Ground-based hybrid dynamic simulation of wind turbine operation

An electrohydraulic pitch-control device has been successfully applied to a 14-m horizontal-axis wind turbine in a demonstrator field test. One of the most important problems related to the pitch controller is to provide it with an adequate control force. In order to solve this problem, a ground-based hybrid dynamic simulation technique was developed. Starting process and pitch- and load-control performance investigated using the hybrid dynamic simulation system. Possible origins of instability were detected and removed, and the optimum condition for pitch and load controllers was determined. Based on the results of simulation, the performance of the wind turbine in field operation was predicted as follows: it starts rotating at a wind speed of 3.5 m/s with the load cut off; the speed of rotation reaches the rated maximum of 87 r/min in 1.5 min when the load is cut into at the rotor speed of 60 r/min, and the maximum pitch control rate which is adequate for the constant speed control in a strong wind is about 7 deg/s. Demonstration tests were carried out, confirming these predictions