Modular-Cell Inverter Employing Reduced Flying Capacitors With Hybrid Phase-Shifted Carrier Phase-Disposition PWM

This paper proposes a new approach of modular-cell inverter with a reduced number of flying capacitors (RFCI) using hybrid carrier-based pulsewidth modulation (PWM) named as phase-shifted carrier phase-disposition PWM (PSC-PD-PWM). The novel multilevel inverter topology is designed by clamping a series of modular cell onto a low-operational-frequency cell. The proposed transformerless RFCI reduces significantly the component counts, cost, and size of the converter. The overall performances of RFCI are greatly enhanced as compared with the classical multilevel flying capacitor inverter (MFCI). Hence, a comparative analysis of the proposed RFCI is made against the classical MFCI in this paper based on seven-level output phase voltages. The feasibility of the RFCI with PSC-PD-PWM is validated through experimental results under dynamic operating conditions.