Research On Hydrogen-Electric Hybrid Ground Vehicle

With the problem of environmental pollution and the short of fossil energy, such as oil, coal and natural gas in the world, the voice of seeking a sustainable clean energy is increasingly strong. As a kind of clean and renewable energy, hydrogen energy has received more and more attention. Fuel cell is a device to transform the fuel’s chemical energy directly into electrical energy through electrochemical reaction, without the use of mechanical movement, only through the proton, electron’s micro mobility, no vibration and noise, and conversion efficiency is high. At present, the fuels used in fuel cell commonly are hydrogen and methanol. The hydrogen-oxygen proton exchange membrane fuel cell is more mature. The hydrogen is fed into the anode and the oxygen is fed into cathode. The anode and the cathode are separated by proton exchange membrane. The hydrogen’s oxidation reaction occurs in the presence of the catalyst to produce electrons and hydrogen ions(protons). The electrons move from the external circuit to the cathode, and the hydrogen ions move to the cathode through the proton exchange membrane. Oxygen, under the action of catalyst, transform into oxygen ion by combining with electrons that come from the anode. The oxygen ions and hydrogen ions that come from the anode through the proton exchange membrane combine into water.Application of fuel cell on the vehicle can greatly reduce vehicle’s emissions, especially without sulfur and nitrogen oxide emissions. At present, several kinds of fuel cell vehicles have come out in the world, such as America, South Korea and China, but these fuel cell vehicles are all cars and buses, and they have only one power source.The fuel cell-battery hybrid ground vehicle is a kind of ground vehicle driven by fuel cell and lead-acid battery. This paper is divided into the following sections:(1) introduce of the background of the subject, significance and the development of fuel cell vehicles’ status and existing problems;(2) the design of power system and the simple control of fuel cell-battery hybrid ground vehicle: According to the requirements of the hybrid ground vehicle’s power system, the power system is designed simply. The designed circuit is controlled by manually switch and the designed circuit can satisfy the requirements of battery-only and fuel cell-battery model;(3) the selection of the key components, arrangement, body structure design and stress analysis: According to the performance of the existing fuel cell, combined with the load and speed of the vehicle, the motor and battery are selected. According the mass and volume of fuel cell, battery, hydrogen storage tank, on-board AC/DC converter, stabilized power supply and battery, the position of them is arranged. By investigation of the market, the square steel tube, rectangular steel tube and angle iron are selected. The body is modeled by Pro/E and imported into ANSYS to do mechanical analysis according to the position and mass of these components and humans. The results show that the body structural design meets the design requirements;(4) the design and optimization of McPherson front suspension based on ADAMS/Car module: several common front suspensions and their advantages and disadvantages are analysis. Finally, the current commonly used Mc Pherson front suspension is chosen to be the front suspension; the model of Mc Pherson suspension and the parallel travel simulation is completed by using ADAMS/Car. The results show that the caster angle and toe angle beyond the reasonable scope, do not meet the design requirements; the x, y, z coordinates of low control arms’ front and rear fulcrums, shock absorbers’ upper and lower installation points are chosen as the design variables. In the ADAMS/Insight module, the caster angle and the toe angle is optimized, so that they comply with the design requirements. The performance of the front suspension is effectively improved;(5)Leaf spring rear suspension design and stress analysis of rear axle based on ANSYS: Considering the layout space of related parts and the load of rear axle, the leaf spring suspension is chosen to be the rear suspension type; To analyze whether the leaf spring can meet the requirements, the rear axle leaf spring’s contour is measured by the three coordinate measure machine, modeled by Pro/E and import into ANSYS to do stress analysis. The results show that the leaf spring’s stiffness is suitable, can satisfy the design requirements of the vehicle;(6) Based on the computer simulation and experiment, the hydrogen-electric ground vehicle is completed.Through real driving test, the full load speed reached 25km/h, meets the design requirements. It provides a good platform for real vehicle experiment of the hybrid ratio.