Measurement delay compensated LADRC based current controller design for PMSM drives with a simple parameter tuning method

For permanent magnet synchronous motor drives, the difficulty of parameter tuning of nonlinear active disturbance rejection control (ADRC) current controller is the bottleneck for its application. This paper proposes a measurement delay compensated linear ADRC (LADRC), and a simple tuning method for LADRC's parameters is presented. Firstly, an ideal model without resistance is acquired, because the current coupling terms, dead-time effects, and motor parameter variations are estimated and canceled out by an linear extended state observer. Secondly, an improved LADRC considering time delay of current measurement is developed. It eliminates unmatched disturbance compensation caused by measurement delay. And frequency responses of current closed-loop gain and disturbance suppression are evaluated. Then, based upon the frequency characteristics of the LADRC controller, a simple tuning method founded on desired frequency bandwidth is presented. It is convenient to be implemented. Finally, experimental results demonstrate that the proposed method is effective.