Overvoltage and voltage unbalance mitigation in areas with high penetration of renewable energy resources by using the modified three-phase damping control strategy

•Solves overvoltage problems in low voltage distribution grids.•Mitigates the voltage unbalance in low voltage distribution grids.•Reduces the active power drooping in areas with high penetration of renewable energy resources. The increasing penetration of renewable energy resources imposes challenges to the distribution system operators to maintain the voltage levels and voltage unbalance within limits. The voltage control by means of reactive power in low voltage grids becomes ineffective due to the mainly resistive feeders. In this article, the performance of some classical control strategies which also include voltage control by using reactive power, active power drooping and the modified damping control strategy is investigated. The modified damping control strategy utilises a local control algorithm where appropriate action for overvoltage and/or voltage unbalance mitigation is taken based on inverter terminal voltage measurements. Furthermore, the modified damping control strategy is tested under different values of the damping conductance and the beneficial impact on the power quality is examined. All control strategies are tested on a residential low voltage feeder by means of simulations and their performance in terms of overvoltage mitigation, voltage unbalance mitigation and drooped power is assessed.