The  choice of the type of motor vehicle in the elderly should take into  account the economic factors such as the technical requirements of the  old scooter, the performance of the motor, the weight, the volume and  other technical factors and the cost. For  older scooters, the efficiency of driving the motor is particularly  important because all the power of the scooter is driven by the motor to  the wheel. Determine  the motor characteristics of the parameters based on the vehicle to  meet the maximum load when driving the continuous power requirements,  but also to meet the vehicle to the maximum peak torque to accelerate or  climbing requirements, continuous power refers to the motor stable  operation of the output power The
The  basic requirements for driving motor performance are: large enough  starting torque to meet the old truck scooter quick start, acceleration,  climbing, frequent Kai, stop the requirements; motor speed range is  small, generally 25% to 100% The  maximum speed range, the approximate small torque, constant power  output characteristics, to meet the requirements of the oldest scooter  maximum speed driving conditions; greater than the power (specific power  is defined as the maximum power per unit mass), the maximum power The (1  ~ 1.25) kW / kg or more; fast torque response characteristics, in a  variety of speed range can quickly and softly control the drive and  braking torque, requiring high controllable motor, steady-state accuracy  and dynamic Good  performance; with good environmental adaptability, in different working  conditions can work reliably; maintenance is simple, low noise. Brushless  DC motor is characterized by permanent magnet and excitation winding,  permanent magnet is usually embedded in the rotor, the excitation  winding fixed on the stator, by adjusting the excitation current control  air gap flux, it can be convenient in the high-speed area Weak magnetic adjustment, improve the motor drive characteristics. At  the same time, the brushless DC motor uses the discrete rotor position  feedback signal to control the commutation and uses the AC square wave  to supply the power, because the square wave magnetic field and the  square wave current interaction produces the torque larger than the sine  wave. Therefore,  the permanent magnet brushless motor has the advantages of high torque,  high power density, simple position detection and control method, and  high efficiency.