Abstract:
This thesis presented the design of a small electric vehicle for the elderly. The design concept focused on the design of the brushless DC motor (BLDC) drive system and the electrical control system for an electric vehicle. The thesis aimed to study the electrical behavior of the system determined by the driving simulation of the elderly driving behavior model and the traffic regulation in urban areas. Moreover, it aimed to find out the efficiency of the small electric vehicle for the elderly.
Regarding the driving behavior and the traffic regulations, vehicle dynamics was considered for selecting the rated power of the BLDC motor. The rated power at 1.5 kW/3kWp with a 48 V, 30 Ah battery was selected. The BLDC motor speed was adjusted with the DC bus voltage of the inverter. The driving test simulator with traffic constraints was then simulated using MATLAB & Simulink software.
The simulators showed that the maximum speed of the electric vehicle with the motor output power of 1.74 kW on a horizontal road was at 39.3 km/h. The maximum distance was 28 km when the state of the battery was decreased to 80%. In addition, the electric vehicle could climb up a 4 percent slope an angle of 2.29 degrees with the motor output power of 2.96 kW at a constant speed of 30 km/h. When going over a 45-degree speed hump, the motor output power was at 3 kW and the torque was at 10.5 Nm. According to the aerodynamic test with the wind speed of 1.6 km/h, the motor output power of the vehicle was at 2.68 kW with the torque of 6.8 Nm at a constant speed of 39.3 km/h. The results indicated that the design of the drive system and the battery capability were appropriate for the range. Finally, it could be concluded that the design and the construction of the small electric vehicle drive system had the efficiency and the possibility for further implementation.