Adaptive constraint control based peak-attenuated disturbance observer for the electric vehicle used permanent magnet synchronous motor

• Speed-current single-loop non-cascade control: Multiple parameters to be tuned, control bandwidth restricted, and complex control structure are the shortcomings of the cascade controlled PMSM system. In this respect, a novel speed-current single-loop controller via backstepping is investigated, as far as the authors knowledge, this method is first proposed. • Adaptive learning constraint gain: It is difficult to balance the steady-state and transient performances in cascade control. Generally, a high gain is necessary to reduce the steady-state error, while a small gain is expected to eliminated the overshoot. For this, an adaptive learning constraint mechanism is designed in the current term to well balance the transient and steady-state performances. • Novel adaptive disturbance observer (ADO): Generally, the disturbances of the PMSM system are compensated by the disturbance observer. However, as far as the knowledge retrieved, the peak problem will be generated (large speed error, sudden overloading) for the gain of these observers are constant. Which will degrade the transient performance, even lead to the system crash. To improve the disturbance observed performance and attenuate the peak problem, a novel adaptive disturbance observer is proposed. This study explores speed-current single-loop constraint control (SSCC) for permanent magnet synchronous motor (PMSM) based on an adaptive disturbance observer (ADO). The SSCC effectively addresses the issues related to cascade-controlled PMSM, including complex parameter tuning, unbalanced transient and steady-state performance, and a complicated control structure. This controller enables simultaneous control of speed and current. Additionally, a penalty mechanism is incorporated to constrain the q-axis current. Moreover, the estimated peak generated by the extended state observer (ESO) with a fixed gain can degrade control quality or even lead to system failure. An adaptive disturbance observer (ADO) is designed, which introduces a fractional order switching function and adaptive gain. Following this, a rigorous stability analysis is performed. Finally, the effectiveness of the SSCC-based ADO (SSCC-ADO) is validated on a 200 W PMSM platform. In the full-speed domain (0 r/min ∼ 3000 r/min) experiments, the overshoot of the proportional-integral (PI) and active disturbance rejection control (ADRC) is at least 5 r/min higher than that of SSCC-ADO. Additionally, SSCC-ADO is 0.08 s faster than PI and 0.1 s faster than ADRC in the start-up phase. The steady-state ripples of SSCC-ADO are reduced by ± 2 r/min compared to both PI and ADRC. Furthermore, the total harmonic distortion (THD) of SSCC-ADO decreased by 0.11 compared with PI and ADRC. In the load disturbance experiments, the speed drop of SSCC-ADO is 47 r/min and 7 r/min less than PI and ADRC, respectively, and the time to return to steady state is reduced by 0.1 s. Notably, the estimated peak of SSCC-ADO is only 0.025 times that of ADRC. These verify that SSCC-ADO can achieve superior transient along with strong robustness.