Small-Signal Analysis of Hybrid Distributed Generation System with HVDC-Link and Energy Storage Elements

A small-signal analysis of isolated autonomous hybrid system with high voltage direct current link (HVDC) or high voltage alternating current (HVAC) line for different energy storage combinations is proposed in this paper. The hybrid systems supplying power to isolated loads comprise of different renewable energy resources such as wind, photovoltaic (PV), fuel cell (FC) and diesel engine generator (DEG) along with the energy storage devices such as flywheel energy storage system (FESS), battery energy storage system (BESS).Ultracapacitor (UC) is incorporated as an energy storing element in order to improve the hybrid system performance. A comparative assessment for deviation in frequency profile for different hybrid systems in the presence of different storage system combinations is carried out which reflects the improvements of the deviation in frequency profile in the presence of the ultracapacitors (UC) as compared to other storage elements.