Modeling and Simulation of Bi-Directional Battery Operation in Microgrid Island Operation

Abstract

In the power system, all generators and RES are linked together considering their power quality and system sta- bility. DC microgrid are essential for long line transmission due to low power loss during transmission. There is various unidirectional voltage gain DC-DC converter like buck converter, boost converter, flyback converter, forward converter, etc. Most of the DC-DC converters are unidirectional i.e., from input to output, but nowadays different switching topologies are designed to move bidirectional power flow by replacing diodes and power BJT. By using high frequency for switching action to power semiconductor switches switching losses are reduced hence efficiency is increased. The present work, modelling of DC microgrid is done in Matlab/Simulink environment includes standalone DC microgrid with battery BDC. The work shows that the theoretical concept how isolated BDC works on both modes and implementing it in MATLAB Simulink in order to verify the results and find the advantage and disadvantage of the converter. The efficiency of isolated BDC is less as compared to non-isolated BDC. Due to conversion of signal beside high frequency transformer, voltage and current ripple content is more in converter due to ac to dc conversion. Energy management of this system can be done easily by selecting this transformer less BDC. To verify the theoretical concept this simulation is done and the effectiveness is analysed. Also, after comparison it has been see that non-isolated DC-DC bidirectional converter has better characteristic than isolated converter for our application purpose.