基于双馈风机短路特性的风电场集电线路继电保护整定方法研究

目前的定值整定工作中往往将风电场作为负荷或常规电源进行分析计算,已经导致了多起事故,因此深入研究风电场的故障特征以及对系统继电保护的影响显得非常重要。首先,在双馈风机短路等值参数模型的基础上,研究了风机短路特性对集电线路保护的影响和集电线路继电保护整定值整定方法。其次,充分考虑了风机短路故障电流的影响,并提出了一套完整的集电线路系统继电保护定值整定方法。该方法分析了三相短路和两相短路的短路电流,提出了集电线路相间过电流保护和汇集线接地故障的零序电流保护的整定原则和计算过程。该策略避免了风机发生故障时产生的过电流对下游集电线路继电保护装置造成冲击和误动,目前已经在实际风电场得到了应用,验证了该方法的有效性。

Discussion on setting scheme of collecting line relay protection in wind farm based on a DFIG short-circuit characteristic

At present, a wind farm is often used as a load or conventional power source for analysis and calculation in a fixed value setting. This has led to a number of accidents. Therefore, it is very important to study in detail the fault characteristics of the wind farm and its impact on system relay protection. First, on the basis of a DFIG short-circuit equivalent parameter model, this paper studies the turbine generator short circuit characteristics of collecting line protection and the collecting line relay protection setting method. Then, it takes the influence of the turbine generator short circuit fault current into account, and puts forward a set of complete relay protection setting methods for the collecting line system. This method analyzes the three-phase short-circuit current and two-phase short-circuit current, and presents the setting principle and calculation process of collecting line inter-phase overcurrent protection and zero-sequence current protection of a collecting line ground fault. This strategy avoids the impact and mis-operation of the relay protection device of the downstream collecting line caused by the overcurrent of a turbine generator fault. It has been applied in a real wind power plant, verifying the effectiveness of the method. This work is supported by National Natural Science Foundation of China (No. 61803219).