Direct Power Control of a Three-Phase PWM Rectifier Based on Backstepping with Integral Action for Enhanced Robustness and Power Quality

Abstract

Introduction: Three-phase pulse-width modulation (PWM) rectifiers require highly efficient control strategies to ensure power quality and system stability. While Direct Power Control (DPC) is widely used, standard approaches often struggle with steady-state errors, power ripples, and sensitivity to load variations.

Objectives: This paper aims to design and validate an advanced DPC strategy that enhances tracking accuracy, eliminates steady-state errors, and improves the overall robustness of a three-phase PWM rectifier under diverse operating conditions.

Methods: The proposed control strategy integrates a nonlinear backstepping design with an added integral action. This combination is specifically engineered to handle system nonlinearities while actively compensating for load variations. The performance and validation of the control loop were carried out through comprehensive simulations within the MATLAB/Simulink environment.

Results: The simulation results demonstrate that the proposed strategy significantly minimizes active and reactive power ripples, reduces the Total Harmonic Distortion (THD) of the grid side currents, and consistently achieves a unity power factor. Furthermore, the system successfully eliminates steady-state errors under load variations.

Conclusions: The backstepping DPC with integral action proves to be a highly effective solution for three-phase PWM rectifiers. It delivers a fast dynamic response, robust disturbance rejection, and superior power quality, making it a viable option for high-performance power conversion applications.