Mathematical Modeling and Analysis of Capacitor Voltage Balancing for Power Converters with Fewer Switches

Abstract

The multilevel inverter (MLI) has been developed as a powerful power conversion scheme for several processes, including renewable energy, transmission systems, and electric drives. It has become popular across medium- to high-power operations due to its many advantages, including minimum harmonic content, low switching losses, and reduced electromagnetic interference (EMI). In this paper, the capacitor voltage balancing technique-based pulse width modulation (PWM) has been proposed. The proposed PWM strategy offers several advantages, such as high-quality output waveforms with reduced harmonic distortion, improved efficiency, and better control over the output voltage. The Xilinx ISE 10.1 software was used for synthesizing, and the VHDL code was written for the proposed method. MATLAB software was used to simulate and hardware was used to verify the proposed system. The SPARTAN 3E FPGA was used for the generation of the PWM. This paper developed a 2 kW single-phase 15-level inverter that created an AC wave from the DC input voltage, with a total harmonic distortion (THD) of 8.02%, which was less than the THD achieved from other conventional MLI. The results indicate that MLI topologies with low total harmonic currents, fewer switches, and higher output voltage levels are better stabilized during load disturbance circumstances.