超高压线路距离保护自整定方案的研究

Study on Scheme of Self-setting for Distance Protection of EHV Transmission Line

超高压线路距离保护离线定值整定繁杂易错,且需配合运行方式及上下级线路或元件保护。鉴于此,文中梳理了目前距离保护的离线整定原则和缺陷,提出了可靠系数和灵敏系数选择的曲线函数,分析了不同运行方式下零序补偿系数的特点,研究单K值整定对保护范围带来的误差。提出了结合线路、系统原始参数以及曲线函数完成各段距离保护自整定方案,避免人为整定误差。另外用实际算例仿真表明采集相关间隔信息自动判别运行方式和计算精确的零序补偿系数来提升保护的有效保护范围,使距离保护动作性能始终处于最佳状态是行之有效的。

The offline setting calculation of distance protection of EHV transmission line is a complicated and error-prone systems engineering, and needs to be coordinated with operation mode, adjacent lines and component protection. For this reason,the offline setting principles and defects of the current distance protection is sorted out, the curve functions about reliable coefficient and sensitive coefficient is designed, and the features of zero-sequence cur- rent compensation coefficient under different operation modes is analyzed to research the error of the scope of pro- tection under the setting with single value of zero-sequence current compensation coefficient. The scheme is proposed to complete self-setting and cooperation of each section of distance protection via the original parameters of line and system and the curve functions. It can avoid the error of human setting. In addition,the simulation results of numerical example show that the operation mode and the corresponding zero-sequence compensation coefficients can be determined and calculated automatically by collecting information of relevant device to promote the effective scope of distance protection. In this way,the operation performance of distance protection is always at its best.