Reactive compensation techniques to improve the ride-through capability of wind turbine during disturbance

World wind energy capacity expanded at an annual rate of 25% during the 1990s. The total world wind turbine installation capacity was approximately 40 000 MW at the end of 2003. Germany has the highest installed capacity of over 10 000 MW, while Denmark, where the wind energy accounts for more than 13 % of electricity consumed, has the highest wind energy level per capita. The United States is catching up in the development of wind farms, with several large-scale wind generation projects currently being materialized. Even though there is significant progress in the wind generation technology, most of the currently installed wind turbines utilize induction generators to produce the electricity. Since the induction generators do not perform voltage regulation and absorb reactive power from the utility grid, they are often the source of voltage fluctuations. It is necessary to examine their responses during the faults and possible impacts on the system stability when the percentage of the wind generation increases. This paper compares the steady-state voltage profile and the voltage ride-through capabilities of the induction-generator-based wind farms with different reactive compensation techniques.