外文翻譯---混合動(dòng)力電動(dòng)汽車(chē)機(jī)械和再生制動(dòng)的整合-汽車(chē)設(shè)計(jì)(編輯修改稿)
2025-06-26 09:10 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 the engine when the vehicle is moving and do not need a second generator to charge the batteries. Series/Parallel Hybrids Combined hybrids have the features of both series and parallel configurations. They use a power split device to drive the wheels using dual sources of power (. electric motor only, ICE only or a bination of both). While the added benefits of both series hybrids and parallel hybrids are achieved for this configuration, control algorithms bee very plex because of the large number of driving possibilities available. Degree of Hybridization Since most HEV’s on the road today are either parallel or series/parallel, it is useful to define a variable called the ‘degree of hybridization’ to quantify the electrical power potential of these vehicles. iceememPP PDOH ?? The degree of hybridization ranges from (DOH = 0) for a conventional vehicle to (DOH = 1) for an all electric vehicle [25]. As the degree of hybridization increases, a smaller ICE can be used and operated closer to its optimum efficiency for a greater proportion of the time, which will decrease fuel consumption and emissions. The electric motor power is denoted by Pem and the internal bustion engine power is 6 denoted by Pice. Micro Hybrid Micro hybrids have the smallest degree of hybridization and usually consist of an integrated starter generator (ISG) connected to the engine crankshaft. The ISG allows the engine to be shut off during braking and idling to conserve fuel and then spins the crankshaft up to speed before fuel is injected during acceleration. The ISG also provides small amounts of assist to the ICE during acceleration and acts as a generator to charge the batteries during braking. Micro hybrids usually improve fuel economy by about 10 percent pared with non hybrids [53]. Mild Hybrid Mild hybrids have a similar architecture to the micro hybrid except that the ISG is uprated in power to typically greater than 20 kW. However, the energy storage system is limited to less than 1 kWh [35]. Mild hybrids usually have a very short electriconly range capability but can provide a greater assist to the ICE during accelerations. The electrical ponents in a mild hybrid are more plex than a micro hybrid and play a greater role in the vehicle operation. Fuel economy can be improved by 20 to 25 percent with a mild hybrid over non hybrid vehicles [53]. Full Hybrid Full hybrids do away with the ISG and replace it with a separate electric motor and alternator/starter that perform the same function. The electric motor has the ability to propel the vehicle alone, particularly in city (stop and go) driving. The energy storage system is upgraded to improve electriconly range capability and the engine is usually downsized to improve fuel economy and emissions. Full hybrids can achieve 40 to 45 percent fuel consumption reductions over non hybrids [53]. Plugin Hybrid Plugin hybrids are very similar to full hybrids except that they have a much larger ESS that can be connected to an outside electrical utility source for charging. These vehicles use only the electric motor to propel the vehicle within the range of the batteries and then operate like full hybrids once the batteries have discharged to a predefined level. Fundamentals of Regenerative Braking 7 One of the most important features of HEV’s is their ability to recover significant amounts of braking energy. The electric motors can be controlled to operate as generators during braking to convert the kiic energy of the vehicle into electrical energy that can be stored in the energy storage system and reused. However, the braking performance of a vehicle also greatly affects vehicle safety. In an emergency braking situation the vehicle must be stopped in the shortest possible distance and must be able to maintain control over the vehicle’s direction. The latter requires control of brake force distribution to the wheels [12]. Generally, the braking torque required is much larger than the torque that an electric motor can produce [12]. Therefore, a mechanical friction braking system must coexist with the electrical regenerative braking. This coexistence demands proper design and control of both mechanical and electrical braking systems to ensure smooth, stable braking operations that will not adversely affect vehicle safety. Energy Consumption in Braking Braking a 1500 kg vehicle from 100 km/h to 0 km/h consumes about kWh of energy based on Equation . 221mvE? If 25 percent of this energy could be recovered through regenerat
畢業(yè)設(shè)計(jì)相關(guān)推薦
鄂ICP備17016276號(hào)-1