基于协同惯量控制的双馈风机并网系统稳定性分析

双馈风力发电机由于其运行特性,失去了一定类似同步发电机的惯性响应能力,导致双馈风力发电机大规模并网之后,电力系统惯性响应能力降低。若系统受到扰动,有时不能够维持频率在允许的范围内变动,将会对含风电的电力系统稳定性造成不同程度的影响。文章推导了采用定子磁链定向矢量控制的双馈风力发电机的惯量控制模型,提出一种基于虚拟惯量控制和转子转速控制的协同控制策略,在Matlab/Simulink中建立虚拟惯量控制模块及转子转速控制模块,仿真分析协同惯量控制下双馈风力发电机并网系统惯性响应的影响以及该控制策略对惯量支撑、系统频率的影响。仿真结果表明,不同工况下,协同惯量控制可为风电并网系统提供一定惯量支撑,在有效防止系统频率深度跌落的同时提升了系统的稳定性。研究结果可为实际工程提供理论指导。

Stability Analysis of DFIG Grid-Connection System Applying Cooperative Inertia Control

Doubly-fed induction generators (DFIGs), because of their operating characteristics, lose inertial response ability like synchronous generators, which will weaken the inertial response ability of the power system after the large-scale grid-connection of DFIGs. During system disturbance, it will not be able to maintain the frequency in the allowable range, which will affect the stability of the system with wind power in different degrees. This paper derives the inertia control model of DFIG with stator-flux oriented vector control, and proposes a cooperative control strategy based on virtual inertia control and rotor speed control. Then the paper establishes modules of virtual inertia control and rotor speed control in Matlab/Simulink platform to simulate and analyze the influence of the inertia response of the grid-connected DFIG system under cooperative inertia control and the influence of the control strategy on the inertia support and system frequency. The simulation results show that, under different working conditions, the cooperative inertia control can provide a certain inertia support for the wind power grid-connection system, which can improve the stability of the system while effectively preventing the system frequency from falling deeply. The research results can provide theoretical guidance for actual engineering.