Faroe Islands Wind-Powered Space Heating Microgrid Using Self-Excited 220-kW Induction Generator

Energy is fundamental to modern society. Increase in the price of oil as well as environmental concerns have spurred the use of alternative renewable energy sources. In the Faroe Islands, the readily available wind energy is an obvious source for space heating. Seasonal correlation exists between wind energy and required space heating and mismatches can be reduced by using simple water tanks as heat storages. A traditional Danish induction generator wind turbine has been erected on the island of Nólsoy to produce energy for space heating. The system is designed as a stand-alone microgrid, which needs its own control of frequency and voltage. A microcontroller is used to control frequency by matching load (heaters) to generated power and to produce the correct reactive power and voltage by switched capacitors. One challenge is the start-up procedure at high wind speeds when nominal speed tends to be reached before voltage builds up by the self-excitation process. This paper reports the initial test and adaptation of the control system.