摘要
针对中段并联电抗器的电缆线路,提出了一种基于参数识别的纵联保护新方法。保护原理利用了故障分量网络,选取并联电抗器安装处作为参考点。根据贝瑞隆分布参数模型,分别将线路两侧电压和电流归算得到参考点处的电压和电流,并将两者的比值作为该侧特征阻抗。定义特征参数为两侧特征阻抗的并联值。区外故障对应的特征参数识别结果为并联电抗器的电抗值,极性为正;区内故障对应的特征参数的识别结果为参考点背侧总阻抗并联值,极性为负。综上可根据区内外故障下特征参数识别结果的差异性构造保护判据。经过理论分析和仿真验证可知,保护原理易于整定计算,具有较高的灵敏度,同时具备较强的抗过渡电阻能力,对采样率的要求不高,具有较高的可靠性。
A novel pilot protection method based on parameter identification for cable lines with shunt reactor in the middle is proposed.The fault component network is used for fault analysis.The installation site of the shunt reactor is selected as the set point.Then,based on the distributed Bergeron model of the cables,the voltage and current at the set point can be calculated using the voltages and currents at two ends of the cable.The ratio of the voltage and the current is defined as the characteristic impedance of the corresponding terminal.The equivalent parallel impedance for characteristic impedances of both terminals is defined as the characteristic parameter,which can be obtained using the proposed parameter identification method.When an external fault occurs,the identification result is the impedance of the shunt reactor,whose polarity is positive.When an internal fault occurs,the identification result is the parallel impedance of the systems behind at both terminals,whose polarity is negative.Therefore,the protection criterion can be constructed based on the polarity of the identified parameters.Theoretical analysis and simulation results prove that the proposed protection method is robust to fault impedance and does not require a high sampling rate.The proposed principle has high sensitivity and reliability.
作者
郭冰
祝磊
陈一悰
宋国兵
侯俊杰
薛健
GUO Bing;ZHU Lei;CHEN Yicong;SONG Guobing;HOU Junjie;XUE Jian(School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710049,China;State Grid Shaanxi Electric Power Company,Xi'an 710048,China;State Grid Shaanxi Electric Power Research Institute,Xi'an 710054,China)
出处
《电力系统保护与控制》
CSCD
北大核心
2021年第6期124-130,共7页
Power System Protection and Control
基金
国家自然科学基金联合基金重点支持项目资助(U1766209)。
