector, and calculating a node harmonic voltage distortion rate according to a harmonic current injection value so as to judge a standard exceeding condition; through a modal analysis method, harmonic current threshold comparison and multi-frequency superposition effect analysis, identifying main factors exceeding the standard, including harmonic injection standard exceeding, multi-frequency superposition and resonance phenomena; and quantizing contribution degrees of resonance and harmonic injection, and distinguishing composite causes of harmonic exceeding. According to the method, the problem that the harmonic cause is unknown in the harmonic exceeding scene is solved, and the accuracy of the harmonic exceeding cause is remarkably improved. Through simulation and actual measurement verification, the accuracy of the method provided by the invention is verified.