A case study on the effect of storage systems on a distribution network enhanced by high-capacity photovoltaic systems

Abstract

Modern distribution networks with intermittent weather-dependent renewable energy resources may require energy storage to smooth out intermittency in their power generation and balance energy production and demand. Therefore, the objective of this study is to present a case study of analyzing the effect of such storage systems (SSs) on a distribution network enhanced by high-capacity photovoltaic (PV) systems. For this purpose, this study defines two metrics that quantify the effect of SSs on peak load reduction, power, and voltage such as a load factor and a change in total power generation. Then a well-known strategy that charges storage at night and discharges it to distribution networks at peak demand times is modeled in steady-state power systems analysis software, or OpenDSS. Next, as a case study, this study modifies the IEEE 37-bus test feeder enhanced by four photovoltaic systems (PVSs) with a capacity of 15 and 30 percent of total peak power, adds SSs with the same capacity as PVSs and a duration of three hours to the test feeder, and calculates steady-state power flow in 15-min intervals during a week. Finally, it presents the effect of SSs from the following point of views: (a) a reduction in peak load, (b) an increase in over-voltage (e.g., 1.05 p.u.), and (c) intermittency in voltage and total power generation.