System for the Safe Operation and Stabilisation of the Rotational Rate of Small Wind Turbines

The article presents the nearly 30-year evolution of the design of a range of small wind turbine units having power restricted within the range of 3 kW to 100 kW (known under the commercial name of ZEFIR). The evolution was primarily triggered by difficulties in achieving the operational safety of the above-named machines without compromising the simplicity of design. The article also discusses the role of PM synchronous machines in achieving previously assumed safety parameters and satisfying the postulate of “fail safe philosophy design”.