Harmonic Oscillations in a Grid-connected PV Generation Farm Caused by an Increased Number of Parallel-connected PV Generating Units and Damping Controllers  

作　　者：Wenjuan Du Zhicheng Ma Yang Wang H.F.Wang 

机构地区：[1]School of Electrical Engineering,Sichuan University,Chengdu 610065,China [2]Electric Power Research Institute,State Grid Gansu Electric Power Co.,Ltd.,Lanzhou 730000,China

出　　处：《CSEE Journal of Power and Energy Systems》2024年第6期2350-2359,共10页中国电机工程学会电力与能源系统学报（英文）

基　　金：supported by the Special Key Project of Science and Technology of Gansu Province entitled key technology and demonstrating applications of market driven consumption and dispatching control of new energy electricity generation based on concentrating solar,photovoltaic and wind power(19ZD2GA003).

摘　　要：This paper examines the harmonic oscillations in a grid-connected PV generation farm(PVGF)caused by the parallel connection of an increased number of PV generation units(PVGUs).An equivalent model of the grid-connected PVGF is derived,which clearly explains why there are internal and external oscillation modes in the grid-connected PVGF.An indicator of impedance multiplication(IIM)is proposed to quantitatively estimate the impact of the increased number of PVGUs in parallel connection.The analysis in this paper reveals the mechanism about why the damping of external oscillation modes may decrease when more PVGUs are in parallel connection under the condition that the IIM is positive.An example grid-connected PVGF is presented in this paper to demonstrate and evaluate the derived analysis and conclusions.A method for designing the damping controllers to ensure a negative IIM is proposed.With the damping controllers being installed,the risk of growing harmonic oscillations caused by the increased number of the PVGUs in parallel connection can be effectively eliminated.

关 键 词：Damping controller equivalent model Harmonic oscillations PV generation farm PV generation units 

分 类 号：TM615[电气工程—电力系统及自动化]