This paper proposes a novel modular multilevel converter (MMC) named ‘T-type MMC’ (T-MMC) for reliable, controllable and efficient performance in energy conversion applications. Circuitry configurations and control structures are presented, with respect to fundamental and additional functions. The T-MMC topology consists of two solid-state power stages (Stage-I and Stage-II), which are coordinated for ac and dc fault tolerance, increased ac-side voltage synthesis, etc. Energy storage elements can be integrated into the submodules. As a result, the T-MMC based energy storage system can not only increase system inertia but maintain continuous power transmission during faults. A thyristor forced-commutation technique facilitates actively-controlled utilization of symmetrical thyristors in the conduction path; thus T-MMC normal-mode operation losses can be equivalent to those of the conventional half-bridge MMC. Simulation and experimentation demonstrate the performance of the T-MMC.
|Journal||IEEE Journal of Emerging and Selected Topics in Power Electronics|
|Early online date||11 Nov 2019|
|Publication status||E-pub ahead of print - 11 Nov 2019|
- modular multilevel converter
- ac/dc fault
- energy storage system