Aiming at the issue of poor robustness in continuous control set model predictive current control (CCS-MPCC) algorithm, a class of model predictive controllers based on linear–nonlinear switching extended state observers has been designed. Theoretical derivations demonstrate the structural equivalence between the extended state observer-based deadbeat model predictive current controller and the active disturbance rejection control (ADRC) and the errors introduced into the MPC algorithm’s predictive output by parameters such as motor resistance, flux linkage, and inductance have been calculated. Subsequently, a linear–nonlinear state observer was employed to detect disturbances in the system caused by parameter deviations and the observed disturbance values were fed back into the current loop controller in real time, thereby improving the prediction accuracy of the CCS-MPCC algorithm. Finally, the control algorithm was verified on a 5.5 kW experimental platform of permanent magnet synchronous motor (PMSM). The experimental results show that when the model parameters and actual parameters have deviations, the model predictive current control algorithm based on the linear–nonlinear switching extended state observer has a better speed response effect, and can reduce the harmonic content of the original method by up to 1.03%, 1.25%, and 1.12% under three operating conditions.

In the framework of the traditional active disturbance rejection controller (ADRC), the state error feedback utilizes estimated values from the extended state observer, which may introduce phase lag. Therefore, academic researchers have proposed a modified version called the improved linear ADRC that employs output values from the plant for state error feedback except the output value from the extended state observer. However, there is limited literature exploring the relationship between traditional linear ADRC and improved linear ADRC. To address this gap, this article establishes mathmatical relationship between traditional linear ADRC and improved linear ADRC from the generalized PID control perspective, highlighting their distinctions in the frequency domain. Compared to the traditional ADRC, the improved ADRC incorporates differential terms and offers a novel approach to realize the generalized PID control via generalized PID interpretation. And to be more specific, the improved ADRC is a new way to realize the generalized PID control by three tuned parameters, and the number of parameters of the improved ADRC is fewer than that of the generalized PID control. From the time domain, numerical simulation results demonstrate that improved ADRC exhibits superior control performance by eliminating overshoot during set value tracking processes compared to the traditional ADRC. From the disturbance rejection simulations in direct current to direct current converter (DCDC), the improved ADRC can achieve better disturbance rejection performance than the traditional ADRC. The DC bus voltage drop values of the traditional ADRC are 55.8 V and 32 V; thus, the biggest voltage drop is 55.8 V, which is 7.44 times the the improved ADRC. The voltage rise of improved ADRC can be neglected compared to the voltage rise of the traditional ADRC. From the tracking performance perspective, the time to fully reach the reference value of the traditional ADRC is about 0.3 s, and the time to fully reach the reference value of the improved ADRC is about 0.15 s.