Analytical comparison and simulations of two DC/DC converters, practical realisation of the optimal topology

Abstract

CE+T Power is a Belgian company and a leading producer of modular inverters and modular UPS. Founded in 1934, CE+T Power has been specializing in power electronics since the 1960's and they invented the modular inverter in the end of the 1980’s. They provide power solutions to enterprises to secure their critical applications against power failures. Therefore, CE+T is always progressing in the field of power electronics by offering the best modular inverters. A DC/DC converter is a building block of an inverter. So, a high-performance DC/DC converter is necessary for their products.

The main objective of this work is two-fold. The first objective is to study a DC/DC converter topology known as Multi Resonant Interleaved Boost Converter and to evaluate its performance and behaviour. The second objective is to utilize the knowledge gained and implement it to optimize a prototype of DC/DC converter called as `CE+T E-Once 350VA DC/DC Converter'.

First the `CE+T E-Once 350VA DC/DC Converter' is tested and its various characteristics such as ripple current, ZCS behaviour of active switches, voltage gain and stability are evaluated. Then the potential improvements are identified. To achieve the improvements, a list of required hardware and software changes is established. The modifications are introduced in the circuit, one at a time and various tests are carried out to validate the modifications introduced. Once, all the necessary changes are done, the new version of the converter is called `Optimized Multi Resonant Interleaved Boost Converter'.

In comparison to the `CE+T E-Once 350VA DC/DC Converter', the `Optimized Multi Resonant Interleaved Boost Converter' has lower input ripple current, lower voltage stress across the MOSFET switches, lower current peaks in the MOSFET's drain current and lower energy circulating in the resonant tank; all of which led to reduced losses and better efficiency.

This project consisted of theoretical research as well as hands-on experience with DC/DC converters. Various concepts such as zero-current switching and resonant converters were studied and implemented in practical.