Robust Direct Power Control of PWM Rectifier for Power Quality Improvement in Distorted Supply Network

Abstract

The widespread integration of nonlinear loads in modern power systems has significantly exacerbated power quality issues, particularly current and voltage harmonic distortion and reactive power imbalance. These effects adversely affect system efficiency, stability, and compliance with grid standards and customer requirements. To mitigate these challenges, this study proposes a novel and effective control strategy based on Direct Power Control (DPC) for a three-phase Pulse Width Modulated (PWM) rectifier.

The proposed DPC approach enables direct control of instantaneous active and reactive power, resulting in a simplified control structure and reduced computational burden. Voltage vector selection is carried out using a predefined switching table governed by hysteresis controllers acting on active and reactive power errors. This control mechanism ensures fast dynamic response, accurate power regulation, and stable DC-link voltage control.

The effectiveness of the proposed strategy is validated through simulation results. The simulations demonstrate a substantial reduction in input current harmonics, achieving a low total harmonic distortion (THD) in compliance with power quality standards. Furthermore, the input power factor is significantly improved and approaches unity, indicating near-zero reactive power consumption. The controller also exhibits robust regulation of active and reactive power while maintaining a stable DC-link voltage with low ripple and accurate reference tracking.