Energy Storage Requirement And Low Capacitance Operation Of Unidirectional Current H-bridge Modular Multilevel Converters

In this project  a concept  for calculating the Energy Storage Requirement(ESR) of Unidirectional Current H-Brigde Modular Multilevel Converter(UCH-MMH). UCH-MMC  is different from other  full-bridge MMC and it consists lesser semiconductor devices and the operation is also different from conventional  half-Bridge MMC's. The ESR of the UCH-MMC under the entire operating area is studied . A new  operating structure  that dynamically chops the sub-module capacitor voltage to permit the low capacitance operation under the entire operating area is proposed. Results verify that the UCH-MMC has much lower ESR than HB-MMC. Evaluation results also show that the cost and volume of the UCH-MMC are much lower than those of HB-MMC because of the low ESR. The low ESR of UCH-MMC was verified by simulations and experiments.