基于模型识别的VSC-HVDC直流输电线路方向元件  

Directional element for VSC-HVDC transmission lines based on model identification

作　　者：宋国兵[1] 蔡新雷[1] 高淑萍[1] 索南加乐[1] 李德坤[1] 

机构地区：[1]西安交通大学电气工程学院,陕西西安710049

出　　处：《电力系统保护与控制》2012年第7期78-83,共6页Power System Protection and Control

基　　金：国家自然科学基金项目(51037005;51177128)~~

摘　　要：电压源换流器型直流输电(Voltage Source Converter HVDC,VSC-HVDC)直流线路两侧并联了大电容,在高频下系统侧阻抗可等效为并联电容阻抗。根据VSC-HVDC特有的系统结构,结合模型识别的基本思想,提出了一种VSC-HVDC直流输电线路方向元件方向判别原理。在高频范围内,采用时域算法,通过两种模型的模型误差、识别的电感值和电容值与实际值的差异构成方向判据。理论分析和仿真实验表明,该方法不受故障类型、过渡电阻以及故障点位置影响,在各种工况下均可快速可靠地判别故障方向。As the impact of the large shunt capacitor on both terminals of the HVDC transmission lines in VSC-HVDC, the system impedance can be equivalent to shunt capacitor impedance in high frequency domain. According to this characteristic, a directional protective scheme based on model identification method for VSC-HVDC transmission lines is proposed. The scheme detects transmission line fault by comparing difference of the model error, inductance and capacitance calculated in two different models and the real values using time domain algorithm in high frequency band. The simulation results show that the method is not affected by fault type, fault location and transition resistance, and it can identify the fault reliably and rapidly in any condition. This work is supported by National Natural Science Foundation of China （No. 51037005 and No. 51177128）.

关 键 词：电压源换流器型直流输电 直流输电线路 方向元件 模型识别 最小二乘法 

分 类 号：TM773[电气工程—电力系统及自动化]