随着风电渗透率不断提高,应用虚拟惯性控制技术解决频率事故下的频率安全问题是未来电网发展的必然需求,含风电虚拟惯性控制的动态频率特性研究也将是电力系统要面临的新问题。文中研究了双馈型风电场等效虚拟惯性时间常数HeqWF的定量表征方法。定义HeqWF并阐明了其物理意义,分析了求解HeqWF与研究电网动态频率特性的关系;建立了含虚拟惯性控制的双馈风电机组简化模型和风电场模型,计算求得了HeqWF频域和时域解析解。通过计算值与仿真值比较验证了HeqWF的正确性和精确性,并探明了HeqWF的时变特性和形成机理。
With the increasing penetration of wind power,using virtual inertial control technology to address the frequency security problem under frequency accident conditions is an inevitable demand of power grids in the future.The newly-presented topic of the dynamic frequency characteristic incorporating virtual inertial control technology of wind turbines will be confronted by the power system.The quantitative representation of the equivalent virtual inertial time(HeqWF)constant of the doubly fed induction generator(DFIG)based wind farm is researched.HeqWFis defined and its physical significance is clarified while the relationship between solving HeqWFand studying the dynamic frequency characteristics of power grid is analyzed.A simplified model of DFIG and a wind farm model incorporating the virtual inertial control are developed and the analytical solutions of HeqWFin the frequency and time domains are solved.The correctness and accuracy of HeqWFare verified by comparing calculated and simulated values,the time-varying characteristic of HeqWFis explored and the resulting mechanism is investigated.