Tvindkraft: Implementing a 500 kW 21-IGBT-based frequency converter for a 1.7 MW wind power conversion system

The 54-meter-high Tvindkraft windmill was built by a group of volunteers during 1975-1978, as an argument for renewable energy sources as well as an argument against nuclear power. At that time it was the world´s biggest windmill. So far, Tvindkraft has been running for 35 years, proving that a well-constructed wind turbine is a sustainable approach to renewable energy utilization. This paper deals with the analysis, simulation, implementation and experimental testing of a new 500 kW 21-IGBT-based frequency converter that will run in parallel with the former 12-Thyristor-based frequency converter to fully utilize the capacity of the windmill. Simulations and experimental results are presented side-by-side to verify the proper functionalities of the frequency converter described in this paper.