Research On Three Phase Unbalance Control Technology Of Distribution Network Based On Improved Genetic Algorithm

The domestic low-voltage distribution network adopts three-phase four wire system,and most of them are single-phase load.These loads have uncertainty of power consumption time and law,which is characterized by large fluctuation and irregularity.Usually,when one phase or two-phase load fluctuates greatly,it will lead to the rise of three-phase imbalance in low-voltage power grid,resulting in the long-term existence of three-phase imbalance in low-voltage distribution network in China,which seriously affects the security,stability and economic operation of power grid.This paper first introduces the research status,basic principle and calculation methods of three-phase unbalance,and puts forward the overall scheme and configuration principle of improving the three-phase imbalance.The multi-objective optimization function and constraint condition based on Improved Genetic Algorithm of niche are established.Then,the optimization strategy of three-phase load imbalance control based on commutation system is proposed.That is,after the self check of the commutation control system is normal,the power consumption data of each load transmitted by each executive terminal is read in,and the number of phase change is not exceeded in this control cycle,Taking the three-phase current unevenness and the cost of phase exchange as the comprehensive consideration,the optimal phase change scheme is obtained by using the improved genetic algorithm.The commutation control system includes DSP Microprocessor,signal conditioning module,AC / DC conversion module,a / D conversion module,power supply module,storage module,communication module and human-computer interaction module,The commutation execution terminal focuses on the zero crossing detection module and switching action unit.In addition,through the simulation analysis of three-phase unbalance,a low-voltage substation with 15 load zones is simulated on the MATLAB platform to verify the feasibility and effectiveness of the commutation system.An experiment is carried out on a commutation system to test the effect of the commutation system on the three-phase imbalance of the distribution network.This paper mainly studies how to solve the three-phase imbalance problem of low-voltage distribution network based on commutation system.Commutation system is an automatic commutation device used to improve the three-phase load imbalance of low-voltage distribution network.It is mainly composed of commutation control system and commutation executive terminal.Its function is to adjust the phase sequence of the user side without interrupting the power supply,The power load is evenly distributed in each phase to achieve the purpose of three-phase balance.