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.