Modelo de projetos para conversores modulares multiníveis em aplicações HVDC

Abstract

High-voltage direct current (HVDC) transmission systems are increasingly essential in a globalized industry scenario that requires efficient energy transmission over long distances, as seen in Europe, China, Brazil, and the United States. In this context, the modular multilevel converter (MMC) topology has emerged as a widely discussed academic solution and a high-tech commercial application. Understanding the physical operation of the MMC converter is crucial for comprehensively analyzing its internal systems and how its parameters interact and influence other components. These parameters form the foundation for implementing the phase-shifted pulse-width modulation (PS-PWM) system and all elements of the control system. The PWM modulation block is interconnected with the vector current control system and the circulating current control, which define the desired physical parameters in real-time using the p-q instanta- neous power theory and Clarke-Park transformations. Additionally, capacitor voltage control is highlighted as critical for the converter’s stability, ensuring proper charging and discharging of capacitor modules at the correct times. Finally, the MMC design characteristics aid in selecting current commercial technology manufacturers, enabling the choice of a safe and viable project model.