Optimal Design of Dual Active Bridge based Boost Inverter

Abstract

This thesis presents a broad study and design of Dual Active Bridge (DAB) converter based Boost Inverter for many applications such as Grid connected inverters, rectifiers and Solid state transformer etc. Inverter has the property to step down the output voltage which reduces the gain therefore, the main purpose of the proposed design is to increase the gain of the inverter. The proposed topology consist of active H-bridge inverter on the primary and Inverter rectifier on the secondary side of single phase high-frequency toroidal transformer. Output voltage can be realized with the help of gate pulse provided by sine Pulse width modulation. Power is transferred from the primary side bridge to the secondary side bridge through high frequency toroidal transformer. DAB converter acts as boost stage for DC supply and converts LV to HV according to the gain/turns ratio of the HFT. HVDC is then applied to DC/AC inverter and fundamental voltage is achieved after passing the output of inverter through LC filter. DAB converter rely only on the characteristics of the transformer to accomplish high gain. Proper design of toroidal transformer and study magnetizing and leakage inductance based on high-frequency is the achieved in the proposed system. In this work, two-winding toroidal transformers are modeled and simulated using ANSYS Maxwell, and the variation of the leakage inductance due to the windings’ distribution is analyzed. Minimizing the leakage inductance of a transformer which is a challenging task is achieved using Finite Element Analysis (FEA). Analysis of transformer in ANSYS Maxwell is more economical and time-saving than repeatedly construct and test prototypes. Simulation results are provided to verify the analytical analysis. Three phase voltage fed inverter with Sic MOSFET module has been designed and implemented. Designed and implemented inverter had been operated using SPWM modulation with the input voltage vii and output voltage has been investigated. Minimum total harmonic distortion (THD) under SPWM has been recorded.