Energy Management and control of Grid-connected Microgrid integrated with HESS

Abstract

Once Microgrids are laboratory projects, but as time passes and along with the technological advancement, they led to falling costs which promotes microgrids' use in commercial markets. Microgrids manage distributed clean energy resources and along with a hybrid energy storage system (HESS), it improves the reliability & resilience of the existing grid system. Energy management of ac-coupled microgrids is quite a challenging task as compared to dc-coupled microgrids as in dc, reactive power and frequency synchronization issues are irrelevant. However, within the microgrid, Energy Management under different modes of operations, i.e., one is Surplus Power Mode and another is Deficient Power Mode, is a demanding piece of work to make efficient, sustainable and reliable use of different distributed renewable energy resources along with their compatibility to different energy storage elements. In this paper, an energy management strategy is suggested to make the existing grid-connected system to fulfil the energy demand effectively and efficiently with the help of a hybrid energy storage system consisting of a supercapacitor and a battery, under different modes of operation. Suggested energy management strategy helps in quick voltage build-up at the DC bus, effective sharing of energy and power between the battery and supercapacitor along with enhanced compatibility in power-sharing between grid and energy storage system thus improves battery life by keeping in check the rate of rising of battery currents, enhances power quality in the system and seamless transition between different modes of operations.