基于线性最优控制和积分控制的励磁控制器设计

Design of excitation controller based on linear optimal control and integral control

为了进一步改善传统线性最优励磁控制中的动态性能和调节精度,基于同步发电机的派克模型推导出了供设计线性最优励磁控制规律用的单机无穷大系统的线性化状态空间方程。以该方程为基础,设计了一种同时以机端电压、有功功率、无功功率、角速度、功角作为反馈量的线性最优励磁控制器,将发电机功角、无功功率这两个与稳定性和品质密切相关的重要参量引入控制规律。同时,为了提高机端电压的调节精度,基于稳态调整与动态调节区分开来的思想,将积分调节引入励磁控制规律。通过Matlab进行算例仿真,结果表明所设计的励磁控制规律与传统规律相比,能够有效地提高电力系统在大、小扰动下的稳定性,同时在电压调节精度方面亦有所改善。

This paper presents a linear state-space equation for a single machine-infinite system based on Park model, which is used for the design of optimal excitation control law. Applying this equation on the basis of optimal control theory, a new excitation controller is designed, in which the terminal voltage, active power, reactive power, angular velocity and angle are the feedback. Load angle and reactive power are introduced to excitation control law, which are closely related to stability and quality. At the same time, in order to improve the terminal voltage regulation accuracy, the integral control is introduced to the excitation control law. The result of MATLAB simulation indicates that compared with other methods, the proposed excitation control can effectively improve the power system＇s stability in large and small disturbance, as well as voltage regulation precision.