Control of Parallel Connected Distributed Generation Systems for Load Sharing and Seamless Transition of Microgrid

Abstract

Abstract newlineConsidering today s worldwide energy crises and global warming issues, power newlinegeneration using renewable energy sources (RESs) are gaining more importance in newlineorder to provide continuous and reliable power supply to all distributed local loads. newlineDistributed generation (DG) units equipped with RES providing local distributed load newlinedemands form a structure of microgrid. This microgrid can operate either in grid newlineconnected mode or in islanded/standalone mode. Many control techniques are used to newlinefor proper active and reactive power sharing among the converters based on their newlinerating. Furthers improvements are made in the control techniques to compensate newlineharmonic currents and unbalanced current without affecting the power sharing among newlinethe converters and to achieve seamless transition of microgrid between grid connected newlinemode and islanded mode. However, the over all control complex is increased. newlineThis thesis presents a reliable microgrid for residential community with modified newlinecontrol techniques to achieve enhanced operation during grid connected, islanded, and newlinere-synchronization mode. A modified power control technique is developed such that newlinelocal load reactive power demand, harmonic currents, and load unbalance are newlinecompensated by respective residential local DG. This control technique achieves newlinetransient free operation of the microgrid during residential load disturbances. An newlineadditional modified control technique is also developed to achieve seamless transition newlineof microgrid between grid connected mode and islanded mode. newlineTo increase the reliability of microgrid, a distributed power management scheme newlinewith combined modified droop and master-slave control is proposed. The proposed newlinecontrol scheme improves the dynamic performance of microgrid under various newlinedisturbances. A modified power control scheme is used to achieve power sharing of newlinelocal residential load demand. Furthermore, the requirement of active power demanded newlineix newlinex newlinein residential loads is shared between the distributed generations in the microgrid with newlineproposed mo