基于风电接入点的配电网分区保护方案研究

风电接入配电网,接入点不同,配电网呈现不同的故障特性,影响传统保护的动作特性。根据建立的含风电的配电网故障电流关系式,分析了风电接入对配网的影响,提出根据风电场并网位置及对保护的影响确定保护配置方案,风电场接入馈线末端时上游区域配置方向纵联保护,接入馈线首端时下游区域和相邻馈线配置自适应电流速断保护。通过FFT变换滤除故障分量中的直流分量,采用对称分量故障分量法计算保护背侧阻抗以适应风电场运行工况的多变性,提高自适应电流保护的动作性能。以PSCAD为平台构建35k V配电系统仿真模型,仿真验证了保护方案的有效性。

A Zoning Protection Scheme for Distribution System with Wind Farm

BSTACT: The distribution system show different fault characteristics when wind farm access to the distribution system, and it will affect the operating characteristics of traditional protection. According to the established distribution network fault current relationship including wind power, the influence of wind power access to the distribution net work was analyzed, a protection scheme is proposed based on the wind farm grid position and influence to the protection. It is concluded that when the wind farm access to the end of the feeder, the upstream area should equip with the directional pilot reaying, and when the wind farm access to the head of the feeder, the downstream area and some adjacent feeders should equip with adaptive current protection. In order to adapt to the variability running way of wind farm and improve the performance of the adaptive current protection, the direct current component of fault component is filtered by FFT. And then calculate the dorsal impedance with a symmetrical component fault method. Simulation results on a 35 kV distribution system have verified the validity of the scheme proposed.