【摘要】 重复控制技术由于具有极低的总谐波失真,在谐波抑制领域得到了广泛的应用。然而在电机控制系统中,系统采样频率与电流谐波频率的比值不为整数时,将导致重复控制器的谐振频率偏离电机电流实际的谐波频率,从而造成传统重复控制器的电流谐波抑制能力显著降低。该文提出一种基于拉格朗日插值法的改进型重复控制器,采用基于拉格朗日插值法的分数阶延时环节,对频率比值小数部分构成的延时环节进行逼近,从而使重复控制器的谐振频率和电机电流实际谐波频率相吻合;为进一步减小电流谐波的跟踪误差,将低通滤波器移出传统重复控制内模,并通过加入相位补偿器保证了系统的稳定性。仿真与实验结果验证了该方法的正确性和有效性。更多还原

【Abstract】 The repetitive control technique is widely adopted in the field of harmonic suppression, due to its low total harmonic distortion. However in the motor control system, when the ratio of the system sampling frequency to the current harmonic frequency is not an integer, the resonant frequencies of the repetitive control deviate from the practical harmonic frequencies of motor current. As a result, the performance of these systems will be significantly degraded using the conventional repetitive control. In this paper, an improved repetitive controller based on Lagrangian interpolation method was proposed, which adopted a fractional-order delay link based on Lagrange interpolation. The fractional-order delay link can approximate the delay function of the frequency ratio’s fractional part, and then the resonant frequencies of the repetitive control will match the practical harmonic frequencies well. In order to further reduce the tracking error of the current harmonics, the low-pass filter located inside the traditional repetitive control module was removed and the stability of the system was ensured by adding a phase compensator. The validity and effectiveness of the proposed method were demonstrated by simulation and experimental results.更多还原