Research on local voltage control strategy based on high-penetration distributed PV systems

With the high-penetration distributed photovoltaic (PV) systems accessed to a distribution network, the peak active power output of PV systems is always greater than the total local load demands, which might lead to the issues of overvoltage and reverse power flow in a distribution system. In this paper, based on the reactive power output capability of distributed PV inverters, a distributed PV reactive power local control strategy is proposed. Three types of voltage reactive power local control modes of PV inverter are analysed, respectively; they are voltage-var control mode (Q(V) mode), adjustable power factor mode (PF(P) mode) and active power curtailment mode (APC mode). The applicable conditions of different control modes are analysed. A simulation example based on IEEE 33-node system is studied, where the method of determining the optimal control mode under different operating scenarios of distribution system with PV is given, and the validity of the three local control modes is verified.