4. Resilient Energy Storage-Based Microgrids

Recent years, deploying of microgrids become key driver due to grid power un-reliability, reduction of environmental pollution (CO₂ emission) by using the renewables, demands of loads beyond the installed capacity, grid rate structure, penalties imposed due to power quality issues, incentives, etc. However, renewable energy sources will not cooperate consistently throughout the year and seasons. Changes in their availability results voltage, frequency changes causing, active, reactive power oscillations and the operation of microgrid will become unreliable. As a result, the key performances of the microgrids such as steady state, dynamic, transient response and power quality are affected. Various technical and economic challenges are introduced while integrating renewable energy sources to the utility grid. Energy storage can be a reliable asset that can bring more benefits to the microgrid. Energy storage places a critical role during the power generation fluctuations in the microgrid system due to renewables power fluctuations. It aids the microgrid to have a smooth transition from ON-grid to OFF-grid (islanded) and vice versa. In the grid connected system, it can support the real and reactive demand of the grid which can yield to shifting the energy from one time to another time. In the islanded electric system, it has the ability to operate as virtual grid for maintaining the rated voltage and frequency. Also they provide significant role in providing the spinning reserve, un-interrupted islanding, etc. In this paper, the microgrid with energy storage and renewables is analyzed in different operating conditions.