双馈风电系统混沌运动分析及解耦自适应反步法控制

CHAOS ANALYSIS AND DECOUPLING ADAPTIVE BACKSTEPPING CONTROL OF DOUBLY FED WIND POWER SYSTEM

为研究双馈风电系统的混沌现象及其控制问题,根据电机d-q轴数学模型,导出非线性微分方程。采用Wolf算法计算其最大Lyapunov指数谱,证明电机在某些工作条件及参数下会出现混沌运动。采用磁场定向矢量控制技术,构造状态反馈解耦,降低混沌系统阶数。基于解耦模型,采用反步法设计混沌控制器。针对含有未知参数或状态的系统,提出自适应反步法,构造虚拟控制量,设计反步控制律,实时跟踪预测系统参数并实现混沌控制。通过构造Lyapunov方程,分析混沌控制系统的稳定性,保证系统状态能快速稳定收敛至给定值。控制系统不同运行工况仿真结果表明,解耦自适应反步法可使双馈电机快速脱离混沌状态,响应速度快、控制精度高,鲁棒性强。

The nonlinear differential equations of the doubly fed induction generator(DFIG)were derived to study the chaos phenomenon and chaos control in DFIG based on d-q axis model of DFIG.Under some operation status and parameters,the chaos motion of DFIG was proved by calculating the largest Lyapunov exponents spectrum of DFIG with Wolf algorithm.The decoupling controller was constructed to reduce the order of the chaos system by the flux-oriented vector control technique.The chaos controller was designed based on state feedback decoupling model with backstepping method.According to uncertain parameters or status of DFIG system,an adaptive backstepping method was proposed with decoupling model.The virtual control quantity was constructed to design control law to real time track and forecast the system parameters to chaos control.The stability of the chaos control system was analyzed to ensure the state of the system converging to set point quickly by structuring the Lyapunov equation.Aiming at different operation condition,the simulation results show that the DFIG system can escape quickly from chaos state to a stable operation by proposed decoupling adaptive backstepping method with fast response,strong robustness and high control accuracy.