MMC high voltage converters

A new method for reducing the power dissipation of MMC high-voltage converters using MPC

The goal of this research project is the development, implementation and testing of a power and real-time capable model predictive control (MPC) with a long prediction horizon for the control of high voltage modular multilevel converter (HVDC-MMC). In this context, the power losses are to be reduced - with at least the same control accuracy - by highly utilizing the converter hardware compared to previous control systems. For this purpose, a completely new approach is to be pursued, which differs from previous approaches in one essential point and thus makes it possible to handle the computation time problem despite the significantly longer prediction horizon.

The planned control concept is separated in two stages. On the one hand, the control objective is to achieve the highest possible accuracy, i.e. the output currents of the phases must have a mostly sinusoidal shape, and on the other hand, the lowest possible power loss, which is to be achieved by as few switching operations as possible with the lowest possible current in each case.