光伏发电系统一次调频技术回顾与发展趋势

Review and Development Trend of Primary Frequency Modulation Technology in Photovoltaic Power Generation System

光伏发电系统具备一次调频能力对于在扩大其并网规模的同时又不至于较大影响电网频率稳定性,具有至关重要的作用。针对此,首先分析光伏系统的并网要求;其次归纳在无电储能系统情况下,多串光伏逆变器协调控制、直流链路电容器、减载控制、模糊控制、光伏系统和其他常规发电机的协调控制5个方面一次调频技术的研究现状,分析各项技术的优缺点;接着对在有电储能系统的情况下,基于电储能系统的虚拟同步发电机、微电网中电储能配合进一步提高一次调频性能2个方面的研究现状进行分析;然后从光伏、风电配置电储能经济性、市场应用、国家政策3个方面分析电储能系统未来在光伏发电系统一次调频技术应用的发展趋势。最后得出结论:无论从技术上还是政策上来看,未来光伏发电系统一次调频技术的发展必然离不开电储能。但目前电储能在光伏发电系统中的规模化应用还需解决2个重点、难点问题:如何优化一次调频、参与电能量市场与辅助服务市场从而使获得的多重收益最优的问题;储能的安全问题。

The primary frequency modulation capability of the photovoltaic power generation system plays a vital role in expanding its grid connection scale without greatly affecting the frequency stability of power grid.Thus,this paper firstly analyzes grid connection requirements of the photovoltaic system,and then summarizes the research status of primary frequency modulation technology in five aspects including coordinated control of multi-string photovoltaic inverter,DC link capacitor,load shedding control,fuzzy control,coordinated control of the photovoltaic system and other conventional generators,and analyzes the advantages and disadvantages of each technology.Then,the paper analyzes the research status of virtual synchronous generator based on electric energy storage system and the cooperation of electric energy storage in the micro-grid to further improve the performance of primary frequency modulation.Meanwhile,it studies the development trend of primary frequency modulation technology application of electric energy storage system in the photovoltaic power generation system in the future from three aspects of photovoltaic,wind power configuration,power storage economy,market application and national policy.Finally,it draws conclusions that in both technical and policy levels,the development of primary frequency modulation technology in the future is definitely connected with electric energy storage.But at the present,it needs to solve two difficulties of obtaining the optimal multiple earnings by optimizing primary frequency modulation to participate in the electric energy market and the auxiliary service market,as well as the safety of energy storage.