Integrated Control Strategy for Grid Connected Photovoltaic Array, Battery Storage and Supercapacitors

Abstract

Upon various renewable based power generation, Solar Photovoltaic (PV) technology is continually developing nowadays. However, the major drawback of this technology is the intermittent issue due to the rapid fluctuations in solar insolation level. Energy storage systems such as batteries and super capacitor banks are used to reduce the above problem. There is a requirement of an integrated controller strategy in order to achieve a power generation unit which includes power share among those energy storage units in between with solar PV array. Using a hybrid system of a battery bank and a super-capacitor bank over using a battery bank alone, helps to increase the lifetime of the batteries. Integrated control strategy is the common method used to control the solar PV array with energy storage units in order to supply the required islanded demand and supply excess energy to the grid while maintaining the DC-link stability through the synchronized control of DC-DC power electronic converters. This paper presents an integrated control strategy for grid connected PV array together with a battery bank and a super-capacitor bank. This further state mathematical proof for the sizing of storage devices. Performance of the integrated control strategy was evaluated using a practical experiment by developing customized DC-DC power electronic converters.