Throughout the developmental process of the wind energy conversion system (WECS), wind tunnel test is essential for the design and performance evaluation of the WECS. However, such a field test inevitably increases design time and cost due to the complex test settlement. Therefore, a wind turbine emulator that can closely imitate the turbine characteristics would merit the cost reduction of the WECS design. This paper reports on the development of wind turbine emulator and on how the emulator is utilized to evaluate the performance of WECS throughout the design flow. Testing results shown in this paper not only verify the emulator in reflecting the dynamic characteristics of the tested wind turbine, but also validate its usefulness in evaluating the performance of the WECS.