Frederic Gustin

Design and New Control of DC/DC Converters to Share Energy Between Supercapacitors and Batteries in Hybrid Vehicles

In this paper, the authors propose the supercapacitor integration strategy in a hybrid series vehicle. The designed vehicle is an experimental test bench developed at the laboratory of electrical engineering and systems (L2ES) in collaboration with the research in electrical engineering and electronics center of Belfort (CREEBEL). This test bench currently has two diesel motors (each connected to one alternator) and lead-acid batteries with a voltage rating of 540 V and a fluctuation margin between +12% and -20% of the rated voltage. The alternators are connected to the dc link by rectifiers. An original strategy of the supercapacitor integration in this vehicle with their control is presented to find a better compromise between the dimensions of the embarked devices, the share energy efficiency, the dynamics of the supply, and the electric power storage. The supercapacitor packs are made up of two modules of 108 cells each and present a maximum voltage of 270 V. The main objective is to provide a peak power of 216 kW over 20 s from supercapacitors to the dc link. Various topologies of dc/dc converters are presented with effective methodologies of electric power management in the hybrid vehicle.

DC/DC Converter Design for Supercapacitor and Battery Power Management in Hybrid Vehicle Applications—Polynomial Control Strategy

This paper presents supercapacitor (SCAP) and battery modeling with an original energy management strategy in a hybrid storage technology. The studied dc power supply is composed of SCAPs and batteries. SCAPs are dimensioned for peak power requirement, and batteries provide the power in steady state. A bidirectional dc/dc converter is used between SCAPs and the dc bus. Batteries are directly connected to the dc bus. The originality of this study is focused on SCAP behavior modeling and energy management strategy. The proposed strategy is based on a polynomial (RST) controller. For reasons of cost and existing components (not optimized) such as batteries and semiconductors, the experimental test benches are designed in reduced scale. The characterized packs of SCAPs include two modules of ten cells in series for each one and present a maximum voltage of 27 V. The proposed strategy is implemented on a PIC18F4431 microcontroller for two dc/dc converter topology controls. Experimental and simulation results obtained from the polynomial control strategy are presented, analyzed, and compared with that of classical proportional-integral control.

Online diagnosis of PEM Fuel Cell

This study consists on online detection of fuel cell dysfunction in embedded applications without additional hardware component. The power converter usually coupled with the fuel cell is used to perform the diagnosis strategy. The main interest of the method presented in this paper is to simultaneously optimize the performances, the cost and the size of the Proton Exchange Membrane Fuel Cell (PEMFC). In this work, we focus on a system including a fuel cell stack coupled with an isolated DC/DC power converter and controlled by a Digital Signal Processor (DSP). These elements associated with measurement sensors and adequate programmings allow the control of the power conversion and the determination of fuel cell health at the same time. The fuel cell harmonic impedance is measured using spectroscopy method for a large frequency range. Specific cases of fault detections related to membrane humidification and reactive gas feeding are treated in this paper.

Control strategy of Hybrid sources for Transport applications using supercapacitors and batteries

In this article, the authors propose an approach to the problem of the power management in transport applications. The mobile experimental platform ECCE is a series hybrid vehicle which currently has three sources of energy: two thermal machines each coupled with an alternator and a lead-acid battery pack of nominal voltage 540 V. The alternators are inter-connected with the DC-link by means of the rectifiers. Our contribution is focused on studying the energy coupling between this battery pack and that of supercapacitors in order to find the best compromise between dimensions of the electric power devices, the efficiency mobile energy storing devices, the energy exchanges, and the capacity of exchange of electric power. The supercapacitors module consists of a pack of 108 cells and can supply a maximum of 270 V. The main objective is to be able to provide a power of 216 kW by supercapacitor module to the DC-link for 20 seconds

Supercapacitors and battery power management for hybrid vehicle applications using multi boost and full bridge converters

This paper presents supercapacitors and battery association methodology for ECCE Hybrid vehicle. ECCE is an experimental Hybrid Vehicle developed at L2ES Laboratory in collaboration with the Research Center in Electrical Engineering and Electronics in Belfort (CREEBEL) and other French partners. This test bench has currently lead-acid batteries with a rated voltage of 540 V, two motors each one coupled with one alternator. The alternators are feeding a DC-bus by rectifers. The main objective of this paper is to study the management of the energy provides by two supercapacitor packs. Each supercapacitors module is made of 108 cells with a maximum voltage of 270 V. This experimental test bench is carried out for studies and innovating tests for the Hybrid Vehicle applications. The multi boost and multi full bridge converter topologies are studied to define the best topology for the embarked power management. The authors propose a good power management strategy by using the multi boost and the multi full bridge converter topologies. The experimental and simulation results of the two converter topologies are presented.

Energy management strategy for coupling supercapacitors and batteries with DC-DC converters for hybrid vehicle applications

In this paper, the authors propose an approach to the problem of the energy management in ECCE laboratory hybrid vehicle project. ECCE is a series hybrid vehicle, which currently has three sources of energy: two diesel motors each coupled with an alternator and a battery module of rated voltage DC 540V. This contribution is focused on the energy coupling between batteries and two supercapacitors modules. The authors present a strategy for coupling these power sources with the batteries in order to find the best compromise between sizes of the on-board devices, dynamics of the supply and efficiency of the energy storage. The target is to provide 200kW power during 20s from the supercapacitors modules.

Design of a High Efficiency Fuel Cell dc/dc Converter Dedicated to Transportation Applications

This work consists in a theoretical and practical study of a dc/dc converter designed to be coupled to a fuel cell stack in transport applications. It also proposes analysis and control of the whole system using digital signal processor (DSP) controller. The research is focused on the integration of a polymer electrolyte fuel cell (PEFC) stack in an embedded system. The fuel cell is characterized by a low-voltage high-current electrical power deliverty. Therefore, it is obvious that a dedicated power interface is necessary to adapt and fix voltage and current levels accordingly to the application requirements. In our case, the power conversion will be done by a high-frequency-transformer-based DC/DC converter. The use of a high frequency transformer allows obtaining significant output voltage ratio (approximately 12 in our case), high efficiency, reduce compactness of used elements and limited semi-conductors losses.

Energetic Macroscopic Representation as an efficient tool for energy management in a hybrid electrical system embedded in a helicopter

The project is based on the design of an electric network embedded in a helicopter. The electric network supplies the aircraft auxiliaries. It is powered by a turbo alternator and hybridized with other electric sources in order to fulfil the demand of the auxiliaries and to limit the consumption on the main source. In this paper, the studied hybrid system is composed of the main source (the turbine and the alternator), the secondary source (batteries and supercapacitors) and the load representing the auxiliaries. The model of this electric network is organized by using the Energetic Macroscopic Representation (EMR). A Maximal Control Structure (MCS) is determined by inversion rules of the EMR model. An energy management strategy is defined to share the power supplied by each of the electrical sources. This share depends on the dynamic of the load. Simulation results, using Matlab Simulink™ software, are presented.

High torque density low speed permanent magnet machine

This paper gives different solutions in order to increase torque density of permanent magnets machines. The study deals with low frequency machines and, in this case, iron losses are less important than copper losses, so that supplying the machines with square wave currents can be interesting. The authors identify an original structure in which the end winding parts are removed. The description of this topology and design comparison with machines having end winding emphasize the limits of this structure: it is difficult to keep a high efficiency system with this new topology due to the losses in the power electronics.

Energetic macroscopic representation of an electric network embedded in a helicopter

The project is based on the design of an electric network embedded in a helicopter, that supplies the aircraft auxiliaries. It is powered by a turbine and hybridized with other electric sources in order to fulfil the demand of the auxiliaries and to limit the consumption on the main source. In this paper, the studied hybrid system is composed of the main source (the turbine and the alternator), a secondary source (batteries) and the auxiliaries load. The model of this system is based on the Energetic Macroscopic Representation (EMR). A Maximal Control Structure (MCS) is determined by inversion rules of the EMR model. Simulation results, obtained by Matlab Simulink™ software, are shown.