摘要
提出基于故障线路两侧电流幅值差异比较的配电网新型保护方案,适于含分布式电源的配电网络。首先对分布式配电网发生故障时,线路两侧故障电流幅值特性进行分析,得出在现有的分布式电源容量渗透率规定以及逆变型分布式电源对输出电流幅值限制的条件下,故障线路两侧电流幅值不相等且差异较明显的结论。以此为基础,提出新型的基于故障电流幅值差异的保护方案,为保证内部故障的灵敏性,外部故障及正常运行时保护的可靠性,提出相应的动作-制动特性方程。新方案借鉴传统差动保护制动判据的形式,但制动特性方程仅需电流幅值信息而无需相量的比较,在通信自动化水平较低的分布式配电网中更易实现。仿真证明了本方案的合理性和有效性。
A new current amplitude differential protection criterion for distribution system with DG is proposed in this paper. Fault current amplitude characteristic at each side of fault feeder is firstly analyzed. Under the condition of prescribed DG capacity penetration and the restriction on output current amplitude, the amplitudes of fault currents are obviously different at each end of fault feeder. Based on this conclusion, there is an action-brake characteristic equation in this new method to ensure fault sensitivity and protection reliability. Even though performing like traditional differential protection, the new method requires only current amplitude parameter, while dispensing with phasor comparison, which makes it easier to be realized in distribution system with DG having low communication automatization level. Simulation tests that the method is rational and effective.
出处
《电工技术学报》
EI
CSCD
北大核心
2015年第18期164-170,共7页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(50977012
51377022)
关键词
分布式发电
电流幅值
制动特性
配电网保护
Distribution system with DG
current amplitude
restraint characteristic
distribution system protection
