Single-phase shunt active power filter based on a 5-level converter topology

José Gabriel Oliveira Pinto is the mentor of the idea of using the 5-level asymmetric full-bridge topology as a single-phase shunt active filter, participated in the development of the experimental prototype by designing some of the PCBs, and coordinated the organization and writing of the paper. Rui Macedo is the responsible for the implementation of the simulation model, hardware prototype, obtainment of the simulation results and experimental results, and participated in the writing of the paper. Vitor Monteiro participated in the design of the hardware prototype, sizing of electronic components, design of the predictive current control and writing of the paper. Luis Barros participated in the development of the hardware prototype, obtainment of the experimental results and writing of the paper. Tiago Sousa participated in the hardware prototype development, design of the SPWM modulation technique and writing of the paper. João L. Afonso participated in the design of the control algorithms based on the p-q theory, in the adaptation of the p-q theory to single-phase systems and in the writing of the paper.This paper presents a single-phase Shunt Active Power Filter (SAPF) with a multilevel converter based on an asymmetric full-bridge topology capable of producing five distinct voltage levels. The calculation of the SAPF compensation current is based on the Generalized Theory of Instantaneous Reactive Power (p-q theory) modified to work in single-phase installations, complemented by a Phase-Locked Loop algorithm and by a dedicated algorithm to regulate the voltages in the DC-link capacitors. The control of the SAPF uses a closed loop predictive current control, followed by a multilevel Sinusoidal Pulse-Width Modulation technique with two vertical distributed carriers, which were specially conceived to deal with the asymmetric nature of the converter legs. Along the paper, some simulation results are used to show the main characteristics of the 5-level converter and control algorithms, and the hardware topology and control algorithms are described in detail. In order to demonstrate the feasibility and performance of the proposed SAPF based on a 5-level converter, a laboratory prototype was developed and experimental results obtained under diverse conditions of operation, with linear and non-linear loads, are presented and discussed in this paper.Thiswork has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT—Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work is financed by the ERDF—European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation—COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT—Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015-POCI-01-0145-FEDER-016434. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency.