计及电网频率偏差的双馈风电机组频率控制策略

针对电力系统发生大扰动时,双馈风电机组采用现有下垂控制方法不能充分利用自身旋转动能为电网提供频率响应服务,提出一种计及电网频率偏差的变系数双馈风力发电机组频率控制策略。该方法通过将下垂系数与电网频率偏差耦合,可根据电网频率变化量灵活地调节下垂系数,实现在系统发生大扰动时风电机组更有效地为电力系统提供频率支撑,并借助EMTP-RV仿真平台搭建含高比例风电渗透率的电力系统模型,验证所提控制策略的有效性。仿真结果表明,在不同风速场景下,当电力系统发生不同扰动时,双馈风电机组采用该策略均可有效提升自身频率响应能力,减少系统最大频率偏差,特别是在大扰动场景下,效果更加明显。

FREQUENCY CONTROL STRATEGY OF DOUBLY-FED WIND GENERATORS CONSIDERING GRID FREQUENCY DEVIATION

When a large distur bance occurs in the power system,the existing droop control method of doubly-fed induction generators （DFIGs） are unable to fully utilize its rotating kinetic energy to provide frequency response service for the power grid. This paper proposed a frequency control method with variable droop control coefficient considering the system frequency deviation. The proposed method couples the variable droop control coefficient with the system frequency deviation so as to regulate the control coefficient according to the frequency deviation and further realizes that the DFIGs provide frequency support for the power system with more efficiency under severe disturbances. The power system model with high wind power penetration is established by using EMTP-RV simulation platform. The simulation results show that DFIGs can effectively improve frequency response capability and reduce the maximum frequency deviation when different disturbances occur in the power system,especially in the case of a severe disturbance.