Electro-mechanical Braking Method in Hybrid Electric Vehicles Based on Feedback Control Theory

In this paper, the hybrid electric vehicle braking process is researched, by using variables consists of HEV speed, motor speed, and state of charge established, fimctions of mechanical braking force, regenerative braking force and efficiency of energy recovery are constructed, and the control goal is to maximization the energy recovery efficiency. Under the feedback control strategy, with the constrain condition of braking strength and braking stability, combining experiments in ADVISOR, in different experiments of different working conditions, we can see that in UDDS Cycle, the regenerative braking efficiency is the best. What＇s more, compared with strategies in ADVISOR, strategy proposed in this paper is obviously better.

Performance,combustion,and emission characteristics of on a diesel engine fuelled with hydrogen compressed natural gas and Kusum seed biodiesel

Renewable fuels have many advantages over fossil fuels because they are biodegradable and sustainable,and help mitigate social and environmental problems.The objective of the present study is to evaluate the performance,combustion,and emission characteristics of a compression–ignition engine using hydrogen compressed natural gas(HCNG)-enriched Kusum seed biodiesel blend(KSOBD20).The flow rate of HCNG was set at 5 L/min,10 L/min,and 15 L/min,and the injection pressure was varied in the range of 180 bar to 240 bar.Brake thermal efficiency(BTE)and brake-specific fuel consumption(BSFC)were improved when HCNG was added to the KSOBD20.Combustion characteristics,namely,cylinder pressure(CP)and net heat release rate(NHRR),were also improved.Emissions of carbon monoxide(CO),hydrocarbons(HC),and smoke were also reduced,with the exception of nitrogen oxides(NO_(x)).The higher injection pressure(240 bar)had a positive effect on the operating characteristics.At an injection pressure of 240 bar,for KSOB20+15 L/min HCNG,the highest BTE and the lowest BSFC were found to be 32.09%and 0.227 kg/kWh,respectively.Also,the CP and NHRR were 69.34 bar and 66.04 J/°.CO,HC,and smoke levels were finally reduced to 0.013%,47×10^(-6)and 9%,respectively,with NO_(x)levels at 1623×10^(-6).For optimum results in terms of engine characteristics,the fuel combination KSOBD20+15 L/min HCNG at FIP 240 bar is recommended.

Performance, emission and combustion characteristics of CI engine fuelled with diesel and hydrogen

Hydrogen （H2） is being considered as a primary automotive fuel and as a replacement for conventional fuels. Some of the desirable properties, like high flame velocity, high calorific value motivate us to use hydrogen fuel as a dual fuel mode in diesel engine. In this experiment, hydrogen was inducted in the inlet manifold with intake air. The experiments were conducted on a four stroke, single cylinder, water cooled, direct injection （DI）, diesel engine at a speed of 1500r/min. Hydrogen was stored in a high pressure cylinder and supplied to the inlet manifold through a water-and-air-based flame arrestor. A pressure regulator was used to reduce the cylinder pressure from 140 bar to 2 bar. The hydrogen was inducted with a volume flow rate of 41 pm, 61 pm and 81 pm, respectively by a digital volume flow meter. The engine performance, emission and combustion parameters were analyzed at various flow rates of hydrogen and compared with diesel fuel operation. The brake thermal efficiency （BTE） was increased and brake specific fuel consumption （BSFC） decreased for the hydrogen flow rate of 81 pm as compared to the diesel and lower volume flow rates of hydrogen. The hydrocarbon （HC） and carbon monoxide （CO） were decreased and the oxides of nitrogen （NOx） increased for higher volume flow rates of hydrogen compared to diesel and lower volume flow rates of hydrogen. The heat release rate and cylinder pressure was increased for higher volume flow rates of hydrogen compared to diesel and lower volume flow rates of hydrogen.