Abstract:

In many countries there are remote communities where connection with powergrid is too expensive or impractical and diesel generators (DG) are often the source of electricity. Under such circumstances, a locally placed small/medium scale off-grid renewable energy system can be a feasible solution. Typical stand-alone power system includes one or more sources, energy storage and their regulation.Control co-ordination among various renewable source, energy management, control of voltage and other power quality problems are key issues in hybrid system. In case of variable speed wind turbine generator (WTG), they are decoupled from rest of system through power electronic converters. Therefore, variable speed WTG do not contribute in the primary frequency regulation during disturbances. Using de-loaded operation of WTG, power can be reserved and reserved power can be used during under frequency events. However, de-loaded operation reduces the power extracted from WTG and capacity factor of wind farm reduces. Therefore, effective control of de-loaded operation of WTG is needed so that power extraction is more from deloaded WTG.