Implementation of a Novel Quadruple-Boost Nine-Level Inverter for Grid-Tied Applications

Abstract

This paper proposes a novel transformer-less quadruple-boost nine-level (QBNL) inverter specifically developed for grid-tied applications. Traditional multilevel inverters (MLIs) typically require numerous components and a transformer for grid integration, which increases cost, weight, size, and losses, thereby diminishing overall efficiency. The proposed nine-level quadruple-boost inverter overcomes these challenges by providing a more streamlined design, significantly enhancing system performance and efficiency. The topology of the proposed inverter consists of ten switches, one diode, and three switched capacitors. These capacitors are self-balanced, maintaining voltage levels at Vdc, 2Vdc, and 2Vdc relative to the input voltage. With a reduced component count (10), lower total standing voltage per unit (5.75), lower cost factor, improved efficiency (97.73), and higher power density, this design offers significant advantages over existing nine-level inverters. The proposed inverter has a soft charging circuit at the DC side to reduce the impulse currents, and a common-mode choke is inserted between the inverter output and the grid to reduce leakage current in PV applications. Additionally, the proposed system incorporates a proportional-integral (PI) controller and phase disposition pulse width modulation technique. A comparative analysis between the proposed nine-level quadruple-boost inverter and existing nine-level inverters highlights its superior performance. The effectiveness of the proposed quadruple-boost nine-level inverter is verified through MATLAB Simulink simulations and Experimental Hardware-in-the-Loop (EHIL) testing, confirming its suitability for grid-tied applications. © 2017 Elsevier Inc. All rights reserved. © The Author(s), under exclusive licence to Shiraz University 2025.