In the active distribution networks penetrated by a proliferation of distributed photovoltaic(PV),traditional central and local voltage control can't solve the voltage fluctuation problem economically and effectively.Therefore,this paper proposes a two-stage voltage control strategy for PV inverters.The local control curve adopts flexible and adjustable improved volt-var(Q-V)droop control curve.The central control stage takes the weighted sum of voltage control cost and the conditional value at risk(CVaR)of voltage violations as the objective function,uses the distributionally robust optimization algorithm and the model predictive control algorithm to consider PV prediction uncertainty,and performs minute-level global collaborative optimization of each PV inverter's curtailed active power reference and adjustable nodes of the proposed Q-V droop control curve.The local control stage dynamically adjusts the reactive power output based on the Q-V droop control curve and the real-time measured local voltage.Simulation results of the modified IEEE 37 bus distribution system show that the proposed control strategy can not only centrally optimize the coordination of the curtailed active power and reactive power output of each PV inverter to avoid voltage violations but also utilize the centrally optimized Q-V droop curve in the local control stage to reduce voltage fluctuations by 40.56％,meeting different economy and robustness requirements of the distribution network operators for voltage control.
关键词
主动配电网/电压越限/高渗透光伏/分布鲁棒优化/不确定性/电压-无功下垂曲线
Key words
active distribution network/voltage out-of-limit/high-proportion photovoltaics/distributionally robust optimization/uncertainty/volt-var droop control curve
维普
万方数据