计及虚拟惯量控制的DFIG等效惯量在线评估与响应特性分析

虚拟惯量控制的引入提高了双馈风机的频率调节能力，然而其惯量表现形式依赖于不同控制方式，导致其惯量响应特性不尽相同，亟需实现对其惯量水平及变化特征的准确感知。对基于转子动能虚拟惯量控制的双馈风机等效惯性定量表征及响应特性问题展开研究。首先，基于利用转子动能的虚拟惯量控制策略，建立了双馈风机在转子转速时间尺度下的简化模型，进而理论推导了双馈风机等效惯性常数的数学解析式。其次，针对解析式中双馈风机控制参数的“黑箱”问题，提出了一种基于自适应扩展卡尔曼滤波的控制参数在线辨识方法。在此基础上，利用双馈风机稳态运行下的量测信息在线评估双馈风机等效惯性常数，定量表征双馈风机的惯量支撑能力。最后，在改进的四机两区仿真系统上验证了该方法的准确性。仿真分析结果表明：虚拟惯量控制参数主要影响惯量响应过程的初始阶段和恢复阶段，速度控制器参数主要影响惯量响应过程的恢复阶段和稳定阶段。

Online evaluation and response characteristics analysis of equivalent inertia of a doubly-fedinduction generator incorporating virtual inertia control

The introduction of virtual inertia control improves the frequency regulation ability of a DFIG. However, its manifestation of inertia depends on different control modes, resulting in different response characteristics. It is important to determine an accurate perception of its inertia level and change characteristics. In this paper, the quantitative characterization and response characteristics of the equivalent inertia of a DFIG based on virtual inertia control of rotor kinetic energy are studied. First, a simplified model of a DFIG in rotor speed timescale is established based on a virtual inertia control strategy utilizing rotor kinetic energy, and then the mathematical expression of equivalent inertia constant of the DFIG is derived theoretically. Secondly, given that there is a problem of unknown control parameters, an online evaluation method of control parameters based on adaptive extended Kalman filter is proposed. The equivalent inertia constant of the DFIG is calculated and the inertia support ability of the DFIG is quantitatively evaluated based on the measurement information of the DFIG in steady-state operation. Finally, the accuracy of the proposed method is verified on an improved 4-machine 2-area simulation system, and the simulation results show that the virtual inertia control parameters mainly affect the initial stage and recovery stage of the inertia response process, and the speed controller parameters mainly affect the recovery stage and stability stage of that process.This work is supported by the National Natural Science Foundation of China (No. 51637005).