Hibrit Enerji Yönetim Sistemi Algoritmalarının Paralel Hibrit Araçlarda Analizi ve Dinamometre Testleriyle Doğrulanması

Abstract

Within the scope of this thesis, based on results based on intensive data collection and simulation activities related to municipal buses serving the city of Ankara, a research study about the analysis of potential fuel savings, that could be provided if municipalities and the Ministry of Transport used electric and/or hybrid vehicles instead of vehicles with internal combustion engines, has been carried out. In other words, the amount of fuel savings has theoretically been calculated by transforming the existing vehicles to either electric or hybrid vehicles and by optimizing their energy management algorithms (according to the driving cycles obtained during the thesis). Original methods were developed to determine driving cycles for the different cities of our country and were used in the subsequent hybridization analyses.For the above mentioned purposes, powertrain and vehicle dynamics models of aforementioned vehicles were established in the virtual environment. The algorithms of the energy management systems of the electric/hybrid vehicles have been investigated from the literature and analyses have been carried out to determine the benefits of advanced methods such as the Equivalent Consumption Minimization Strategy (ECMS) based methods compared to simpler rule based methods. In particular, an original method based on adaptive- ECMS, which consists in scheduling control parameters according to the real–time driving cycle has been developed. By using this method, it was found that fuel consumption savings up to 50% fuel consumption were possible. Within the scope of the method, the parameters of the energy management system were adapted to the traffic density information provided by the vehicle tracking system. In other words, in the virtual environment, the speed time graph for the road segment where the ego vehicle is about to travel is predicted theoretically, using the vehicle tracking system data of vehicles that travelled on the same road segment in the recent past. Thereby, the calibration of the hybrid energy system algorithms is made possible by using driving cycles calculated for the road segment under interest. In the final stage of the thesis, a three–wheeled parallel hybrid vehicle with electric hub motors at the front wheels and an internal combustion engine driven rear wheel has been constructed. The hybrid energy management system algorithms designed during the theoretical stages of the thesis, have been coded to the vehicle control computer of this vehicle. Speed – time data have been collected in the Hacettepe University campus and a simplified driving cycle has been obtained according to the data. In order to carry out controlled experiments, a unique test procedure has been developed on the dynamometer test setup in the Hacettepe University Automotive Laboratory. During the tests, internal combustion engine and electric hub motors (which were disassembled and mounted to a separate vehicle chassis) were made to drive dynamometer drums simultaneously. Experimental results show that ECMS can provide much more fuel savings than other methods as also shown in the theoretical stages of the thesis. Both the theoretical and practical results prove that the hybrid energy management algorithm mentioned above has a great potential in reducing fuel consumption, when the driving cycle is more or less known, which is quite valid for vehicles used in urban passanger transportation that generally have fixed routes.