频率时变的谐波扰动抑制方法

A Harmonic Disturbance Suppression Method For Frequency Time-variable Systems

为抑制谐波扰动对控制系统的影响,对频率时变的谐波扰动进行分析,提出两种针对频率时变的谐波扰动的抑制方法:线性反馈方法与基于非线性干扰观测器的方法。线性反馈方法依据于线性矩阵不等式理论,将频率变化的谐波扰动分解为频率固定的谐波扰动与非线性不确定项,采用一般的干扰观测方法对固定频率扰动进行观测,并采用线性反馈方法对非线性不确定项进行抑制。基于非线性干扰观测器的方法直接对谐波扰动进行观测,并采用鲁棒控制器进行干扰补偿。采用李亚普诺夫理论来验证扰动抑制方法的稳定性。将两种扰动抑制方法应用于磁悬浮飞轮电机控制系统,通过仿真与实验结果表明,两种方法具有很好的扰动抑制能力。基于非线性干扰观测器的扰动抑制方法依据扰动的特性设计,具有更好的动态、稳态特性与鲁棒性。

To weaken the impact of harmonic disturbance on control system, the harmonic disturbance whose frequency is time-varying was analyzed. Two methods were proposed to suppress the harmonic disturbance： linear feedback method and nonlinear disturbance observer method. The linear feedback disturbance rejection method was based on linear matrix inequalities theory. In this method the harmonic disturbance was decomposed into fixed-frequency harmonic disturbance and nonlinear uncertainties. The fixed-frequency harmonic disturbance can be estimated by general disturbance observer, and the nonlinear uncertainties can be suppressed by linear feedback. In the nonlinear disturbance observer method, harmonic disturbance was observed directly and compensated by robust controller. The stability of two methods was analyzed by Lyapunov theory. The validity of the proposed control techniques was verified through simulation and experimental results, from which we can see the two methods had good disturbance rejection capability. In addition, the nonlinear disturbance observer method was designed based on the characteristics of harmonic disturbance. It has better dynamic/static performance and robustness.