基于电流相角突变量方向的有源配电网保护

随着分布式电源(DG)的大量接入,配电网的结构由传统的辐射型改变为多端电源系统。由于DG出力的随机性,传统的基于电流幅值的保护方案很难整定。通过研究故障前后电流相角的变化,得出了电流相角突变量方向与故障位置的关系,并由此提出一种新的电流纵联方向保护方案。由于该方案只利用电流信息,避免了安装电压互感器。对于规模巨大的配电网,具有经济性。由于只需传输判定结果,降低了对通信通道的要求。最后,通过仿真分析,对保护方案进行了验证。

Protection Scheme for Active Distribution System Based on Directions of Current Phase Angle Variation

With the increasing interconnection of distributed generators (DGs), the radial structure of conventional distribution system will change to multi-terminal. Because of the randomness of the DG power output, the traditional protection scheme based on the current amplitude is difficult to set. The difference in phase angle between the currents before and after fault conditions is investigated, and the relationship between the direction of current phase angle variation and fault location has been found to present a new current directional pilot protection scheme. This scheme uses only current information to avoid the installation of voltage transformers. For a huge distribution network, this scheme leads to a very high economy coefficient. As it only needs transmitting the determination result signals, the demand for the communication channel is reduced. Finally, verification of the protection scheme is carried out by simulation analysis.