Hybrid AC or DC Micro grid Control Using Decentralized control for Power Management

Abstract

This paper proposes a hybrid ac/dc micro grid to reduce theprocesses of multiple dc–ac–dc or ac–dc–ac conversions in anindividual ac or dc grid. The hybrid grid consists of both ac and dcnetworks connected together by multi-bidirectional converters. Theproposed model is in such a way that the reliability of power can bemaintained during the whole day. This is obtained by connecting aPEM Fuel cell stack in parallel with the PV system. The proposedhybrid grid can operate in grid-tied or autonomous mode. Thecoordination control algorithms are proposed for smooth powertransfer between ac and dc links and for stable system operationunder various generation and load conditions. Uncertainty incharacteristics of wind speed, solar irradiation level, ambienttemperature, and load are also considered in system control and operation. A small hybrid grid has been modeled and simulatedusing the Simulink in the MATLAB. The simulation results show that the system can maintain stable operation under the proposedcoordination control schemes when the grid is switched from oneoperating condition to another.