Research on Active and Reactive Power Coordination Control Strategy for Overvoltage of PV Distribution Network in High Penetration Area

Abstract

With the large amount of renewable energy connected to the distribution network, the uncertainty of photovoltaic output and the mismatch between the load have caused the voltage fluctuation of the distribution network, reducing the power quality and power supply reliability of the distribution network, which has affected the safe operation of the distribution network. It is of great significance to study the control strategy for the overvoltage problem of the highpenetration photovoltaic distribution network to realize the consumption of photovoltaic equipment.The paper analyzes the mechanism of voltage over-limit firstly, under the background that various existing schemes have poor controllability of voltage regulation and cannot meet power quality requirements, an active-reactive power coordinated control strategy is proposed. When the distribution network is facing the risk of voltage exceeding the limit, combined with Q-U droop curve, power constraint equation and inverter capacity constraint, the reactive power of the line is regulated by the residual capacity of the inverter; in order to ensure that the power factor of the grid meets the system requirements, when the maximum reactive power adjustment capability of the inverter is reached, the active power control so that voltage requirements are finally met. The effectiveness of this control strategy in solving the voltage crossing problem in a five-node distributed PV distribution network is verified by MATLAB simulation.