Effects of Ramp Rate Limit on Sizing of Energy Storage System for PV-Wind Power System

Abstract

The power produced by variable renewable energy power plants (VREPP) can fluctuate heavily and cause issues in the power grid. To prevent the power quality issues in the grid, some countries have set a ramp-rate limit (RR) that the generated output power of power plants may not exceed. The power fluctuations of VREPPs are often mitigated by an energy storage system (ESS) and a power smoothing method. This paper presents how the RR limit value affects the size of an ESS needed for a photovoltaic (PV)-wind power system. Also, the size of the power plant is considered, and how it affects the size of the ESS. The generated power of the PV-wind power system was simulated using measured irradiance, temperature and ind speed. An RR-based control algorithm was used to operate the virtual ESS. It was found that the increase in the RR limit greatly decreases the size of the ESS. The size of the power plant also significantly affects the size of the ESS.