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This article presents the analysis and management of differential mode conducted EMI in modular converters made from associations of standard conversion cells. Two main configurations, inputs in series—outputs in parallel and inputs in parallel—outputs in series are studied with the objective to define a generic EMI management technique, independent from the number of conversion standard cells implemented. First, analysis is carried out from a theoretical point of view based on simplified models. Second, filtering solutions are introduced and compared. Especially, centralized versus distributed filtering techniques are compared with the objective to find generic solutions. The results are compared and validated with practical characterizations. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a novel direct maximum power point tracking (MPPT) approach that combines the backstepping controller (BSC) and the super-twisting algorithm (STA). The direct backstepping super-twisting algorithm control (BSSTAC) MPPT was developed to extract the maximum power point (MPP) produced by a photovoltaic (PV) generator connected to the battery through a boost DC-DC converter. To reduce the number of sensors required for the BSSTAC implementation, a high gain observer (HGO) was proposed to estimate the value of the state of the PV storage system from measurements of the PV generator voltage and current. The suggested technique is based on the quadratic Lyapunov function and does not employ a standard MPPT algorithm. Results show that the suggested control scheme has good tracking performance with reduced overshoot, chattering, and settling time as compared to the prevalent MPPT tracking algorithms such as perturb and observe (P&O), conventional sliding mode control (CSMC), BSC, and integral backstepping controller (IBSC). Finally, real-time findings using the dSPACE DS 1104 software indicate that the generator PV can accurately forecast the MPP, as well as the efficacy of the suggested MPPT technique. The provided approach's effectiveness has been validated by a comprehensive comparison with different methods, resulting in the greatest efficiency of 99.88% for BSSTAC. [ABSTRACT FROM AUTHOR]

This paper deals with the study of technologies for flip-chip assembly of CMOS integrated power converters on standard FR4 organic substrates. Tests for the characterization of commercially available technologies for microassemblies, such as anisotropic adhesive bonding, thermocompression bonding, thermosonic/ultrasonic bonding, and solder bonding, are carried out. The aim of this paper is to determine the most suitable flip-chip bonding technology for power CMOS circuits with more than 50 pads. First, the coupled design of the CMOS chip and the corresponding substrate dedicated to low-power microconversion (10 W) is presented. It is shown that the parasitic resistances and inductances of the interconnections increase the conduction and switching losses of the device. This leads to a temperature rise, which can limit the operating ratings of the circuit. The experimental results are provided to evaluate each technology for flip-chip assembly. [ABSTRACT FROM PUBLISHER]

This paper proposes a new class of converters based on the inductive input converters for the design of a power electronic interface for fuel cell (FC) applications. After studying the half-bridge structure, two soft-switching dc-dc converters are analyzed: one operating in zero-voltage-switching (ZVS) mode and the other in zero-current-switching (ZCS) mode. The ZYS converter can overcome the drawbacks of the original structure but is more complicated. The ZCS converter cannot operate at duty cycles below 0.5, but is simpler and more suitable for FC applications. Flexible choice of components, low losses, high efficiency, and modular converter possibility are all interesting characteristics of these converters. Their operation principle and characteristics are presented in this paper. Experimental results on 2 kW converters of each structure validate the theoretical analysis. [ABSTRACT FROM AUTHOR]

In a resonant dc/dc converter, the major part of the volume is filled by passive components. Moreover, all these components have to support all the power flow. On the one hand, this leads to losses in these components and their connections and on the other hand to an important cost of the converter. Concept of integrated passive component, called inductor-capacitor-transformer (L-C-T), is now well known [1], [3], [4], [6], [8] and this paper will present a new prototype which permits to integrate in an unique part an inductor, a capacitor and a transformer. Because it uses only one core with three windings, this component will reduce the volume of the passive part of the converter. By reducing the number of connections it will, also, have a positive effect on losses. After a presentation of L-C-T components, this paper describes a design of this device, using new windings disposition. The proposed structure permits to adjust separately L and C values. Then, to validate the approach, a characterization is carried out, leading to a new model, including dielectric, iron and copper losses. [ABSTRACT FROM AUTHOR]

In general, the structures of Multi-Active Bridge (MAB) converters that can be found in the literature are usually based on voltage converters. However, in some cases, it could be interesting to have a current-fed input due to load characteristics or operation constraints. This leads to a hybrid MAB structure mixing both current-fed and voltage-fed bridges. In this paper, a new hybrid-fed, fully coupled Triple-Active Bridge (TAB) converter topology with two voltage-fed ports and one current-fed port is studied, modelled and controlled. In the first place, a generalized average model (GAM) is developed for this system. After that, a reduced-order model is elaborated in order to simplify the behavioral study and control of this coupled system. A control strategy was also proposed in this paper, based on the developed mathematical model. Simulation results using Matlab/Simulink are presented to validate this study. [ABSTRACT FROM AUTHOR]

This paper deals with multilayer magnetic components for power electronics application and specifically for high frequency switching. New formulations based on nickel-zinc-copper spinel ferrites were developed for high power and high frequency applications. These ferrites can be sintered at low temperature (around 900°C) which makes them compatible with the LTCC (Low Temperature Co-fired Ceramics) technology. Metallic parts of silver or gold can be fully integrated inside the ferrite while guaranteeing the integrity of both the ferrite and the metal. To make inductors or transformers with the required properties, it is mandatory to have nonmagnetic parts between the turns of the winding. Then it is essential to find a dielectric material, which can be co-sintered both with the ferrite and the metal. We will present the solution we found to this problem and we will describe the results we obtained for a multilayer co-sintered transformer. We will see that these new components have good performance compared with the state of the art and are very promising for developing high density switching mode power supplies. [ABSTRACT FROM AUTHOR]

This paper deals with the design and the implementation of an isolated and highly integrated low voltage, low power microconverter. A dual active-bridge topology is considered as a good candidate for reducing the number of passive elements. The design of a “power die” integrating power inverter legs and their driver circuits is carried out in order to benefit from the high level of integration and to reduce the amount of active components and the volume of the converter. Thus, a microconverter is built for 10 W power supply (5 V/2 A) and is operating at 1 MHz switching frequency. The measured efficiency of the converter is 88% for 6.5 W transferred power and 86% for 8.5 W transferred power without taking into account its control unit. The converter is operating in natural convection, and no cooling system is implemented. Therefore, a power density of 9.9 kW/L is achieved, which is beyond the state of the art of the conventional isolated converters whose power densities are around 1–2 kW/L at the same power level. [ABSTRACT FROM AUTHOR]

Power electronics converters are traditionally designed regarding efficiency, power density, cost, and reliability figures of merit. Today, with the extreme spread of power electronic applications in our modern societies, together with the earth limits in terms of materials resources, it is important to consider the ecological impact of the converter not only during its usage, but over its whole life cycle. This article introduces an eco-dimensioning methodology for analyzing and accounting for the energy consumption over the entire converter life. The analysis is applied on a small DC-DC converter considering the main components dual active bridge (DAB) converter. The planar transform is one of the key elements modeled in this article, including material and manufacturing conditions. The traditional and eco-dimensioning approaches are carried out and compared in order to emphasize the possible consequences on total energy cost. [ABSTRACT FROM AUTHOR]

As a consequence of the increase of power needs in low-voltage applications, wiring several windings in parallel to sustain large currents has become common. This choice may have a serious impact on the transformer reliability. In practice, due to additional currents that we call "circulation currents," highly localized extra losses occur. Although hot points resulting from these currents can destroy the component, the related losses are generally not taken into account by analytical approaches. In planar transformers, windings are made of printed circuit board layers, and circulation currents lead to severe unbalance of current sharing between parallel layers. This paper presents an analytical method enabling the evaluation of the currents in every layer using only a circuit simulation software such as Pspice or PSIM. For a designer, this method is very intuitive and fast compared with the use of finite element method simulations. Several extensions of the modeling method used here are also presented. [ABSTRACT FROM AUTHOR]

This letter introduces a self-oscillating very high-frequency (VHF) class $\phi$ 2 inverter based on a free-running oscillator. The class $\phi$ 2 is a low-voltage semiconductor stress, fast-transient, single-transistor inverter topology suitable for VHF applications. With new advancements in GaN technology, the tendency to increase the switching frequency in power converters is on the rise. Switching at VHF (VHF: 30–300 MHz) allows for smaller passive components and more compact power converters. However, although GaN components are able to switch at 100 MHz and beyond, gate drivers available in the market struggle to provide the adequate switching signal at VHF. Hence, there is a need for an alternative to VHF converters using those gate drivers—self-oscillating topologies. To that end, a self-oscillating class $\phi$ 2 inverter switching at 30 MHz is presented and a design methodology is provided. A 30 MHz prototype with 30 V input voltage using a GaN Systems GS61004B is also built and tested, showing good matching between the simulation and experimental results. [ABSTRACT FROM AUTHOR]

This paper deals with the design and the realization of an integrated isolated HF dc-to-dc converter for low-voltage and low-power conditioning applications (3.3 V and 1 W) including galvanic isolation. It is based on the 3-D integration of several elementary silicon dies in which essential components such as the inverter, the rectifier, the HF transformer, the input and output capacitors, and the output inductor have been integrated. The paper deals with the silicon integration of all these elements, with the presentation of our work being related with the state of the art. Then, it focuses on an estimate of the whole converter functional performance at 1-MHz switching frequency. Practical but partial implementation was carried out. The inverter and the rectifier are designed in CMOS technology (Austria Micro Systems 0.35 \mu\m) and have been optimized to operate at HF (1 MHz) to reduce the size of passive devices. We have monolithically integrated all that is necessary for this function. The transformer, as well as the inductor and the capacitors, is also integrated on separate silicon dies. Their integration is discussed, as well as their design and practical characterization. Based on a distributed construction, the overall converter efficiency is estimated in simulation based on practical characterizations. It appears that correct efficiency with a reasonable silicon surface and volume can be reached. [ABSTRACT FROM PUBLISHER]