Study of start-up decoupling controller for modular multilevel converter

Modular multilevel converters are widely used in power systems because of their significant advantages. In this paper, a dynamic mathematical model is established by analyzing the topology, operating principle and switching function modular converter, so as to construct an inner outer loop decoupling controller dq coordinates. The carrier phase-shift pulse-width modulation selected control sub-module operation, uncontrolled pre-charging method adopted charge sub-module. Finally, simulation experiments carried out MATLAB/Simulink, results show that achieves smooth start-up converter.