DC-Side Impedance Estimation of a Modular Multilevel Converter Through System Identification of a Partially Black-Boxed Control System

The stability of a power electronicssystem can be assessed by means the impedance-based criterion. Impedance modeling is useful tool to analyze effect different circuit parameters and control schemes on behavior converter. Modeling input impedance electronics converter often successful when having full knowledge topology, parameters, implementation system. However, due proprietary nature voltage source converter-based high direct current systems, their exact structure concealed. This complicates calculation modular multilevel converter, known for its complex internal dynamics. paper proposes method estimate with partially black-boxed control. A discussion partitioning system into open closed parts made, results are verified simulations in time frequency domains.