PV ramp limiting controls with adaptive smoothing filter through a battery energy storage system

Photovoltaic (PV) variability can adversely affect system frequency and voltage stability in a high PV penetration location. High cloud cover in a short time scale can cause excessive ramp rates for large PV array installations. Smoothing is desired to limit the impact of cloud shading on the distribution circuit. Existing algorithms typically are simple moving averages that introduce time lag. The goal of this paper is to introduce a control method to smooth PV power ramp rates with a focus on reducing battery size (cost) and energy throughput (life) requirements. Simulated data from a high PV penetration multi-megawatt (MW) solar array site with large ramp rates is analyzed. Simulations verify that the control schemes work for a reduced size battery system.