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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.

DC/DC converter --- resonant converter --- ZCS for MOSFET --- inverse coupled inductor --- Ingénierie, informatique & technologie > Ingénierie électrique & électronique

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This book covers several research items related to LLC resonant converters, which were published in a Special Issue of Energies on the subject area of "Advances in High-Efficiency LLC Resonant converter". It focuses on emerging power electronic topologies related to the LLC resonant converter, and its design methodology and control algorithms. Topics of interest include LLC resonant topologies, resonant tank design methodology for high efficiency, power loss analysis in LLC resonant converters, high-frequency magnetics for resonant converters, wide band-gap devices applied to LLC resonant converter, and advanced control algorithm for LLC resonant converter.

History of engineering & technology --- resonant converter --- bidirectional power conversion --- zero voltage switching --- asymmetric pulse width modulation --- LLC resonant converter --- integrated transformer --- adjustable leakage inductance --- LED driver --- aircraft power conversion --- LLC resonant converters --- high efficiency --- ZVS auxiliary circuit --- dual output converter --- pulse frequency modulation (PFM) --- asymmetric pulse width modulation (APWM) --- control --- current mode control --- voltage control --- transfer function --- power converter --- soft-switching converter --- battery charging --- PV micro-inverter --- LLC converter --- high switching frequency --- transformer loss --- center-tapped transformer --- flux walking --- flux-balance control loop --- magnetizing current estimation --- LLC Converter --- Duty Control --- Extended Describing Function --- Small Signal Modeling --- solid-state-transformer (SST) --- isolation dc-dc converter --- series-connected devices

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Nowadays, renewable energy sources take a larger share in energy production. The power systems encounter a significant turn because of the growth of renewable energy sources, which brings more power electronics into the grid. For instance, modern wind farms are equipped with full converter wind turbines to ensure a higher energy yield. Furthermore, HVDC links, equipped with power electronic converters, have become popular because of their controllability and are installed in various power systems. The power electronic converters replace the synchronous machines, and instabilities at higher frequencies may now occur. It thus has led to a reshape in the classification of power system stability.
Wind turbines are placed where the wind potential is the highest. They are grouped in wind parks which concentrate a large amount of active power production. Variations in wind speeds thus lead to rapid changes in the loading of the system, which may jeopardize its stability.

This thesis aims at assessing the stability of a system mainly composed of power electronic converters. A fictitious network is tested under various scenarios, and solutions are proposed to ensure a secure system for the different tests realized. The simulation tool used applies the phasor approximation method, therefore, the fast interactions that may occur between the converters and the network are not analyzed here.

The thesis is divided into five parts. The first part introduces the stability issues encountered in a power system mainly composed of power electronics. It also describes the classification of wind events and their intensity. The second part illustrates the network studied and the modeling of the converters. It highlights their different control modes. The third part focuses on wind events and their impact on the stability of the system. The evolution of the voltages is studied for two different wind events: the Ramping event and the Storm event. Those events are combined with operations on HVDC links. Their active power productions are changed according to the rules of the energy market. Solutions are proposed to mitigate the impact of those events on the network voltages. The fourth part focuses on transmission outages. Solutions are proposed to ensure a secure system after the incident occurred. Finally, the last part describes the necessity of having grid forming converters in the system. It shows the evolution of voltage phasors for the system with and without a grid forming converter. Finally, an overall conclusion is drawn.

renewable energy sources --- power systems --- system stability --- offshore wind parks --- HVDC links --- grid forming converter --- grid following converter --- Ingénierie, informatique & technologie > Ingénierie électrique & électronique

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This work describes the influence of catalytic converter heating strategies on the emissions during heating operation, as well as during the subsequent load demand at different engine start temperatures. A novel strategy is presented, that provides heating of the combustion chamber, without decreasing the catalyst converter heating significantly. The studies were carried out on a gasoline engine. Emissions were examined in detail. In addition, the flame propagation is evaluated experimentally.

Katalysatorheizen --- cold start --- combustion process --- Flammenausbreitung --- particulate emission --- Partikelemissionen --- Brennverfahren --- Kaltstart --- flame Development --- catalytic converter heating

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Nowadays, power electronics is an enabling technology in the energy development scenario. Furthermore, power electronics is strictly linked with several fields of technological growth, such as consumer electronics, IT and communications, electrical networks, utilities, industrial drives and robotics, and transportation and automotive sectors. Moreover, the widespread use of power electronics enables cost savings and minimization of losses in several technology applications required for sustainable economic growth. The topologies of DC–DC power converters and switching converters are under continuous development and deserve special attention to highlight the advantages and disadvantages for use increasingly oriented towards green and sustainable development. DC–DC converter topologies are developed in consideration of higher efficiency, reliable control switching strategies, and fault-tolerant configurations. Several types of switching converter topologies are involved in isolated DC–DC converter and nonisolated DC–DC converter solutions operating in hard-switching and soft-switching conditions. Switching converters have applications in a broad range of areas in both low and high power densities. The articles presented in the Special Issue titled "Advanced DC-DC Power Converters and Switching Converters" consolidate the work on the investigation of the switching converter topology considering the technological advances offered by innovative wide-bandgap devices and performance optimization methods in control strategies used.

History of engineering & technology --- interleaved operation --- three-winding coupled inductor --- high step-up DC–DC converter --- DC/DC converter --- multi-input-port --- bidirectional --- energy storage --- three-phase bidirectional isolated DC-DC converter --- burst-mode switching --- high-frequency transformer configurations --- phase-shift modulation --- intermittent switching --- three-phase dual-active bridge --- bidirectional converter --- high efficiency --- GaN --- SiC --- buck-boost converter --- high switching frequency --- electric vehicle (EV) --- fast charging --- interleaved dc–dc converter --- SiC devices --- Si devices --- Component Connection Method --- power electronics-based systems --- stability analysis --- state-space methods --- virtual synchronous generators --- DC-DC converters --- photovoltaics --- single-diode model --- state-space --- multi-port dual-active bridge (DAB) converter --- wide-band-gap (WBG) semiconductors --- silicon carbide (SiC) MOSFETs --- power converter --- automotive --- battery charger --- circuit modelling --- power electronics --- SiC MOSFET --- interleaved operation --- three-winding coupled inductor --- high step-up DC–DC converter --- DC/DC converter --- multi-input-port --- bidirectional --- energy storage --- three-phase bidirectional isolated DC-DC converter --- burst-mode switching --- high-frequency transformer configurations --- phase-shift modulation --- intermittent switching --- three-phase dual-active bridge --- bidirectional converter --- high efficiency --- GaN --- SiC --- buck-boost converter --- high switching frequency --- electric vehicle (EV) --- fast charging --- interleaved dc–dc converter --- SiC devices --- Si devices --- Component Connection Method --- power electronics-based systems --- stability analysis --- state-space methods --- virtual synchronous generators --- DC-DC converters --- photovoltaics --- single-diode model --- state-space --- multi-port dual-active bridge (DAB) converter --- wide-band-gap (WBG) semiconductors --- silicon carbide (SiC) MOSFETs --- power converter --- automotive --- battery charger --- circuit modelling --- power electronics --- SiC MOSFET