Seamless Connection of Wind and Small Hydro Based Energy Conversion System With Storage

This work presents seamless connection of wind generation system with permanent magnet synchronous generator (PMSG) based small hydro energy conversion system (SHEC). Distributed generators (DG) such as wind and hydro connected at AC link may not always have same amplitude and phase of voltages. Connection of such DGs without proper synchronization might lead to flow of high currents. Considering it, a sequential procedure is developed and verified experimentally, for different modes involved in process of interconnection. These include grid formation mode, voltage synchronization mode and maximum power extraction mode. Control algorithms are established for all converters before and after seamless connection. Developed algorithms ensure that upon closing of static transfer switch, stator, and rotor currents of DFIG flow smoothly. Besides, it also assures that load currents and PMSG currents remain unaffected during synchronization. This provides uninterrupted power to local loads. Obtained results certify transient free operation of microgrid (MG).