基于频率变化极值时间的风电虚拟惯量约束与支撑控制

Virtual Inertia Constrain and Support Control of Wind Turbines Based on Variable Frequency Limit Time

在系统频率变化极值时间内约束变速风机的虚拟惯量,是提升风电对系统频率主动支撑可靠性的关键。为此,首先分析了风电机组虚拟惯量的可控特性及评估方法。其次,量化风电高比例并网系统的频率变化极值时间,并考虑风机转速及功率裕度,在频率跌落或抬升期间约束虚拟惯量,提高风机惯量评估的可信度。在此基础上,分析系统频率安全下的惯量需求,利用风机转速追踪性能,提出频率变化极值时间内变速风机的虚拟惯量控制策略。最后,搭建风电高渗透电网仿真系统,对所提控制策略进行验证。研究结果表明:变速风机在所提控制策略下能够可靠满足系统调频需求,显著提升其对电网的主动支撑性能。

Constraining the virtual inertia of variable-speed fans within the extreme time of system frequency change will be the key to improve the reliability of active support of wind power for system frequency.In this paper,firstly,the controllable characteristics and evaluation methods of virtual inertia of wind turbine are analyzed.Secondly,the frequency change extreme value time of the high-proportion wind power grid system is quantified,and the fan speed and power margin are considered to constrain the virtual inertia during the frequency drop or rise,so as to improve the credibility of the fan inertia evaluation.On this basis,the inertia demand of the system under frequency safety is analyzed,and the virtual inertia control strategy of variable-speed fan in the extreme time of frequency change is proposed by using the fan speed tracking performance.Finally,a high-permeability wind-power grid simulation system is built to verify the proposed control strategy.The research results show that the variable speed fan can reliably meet the frequency regulation requirements of the system under the proposed control strategy,and significantly improve its active support performance for the power grid.