FPGA based control of a PWM inverter by the third harmonic injection technique for maximizing DC bus utilization

Abstract

The objective of this paper is to design and implement a third harmonic injection PWM strategy THIPWM on an FPGA, to control a two-level three phase PWM inverter, in order to generate a fundamental component, with variable amplitude and frequency of the inverter output voltage, by varying the modulation index and reference frequency. The developed strategy aims to explore the maximum of the available DC bus that supplies the inverter with a minimum level of THD, and uses the minimum number of logic elements LEs available on the FPGA. This technique is verified through simulation results. An experimental power electronics set-up that consists of a DC to AC PWM inverter, a DC supply, and an output LR low pass filter is built and controlled using the Altera DE2 development and education board based on a Cyclone II ALTERA FPGA to test the proposed THIPWM architecture.