Yaw braking system of wind turbine generator system and control method thereof

Abstract

The invention discloses a yaw braking system of a wind turbine generator system. The yaw braking system comprises a hydraulic braking system and an electromagnetic braking system; the hydraulic braking system comprises a hydraulic station and a hydraulic brake; the hydraulic brake is contacted with a yaw brake disc; the yaw brake disc is in bolt connection with a sleeve, with a gear, of a yaw bearing and a flange at the top of a tower; a cabin base plate is in bolt connection with a ring, not with a gear, of the yaw bearing; the hydraulic brake is connected with the hydraulic station; the electromagnetic braking system comprises a yaw motor, a yaw speed reducer and an electromagnetic brake; the electromagnetic brake is mounted in the yaw motor; an output shaft of the yaw motor is connectedwith an input shaft of the yaw speed reducer; and an output gear of the yaw speed reducer is engaged with a gear ring of the yaw bearing. The yaw hydraulic braking system can be in a low-voltage state during power failure, and can realize long-time damping passive yaw without depending on UPS power supply during power failure, so that the load of the system under the working condition of storm wind is effectively reduced, and meanwhile, the impact to the yaw gear by external load is prevented.

Description

technical field [0001] The invention relates to the field of wind power, in particular to a yaw braking system and a control method for a wind power generating set. Background technique [0002] The operating conditions of wind turbines are complex, and the wind turbines need to face various abnormal conditions such as power outages, storms, and sudden changes in wind direction. The yaw braking system and its control strategy are crucial to the safety of the wind turbines under these conditions. The yaw braking system of the wind turbine generator set needs to be powered by the unit UPS to keep the unit in the braking state when the power grid fails. However, the UPS power supply time is limited, generally only a few hours. If there is a long-term power failure, the UPS is not enough to maintain When the power is supplied for a long time, if the wind direction changes suddenly, the hydraulic brake pressure drops, and the electromagnetic brake of the yaw motor is in the braki...

AI Technical Summary

Problems solved by technology

However, this plan does not take into account that when the crew turns on the brake of the yaw braking system and is in a free yaw state, the friction torque of the nose yaw system is small, and sudden changes in the wind direction will cause the nose to yaw excessively and frequently passively yaw. The yaw transmission parts of the unit cause damage, or even twist the cable, and this control method needs to rely on UPS and battery power supply when the grid is powered off. When the UPS or battery is exhausted, it needs to exit the free yaw state, and the yaw motor brakes and yaw The aviation hydraulic brake returns to the braking state. At this time, the unit is in the brake lock state. If the wind direction changes during the period, the unit cannot yaw, and the fan will bear a large load, which poses a safety risk.

Images