Research On Voltage Regulation Of Distribution Network With High Permeability Photovoltaic Power Participated

With the development of national economy,the contradiction between the sharp increase in energy demand and the shortage of traditional fossil energy supply is becoming more and more obvious,and the use of fossil fuels has made the ecological environment of human being deteriorated rapidly.For various reasons,the renewable energy,such as photovoltaic power generation has been favored by many countries.With the increasing penetration of photovoltaic power generation,the effect of photovoltaic power generation on the distribution network voltage is increasing.The mismatch between high permeability photovoltaic power output and load consumption and the randomness and uncertainty of photovoltaic power output make the voltage fluctuation of distribution network is more obvious,and increase the difficulty of voltage control,which make the voltage the voltage easier to limit.In the background of the grid power quality requirements of the national economy getting more and more high,this paper analyzes the mechanism of the influence of photovoltaic power generation on the distribution network voltage,and deeply studies the voltage regulation of distribution network with high photovoltaic power participated.The main contents are as follows:At first,the influence mechanism of the access of photovoltaic power to the distribution network voltage deviation and voltage limit are analyzed;the conclusion of the influence of grid connected photovoltaic power on distribution network voltage is obtained.By using MATLAB simulation software,the influence of different load power and grid connection parameters on distribution network voltage is studied,the influence of grid connected photovoltaic system on voltage in distribution network under different conditions is obtained.Moreover,the voltage and reactive power optimization problem of distribution network with photovoltaic power is studied.Mathematical models of static optimization and dynamic optimization are established,and the objective function is to minimize the sum of active power loss and total voltage deviation in the distribution network.The dynamic optimization model considers the fluctuation of photovoltaic output and the change of load,and control equipment action frequency constraints;proposes the methodof discrete optimization variables and control device action frequency constraints;the linear decreasing weight particle swarm optimization(LinWPSO)is used to verify the example.At last,aiming at the problem of voltage fluctuation and over limit caused by the mismatch between high permeability photovoltaic power output and load consumption and the randomness and uncertainty of photovoltaic power output,this paper proposes a voltage and reactive power optimal control strategy for distribution network with active-reactive power of photovoltaic power generation coordinated participation.According to the different operation status of distribution network,the control strategy includes two models,which are only optimizing the photovoltaic reactive power and optimizing the photovoltaic active power and reactive power,and mathematical models are established.Taking IEEE33 node system as an example,simulation results show that the voltage optimization strategy proposed by this paper can control the active power and reactive power rationally;solve the voltage fluctuation and over limit problem of grid connected photovoltaic system,and improve the distribution network voltage qualified rate.