考虑概率分布的分布式光伏无功下垂控制策略

Droop Control Strategy of Distributed Photovoltaic Reactive Power Considering Probability Distribution

分布式光伏接入配电网逐渐成为趋势,然而大规模分布式光伏并网将引起严重的潮流逆向,导致电压越限和网损增加。针对分布式光伏接入配电网产生的电压越限问题,提出一种考虑概率分布的分布式光伏无功下垂控制策略,首先,考虑光伏出力的概率分布对光伏电站不同光伏单元当前有功功率的影响,评估计算每个光伏逆变器的可用无功容量;然后,根据各光伏单元当前可用无功容量大小对无功下垂系数进行调整,在不牺牲有功功率的情况下最大限度地利用光伏电站的无功支撑能力;最后,通过PSCAD/EMTDC仿真软件,验证了所提控制策略的有效性。

Distributed photovoltaic access to the distribution network has gradually become a trend,but the large-scale distributed photovoltaic grid connection will cause serious power flow reversal,resulting in out-of-limit voltage and network loss increase.Aiming at the out-of-limit voltage problem generated by distributed photovoltaic access to distribution network,a distributed photovoltaic reactive power droop control strategy considering the probability distribution was proposed.Firstly,the influence of probability distribution of photovoltaic output on the current active power of different photovoltaic units of photovoltaic power plants was considered,and the available reactive capacity of each photovoltaic inverter was evaluated and calculated.Then,the reactive power droop coefficient was adjusted according to the current available reactive capacity of each photovoltaic unit,and the reactive power support capacity of the photovoltaic power station was maximized without sacrificing active power.Finally,the effectiveness of the proposed control strategy was verified by PSCAD/EMTDC simulation software.