Power distribution and system design of parallel hybrid electric vehicle powertrain

When engine works in low-speed conditions, the quality of mixture is poor and the heat loss is very much, resulting in the fuel economy declines seriously and the emission increases significantly. This paper studies a powertrain of parallel hybrid electric vehicle (PHEV), when the vehicle travels with low-speed, only the motor works as the power source instead of engine, while the vehicle travels with high-speed, the engine and the motor work together to meet the dynamic performance. This mainly introduces the distribution of PHEV´s engine power, motor power, drive accessory power and the transmission ratio, also makes relevant calculations with an example, finally contrasts the performance of traditional vehicle with hybrid vehicle powertrain.