System design and development of parallel-hybrid electric vehicle based on CAN bus

Hybrid electric vehicles (HEV) are enjoying more widespread customer acceptance than battery electric vehicles (EV) because of their performance and economy. In a parallel-type HEV, the torque assisting and battery recharging control using the electric machine is the key point for efficient driving. This paper describes electric machine drive system based on DSP and CAN bus. The TMS320LF2407A DSP is employed to realize the functions as driving and generating (especially regeneration) function, pulse width modulation (PWM) waveforms production, signal receiving and their processing function. Control commands are transmitted to the DSP core via CAN bus. The electric machine torque command is generated from control command and its rotational speed. In the end, a PMDC of 20 KW drive system based on DSP and CAN bus is used as an example. Some circuit and flow chart of controller are presented.