风电接入VSC-HVDC系统的附加频率控制

为了使风电场系统和电网系统能相互提供惯性支撑和进行频率响应,提出了一种换流站级的附加频率控制策略。该附加控制策略在风电场侧换流站(WFVSC)的定频率控制和电网侧换流站(GSVSC)的定直流电压控制中分别引入了频率-直流电压(f-Udc)下垂特性,人为的耦合两侧交流电网系统频率的关系,在不需要通信的条件下,实现了在事故期间可以灵活相互支援的目的,从而缓解了事故端系统调频的负担。最后在仿真软件PSCAD/EMTDC中搭建了风电场并网直流外送的模型,仿真结果表明所提附加频率控制策略增强了系统的惯性支撑水平和频率控制储量。

Additional Frequency Control of Wind Power Access VSC-HVDC System

In order to ensure the mutual inertial support and frequency response between the wind farm system and the power system, an additional frequency control strategy for converter station level is proposed. The additional control strategy adds the f-Udc droop characteristic in the WFVSC constant-frequency control and the GSVSC constant- DC voltage control, respectively, the relationship of the frequency in the AC power systems can be flexibly supported by each other under the condition of no need of communication, thus easing the burden of frequency modulation in the accident system. Finally, the model of wind farm and DC transmission is set up in PSCAD / EMTDC. The simulation results show that the proposed additional frequency control strategy enhances the inertial support level and the frequency control reserve of the system.