基于海上风力发电机组中虚拟飞轮储能系统的频率支撑协调控制策略

Coordination Control Strategy for Frequency Support Based on Virtual Flywheel Energy Storage System in Offshore Wind Turbines

针对海上风力发电场并入电网导致电网等效惯量下降问题,提出基于海上风力发电机组(OWTs)中虚拟飞轮储能系统(VFESS)的频率支撑协调控制策略,并利用遗传算法优化VFESS吸收和释放功率的曲线。首先,OWTs采用宽转速运行控制方法形成VFESS,通过释放和吸收能量来短时支撑电网频率;然后,考虑负荷扰动、VFESS存储容量、同步发电机组一次调频时间等条件后,利用遗传算法优化VFESS释放和吸收能量的功率曲线,以实现电力系统频率跌落幅度最小、频率变化率最小的目标。最后,算例分析表明采用该方法的OWTs能提供短时频率支撑,减小电力系统低频减载装置动作次数。

Targeting the problem of equivalent inertia reduction in power grid when a offshore wind farm is integrated into the power grid,the paper proposes a coordination control strategy for frequency support based on virtual flywheel energy storage system(VFESS)in offshore wind turbines(OWTs),and employs a genetic algorithm to optimize the curves for the power release and absorption by VFESS.Firstly,a wide-speed operation control method is employed by OWTs to establish VFESS,supporting the grid frequency for a short time by energy release and absorption.Then considering the load disturbance,the storage capacity of VFESS,and the primary frequency regulation time of synchronized generators,the power curves for the energy release and absorption by VFESS is optimized with genetic algorithm to achieve the goal of a minimum frequency drop and frequency change rate for power systems.Finally,an example analysis shows that the OWTs using this method can provide short-time frequency support and reduce the action number of low-frequency load shedding device in the power system.