The RBS described previously has been successfully type tested. In the real test system shown in Fig. 20, we use the
TMS320F2812 as the control chip, and the specifications of the motor are listed in Table II. As shown in Fig. 21, we can obtain different voltages for different PWM duties with the same speed. Therefore, at different speeds, we can adjust the PWM duty to obtain different voltages. In Fig. 21, we made the speed 60 km/h. Through adjusting the PWM duty, the dc bus voltage can reach and is even over the rated voltage. At the same time, when the speed is 30 km/h, 50% of the PWM duty can make the dc bus voltage reach the rated voltage, so we can adjust the PWM duty to 70% and the voltage rise as shown in Fig. 22. Fig. 23 shows the voltage, current, and speed wave forms at the breaking state. When the EV speed descends from 70 km/h to about 30 km/h, the dc bus voltage keeps a high value at the regenerative region. The EV will switch to mechanical braking if the speed is too low. At the same time, the dc current will descend to 0 when EV stops.