Study on the brake resistor and energy consuming brake process of hybrid electric vehicle

On purpose of high efficient energy recycle and brake security, the electric energy consuming brake is applied in the hybrid electric vehicle. The energy consuming brake is a kind of electric brake process, which is realized by motor, brake resistor and its heat dissipation subsystem. In this study, the calculations and numerical simulation models of the brake resistor and its cooling subsystem of a heavy duty series-parallel hybrid electric vehicle is developed to investigate the heat transfer regulations in the electric brake process. The factors that affect the requirement of system cooling air mass flow and power consumption of the whole thermal management system in electric brake process are identified and studied. The results show that the main influencing factors of heat transfer in electric energy consuming brake process include ambient temperature and initial brake velocity. When ambient temperature is constant, the needed cooling air mass flow is basically unchanged as initial brake velocity varies between 15km/h and 30km/h for the small brake energy. The requirement of system cooling air mass flow increases as initial brake velocity grows between 30km/h and 70km/h. They perform three times power function relationship. The requirement of system cooling air mass flow increases as ambient temperature grows when initial brake velocity is constant. They perform exponential function relationship. For the small brake deceleration in light brake, it has small influence on the needed cooling air mass flow and can be neglected.