Peak Shaving and Duck Curve Mitigation With BES Based Ramp Rate Limit Strategy and MATOIGI Control for Improving PQ of SPV-BES Microgrid

Abstract

The intermittency of renewable energy sources (RES) and sudden variations in load demand cause high power ramps at the grid side. However, the power ramp rate of the grid is limited due to the higher mechanical time constant of the alternators. Higher power ramp rates lead to grid side instability and may deprive the load of getting continuous power. Moreover, from a microgrid perspective, due to the power generation profile of solar-based RES, the power demand from the grid is highly reduced during daytime peaks and increased with high ramp rates during the evening peaks leading to the formation of a duck curve, which economically affects the power generation companies. To reduce the effect of intermittency of the RES on the grid, to flatten the duck curve and reduce the peak demand from the grid during increased load demands, this paper presents an advanced ramp rate-limit (ARRL) control with battery energy storage (BES) for a grid-tied rooftop solar photovoltaic array (SPVA) based microgrid. The control utilizes the power leveling feature of the BES to ensure continuity of power supply to the loads during RES intermittency or high load demand conditions. This paper also presents a modified adaptive third-order interweaved generalized integrator (MATOIGI) based control to enhance the power quality of the microgrid during distortions/unbalance in grid voltages or load currents and to ensure that the MG performance is not deteriorated as per the IEEE std. 1547.