An optimal on-line-tuning current regulator for high-power IGBT converters

This paper presents a new optimal current controller for high-power voltage-source inverters. The aim of the controller is to optimize the harmonic content of the output voltage or current waveform, while maintaining acceptable losses in the inverter. It is suited to both sinusoidal and nonsinusoidal current references and is computationally inexpensive. The paper presents a description of the control strategy, followed by numerical simulations and a practical evaluation using a floating-point digital signal processor. By using this new optimal control strategy, a reduction of 30%-40% in the harmonic content of the output voltage waveform was achieved, while maintaining constant switching losses.