Station de recharge | EPFL Graph Search

vignette|redresse|Une borne de recharge électrique compatible multi-standards à Medenbach West. Une station de recharge de véhicules est une infrastructure équipée d'une ou plusieurs borne de recharge permettant la recharge des véhicules électriques. La borne comporte au minimum un point de charge, matérialisé par un socle de prise. Une station de charge comporte l'espace nécessaire au véhicule pour stationner, le point de charge (borne, coffret…), et les autres éléments nécessaires, le cas échéant (armoire électrique de gestion « intelligente » de la charge). Elle doit répondre à des normes et standards techniques ; un standard européen a été décidé en 2014 par la Commission européenne. Les véhicules électriques se rechargent usuellement à domicile ou sur le lieu de travail, mais on compte environ de recharges publiques dans le monde en 2020, dont en Chine, en Europe et aux États-Unis. 30 % de ces bornes sont à charge rapide, mais ce taux est plus élevé en Chine (38 %) qu'en Eur

The online electric autonomous dial-a-ride problem

Anouk Larisse Allenspach

The DARP (Dial-a-Ride Problem) is concerned with providing service to a number of requests, specifying their location of origin and destination, as well as time windows indicating their desired service time for at least one of the locations. In the dynamic DARP, requests can also occur in real-time which, in case the request is accepted, must then be inserted into the existing vehicle routes. In this work, an online algorithm for the dynamic DARP with electric, autonomous vehicles, the e-ADARP (Electric Autonomous Dial-a-Ride Problem) is developed. In addition to classic constraints from the DARP (i.e. time-windows, origin-destination precedence, users’ maximum ride-times, vehicles’ maximum route durations), the e-ADARP includes online battery management, decisions regarding detours to charging stations, partial vehicles’ recharging and selection of destination depots. We develop a two-step heuristic which, in the general framework, is comprised of a simple insertion heuristic for the dynamic requests, followed by an improvement phase. In this work, we present the first step, namely the insertion heuristic. An event-based simulation environment is designed to perform computational experiments on adapted benchmark instances from DARP literature and instances based on real data from Uber Technologies Inc.

2018

Contribution to the Ultra-Fast Charging of Electric Vehicles

Rosa Martel Danoary Tsirinomeny

It is generally agreed that one of the drawbacks of a conventional vehicle is the inability to always reach the best operating point of the engine and the inability to regenerate the kinetic energy. Meaning, even with the help of the gearbox or automatic transmission, there is no way to reach more efficient operating points without increasing the power and then there is nowhere to store the excess of the energy converted. Electric vehicles (EVs) offer an opportunity for intelligent motion by working at the best operating point during driving mode, as well as a smart energy management during charging mode. However, it is well-known that the EV has been criticised due to its range anxiety, its limited compatibility with various charging points, its high cost, as well as its limited capability to ride-through a thermal runaway, etc. Today, the range anxiety seems to be resolved by the fact that a significate development is foreseen in the field of the battery cells market for portable equipment such as cell phones, pads, laptops, etc; the same battery technology can be deployed for EVs. Actually, battery packs in EVs tend to have high energy and power densities which will exert a strong thermal stress upon them. This means that individual battery cells are more prone to decline away and eventually fail early because of an excessive loss of capacity and an increase of the internal resistance caused by accelerated aging. Moreover, for electromechanical reasons, each cell is totally unbalanced in operating mode. Therefore, a suitable battery management system should be installed and the capability of the EV to ride-through thermal runaways must be guaranteed. Furthermore, in order to overcome the difference between AC and DC charging station standards, the EV on-board charger has to be flexible for various levels of charging modes (from AC household basic supply to AC or DC ultrafast charging). In order to meet the EV requirements, an advanced power converter which driven efficiency, power density is required. Therefore, the configurable modular multilevel converter (CMMC) has been introduced. It is part of a family of modular multilevel converters, also known as MMC, M2C or DSCC. Hence, its heritage allows bringing the whole advantages to EV applications. In addition it carries the surname of configurable because the converter plays a double role: in fact, it merge the traction converter and the bidirectional charger as well as the battery balancer converter, which not only increases the modularity and the scalability of the power modules but it reduces the cost, condenses the volume. In detail, the concept is linked to the idea of replacing the branch inductance of the standard MMC by the tapped stator windings of the traction motor itself. This allows operating the stator windings as current filter during charging mode. In addition, the famous EV battery pack is split into the MMC submodule. This will increase the fault ride-through capabilities of the Flex-EV battery against thermal runaways, by increasing the capability of the system to work under fault condition. In addition, states of charge (SoC) balancing are implemented at the level of modulation in order to balance that submodule battery state of charge. This is based on a selecting and sorting algorithm, which connect and disconnect the batteries submodules actively according to the sign of the generated AC current wave form and the SoC of the submodules batteries.

EPFL2016

Modular multilevel battery packaging for a universal and flexible EVs charging system

Rosa Martel Danoary Tsirinomeny

Electric Vehicles (EVs) carmakers are heavily confronted by the limited fault ride-through capabilities of actual EVs battery packs. Therefore, this paper introduces a new method of EVs battery packaging based on modular multilevel battery modules as well as a universal and flexible integrated charging system. This allows isolating damaged battery modules and keeping the whole system working. In addition, the concept allows charging the batteries from a wide range of charging infrastructure; from AC household basic supply to AC fast-charging as well as DC ultra-fast charging. This method consists of cascading half bridge switching cells, which are connected with battery modules in order to form a modular multilevel converter (MMC). A three phase electrical machine with slip stator windings is needed in order to use the stator winding as filtering inductance during charging mode. Moreover, the concept integrates a selecting and sorting algorithm for balancing the battery modules state of charge without using dissipative strategies.

2014

Contribution to the Ultra-Fast Charging of Electric Vehicles

Rosa Martel Danoary Tsirinomeny

EPFL2016