Abstract:

In this paper， the energy?consuming braking state and the regenerative braking state of a built?in PMSM are analyzed first based on the equivalent circuit model of the motor. Then the control current instruction of the motor is analytically analyzed according to the principle of motor vector control and is verified by test data. Next， the optimal regenerative torque curve of PMSM is calculated， and based on which an optimal series braking control strategy for regenerative braking is proposed. Finally， a simulation is conducted to acquire the L/100km fuel consumption and the energy recovered by regenerative braking of a P4 parallel hybrid electric commercial vehicle under C?WTVC， CHTC?TT and a section driving cycle of provincial road with both the parallel braking control and the optimal series braking control strategy. The results show that compared with parallel braking control， the series braking control strategy based on the optimal regenerative torque curve of the motor can reduce fuel consumption and recover more braking energy， achieving the enhancement of braking energy recovery and fuel economy.

Key words: regenerative braking, permanent magnet synchronous motor, optimal regenerative torque curve, P4 hybrid electric vehicle