Droop Control Strategy of Distributed Photovoltaic Reactive Power Considering Probability Distribution

Abstract

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.

Keywords

• distributed photovoltaic
• out-of-limit voltage
• photovoltaic probability distribution
• reactive power and voltage control
• droop control