风电机组偏航电机驱动能力的分析与设计

ANALYSIS AND DESIGN OF YAW MOTOR DRIVING CAPACITY FOR WIND TURBINES

风电机组的偏航系统通常采用常规的三相异步电机,当偏航电机承受超过其额定设计荷载时会导致其电流增大,较长时间的大电流热累积之后会触发偏航马达保护开关跳闸,进而报出风电机组偏航故障,导致风电机组停机。在风电机组的全寿命期内,偏航时长通常仅占总运行时长的5%左右,若风电机组设计时要求最大外部荷载不能超过偏航电机的最大有效驱动能力,则可能会导致设计和偏航电机选型过于保守。首先对偏航马达保护开关跳闸过程的故障特征及偏航电机运行特性进行分析,然后根据实际风电机组测量数据对偏航电机运行特性进行了验证,基于此提出了一种适用于风电机组偏航电机驱动能力设计和评估的方法,最后对该方法的实际效果进行了验证。分析结果表明:偏航电机发生堵转及偏航马达保护开关跳闸故障,并不是由某一时刻的外部荷载大小造成的,而是与偏航电机运行特性密切相关的一段时间内的外部荷载历程有关。基于所提评估方法并结合实际风电机组设计的可靠性要求,可以更为合理地进行偏航电机驱动能力的设计与偏航电机的选型,并指导风电场项目的定制化开发,从设计和适应性分析源头降低偏航故障发生的概率,提升风电机组运行可靠性。

The yaw system of wind turbines usually uses conventional three-phase asynchronous motors.When the yaw motor bears more than its rated design load,its current will increase.After a long period of high current heat accumulation,it will trigger the yaw motor protection switch to trip,which will then report a wind turbine yaw fault and cause the wind turbine to shut down.During the entire lifespan of a wind turbine,the yaw duration usually only accounts for about 5%of the total operating time.If the wind turbine design requires that the maximum external load cannot exceed the maximum effective driving capacity of the yaw motor,it may lead to overly conservative design and selection of the yaw motor.This paper first analyzes the fault characteristics of the tripping process of the yaw motor protection switch and the operating characteristics of the yaw motor.Then,the operating characteristics of the yaw motor are verified based on actual wind turbine measurement data.Based on this,a method suitable for the design and evaluation of the yaw motor driving capacity of wind turbines is proposed,and the actual effect of this method is verified.The analysis results show that the locked rotor of the yaw motor and the tripping of the yaw motor protection switch are not caused by the magnitude of external load at a certain moment,but by a period of external load history closely related to the operating characteristics of the yaw motor.Based on this evaluation method and combined with the reliability requirements of actual wind turbine design,the design of yaw motor driving capacity and selection of yaw motor types can be more reasonable,and guide the customized development of wind farm projects to reduce the probability of yaw fault occurrence from the source of design and adaptability analysis,improve the reliability of wind turbine operation.