Control strategy of increasing three way catalytic converter lightoff for hybrid electric vehicle in combination driving cycle
1.The State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing 400044, China; 2.College of Mechatronics and Automotive Engineering, Chongqing Jiaotong University, Chongqing 400074, China; 3.Chongqing Chang′an New Energy Vehicle Co., Ltd., Chongqing 401120, China
Abstract：To lighten the influence of threeway catalyst characteristics on vehicle emission during cold start，a fuzzy logic controller of energy management with decreased engine output power to improve engine exhaust temperature in combination driving cycle was designed to speed up the catalytic converter light off. Based on the minimum principle, the catalyst optimum lightoff control strategy was proposed. According to lumped method of neat capacity, vehicle dynamic model was established with consideration of the transient characteristics of catalytic converter in Matalb/simulink. The influence of the two control strategies on the fuel consumption and emission performance was analyzed. The simulation and the bench test results show that both the control strategies can increase transferred heat from exhaust emission to catalytic converter and shorten catalyst lightoff time. The engine emission performance of hybrid electric vehicle during cold start can be improved effectively by the proposed strategies.
2012, Vol. 33 
