Damping-Based Droop Control Strategy Allowing an Increased Penetration of Renewable Energy Resources in Low-Voltage Grids

The increased penetration of renewable distributed energy sources increases the challenges for distribution systems operators to keep the voltage variations within the prescribed limits. One of the voltage problems is caused by single-phase systems leading to voltage unbalance. Another problem is overvoltages caused by local injection of distributed energy sources. An effective solution for this problem is by active power curtailment. In this paper, a control strategy is proposed that mitigates voltage unbalance by using active power and it is equipped with a linear active power curtailment solution. The effect of the proposed control strategy and three state-of-the-art control strategies on the voltage profile and the curtailed power are studied. It can be concluded that the proposed control strategy has a beneficial effect on the voltage profile along a feeder and leads to less power curtailment compared to the state-of-the-art solutions. The proposed control strategy thus allows an increased penetration of distributed energy sources in the low-voltage grid.