Enhanced ADRC Using Tracking Differentiator with Phase Compensation to Strengthen the Ability of Measurement Noise Suppression

Applications such as electric vehicles require high-precision induction motor (IM) controllers. A large amount of measurement noise is introduced during position and speed detection, which seriously affects the tracking and anti-disturbance performance of the controller. To solve this problem, a novel enhanced ADRC framework is proposed in this paper. On the one hand, a novel third-order observer is developed for the enhanced ADRC by embedding an LPF into a phase-locked loop observer (PLLO) so that the motor’s actual speed, filtered speed, and total disturbance can be estimated simultaneously. Meanwhile, the observed actual speed is utilized as the feedback signal to enhance noise suppression while maintaining the original structure’s tracking performance and disturbance rejection ability. On the other hand, to address the inherent phase-lag problem in LPFs, a tracking differentiator with phase compensation (TDPC) is designed, which performs filtering while compensating for the phase lag induced by low-pass filtering through its derivative lead characteristic. Experimental validation on an IM test platform demonstrates significant performance enhancements: the total harmonic distortion represents the noise suppression ability is reduced by more than 68%, and the root mean square error (RMSE) representing the speed fluctuation is reduced by more than 63% at speeds below 30 rpm with rated-load. The phase lag is reduced by at least 80% at the frequency is 5Hz with rated-load. And the transient response improved more than 27%, with the disturbance rejection improved more than 18%.