A New Modular Multilevel Converter Topology Using Flying Ultra-Capacitor and Cascaded H-bridges

摘要

A new multilevel converter topology using cascaded h-bridges with ultra-capacitor sub-DC voltage step generator has been presented. From the analysis and results of simulation the proposed topology has attained reduction of THD without filters while operating at low carrier frequency or fundamental frequency and using low dV/dt rated switches. The EMI and RFI produced by the setup are also low because the switching frequency is kept low. The number of switches used is also low in compar- ison to a simple CMLC, while retaining the stress distribution among switches and the ability to have smaller separate DC sources. This topology can find applications in situations where lower THD is required without filtering, in renewable energy and automotive applications as well.