一种基于功率方向的智能变电站中低压母线保护方案

A scheme of mid-low voltage busbar protection based on power direction in intelligent substation

长期以来,10 kV(或35 kV)及以下电压等级的中低压母线保护一直没有得到重视,存在保护动作时间长、选择性差的问题。为了改进中低压母线保护,结合中低压系统的特点,给出一种适用于智能变电站的基于功率方向的中低压母线保护方案,包括其构成方式、功能逻辑及网络结构。利用仿真系统,对其中的功率方向元件进行验证及分析。方案原理简单,具有很好的选择性和速动性,且不增加变电站的建设成本,可在智能变电站中推广应用。

For a long time, there is no enough attention on the 10 k V（or 35 k V） and below mid-low voltage busbar protection. If bus fault occurs, the selectivity and rapidity of busbar protection is poor. To improve mid-low voltage busbar protection, this paper proposes a scheme of mid-low voltage busbar protection for intelligent substation based on power direction combining with the characteristics of mid-low voltage system, which includes its constitution mode, function logic, and network structure. Moreover, it uses simulation system to verify and analyze power directional element. The scheme is of simple principle, excellent selectivity and rapidity, so it can be popularized and applied in intelligent substation without increasing investment cost.