طراحي و شبيه سازي قواي محركه ي هيبريد فلايويلي براي يك ميني-خودرو

چكيده انگليسي :

Designing and Simulation of a Flywheel Hybrid Power train for a Mini car Mohammad Salehi Malekabadi m salehi@me iut ac ir th April Department of Mechanical Engineering Isfahan University of Technology Isfahan Iran Degree M Sc Language Farsi M Esfahanian Assist Prof Supervisor mesf @cc iut ac ir Abstract Nowadays hybrid power trains represent one of the most effective ways of reducing fuel consumption and exhaust gas emissions in vehicles Electric hybrid power trains has been in focus of hybrid technology since but instinctive limitations of electric systems like low round trip efficiency and low power density motivate some researchers to search for alternative systems in power train hybridization Storing energy in a high speed rotating wheel is one of them Despite of its benefits like high power density and large round trip efficiency it has some complexities One of them is to maintaining continuous power flow between three rotating shaft with independent varying speed In this thesis an innovative parallel structure of flywheel hybrid power train is introduced which consists of a high speed flywheel a fixed ratio gear set a clutch an infinitely variable transmission IVT and a torque coupling Reducing energy dissipation by disengaging the flywheel clutch in flywheel standby mode and maintaining power flow in flywheel power train with its slipping mode are some privileges of the represented structure It is shown that an IVT structure with proposed power flow represent better efficiency than other types Using a fixed ratio gear set before the flywheel reduces power loss in IVT Avoiding greedy design a steel flywheel ball bearings and mbar vacuum pressure in flywheel contaminant is preferred A full discussion about choosing cylinder shape for flywheel is presented Mechanical behaviors of all consisting components are modeled considering the effect of inertia aerodynamic drag and friction This model is integrated with a conventional power train in ADVISOR software and is controlled by a combined control strategy consisting operating point optimization regenerative braking and automatic engine start stop For optimizing operating points the controller checked some specified conditions and let the engine to produce design power in operating speed with changing the gear ratio of IVT For intermittent engine start stop mode four conditions must be checked One of them is that the engine temperature must be over than percent of its design temperature The Simulation results of the system in standard drive cycles for a light car shows reduction of about percent in fuel consumption and percent in exhaust gas emissions The ratio of the flywheel gear set has been optimized A further investigation about comparing flywheel hybrid power trains with electrical ones is also carried on which shows that a mechanical power train represent better efficiency in low power density vehicles like city buses The results also indicate that mechanical hybrid power trains have better efficiency in high power density vehicles like light vehicles In conclusion simulating a city bus in city bus drive cycles shows about percent reduction in fuel consumption even without start stop mode which confirms that mechanical power trains are more efficient in heavy vehicles Key Words

صالحي ملك آبادي، محمد

طراحي و شبيه سازي قواي محركه ي هيبريد فلايويلي براي يك ميني-خودرو

خودروهاي هيبريد مكانيكي , كاهش مصرف سوخت , كاهش آلاينده ها