Analysis and experimental validation of a modular multilevel converter with 3-level T-type submodules
- Citation data:
2017 IEEE Applied Power Electronics Conference and Exposition (APEC), Page: 1865-1872
- Publication Year:
conference paper description
Modular multilevel converters (MMC) have become an attractive solution for high voltage direct current (HVDC) transmission applications due to its scalability, reliability and easy maintenance. Considerable work has been around the conventional 2-level half-bridge submodule. Use of multilevel submodules can result in smaller overall footprint, reduced components and lower losses. This paper presents the analysis and experimental validation of a MMC based HVDC system using 3-level T-type submodule. A hybrid modulation scheme, modified voltage balancing algorithm and circulating current control is presented. For practical implementation, an intelligent commutation technique is proposed that results in 66% of the switching transitions to be soft switched. The working principle is validated by simulations in MATLAB/Simulink and experimental results on a scaled down laboratory prototype.