Hybrid Electric & Hydraulic Drivers

Abstract: The environmental impact of fossil fuel consumption has been a significant issue over the last decade. Mainly because of public awareness, increased fuel cost and stricter legislation. Today’s technological improvements have reduced fuel consumption and also emission of vehicles considerably. One of the most important solutions to this problem is hybridization. Hybridization in vehicle is using two or more distinct power sources. Additionally, the main objective of hybridization in vehicle is improving the fuel consumption and reducing hazardous air pollutants without lowering vehicle performance and other satisfaction criteria. Development of hybridization systems can be fallen into two categories: electric and hydraulic hybrids. This project illustrates performances of HHV (hybrid hydraulic vehicles) and HEV (hybrid electric vehicles) in NEDC (New European Driving Cycle) and 10-15 mode (Japanese Driving cycle) by using simulation models, which has been done by the LMS Imagine Lab Amesim rev 7 thand 8th. The following paper compares HRB (hydraulic regenerative braking system) as a hydraulic system and a parallel hybrid electric system (HEV) with the Nickel-metal hydride (NiMH) battery on the light weight vehicle (1 ton). Results show higher performance in HEV, about 13.7% during NEDC and 25.4% during (10-15) improvement in fuel consumption although high energy density and low power density are inherent battery characteristics. Also, all the evidence point to high cost components and short- life time. The HRB model saves around 11% during NEDC and 23.3% during 10-15Mode in fuel consumption in addition to high power density and low energy density .In other words, limitation for accumulating energy is an intrinsic system character. However, high response, low component cost and weight with long life time are advantages of HRB. Two problems exiting in HRB model are: firstly, the necessity of using big size pumps for fully charging hydraulic accumulators that would be impossible in a light vehicle; and secondly the limitation of capturing huge amount of energy in accumulators. In this paper the attempt is made to explicate some of the brand new solutions to alleviate some of these weak points.