A decentralised adaptive voltage droop control for inverters in power distribution networks

This paper investigates voltage control in distribution power systems with high penetration level of inverter-based distributed generation. The proposed controller locally adapts automatic Volt/Watt and Volt/VAr droop control coefficients taking into account the location of the distributed generator in the feeder to mitigate voltage deviations while ensuring that voltage deviations at all buses are kept within tight bounds. The proposed controller consists of voltage zones with different characteristics which renders the closed-loop system to be a switched system. We study analytical stability of this system and give sufficient conditions to ensure boundedness of the switched control system within safe voltage limits. An illustrative example shows effectiveness of the proposed control design.