SUMMARYA practical-scale hybrid wind turbine generating system is developed for generating a constant output power even when the wind velocity fluctuates. The system consists of a wind turbine synchronous generator (SG), a rectifier, a current-source thyristor inverter, an SG driven by a prime mover, and a duplex reactor. A high-quality output voltage waveform is always obtained from the system, which has a very simple configuration. Experimental results show the feasibility of the system. A model of the system is also developed to predict the dynamic performance when the system conditions such as the wind velocity and load are changed, and good agreement between the simulated and experimental performance is observed, confirming the validity of the dynamic model. C⃝ 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 188(1): 60-69, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com).