Experimental Comparison of Model Predictive Control and Cascaded Control of the Modular Multilevel Converter

This paper evaluates two different concepts for the control of the modular multilevel converter (MMC). Generally aiming at medium voltage applications, the considered MMC topology has a low number of submodules, and a pulse-width modulation (PWM) scheme is applied. A model predictive control (MPC) algorithm is developed and experimentally compared to a cascaded control scheme based on conventional PI controllers, which has been proposed by Hagiwara and Akagi. Steady-state and dynamic system performance as well as computational power requirements are discussed. The basis for the comparison is a scaled converter test bench operating from 560-V dc voltage.