Matlab-based modeling,simulation and design package for Eletric,Hydraulic and Flywheel hybrid powertrains of a city bus

In this paper a package for designing, modelling and simulation of three hybrid powertrains are presented. These powertrains are Electric hybrid, Hydraulic hybrid and Flywheel hybrid. The differences among the proposed hybrid powertrains include the energy storage system components, the secondary power converter and also the powertrain configuration. The O457 city bus is considered as the benchmark vehicle. At first, the design process for each hybrid powertrain which is based on the power requirements of the bus in any driving condition is presented. Then, the powertrains modelling using MATLAB/Simulink as a powerful simulating tool is presented. The models are feed-forward and resemble the real world driving conditions. Each model has the blocks for the main components of the corresponding propulsion system. The most important stage in the modeling process is implementing of the components efficiency in each powertrain. Moreover, there is a block in each hybrid powertrain model for the energy management. Finally, the simulation results for comparing the usefulness of the hybrid powertrains are presented. The results indicate that the electric hybrid powertrain has the most effect on reducing the bus fuel consumption. But regarding the fabrication expenses and manufacturing complexity, the hydraulic hybrid powertrain is recommended.