English

Abstract

In this paper proposes a simple but effective method of electric brake with energy regeneration for a brushless dc motor, of electric vehicle (EV). BLDC motor control utilizes the traditional proportional-integralderivative (PID) control and the distribution of braking force adopts fuzzy logic Conventionally, EVs use mechanical brake to increase the friction of wheel for the deceleration purpose. However, from the viewpoint of saving energy, the mechanical brake dissipates much energy since the EV’s kinetic energy is converted into the thermal one. In view of this, this paper discusses how to convert the kinetic energy into the electrical one that can be recharged to the battery. Thus, both the electric brake and energy regeneration are achieved. In comparison to other solutions, the new solution has better performance in regard to realization, robustness and efficiency. In this paper, we have chosen the three most important factors: SOC, speed and brake strength as the fuzzy control input variables. We have found that RBS can obtain appropriate brake current, which is used to produce brake torque. At the same time, we have adopted PID control to adjust the BLDC motor PWM duty to obtain the constant brake torque. PID control is faster than fuzzy control so the two methods combined together can realize the smooth transition since the braking kinetic energy is converted into the electrical energy and then returns to the battery, the energy regeneration could increase the driving range of an EV.