基于虚拟惯量的风电场黑启动频率协同控制策略

Cooperative Frequency Control Strategy for Wind Farm Black-start Based on Virtual Inertia

在传统黑启动电源匮乏的电网中,采用风电场作为黑启动电源是一种有益的尝试。风电场采用虚拟惯量控制方式可避免风电机组转速与频率解耦导致的频率支撑能力不足问题,从而有效提升风电场作为黑启动电源过程中的系统频率稳定性。通过对风电场黑启动场景下传统虚拟惯量策略的适应性分析,文中提出了一种新的频率协同控制策略。首先,针对实际工程背景提出了一种以柴油发电机作为配套小容量支撑电源的风电场黑启动方法,并分析了风电场黑启动的关键问题及其过程。其次,通过附加功率外环控制和跟踪曲线切换控制在不同启动阶段的柔性切换,且辅以桨距角参与调节的频率响应策略,提出了一种基于虚拟惯量的频率协同控制策略。最后,通过PSCAD仿真验证了所提策略的合理性和先进性。

In a power grid lacking conventional power sources for black-start, adopting wind farm as a black-start power source is a meaningful effort. The lack of frequency support caused by the decoupling of wind turbine speed from the main system frequency can be avoided in the virtual inertia control mode, thus the frequency stability can be efficiently enhanced. A new cooperative frequency control strategy is introduced based on the adaptability analysis of conventional virtual inertia strategies in the black start scenario.Firstly, based on a practical project, a back-start method for wind farms is proposed by adopting diesel generator as a matched support power supply with small capacity, and the main problems and process of wind farm black-start are analyzed. Secondly, through the flexible switching of additional power loop control and tracking curve switching control at different start stages, and supplemented by regulating frequency response strategy involved pitch angle, a cooperative frequency control strategy based on the virtual inertia theory is proposed. Finally, the results of the simulation using PSCAD show the rationality and advantage of the proposed strategy.