Finite-Set Model Predictive Current Control of Induction Motors by Direct Use of Total Disturbance

Mahdi S. Mousavi,Jose Rodriguez,Vahab Nekoukar,Cristian Garcia,S. Alireza Davari

doi:10.1109/access.2021.3100506

Abstract

Disturbance rejection strategies are very useful for the robustness improvement of the predictive control method. But they can only be used in the modulated-based predictive control methods such as continuous set model predictive control (CS-MPC) and deadbeat control. This paper presents a robust current prediction model based on total disturbance observer (TDO), which is applicable in the finite set model predictive current control (FS-MPCC). In the proposed method, the disturbance is directly used as a part of the prediction model instead of the disturbance rejection loop. So, the proposed method has two advantages over the disturbance rejection-based CS-MPC schemes. The first advantage is no need for a controller, which is an essential part of the disturbance rejection-based CS-MPC. Therefore, the proposed method is simpler and has fewer control parameters. The second feature is that the proposed model is in the stationary frame. In this way, the frame transformation is avoided in the prediction model. Moreover, to guarantee zero steady-state error in the current prediction model, this paper proposes a complete designing process for TDO based on the convergence analysis. The performance of the proposed control system is evaluated through simulations and experimental tests.

Highlights

Model predictive control (MPC) theory has been extensively studied in power electronics over the past decade [1]
The replacement of the conventional model of a plant with an ultra-local model in Model-free predictive control (MFPC) or with the model of auto disturbance rejection control (ADRC) theory significantly improves the robustness of a predictive control method, this strategy is suitable for continuous set model predictive control (CS-MPC) or deadbeat control methods, and it’s not normally applicable in finite set model predictive control (FS-MPC) schemes
The second difference is that, unlike the disturbance rejection method in CS-MPC, the proposed total disturbance observer (TDO) based prediction model is applied in the stationary frame

Summary

INTRODUCTION

Model predictive control (MPC) theory has been extensively studied in power electronics over the past decade [1]. In FS-MPC, the future state of the controlled variables is predicted based on the possible voltage vectors (VV) of the power converter. The second difference is that, unlike the disturbance rejection method in CS-MPC, the proposed TDO based prediction model is applied in the stationary frame. CLASSIC DISTURBANCE REJECTION BASED PREDICTIVE CURRENT CONTROL The concept of ‘‘total disturbance’’ was firstly introduced by Han in [19] to control the uncertain systems with the disturbance rejection methods In this idea, only the input and the output of the system are utilized to derive the control law, without knowing other parts of the system, which may be nonlinear, time-varying, or uncertain. This method can be used in the model predictive torque control

TOTAL DISTURBANCE OBSERVER

TUNING TDO PARAMETERS

SIMULATION RESULTS

COMPARISON OF THE PROPOSED METHOD WITH OTHER MPC METHODS

VIII. CONCLUSION