AbstractsEngineering

Effect of extreme cold temperatures on the usage of a utility electric snowmobile

by Francis De Broux




Institution: McGill University
Department: Department of Mechanical Engineering
Degree: M. Eng.
Year: 2015
Keywords: Engineering - Mechanical
Record ID: 2062173
Full text PDF: http://digitool.library.mcgill.ca/thesisfile130481.pdf


Abstract

As electric vehicles (EVs) are gaining traction in the automotive industry, technology innovators are pushing the boundaries of EVs to new industries and harsher climates. Advancements in battery technologies, reduced EV component costs, and government incentives have permitted other industries, such as off-road vehicles, to begin experimenting with electrified vehicles.This thesis examines an actual utility electric snowmobile application at a research station within the Arctic Circle to determine how the cold weather limits the usage of the snowmobile for its operators. An experimental campaign comprised of constant discharge cycles at different temperatures was devised based on the vehicle's battery pack and the real life operation of the snowmobile. Experimental data was then processed to build a battery pack model which was used to simulate typical drive cycles and to determine how much time the snowmobile operator could spend at an outdoor work site, in -30°C weather, before the snowmobile battery is effectively disabled by the cold.The key simulation takeaways are that depending on initial pack temperature, work site distance from base, and towing load, the maximum amount of time spent at the work site ranges from 1.5 hours to 9.5 hours. Simply from a towing perspective, a rule of thumb of 4 hours at the work site for no towing load and 1.5 hours for a heavy towing load can be extrapolated from the results. After this critical time is reached, the cold causes an increase in internal resistance in the battery pack which would then cause a voltage drop below the lower voltage limit and hence the snowmobile would not be able to return to base safely. Also, an exploratory discussion and preliminary analysis of battery pack heaters are presented. Although they can increase the usage of an electric snowmobile significantly in very cold weather, much design optimisation and testing remain. Alors que les voitures électriques sont de plus en plus nombreuses sur les routes, des véhicules électriques spécialisés débutent leur apparition dans plusieurs nouvelles applications, tel qu'en environnement beaucoup plus hostile. Les progrès continus en technologies de batteries, la réduction du coût des composantes et les incitatifs gouvernementaux ont tous permis l'introduction des véhicules électriques dans de nouveaux marchés comme les applications hors-route.Cette thèse évalue la performance d'une motoneige électrique utilitaire en opération sur une base de recherche au Groenland. Plus spécifiquement, l'objectif est de comprendre comment le grand froid limite l'utilisation de la motoneige pour ses opérateurs. Une campagne expérimentale centrée sur les batteries utilisées dans la motoneige et qui reflète les réelles conditions d'opération a été mené à terme. Les données ont ensuite été utilisées pour créer un modèle électrique et thermique des batteries. Ultimement, ce modèle a été utilisé pour simuler et déterminer les limites d'opérations de la motoneige en température ambiante de -30°C. En résumé, les simulations…