Coordinated Control of OLTC and Energy Storage for Voltage Regulation in Distribution Network With High PV Penetration

Accommodating increased penetration of renewable energy resources like solar Photo-Voltaics (PV) imposes severe challenges on the voltage regulation of the traditionally designed distribution system. Battery Energy Storage Systems (BESS) can mitigate voltage regulation issues, as they can act quickly in response to the uncertainties introduced due to solar PV. However, if there is no coordination between existing devices such as On Load Tap Changing Transformers (OLTC) and BESS, then BESS takes all the burden and is generally over-utilized. The uncoordinated control schematic shall also lead to underutilization of OLTC. Hence, in this paper, a coordinated control strategy to control BESS along with OLTC is proposed to warrant acceptable voltage magnitudes across the distribution feeder. The formulated optimization problem aims to mitigate the voltage deviation from its required values while reducing the number of changes in tap positions and also enhancing the battery life. The improvement in voltage regulation and optimal utilization of resources by using the proposed coordinated scheme over the traditional uncoordinated scheme is demonstrated for the IEEE 13 bus and 33 bus distribution systems in MATLAB/ Simulink.