Theoretical Evaluation of Semiconductor Loss Components Behavior in ISOP-DAB Converters

Input-Series Output-Parallel (ISOP) connected Dual-Active-Bridges (DABs) form an interesting topology which enable step down MVDC to LVDC by employing medium frequency transformers. Si-IGBT semiconductor devices are commonly used in power distribution grid applications such as Smart Transformers (STs) where both MVDC and LVDC energy ports can be presented. In this paper, Si-IGBT semiconductor loss components such as conduction, switching and gate driver losses behavior are theoretically evaluated in a wide range of blocking voltage, switching frequency and phase-shift angle of DAB converters. In addition, gate driver losses are approximated as a continuous function of blocking voltage based on available datasheets. The behavior of the loss components are analyzed for two 50 and 500 kW ISOP-DAB converters where DC voltage ratio is 10 kV/400V