The Energy Management Strategy of FC/Battery Vehicles Winner of the 2017 IEEE VTS Motor Vehicles Challenge Eduardo G. Amaya †1 , H´ ector Chiacchiarini * , Cristian De Angelo † and Maximiliano Asensio † † Grupo de Electr´ onica Aplicada, Universidad Nacional de R´ ıo Cuarto - CONICET - C´ ordoba, Argentina. 1 e.g.amaya@ieee.org * Dpto. de Ing. El´ ectrica y de Computadoras, Universidad Nacional del Sur (UNS), Bah´ ıa Blanca, Argentina. Instituto de Inv. en Ing. El´ ectrica “Alfredo Desages” (IIIE), UNS - CONICET, Bah´ ıa Blanca, Argentina. Abstract—In this paper we present the Energy Management and Braking strategy for a Full Cell - Battery powered electric vehicle which won the IEEE VTS Motor Vehicles Challenge 2017. The proposed strategy achieved the best performance by minimizing the H2 fuel consumption while preserving the energy sources’ lifetime. Simulation results for different critical cases as well as for the scoring driving cycle are presented. I. I NTRODUCTION During the 13th IEEE Vehicle Power and Propulsion Con- ference (VPPC2016) it was launched a challenge organized by multiple research institutions from different parts of the world. The challenge called IEEE VTS Motor Vehicles Challenge 2017 consisted on the design of the most efficient Energy Management (EMS) and Braking Strategy (BS) for a Fuel Cell - Battery powered electric vehicle [1]. Fuel Cell (FC) electric vehicles constitute a promising technology for the next generation of transportation vehicles. Fuel Cells are electrochemical devices that generate electrical energy as a result of an electrochemical reaction based on hydrogen (nonpolluting fuel, with a high energy content per unit of weight). In addition, the fuel cell reaction product is water steam. However, hydrogen is not naturally obtained, therefore the production methods are expensive [2]. Besides, FC have still some shortcomings, mainly due to their dynamic limitations. If they are subjected to high dynamical loads and start/stop events, their lifetime is rapidly reduced. For these reasons, batteries or ultracapacitors are used to supply the dynamical power required by the traction drive, so as to make the FC supply the mean (slowly variant) energy on a driving cycle [3], [4]. However, batteries also suffer from premature degradation when operating far from their optimal State of Charge (SoC), or when they are subjected to high currents. Then, in order to increase the acceptance of FC electric ve- hicles, both batteries and FC degradation must be minimized, while also the H 2 consumption should be limited in order to reduce their operating costs. As a result, control strategies for energy flow management are a key issue in the implementation of these vehicles, in order to preserve battery’ lifetime and minimize FC degradation, among other objectives [5]–[7]. The objective of this challenge was to develop a robust EMS and BS taking into account the efficiency of each component and degradation of the energy sources, in order to: • Minimize the fuel consumption of H 2 . • Preserve the energy sources’ lifetime minimizing start/stop cycles of the FC and restricting the state of charge of the batteries. • Provide the necessary power to the vehicle in all circum- stances. The studied FC electric vehicle is a commercial Tazzari Zero EV equipped with a Proton Exchange Membrane Fuel Cell (PEMFC) and a battery pack, which feed the traction system. According to the vehicle configuration, only the FC current and the amount of regenerative braking energy can be controlled to achieve these goals. In order to develop and test the EMS and BS, the participants received the system model (complete vehicle model and its control) in Matlab Simulink TM simulation tool depicted using Energetic Macroscopic Rep- resentation (EMR) [1]. The submitted proposals were tested using a scoring driving cycle that was not previously known by the participants. In this paper, we present the winner EMS and BS designed taking into account those premises. Our proposal achieved the best performance over the scoring driving cycle, closer to an optimal solution. Details about the strategy design, as well as simulation results for different critical cases are presented. II. ARCHITECTURE AND FUNDAMENTAL ASPECTS In order to design an energy management strategy, it is necessary to know the architecture of the vehicle and the model of the elements that compose it. Besides, the factors that affect the components degradation and operating costs must be considered. A scheme of the considered FC/Battery EV is shown in Fig. 1. As can be seen in Fig. 1, the traction subsystem is composed by a three-phase bidirectional converter connected to a 15 kW induction machine which is coupled to the driving wheels. The 80 V- 40 Ah battery pack is composed by Lithium Iron Phosphate (LiFePO4) batteries and is directly connected to traction subsystem. Meanwhile the 16 kW, 40-60 V, PEMFC