Impact of energy storage in micro-grid systems with DGs

This paper presents an impact study of energy storage on a micro-grid system consisting of a very small power producer of a biomass type. The energy storage used in this paper is a battery bank. It comprises a combination between shunt and series battery cells in order to implement a sufficient battery storage system. To verify the simulated battery storage system, one day operation of an electric power distribution system was tested. This simulation was performed using MATLAB software in order to support and also to balance the energy exchange between the generation (drawn from both substation and renewable energy plants) and the power demand of the entire system. With the energy storage plant of battery banks, a simple 6-bus test system with a total power generation of 6 MW is situated for test. Considering of four test cases (case 1: without energy storage installation and neglecting power losses, case 2: without energy storage installation but considering power losses, case 3: with energy storage installation but power losses neglected, case 4: with energy storage installation and also considering power losses). Power transmission losses used in this paper can be determined by using Newton-Raphson power flow solution method. The simulation of the test system was carried out by performing one day simulation with energy storage and energizing stored energy by using an appropriate algorithm. The results showed that the system with energy storage can lead to efficient energy usage and power loss reduction.