Harmonic State Space Based Impedance Modeling and Virtual Impedance Based Stability Enhancement Control for LCC-HVDC Systems  

作　　者：Yifeng Liu Xiaoping Zhou Quan Chen Hanhang Yin Lerong Hong Hao Tian Ying Chen Siyuan Li 

机构地区：[1]the College of Electrical and Information Engineering,Hunan University,Changsha 410082,China [2]the Zhejiang Magtron Intelligent Technology Limited Cooperation,Jiaxing 314000,China [3]the State Grid Qianjiang Electric Power Company,Qianjiang 433100,China

出　　处：《Journal of Modern Power Systems and Clean Energy》2024年第1期287-298,共12页现代电力系统与清洁能源学报（英文）

基　　金：supported in part by the National Natural Science Foundation of China(No.U2166602);in part by the Major Special Project of Hunan Province(No.2020GK1010);in part by the Innovation Young Talents Program of Changsha Science and Technology Bureau(No.kq2107005).

摘　　要：Line commutated converter based high-voltage direct-current(LCC-HVDC)transmissions are prone to harmonic oscillation under weak grids.Impedance modeling is an effective method for assessing interaction stability.Firstly,this paper proposes an improved calculation method for the DC voltage and AC currents of commutation stations to address the complex linearization of the commutation process and constructs an overall harmonic state-space(HSS)model of an LCC-HVDC.Based on the HSS model,the closed-loop AC impedances on the LCC-HVDC sending and receiving ends are then derived and verified.The impedance characteristics of the LCC-HVDC are then analyzed to provide a physical explanation for the harmonic oscillation of the system.The effects of the grid strength and control parameters on system stability are also analyzed.To improve the impedance characteristics and operating stability of the LCC-HVDC system,a virtual impedance based stability enhancement control is proposed,and a parameter design method is considered to ensure satisfactory phase margins at both the sending and receiving ends.Finally,simulation results are presented to verify the validity of the impedance model and virtual impedance based stability enhancement control.

关 键 词：Line commutated converter based high-voltage direct-current(LCC-HVDC)transmission harmonic state space stability analysis harmonic oscillation virtual impedance 

分 类 号：TM46[电气工程—电器]