Design of a Plug-In Repetitive Control Scheme for Eliminating Supply-Side Current Harmonics of Three-Phase PWM Boost Rectifiers Under Generalized Supply Voltage Conditions

Abstract

This paper presents a digital repetitive control (RC) scheme to minimize the even-order harmonics at the dc link voltage and odd-order harmonics in the line-side currents under distorted and unbalanced supply voltage conditions. The proposed current control scheme consists of a conventional PI and a plug-in repetitive controller. On the basis of the mathematical model of the three-phase pulsewidth-modulated (PWM) boost rectifier under the generalized supply voltage conditions, the control task is divided into: 1) <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc-link voltage harmonics control</i> and 2) <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">line-side current harmonics control</i> . In the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">voltage harmonics control</i> scheme, a reference current calculation algorithm has been derived accordingly to ensure that the dc link voltage is maintained constant at the demanded value and the supply-side power factor is kept close to unity. In the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">line-side current harmonics control</i> scheme, a plug-in repetitive controller is designed to achieve low total harmonic distortion (THD) line-side currents of the three-phase PWM boost rectifier. The experimental test results obtained from a 1.6-kVA laboratory-based PWM rectifier confirm that the proposed control scheme can reduce the line-side current THD from 16.63% to 4.70%, and improve the dc-link voltage tracking accuracy substantially over the conventional PI-based controller.