Energy Storage Unit for Dynamic Voltage Support in Distribution Networks

Abstract

The increasing participation of distributed energy resources in the low voltage distribution network prompt mandated grid-supporting activities from these entities during short-term disturbances. The primary idea of the work presented in this paper is to leverage the dynamic voltage support capability of the grid-connected energy storage units during voltage fault ride through conditions on the distribution network. Firstly, a detailed analysis about the role of energy storage units in providing dynamic voltage support for both low and high voltage disturbances is presented and the conditions for maximizing the voltage support are derived. Further, the dynamic voltage support oriented control strategy for the converters of the energy storage unit is presented in detail along with the state-of-charge management of the storage device. Finally, a simulation study considering a supercapacitor energy storage unit connected to the CIGRE European LV residential distribution test feeder is carried out using Matlab/Simulink to validate the proposed control strategy. The results assert the fact that the grid-connected energy storage units aid the network voltage during disturbances with the proposed control strategy within their design limits.