(Hebei Key Laboratory of Distributed Energy Storage and Microgrid (North China Electric Power University), Baoding 071003, China
This work is supported by Hebei Provincial Natural Science Foundation of China (No. E2018502134) and State Grid Corporation of China (No. SGHEDK00DYJS1900061).
Under the maximum power point tracking control of the doubly-fed induction generator (DFIG), the output power of DFIG is difficult to respond to grid frequency fluctuations. While, conventional overspeed load shedding control can retain active power reserve to participate in system frequency adjustment, which has the problems such as reduced power generation efficiency, small speed adjustment range and frequent start of pitch angle control. To this end, combined with the control characteristics of the grid-side converter of DFIG, this paper proposes a strategy of DFIG inertia and primary frequency regulation based on supercapacitor energy storage control. Both the virtual inertia adjustment and the primary frequency adjustment are realized by supercapacitor control and there is no need to change or increase the additional control of the wind turbines, which improves the disturbance resistance and self-stabilizing of the single wind turbine. According to the actual cost of the supercapacitor module and charging/discharging efficiency, the capacity of the energy storage unit is optimized. By comparing and evaluating the economics of the primary frequency modulation scheme of active power reserve, the proposed scheme has strong economic advantages. Finally, the simulation experiments show that its inertia support, primary frequency adjustment capability and power generation efficiency are significantly improved compared to conventional primary frequency control.
YAN Xiangwu,CUI Sen,SONG Zijun,et al.Inertia and Primary Frequency Modulation Strategy of Doubly-fed Wind Turbine Based on Super-capacitor Energy Storage Control[J/OL].Automation of Electric Power Systems,http://doi.org/10.7500/AEPS20200120001.