提高大规模风电接纳及送出的系统保护研究

为了提高酒泉风电的接纳和送出,从系统视角提出一种大规模风电接入电网线路的继电保护与控制一体化新方法。利用基于统计分析的潮流波动判据和基于本地信息量的潮流转移识别,从风电潮流波动中甄别出某重负荷线路发生了故障、判别出该线路因故障被继电保护动作切除、进而还识别出原先由故障线路承担的负荷潮流转移到了非故障线路上,并导致非故障线路过负荷。结合自适应过负荷保护,在线路安全的前提下尽可能挖掘其潜在载流能力。同时融合紧急控制功能,按实际需要切除风电,消除非故障线路的过负荷而不是切除该线路,解决连锁解网问题。在理论和仿真研究的基础上,研制并现场安装保护装置并检验所提系统保护方案的正确性。

Research on the system protection for enhancing the accommodation and transmission of large scale wind power

A novel integrated protection and control method for power lines connecting with large scale wind power is presented to improve Jiuquan wind power accommodation and delivery from the system viewpoint. The criteria based on statistics analysis of power flow fluctuation and identification of power transfer using local information are proposed to identify a heavy loading power line with a fault under wind power flow fluctuation, determine that the fault line is tripped by protection operation, and the power flow is transferred from the fault line to sound lines, which will lead to over load in sound lines. The potential loading capability of lines will be exploited under safety prerequisite with adaptive over load protection. Emergency control is used together to curtail wind power according to field conditions, and eliminate over loading in sound lines in replacement of tripping these lines, which will prevent cascading failure of grid. Based on the theory and simulation studies, protection devices are implemented and commissioned in the field and the correctness of the proposed system protection scheme is verified.