Jean-Christophe Crebier

Multi-cell battery emulator for advanced battery management system benchmarking

This paper presents a hardware-in-the-loop battery simulation platform capable of emulating individual cells of a series connected string. The platform enables an efficient and reproducible way to benchmark battery management systems. The focus is put on battery modeling, embedded system architecture and software development. A practical implementation of a lithium-ion cell emulator based on a linear amplifier is described.

Implementation and analysis Of large winding ratio transformers

The paper presents the work that has been carried out trying to improve the behavior and the performances of DC to DC step up converters with high conversion ratio. Especially, it is studied how the design and the realization of the magnetic HF transformer can be improved in order to increase the global efficiency of hard switch isolated DC to DC converters. It is shown that a split in conductors and then in magnetic core can be consedred to improve the performances of the converter. Practical realization and implementation are used to validate the approaches considered in this paper. Thermal imaging helps to conclude on the work. Especially, it is shown that new technological approaches, for the passive but also the active devices, lead to better operations. The important results of the work are the presentation of a simple and very effective way to design and to build HF magnetic transformers with high transformation ratios thanks to an original winding technique. The new transformer structure is named SSWT. The second important result coming from this work is that interleaved structures added to technology and design may bring interesting results from electrical and thermal point of views.

A Busbar Like Power Module Based On 3D Chip On Chip Hybrid Integration

The paper focuses on a new generation of power modules, trying to optimize the tradeoff between thermal and EMI managements. At the same time, the packaging approach is considered in order to simplify the implementation of the power dies while improving the reliability of the structure. The approach considers the hybrid integration of the power dies, one on top of the other into a 3D Chip On Chip configuration. Thanks to this structure, the power dies can be directly inserted within electrical plates, the whole structure emulating a busbar like power module. The paper presents the characteristics and the benefits of the approach. Then, it focuses on the practical characterization of two prototypes: a buck converter structure and a full bridge, single phase diode rectifier. Both of them are based on double sided thermal cooling and electro-thermal contacts are obtained by pressure. The prototypes exhibit great performances while offering really reduced parasitic and EMI coupling.

Design of Modular Converters; Survey and Introduction to Generic Approaches

This paper presents a new approach based on converter networks using elementary cells (ec). It deals with the beginning of research and development carried out on the design of the ec, the random command and the magnetic coupling among the elementary cells. This paper introduces at first the recent works carried out on interleaved ec and power electronics converters (cvs) into networks: from basic interleaving approaches, trying to minimize filter sizes up to highly coupled solutions trying to optimize sizes but also current and voltage levels. In the next sections of the paper, the modular approach will be presented. The paper presents a study showing how a random mode control is used to simplify the implementation of a generic ec into any network. Evaluating the output voltage filtering criteria, we compare classical synchronous interleaved and random mode controls. Then, the paper focuses on the design and the characterization of the elementary cell and especially on its active part. The last part of the paper focuses on magnetic coupling for converter coupling and filtering. Experimental results underline the importance of coupling among elementary cells and inside the corresponding cvs and an analytical study of magnetic coupling is presented. An 2n-windings transformer formed of n identical three-winding transformers is used to connect the ec among them. The aims of these studies are to improve electrical management of modular cvs network without any constraints on the modularity and the genericity of the approach.

Toward integrated gate driver supplies : Practical and analytical studies of high-voltage capabilities

The paper presents the study and the analysis of a gate driver power supply integrated within a vertical power MOSFET. The supply is co-integrated without any technological extra step and presents interesting operational behavior and characteristics. Thanks to a specific analysis, the behavior and the characteristics of the supply are well described. Especially, numerical and analytical modellings are used in the view of helping the design of the full structure as a function of the power device technological process and physical structure. A special care is given to the consequence of the integration in terms of interactions, functional operation and performances. A practical realization is used in order to validate the behavior and the analysis carried out in this paper.

Single die multiple 600V power diodes with vertical voltage terminations and isolation

Integrating multiple power devices in the same die makes their implementation more simple and reliable. In this paper, a new concept for low cost and high efficiency monolithic integration of 600V vertical power diodes is proposed and experimentally validated. The concept relies on the creation of vertical voltage terminations on the periphery of the devices, thus allowing to terminate and to isolate each one of the integrated power devices. Simulation results show that the stress of the electric field can be minimized by introducing an angle on the vertical termination walls. The fabricated prototypes fulfill the initial design electrical specifications with excellent dynamic and operational behavior.

Implementation and operational investigations of bipolar gate drivers

This paper deals with the investigation of simple implementation and design of bipolar gate driver for high side power transistor control. Bipolar gate signals are usually preferred for high switching dynamic control and power device shielding. Nevertheless, bipolar supplies are harder to implement and rely on numerous components that may result in significant reduction of overall converter robustness. An alternative solution is to use unipolar supplies which are more complex but integrable with specific gate driver circuits. The addition of resonant structure gives the possibilities for involving the efficiency of the gate driver and reducing further gate driver supply requirements. The paper presents theses issues based on several gate drivers and their supplies.

Quantification of Benefits and Drawbacks in Power Conversion Based on Complementary MOS Structures

The paper deals with the advantages and drawbacks using complementary MOS structures in power converter. Approaching from the common mode conducted EMI perspective, the paper shows, at first, how beneficial the complementary structures are. Experimental and simulation results underline the specific behavior of such structures. Then, other advantages and also drawbacks are discussed and analyzed. This is made regarding the converter efficiency and the gate drivers operation for each converter leg. These issues are examined using simulations and experiments.

Quantification of benefits and drawbacks in power conversion based on complementary MOS structures

This paper deals with the advantages and drawbacks using complementary MOS structures in power converter. Approaching from the common-mode conducted electromagnetic interference (EMI) perspective, this paper shows, at first, how beneficial the complementary structures are. Experimental and simulation results underline the specific behavior of such structures. Then, other advantages and drawbacks are discussed and analyzed. This is made regarding the converter efficiency and the gate drivers operation for each converter leg. These issues are examined using simulations and experiments.

Modeling and analysis of lateral MOS integrated within power VDMOS for functional integration purposes

The paper deals with the monolithic and functional integration of a gate drivers within a 600 V power VDMOS. The gate driver is based on the N-MOS technique, simple to integrate at reduced technological expense. The analysis is carried out in order to identify the optimal tradeoffs among the lateral and vertical devices in terms of operating characteristics but also performances. Especially, the paper presents how the physical structure and electrical characteristics of the power device can be adjusted in order to emulate a fully isolated and functional lateral N-MOS used afterwards as the main element of the integrated gate driver. The paper addresses static an dynamic issues of the power switch and its integrated gate driver. Susceptibility issues between the power device and the drive parts are not considered in this communication. The analysis is validated by practical results on N-MOS characteristics. Based on the results, estimated gate driver operation is given. It appears that the time domain characteristics can match state of the art discrete CMOS solutions at limited technological expense. This integration effort ends up comparable to CMOS solutions in terms of performances but it adds several advantages such as simplified implementation and reduced electromagnetic coupling interferences.