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Contact

SANCHEZ Sébastien

sebastien.sanchez@icam.fr

Laplace – Laboratory on plasma and conversion of energy UMR 5213-CNRS-INP-UPS

Results

Experimental measurements

Three-Level Boost Chopper : efficiency greater

than 99.4% over the full operating range

(Vpv= 2000 V, P = 200 kW, fchopper = 10 kHz, tdead= 2 μs,

Twater = 25◦C)

Solid State transformer : peak efficiency reaches 99.06% (Vin = 2000 V fsab = 20 kHz, tdead = 2μs, Twater = 25◦C)
5-Level current source inverters with 3.3kV discrete SiC

Methodologies/methods

analytical analysis of losses/THD/compactness in high power multilevel converters (AC/DC, isolated and non-isolated DC/DC, DC/AC, SiC power modules, ZVS/ZCS commutation)
power converter simulations including thermal management (PLECS software)
Experimental test benchs Vs. analytical approach

Keywords : Multilevel, High power conversion , MFT, SiC, IGCT, HDVC, MDVC, Railway

Context/Research purpose

Design and optimization of multilevel converters for high power and medium and high voltage applications (Railway station, H-MVDC transmission & distribution, Photovoltaic farms, Off-board charger for EV)

High efficiency and integration/compactness
Medium Frequency Transformers (MFT)
Power SiC modules, IGBT, IGCT
Experimental Test benchs (opposition methods, double Pulse Test)

Overview of fast charger for EV station

PV power plant architectures with

a MVDC collector

Multilevel converters for high power

and medium/high voltage applications

Future work

Study of low-cost/high efficiency AC/DC converter for Fast off board chargers
Modular multilevel converters (MMC)for supplying 25 kV/50 Hz electrified railway lines

Full SiC Isolated DC/DC converters PEBB with 1.7kV SiC MOSFET / 3.3kV SiC Diodes power modules

Experimental results of Isolated DC/DC converters PEBB

Illustration of new technological solutions for supplying electrified 25kV/50Hz railway lines

www.icam.fr @Icam_fr

My research activities play a key role in the energy transition we've been undergoing for several years now.

As you know, this transition is based on the development of different sources of electrical energy (hydraulic, wind, photovoltaic, etc.).

In this complex electrical network, we find a large number of power converters of different types. Examples include AC/DC converters for recharging electric vehicles or producing carbon-free hydrogen, and DC/AC converters for photovoltaic applications.

My research focuses on the study of new medium- and high-power multicell power converter topologies (from kW to MW) using original combinations of series and/or parallel interleaved switching cells. These configurations are used to produce multilevel electrical waveforms at high apparent frequency, thereby reducing filtering costs, optimizing energy efficiency (i.e. converter output) and consequently reducing overall volume. The use of new grand-gap materials, such as SiC and GaN, helps optimize all three criteria (efficiency, volume, cost).

We carry out analytical comparisons of converter topologies depending on the application, coupled with simulations using PLECS software, by changing the type of power semiconductors and the number of levels, with the aim of achieving the best efficiency, compactness and price. We then run test benches to validate our theoretical approaches.Here are some of the results obtained for a thesis. It deals with a new PV power plant architecture with an MVDC collector. For this, we designed a double-boost topology followed by a medium-frequency transformer with 1.7kV and 3.3kV power components. The experimental results are excellent, with an overall efficiency close to 99%.

My next research project concerns the study and realization of a low-cost/high-efficiency AC/DC converter for electric vehicle fast-charging stations, in collaboration with CIRTEM. Another topic concerns the integration of MMC-based power converters to supply electrified 25kV/50Hz railway lines.