CN-121124122-B - Three-phase balance power supply energy-saving control method and system

Abstract

The invention discloses a three-phase balanced power supply energy-saving control method and system, the method comprises the steps of building a three-phase four-wire system soft switch topology model, collecting real-time operation parameters of a power supply system and transmitting the parameters to a complex domain convex optimization decision platform, extracting parameter characteristics from the platform, determining key parameters and building a mapping relation between the key parameters, three-phase unbalance and energy consumption loss, inputting the mapping relation into a multi-objective symmetrical semi-positive programming algorithm, building constraint conditions by taking the three-phase unbalance and energy consumption loss minimization as targets, solving to obtain optimal conduction time sequence, duty ratio and optimal parameters of a filter assembly of a controllable switch element, feeding the optimal parameters back to the topology model, and adjusting the working state of the assembly to realize control. The system comprises six units, each cooperating. The invention can reduce energy consumption, accurately control three-phase balance, adapt to complex working conditions, improve the operation efficiency and stability of a power supply system, and meet the dual requirements of the power supply system on energy conservation and balance.

Inventors

• HAO ZEZHONG

Assignees

• 北京中科宇杰节电设备有限公司

Dates

Publication Date

20260512

Application Date

20250912

Claims (2)

1. 1. A three-phase balanced power supply energy-saving control method is characterized by comprising the steps of S1, constructing a three-phase four-wire soft switch topology model, wherein the model comprises three-phase main circuit branches and neutral line branches, each branch is provided with a controllable switching element and a filtering component, the output voltage and current waveforms of the topology model meet preset three-phase electric characteristics by adjusting the conduction time sequence and the duty ratio of the controllable switching elements, S2, acquiring real-time operation parameters of a power supply system based on the three-phase four-wire soft switch topology model, the real-time operation parameters comprise voltage amplitude of each phase, current amplitude of each neutral line, power factor and harmonic content of each phase, transmitting the acquired real-time operation parameters to a complex domain convex optimization decision platform, S3, conducting characteristic extraction on the real-time operation parameters in the complex domain convex optimization decision platform, determining calibration parameters affecting three-phase balance and energy-saving effects, establishing a mapping relation between the calibration parameters and three-phase imbalance, S4, inputting the mapping relation into a multi-target symmetrical semi-positive-definite algorithm, constructing constraint conditions of the three-phase imbalance degree and the three-phase imbalance degree to be minimum optimal targets, the three-phase imbalance degree and the optimal time sequence constraint conditions, conducting the acquired real-time operation parameters to the optimal parameters by the optimal switching elements, conducting constraint conditions of the optimal constraint conditions and the optimal time sequence, and the optimal constraint conditions are obtained by the optimal constraint conditions, S6, the optimal constraint conditions of the three-phase equilibrium and the optimal phase element and the optimal phase optimization parameters are conducted by the three-phase control element, the optimal constraint conditions, and the optimal phase constraint conditions and the optimal phase control element under the three-phase control conditions, and the optimal phase control conditions, the control topology model adjusts the working state of each branch controllable switch element and the operation parameters of the filter assembly, and performs three-phase balance power supply and energy-saving control; the voltage output expression of the three-phase four-wire system soft switch topology model is as follows: wherein For a matrix of three-phase output voltages, As a matrix of topological structure coefficients, For a matrix of on-states of the controllable switching elements, For the input voltage on the dc side, For each of the branch inductance value matrices, For a three-phase output current matrix, The matrix of topological structure coefficients is a matrix of the resistance values of each branch The connection mode of the three-phase main circuit branch and the neutral line branch determines the conduction state matrix The value of the element in the control circuit is 0 or 1, and the element corresponds to the off and on states of the controllable switch element respectively; the objective function expression of the multi-objective symmetrical semi-positive programming algorithm is as follows: wherein In order to comprehensively optimize the target value, Is a weight coefficient of the three-phase unbalance degree, For the degree of imbalance of the three-phase voltages, In order to be able to lose the weight coefficient, The three-phase voltage unbalance degree is the active power loss of the power supply system For the maximum amplitude in the three-phase voltage, Is the minimum amplitude value in the three-phase voltage, Is the average amplitude of three-phase voltage, active power loss , Respectively is The amplitude of the three-phase current, Respectively is The resistance value of the three-phase branch circuit, For the neutral line current amplitude value, The resistance value of the neutral line branch is; The parameter optimization constraint expression of the complex domain convex optimization decision platform is as follows: wherein For the optimal parameter matrix of the platform output, As the matrix of the initial values of the parameters, Is a two-norm number of the two-norm, Optimizing an error threshold for a parameter, the optimizing a parameter matrix Comprises a duty ratio parameter of a controllable switch element, a capacitance value and an inductance value parameter of a filter component, and a parameter initial value matrix The error threshold value is determined by rated operation parameters of a three-phase four-wire soft switch topology model Setting according to the precision requirement of a power supply system; The neutral line current control expression of the three-phase four-wire system soft switch topology model is as follows: wherein For the real-time current of the neutral line, As the number of parallel branches in the topology model, Respectively the first The real-time current of A, B, C three phases in the parallel branch circuit is regulated by the multi-target symmetrical semi-positive programming algorithm to make the neutral line real-time current Satisfy the following requirements Maximum allowable current for the neutral line; the optimal solution solving expression of the multi-objective symmetrical semi-positive programming algorithm is as follows: wherein For the optimal parameter vector output by the algorithm, As a result of the feasible domain of the parameters, For the operation of the matrix trace, Is a matrix of coefficients of the quadratic term of the objective function, Coefficient vector of primary term of objective function, the said parameter is feasible The quadratic term coefficient matrix is determined by the conduction time sequence limit, the output voltage amplitude range and the current amplitude limit of the controllable switch element And a first order coefficient vector Setting according to the weight relation between three-phase balance and an energy-saving target; S31, performing time domain and frequency domain conversion on the acquired real-time operation parameters, converting time domain signals of voltages and currents of each phase into frequency domain signals through Fourier conversion, extracting fundamental wave components and sub-harmonic components in the frequency domain signals, S32, performing feature screening on the fundamental wave components and the harmonic components, reserving components with amplitudes exceeding a preset threshold, removing interference components with amplitudes lower than the threshold, wherein the preset threshold is determined according to harmonic standards of a power supply system, S33, establishing correlation functions of the screened components, three-phase imbalance and energy consumption loss, calculating correlation coefficients of each component, three-phase imbalance and energy consumption loss through correlation analysis, selecting components with absolute values of the correlation coefficients greater than 0.8 as calibration parameters, S34, classifying the calibration parameters according to types, forming a voltage calibration parameter set, a current calibration parameter set and a power calibration parameter set, and storing the calibration parameters into a parameter database of a complex domain convex optimization decision platform respectively; The step S4 comprises the following substeps of S41 converting the mapping relation obtained in the step S3 into a mathematical expression of a multi-objective symmetrical semi-positive programming algorithm, wherein the optimization variables of the algorithm are the conduction time sequence, the duty ratio and the parameters of a filter component of a controllable switching element, S42 setting inequality constraint conditions of the algorithm, including the maximum conduction current constraint of the controllable switching element, the maximum fluctuation range constraint of the output voltage and the upper limit constraint of the neutral line current, and converting each constraint condition into a mathematical inequality; The step S5 comprises the following steps of initializing iteration parameters of the multi-objective symmetrical semi-forward planning algorithm, including iteration times, iteration step length and convergence threshold, setting the initial value of the iteration times to be 100, setting the initial value of the iteration step length to be 0.01, setting the initial value of the convergence threshold to be 0.001, inputting the constraint system constructed in the step S4 into the algorithm, performing first iteration calculation according to the set iteration parameters to obtain a preliminary optimized parameter value, calculating three-phase imbalance and energy consumption loss corresponding to the preliminary optimized parameter value by S53, comparing the three-phase imbalance and energy consumption loss with the previous iteration result, adjusting the iteration step length to continue iteration if the difference is larger than the convergence threshold, and repeating the iteration process by S54 until the three-phase imbalance difference and the energy loss difference of two adjacent iterations are smaller than the convergence threshold, and outputting the optimized parameter at the moment as an optimal solution.
2. 2. The three-phase balanced power supply energy-saving control system is characterized by being applied to the three-phase balanced power supply energy-saving control method according to claim 1, and comprises a three-phase four-wire soft switch topology construction unit, a control unit and a control unit, wherein the three-phase four-wire soft switch topology construction unit is connected with a main circuit of the power supply system and is used for constructing a topology structure comprising three-phase main circuit branches and neutral line branches and outputting real-time operation parameters of a topology model; the system comprises a parameter acquisition and transmission unit, a complex domain convex optimization decision unit, a multi-target symmetrical semi-positive rule calculation unit, an optimal parameter feedback control unit, a system operation monitoring unit, a three-phase four-wire soft switch topology construction unit and a system operation monitoring unit, wherein the input end of the unit is connected with the output end of the complex domain convex optimization decision unit and used for acquiring real-time operation parameters and transmitting the real-time operation parameters to the complex domain convex optimization decision unit, the input end of the complex domain convex optimization decision unit is connected with the output end of the complex domain convex optimization decision unit and used for acquiring the real-time operation parameters and transmitting the real-time operation parameters to the complex domain convex optimization decision unit, the input end of the complex domain convex optimization decision unit is connected with the output end of the parameter acquisition and transmission unit and used for extracting characteristics of the real-time operation parameters and establishing mapping relations between calibration parameters and three-phase imbalance and energy consumption loss, the input end of the multi-target symmetrical semi-positive rule calculation unit is connected with the output end of the complex domain convex optimization decision unit and used for solving the optimal parameters under the constraint condition, the optimal parameter feedback control unit is connected with the output end of the three-phase symmetrical semi-positive rule calculation unit and the three-phase soft switch topology construction unit and the system operation monitoring unit respectively used for monitoring states of the three-phase four-phase system, and transmitting the monitoring result to a complex domain convex optimization decision unit.

Description

Three-phase balance power supply energy-saving control method and system Technical Field The invention relates to the technical field of power supply energy-saving control, in particular to a three-phase balance power supply energy-saving control method and system. Background In the running process of the power system, the three-phase power supply mode is widely applied to multiple fields of industrial production, commercial operation, residential electricity consumption and the like, and the running efficiency and economic benefit of the whole power system are directly influenced by the power supply stability and the energy-saving effect. With the increase of the types of electric equipment and the aggravation of fluctuation of electric loads, the three-phase power supply system is easy to generate the unbalance phenomenon of three-phase voltage and current, the neutral line current is increased, and the problems of increased energy consumption, reduced power factor and the like are accompanied, so that the normal operation life of the electric equipment is influenced, and the waste of electric power resources is caused. In order to solve the problems, the related art needs to construct a technical scheme with three-phase balance adjustment and energy-saving control functions, and the power supply system topology structure is optimized, a high-efficiency algorithm and a decision platform are introduced to realize accurate adjustment and control of power supply parameters, so that the dual requirements of an electric power system on operation stability and energy conservation are met, and therefore, the development of the three-phase balance power supply energy-saving control method and system becomes an important direction in the current electric power technical field. The prior art has two remarkable disadvantages in the aspect of three-phase balance power supply energy-saving control. On one hand, the topology structure of the power supply system adopted in the prior art is mostly a traditional hard switch topology, the on and off processes of controllable switch elements in the topology structure are easy to generate larger switching loss, neutral line current is difficult to effectively control, energy consumption of the system is higher in the operation process, three-phase unbalance degree is difficult to control in an ideal range, balance adjustment and energy saving effects cannot be considered, on the other hand, algorithms for parameter optimization in the prior art are mostly single-target optimization algorithms, optimization can be carried out only aiming at single indexes in three-phase unbalance degree or energy consumption loss, multi-target collaborative optimization capability is lacked, accurate analysis and screening of parameters are not combined with a complex domain convex optimization decision platform, practicality and reliability of an optimization result are insufficient, the system is difficult to adapt to complex and variable operation conditions of the power supply system, and comprehensive and efficient control support cannot be provided for the power supply system. Disclosure of Invention In order to overcome the defects and shortcomings in the prior art, the invention provides a three-phase balanced power supply energy-saving control method and system. The technical scheme adopted by the invention is that the three-phase balanced power supply energy-saving control method is characterized by comprising the steps of S1, constructing a three-phase four-wire soft switch topology model, S3, conducting feature extraction on the collected real-time operation parameters in a complex domain convex optimization decision platform, determining calibration parameters affecting three-phase balance and energy saving effect, establishing a mapping relation between the calibration parameters and three-phase imbalance and energy loss by adjusting the conduction time sequence and duty ratio of the controllable switch elements, S4, inputting the mapping relation into a multi-target symmetrical semi-positive calibration method, constructing a constraint condition with the three-phase imbalance minimum and energy loss limit rule by using the three-phase imbalance minimum and energy loss constraint rule, conducting the optimal constraint condition by using the three-phase four-wire soft switch topology model to collect real-time operation parameters of a power supply system, wherein the real-time operation parameters comprise current amplitude of each phase, neutral line current amplitude, power factor and harmonic content of each phase, conducting the collected real-time operation parameters to the complex domain convex optimization decision platform, S3, conducting feature extraction on the real-time operation parameters in the complex domain convex optimization decision platform, determining the calibration parameters affecting three-phase balance and energy saving effect, S4, conducting the m