风电机组虚拟惯量控制的响应特性及机理分析

Response Characteristics and Mechanism Analysis About Virtual Inertia Control of Wind Generators

虚拟惯量控制是风电机组参与系统调频的一种有效方式。基于风电机组比例微分（PD）虚拟惯量控制的基本原理以及单机并网系统的频率响应简化模型,对PD虚拟惯量控制的响应特性及机理进行了分析,推导了PD虚拟惯量控制与系统频率的量化关系。分析结果表明：风电机组PD虚拟惯量控制本质上为暂态频率调节过程,比例控制主要影响系统暂态频率响应的最低值,微分控制主要影响系统频率的下降速度和达到频率最低值的时间。利用实验室风电并网实验平台,在相同负荷扰动下增大PD虚拟惯量控制的比例系数后,风电机组参与系统调频的转子动能增加,最大频率偏差由0.84 Hz减小为0.59 Hz,风机转速由15.7 rad/s降低为13.4 rad/s;而增大微分系数后,系统频率的下降速度减小。实验结果与理论分析结果一致,从而证明了所述特性分析和机理分析方法的有效性,为风电机组虚拟惯量控制的参数整定和控制方法优化提供了一定的理论参考。

Virtual inertia control is an efficient way for wind generators to participate in system frequency regulation.Based on the principle of PD virtual inertia control and the simplified model of frequency response of wind generators integrated system,the response characteristics and the mechanism of PD virtual inertia control were analyzed,and the quantitative relation between PD virtual inertia control and system frequency was deduced.It is indicated that PD virtual inertia control is a temporary frequency modulation process,and the proportional control has a direct effect on the minimum frequency,while the differential control mainly affects the frequency descent rate and the time to reach the minimum value.Experiments were performed in the laboratory,and the results indicated that the maximum frequency deviation reduced from 0.84 Hz to 0.59 Hz and the rotor speed of the wind turbine reduced from 15.7 rad/s to 13.4 rad/s respectively with the increase of the proportional control coefficient under the same load disturbance,while the frequency descent rate reduced with the increase of the differential control coefficient.The experimental results are in accordance with the theoretical analysis,and validity of the response characteristic and mechanism analysis are proved,which provide some references for the PD virtual inertia control on parameters setting and control method modification.