基于最大转子储能的风电场风机变利用率的有功功率分配策略优化

Optimization of a variable utilization level scheme for load sharing control of a wind turbine ina wind farm based on maximum rotor energy storage

风机采用最大功率追踪控制时无功率备用量,当系统供需发生变化时,易对系统稳定性造成较大影响。提出了一种风场变利用率的有功功率分配策略,在满足系统调度命令的同时,减少风能的损失,提高风能利用率。考虑到风场的尾流效应,所提方案通过改变每台风力机的利用率来控制风机的有功功率输出。其中,每台风力机的利用率根据其自身转速而自适应调整。当风机转速较高时,风力机的利用率则较高。当风机转速较低时,则降低风力机的利用率,这样风电场可存储更多的旋转动能,可在系统需要时释放回系统。通过在基于双馈风机的风电场中对所提变利用率策略进行研究,结果表明,在满足调度需求的同时,所提控制策略比传统的等利用率方案更加节能。

Under Maximum Power Point Tracking (MPPT) control,the wind turbine has no power reserve,which tends to have a large impact on system stability when system supply and demand change.A variable utilization level (UL) scheme is proposed for a wind power plant (WPP) to fulfill the dispatch order while reducing the loss of wind energy and improving wind energy efficiency.Considering the weak effects of a wind farm,the proposed scheme controls the active power output for each wind turbine (WT) according to its utilization level (UL),which is adaptively adjusted according to WT rotor speed.When the turbine speed is higher,the wind turbine utilization level is higher;when the turbine speed is lower,the wind turbine utilization level is lower.Thereby the wind farm can store more rotational kinetic energy that can be released back into the system when needed.The proposed variable UL strategy is fully investigated in a doubly fed induction generator(DFIG)-based WPP and the results show that the proposed control strategy has better energy efficiency than the conventional equal UL while meeting the dispatch demand.