| 摘要 |
Systems for controlling yaw rotation of a horizontal-axis wind turbine generator are provided. In one system, yaw rotation is generated by motors 10, the output torque of which is maintained substantially constant when the motor speed is within a predetermined range, so as to reduce the variation in the output torque. In another system, yaw rotation is generated by pinion gears 9 each controlled by a motor 10 mounted on the tower of the generator and arranged to rotate a main gear wheel 8 attached to the nacelle. To prevent wear on the motors 10 arising from differences in backlash between the pinion gears 9 and the main gear wheel 8, each motor 10 is controlled to generate a low output torque until all pinion gears 9 have engaged the main gear wheel 8, after which the full output torque is applied to all motors 10. In a further system, in which mechanical friction brakes 11 are provided, braking is arranged to be provided either by the mechanical brakes 11 or by generating a counter-torque in the motors 10, in dependence on the sensed external load. |
