基于输入-状态稳定理论的双馈风力发电系统故障穿越控制方法

Input to state stability based fault ride through control strategy for doubly fed wind generator

增强双馈风力发电系统在故障期间和故障后的稳定性是减少风机故障脱网、提升双馈风机对电网的功率支撑、提高电网稳定性的重要措施。为实现此目标,本文提出基于输入-状态稳定(ISS)理论的双馈风机控制器设计方法,利用平方和约束构造局部输入-状态稳定控制李亚普诺夫函数(LISS-CLF),并通过上述得到的LISS-CLF构造鲁棒局部输入-状态稳定控制律,以提高双馈风机系统的故障穿越能力。上述方法有效地避免了求解HJI偏微分方程,并且所得到的ISS控制律具有逆最优性,保证风力发电系统在外界扰动下的稳定性。通过单机无穷大系统在三相对称和不对称故障下的仿真算例,验证了所提出ISS控制器的有效性。与传统的PI控制器、滑模控制器相比,所提出的ISS控制器具有更好的故障穿越性能,能更有效地给电网提供电压与无功功率支撑。

Enhancing the transient stability of doubly-fed wind power generation system during grid fault is an important measure to remain them grid-connected,offer their dynamic reactive power support,and improve the stability of power system.To achieve these goals,this paper proposes methods to design a flexible controller for doubly fed generator based on input-state stability theory.By constructing locally input-to-state stabilizing control Lyapunov functions(LISS-CLF)using Sum of Squares and designing LISS robust control law based on LISS-CLF,the stability of doubly-fed wind power generation system under external disturbances can be improved effectively.This method avoids to solve the Hamiton-Jacobi-Issacs partial differential equation,and the obtained ISS control law is inverse optimal,which guarantee the stability of wind power generation system under external disturbances.The simulation results for a single machine infinite bus(SMIB)system under three phase fault and phase-a fault verified the effectiveness of the proposed ISS controller.Compared with traditional PI controller and sliding mode controller,the proposed ISS controller has a better fault ride through performance,which offers dynamic reactive power support and improves the stability of power system more effectively.