Frequency-dependent Parameter Identification for Improved Dynamic State Estimation Based Protection Based on Characteristic Signal Injection of Half-bridge MMC in Flexible DC Grids  

作　　者：Ming Nie Jinghan He Meng Li Huiyuan Zhang Keao Chen 

机构地区：[1]School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China [2]China Electric Power Research Institute,State Grid Corporation of China,Beijing 100192,China

出　　处：《Journal of Modern Power Systems and Clean Energy》2024年第6期1823-1836,共14页现代电力系统与清洁能源学报(英文)

基　　金：This work was supported by National Natural Science Foundation of China-State Grid Corporation Joint Fund for Smart Grid(No.U2066210).

摘　　要：In flexible DC grids,the rapid rise of fault current requires that the line protection must complete the fault identifi-cation within a few milliseconds.Dynamic state estimation based protection(DSEBP)provides a new idea for flexible DC line protection with good performance.However,the operating frequency in the DC grid is O Hz.When the DC grid is operat-ing normally,it is difficult to identify the line parameters online to improve the performance of the protection method.This pa-per proposes a method to identify the frequency-dependent pa-rameters of flexible DC grids based on the characteristic signal injection of half-bridge modular multilevel converter(HB-MMC).The characteristic signal is extracted by the Prony algo-rithm to calculate the line parameter under different frequen-cies.Afterwards,the number and position of residues and poles of frequency-dependent parameters are determined using the vector fitting method.Finally,an improved DSEBP is proposed.The simulation shows that the frequency-dependent parameters obtained by the proposed parameter identification method can be used in the improved DSEBP normally,and the identified pa-rameters have betterprecision.

关 键 词：Parameter identification modular multilevel converter(MMC) state estimation PROTECTION flexible DC grid 

分 类 号：TN9[电子电信—信息与通信工程]