Power Loss Estimation for Dual Active Bridge DC-DC converter

  • Yosief Hailemariam Abraham

Student thesis: Master's Thesis

Abstract

In this study a power loss model is developed for the dual active bridge DC-DC converter. A prototype was initially built to prove the theoretical analysis and verify the model accuracy. To simplify the analysis the isolation transformer is modeled by its leakage inductance, hence it only includes an inductor to connect the two bridges of the DAB. The study also covers different operation modes of the DAB. The input and output voltages are set to be equal to 40V. Hence, the mode of operation results in a flattop inductor current, where the converter operates in soft switching for the full power range. A loss model that includes component losses and system losses has been developed. The component losses include semiconductor losses (switching and conduction losses) and inductor loss (conduction loss) system losses are the sum of all the losses monitored above. To calculate the switching and conduction losses the information from the data sheets are used. For the inductor its equivalent series resistance (ESR) is directly measured using the impedance analyzer. Theoretical analysis has been conducted for the full range of operating points that is from the minimum phase-shift angle ( 0 degrees ) to the maximum phase-shift angle ( 90 degrees ). The trend of the efficiency for both the theoretical and experimental results has been compared and has shown a matching trend. The gap between these results can be estimated to be the measurement errors, and losses that are not included in the loss model (printed circuit board (PCB), input and output capacitor losses).
Date of Award2012
Original languageAmerican English
SupervisorMichael Weidong Xiao (Supervisor)

Keywords

  • Power (Mechanics)
  • Bridge Failures

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