Loss and load reduction by coordinated control of community energy storage and OLTC

Renewable energy sources are usually integrated with a distribution system through a small-size-generator with low voltage level. As a consequence, distributed energy storage systems have been connected to a distribution system to help with renewable energy resources integration. Community Energy Storage (CES) is a small distributed energy storage connected to the secondary part of a transformer and is an advanced energy storage system close to the customer. CES provides many benefits such as peak shaving, load shifting and voltage control. Meanwhile, distribution system operators conduct Conservation Voltage Reduction (CVR) to reduce power consumption in the system. To implement CVR on the system, flat voltage profile is required. CES is distributed in the distribution system and is capable of controlling system voltage. In this paper, a control method of CES is proposed in order to implement CVR. Based on day-ahead load forecasting, power consumption including load demand and active power loss is reduced by the optimal schedule of CES output power and On-Load Tap-Changer (OLTC) operation. With a case study using Matpower, this paper validates the effect of the proposed method.