Power-split Hybrid Electric Vehicle의 동력 성능해석 및 제어

Abstract

The conventional vehicle with internal combustion engine has economical and environmental problems. To overcome these problems, the EV (Electric Vehicle) and the FCV (Fuel Cell Vehicle) are proposed but they have some limitations to commercialize. The HEV (Hybrid Electric Vehicle) system driven by more than two power sources is then developed as a new substitute. In this study, the performance of the power-split HEV is investigated through the analysis of the power flow. To do this, the components of the powertrain and vehicle driving conditions are modeled and served as modules in the simulation software. The full model of the target vehicle is modeled and the equations of motion are derived from the full vehicle model by the bond graph method. The driving control modules are developed to optimize the target vehicle while maintaining the performance of the IC engines and minimizing the fuel consumption. Simulation using Matlab/Simulink is carried out by LA4 city driving mode and US06 highway driving mode. The simulation results show that the fuel economy under LA4 city driving mode can be improved with 81.6% compared to a conventional vehicle. The fuel economy under US06 highway driving mode can be improved with 59.3% compared to a conventional vehicle.; Hybrid vehicle system은 두 가지 이상의 power sources로 구동되는 vehicle system을 말한다. 기존의 IC engine vehicle은 fuel consumption의 economical problem과 emissions와 같은 environmental problem의 측면에서 단점을 가지고 있다. 이를 해결하기 위해 EV (Electric Vehicle)가 개발되었지만, 잦은 충전이 필요함에 따라 장시간 운전에 적합하지 못하다는 단점을 극복하지 못하고 있다. 이러한 IC engine vehicle과 electric vehicle의 단점을 서로 보완하고 장점을 살릴 수 있는 개념으로 개발된 것이 HEV (Hybrid Electric Vehicle)이다. 본 연구에서는 HEV의 한 system인 power-split HEV를 연구대상으로 하였다. Power-split HEV의 powertrain을 구성하는 각 components와 vehicle의 driving에 관여하는 vehicle dynamics를 modeling하여 bond graph를 이용하여 equations of motion을 유도하였다. 기존의 internal combustion engine을 사용한 vehicle과 비교하여 power performance를 유지하면서 fuel consumption을 최소화할 수 있도록 driving control module을 설계하였고, Matlab/Simulink를 이용하여 city driving mode와 highway driving mode에 대하여 simulation하여 각 driving mode에 대한 power-split HEV의 동력성능을 해석하였다.