基于S函数的并网型交流励磁双馈电机风力发电系统研究

SIMULATION OF AC-EXCITED DOUBLY-FED INDUCTION GENERATOR FOR GRID CONNECTED WIND POWPER GENERATION BASED ON S FUNCTION

介绍了交流励磁变速恒频双馈电机的运行原理,推导了双馈电机在发电机惯例下的数学模型,采用S函数实现了双馈电机动态系统的状态方程数学描述,并使其和Simulink解法器进行交互。变速恒频双馈电机风力发电是一个受并网前后发电机运行状况影响的暂态过程,利用S函数编写双馈电机的仿真程序,建立了空载运行和发电运行的变速恒频双馈电机风力发电子系统模型,在仿真过程中可对双馈电机进行精确控制,然后对其进行了系统整合,最后对系统在不同工况下的响应特性进行了仿真研究。变速恒频双馈电机风力发电系统的仿真与理论分析高度一致,同时,仿真结果验证了系统对转速突变和电网电压跌落工况的有效性。

The function principle of AC-excited variable speed constant frequency （VSCF） doubly-fed induction generator （DFIG） was introduced and the accurate mathematical model of DFIG was derived according to generator convention. A novel S-Function is adopted to describe the mathematics model of DFIG based on state equation and to become mutual with Simulink＇ s solver. The VSCF DFIG wind power generation is transient response process, which is influenced by operation characteristics of generator before and after grid connected. A complete simulation model of VSCF DFIG wind power generation based on S-Function was established, which can be used to simulate subsystems of no-load operation and generation operation, as well as control parameter of DFIG in simulation. The behavior of VSCF DFIG wind power generation system under various run conditions is studied using this simulation model. The reasonable agreement between the theory and research results and excellent dynamic response of system were demonstrated by the simulation results. At the same time, the simulation confirms the effectiveness of the proposed dynamic model during variatious of rotating speed and the three-phase voltage sags.