A Novel Nine-Level Quadruple Boost Inverter for Electric Vehicle Applications

Abstract

Lithium cells are commonly arranged in series and parallel configurations to fulfil the specific voltage and current necessities within electric vehicles (EVs). Voltage and charge equalization methods are implemented to safeguard these lithium cells. However, integrating these equalization circuits introduces some degree of loss into the overall circuit, and as a precautionary measure, the battery pack disconnects in case of any cell malfunction. Switched-capacitor (SC) inverters have gained prominence as an alternative approach to address voltage requirements. This article introduces a novel voltage boost multilevel inverter tailored for EV applications. The proposed nine-level quadruple boost (NLQB) inverter boasts an intrinsic capability for capacitor self-voltage balancing, streamlining its operational efficiency. Remarkably, capacitor voltage balancing algorithms or supplementary sensor circuits are rendered unnecessary due to this intrinsic self-balancing feature. Capacitors interfaced with a voltage source generate output levels with an appropriate charge/discharge pattern. The resultant output waveform spans nine levels, achieving a fourfold magnitude boost. A comprehensive comparison encompassing various parts, such as the number of power electronics, gate driver circuits, and capacitors, is presented. Additionally, system parameters, including voltage gain, blocking voltage, and total standing voltage (TSV) are evaluated to underscore the merits of the proposed NLQB inverter in contrast to recently proposed inverters.

Keywords

• Switched capacitor
• multilevel inverter
• boosting gain
• self balancing
• electric vehicles