Study on hydraulic system of hydraulic hybrid vehicle

Concern about air pollution and hydrocarbon fuel resources has increased interest in high efficiency hybrid vehicles Hydraulic hybrid technology has received much attention of research institutes and automakers. This paper presents a new type of hydraulic hybrid vehicle (HHV) and its design conception and working principle are discussed. The dynamic characteristic of HHV has important influence on its holistic performance. In order to research the dynamic performance of the vehicle, it is needed to analyze the models of its hydraulic system. The mathematical models of the main hydraulic components and hydraulic system are described. Modelling problems of hydraulic system are discussed and methods to reduce the stiff problems in dynamic simulation of hydraulic system are studied. The analysis for the dynamic performance is implemented based on simulation results. The experimental verification is performed on the self-developed test bench. By comparing the results of simulation and experiments, the accuracy of systematic model and simulation algorithm is proven. Modelling methods and simulation parameters are proven to be right and lay the basis for the further research of hydraulic hybrid vehicle's dynamic characteristic.