基于功率平衡控制原理的双馈风电机组辅助调频方法

高比例的风电并网给电网的功率平衡与频率稳定带来了严峻的挑战,如何充分发挥变速风电机组的有功备用潜力,研究风电场快速可控的调频控制方法成为提高风电消纳能力的关键问题。提出适用于全风速工况的变速变桨距风电机组的改进型有功控制策略,有效地实现了风电场响应电网功率调度指令减载运行并提供旋转备用。考虑风电场分散接入场景,针对机组跳机和负荷脱网等可监测的、大容量的单一扰动/故障事件,基于功率平衡控制原理提出风电场的辅助调频协调控制新方法,在电网功率发生突变时,根据风电场与扰动节点的最短电气距离,合理启动和分配不同风电场的紧急功率控制容量。仿真结果表明,所设计的风电场有功-频率控制方案能从降低暂态频率偏差幅值及减小频率恢复时间两方面,有效地提升系统发生扰动后的频率稳定性。

Auxiliary frequency modulation method of DFIG-based wind turbine based on principle of power balance control

The high proportion of grid-connected wind power brings severe challenges of power balance and frequency stability to the power grid. How to make full use of the active reserve of variable-speed wind turbines and study the fast-flexible frequency modulation control method of wind farm become the key issues to improve the wind power consumption capacity. An improved active power control strategy for variable-speed variable-pitch wind turbines under full-wind speed condition is proposed, which can make the wind farm realize load shedding to response to the power dispatching order and provide active power reserve effectively. Considering the decentralized accessing scenario of wind farms and aiming at the monitorable, large-capacity single disturbance or fault event such as generator trip, load off-network, and so on, a new coordinated auxiliary frequency modulation method is proposed based on the principle of power balance control. When the power of the grid changes suddenly, the emergency power support capacity of different wind farms are started and allocated reasonably according to the shortest electrical distance between the wind farms and the disturbance node. Simulative results show that the designed power-frequency control strategy can effectively improve the frequency stability of the power grid after the disturbance from two aspects of reducing the amplitude of transient frequency deviation and the frequency recovery time.