A. Berthon

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.

Modeling and simulation of a traction control algorithm for an electric vehicle with four separate wheel drives

The aim of this paper is to present a traction control algorithm for an electric vehicle (EV) with four separate wheel drives. This algorithm is necessary to improve the handling and stability of EV during cornering or under slippery road conditions. It distributes the traction power among four drives and especially an independent torque reference on each wheel. The proposed algorithm is implemented in terms of a hierarchical architecture, which incorporates all new known vehicle systems ABS (anti-lock brake system), ASR (anti slip regulation), ESP (electronic stability program). To achieve good performance a correlation of the traction controller with motor performance has been implemented. Several simulation results, which show the potential of such a algorithm, are presented.The aim of this paper is to present a traction control algorithm for an electric vehicle (EV) with four separate wheel drives. This algorithm is necessary to improve the handling and stability of EV during cornering or under slippery road conditions. It distributes the traction power among four drives and especially an independent torque reference on each wheel. The proposed algorithm is implemented in terms of a hierarchical architecture, which incorporates all new known vehicle systems ABS (anti-lock brake system), ASR (anti slip regulation), ESP (electronic stability program). To achieve good performance a correlation of the traction controller with motor performance has been implemented. Several simulation results, which show the potential of such a algorithm, are presented.

Position Control of a Sensorless Stepper Motor

In this paper, the experimental results of position control of the hybrid stepper motor without a mechanical sensor are exhibited. Use of the steady-state extended Kalman filter to estimate the mechanical variables of the motor is shown. With this method the computing time is reduced. The initial rotor position is estimated by the impulse voltage technique. For position control, a simple state feedback control that can compensate the load torque variations was designed. The robustness against the motor parameters variation was also studied. A field-oriented control strategy is chosen. It is known that the mechanical position is crucially important to achieve this strategy. Finally, favorable experimental results are shared.

Global modeling of different vehicles using Energetic Macroscopic Representation

A hybrid electric vehicle is a combination of two power sources: one unidirectional power source based on an internal combustion engine (ICE), and the other bidirectional based on batteries or electric energy storage, plus electric machines (EM). Different ways of combination lead to different vehicle architectures. But these hybrid vehicles have the same basically energy flow paths. So from this point of view, one global energetic modeling using Energetic macroscopic representation (EMR) which can be applicable to ICE vehicles, a battery powered electric vehicles, series hybrid vehicles, parallel hybrid Vehicles and series-parallel hybrid vehicles has been established. This causal modeling focuses on the system function not only on the structure of system and presents a global energetic view.

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

Sensorless control of hybrid stepper motor

Today thanks to low cost and high performance DSPs, Kalman filtering (KF) becomes an efficient candidate to avoid mechanical sensors in motor control. We present in this work experimental results by using a steady state KF method to estimate the speed and rotor position for hybrid stepper motor. With this method the computing time is reduced. The Kalman gain is pre-computed from numerical simulation and introduced as a constant in the real time algorithm. The load torque is also on-line estimated by the same algorithm. At start-up the initial rotor position is detected by the impulse current method.

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.

Comparison of two series-parallel Hybrid Electric Vehicles focusing on control structures and operation modes

With the aim to significantly reduce fuel consumption and exhaust emission, Hybrid Electric Vehicles (HEVs) are more and more developed. Among the different architecture, series-parallel HEVs have flexible mode operations and high efficiency. There are two basic kinds of series- parallel HEVs, one uses a planetary gear, and another uses two concentric arranged electric machines or one machine with the two rotors. Despite the advantages of seriesparallel hybrid vehicles, the systems and their controls are quite complex. This paper aims at the comparison of their control structures and their operation modes. In order to describe the two systems and organize their control structures, Energetic Macroscopic Representation (EMR) and the inversion-based control are used in this study. The same EMR and its associated control are used to describe these two kinds of series-parallel hybrid vehicles. Some simulation results are showed, discussed and compared.

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.