Placement of energy storage coordinated with smart PV inverters

Energy storage (ES) is increasing used in electrical transmission and distribution systems because it can perform many functions. These include peak shaving, voltage regulation, frequency regulation, spinning reserve, and aiding integration of renewable generation by mitigating the effects of intermittency. This work focuses on the usage of energy storage for peak shaving and voltage regulation on a distribution system having a high penetration of photovoltaic (PV) generation. The PV stations considered make use of smart PV inverters as proposed by the Electric Power Research Institute (EPRI). These inverters assist the energy storage with voltage regulation. Additionally, the proposed method includes support for varying energy storage unit (ESU) sizes, non-radial distribution systems, and reverse power flow, both real and reactive. The method is applied to the worst-case voltage regulation scenario. The impact of the placement and voltage regulation on the profitability of energy storage is assessed. This is accomplished by adding voltage regulation as a constraint to the problem scheduling energy storage in order to maximize profit. Applying the method shows that the best place to put an ESU is near the end of a feeder. Validation of the method shows that it does not impact the ability of ES to be scheduled in order to maximize economic benefits with time-of-use pricing.