Engineering Science and Technology, an International Journal (Apr 2020)
Three-phase modular multilevel converter based unified power flow controller
Abstract
Flexible AC Transmission Systems (FACTS) when added to power systems provide them with flexibility making them able to cater for increasing power demands. FACTS devices use power electronics to control some system parameters with the Unified Power Flow Controller (UPFC) is adaptable and robust as compared to other FACTS devices. This work introduces a detailed model of an MMC based UPFC. A high frequency switching technique known as Carrier Phase Shifted Sinusoidal Pulse Width Modulation (CPS-SPWM) is also used to balance the capacitor voltages of the half-bridge (HB) converter sub modules. The model and balancing strategy is then evaluated in a simulation environment via case studies.
