Analysis Of Influence Of PV Access Distribution Network On Voltage Quality

With the increase of photovoltaic installed capacity,the application of photovoltaic is more and more extensive.A large number of distributed PV access distribution network,reducing the use of conventional energy sources.However,it also brings new challenges to the voltage quality of distribution network at the same time.PV access changed the load flow distribution of the original distribution network,which affected the voltage distribution in the distribution network.In order to rationally take advantage of the photovoltaic and improve the permeability of the PV system,we must make a reasonable planning of the access position and capacity of the PV system.As long as we reduce the voltage harmonics and over voltage problems,we can safely ensure the good quality of the voltage.This paper studies the voltage problems caused by PV access to distribution network.Firstly,the basic characteristics of photovoltaic generation and the standards of power quality are studied.Secondly,it made comprehensive and deep study on the problems of voltage harmonics,voltage distribution,overvoltage caused by PV access to distribution network.For the problem of voltage harmonic,it firstly analyzes the impact of PV access location and capacity on voltage harmonic in theory,then the simulation is performed to confirm the efficiency of conclusion,so that a general rule of effect on voltage caused by access location and capacity is obtained.In the second part,it makes a research on the theory of photovoltaic access improving the voltage distribution,and the simulation results show that,as long as the PV penetration in a reasonable range,it will effectively improve the voltage problem in distribution network.In the last part,three solutions are proposed to solve the overvoltage problem caused by the large capacity centralized access of photovoltage,including active power limits scheme,VSI reactive power control scheme as well as SVG reactive power compensation and control scheme.And the three schemes are simulated and verified respectively.