power supply
The power source supplies electrical energy to the drive motor of the electric motorcycle, which converts the electrical energy of the power source into mechanical energy, through the transmission or directly drives the wheels and working devices. Today, the most widely used power source for electric vehicles is lead-acid batteries. However, with the development of electric vehicle technology, lead-acid batteries are gradually replaced by other batteries because of lower specific energy, slower charging speed and shorter life. The application of new power sources is being developed, opening up broad prospects for the development of electric vehicles.
Drive motor
The function of the drive motor is to convert the electrical energy of the power source into mechanical energy, through the transmission or directly drive the wheel and the working device. DC series motors are widely used in today's electric vehicles. These motors have "soft" mechanical characteristics that closely match the driving characteristics of the car. However, due to the existence of reversing sparks, DC motors have lower specific power, lower efficiency, and large maintenance workload. With the development of motor technology and motor control technology, DC brushless motors (BCDM) and switched reluctance motors are bound to be gradually adopted. (SRM) and AC asynchronous motor replaced.
Motor speed control device
The motor speed control device is provided for shifting and direction change of the electric vehicle, and functions to control the voltage or current of the motor to complete the control of the driving torque and the rotation direction of the motor.
In previous electric vehicles, the speed regulation of the DC motor was achieved by using a series resistor or changing the number of turns of the motor field coil. Because the speed regulation is stepped, and the additional energy consumption or the structure of the motor is complicated, it is rarely used today. Today's electric vehicles are widely used in thyristor chopper speed regulation. By uniformly changing the terminal voltage of the motor and controlling the current of the motor, the stepless speed regulation of the motor is realized. In the continuous development of electronic power technology, it has gradually been replaced by other power transistors (into GTO, MOSFET, BTR and IGBT, etc.) chopper speed control devices. From the perspective of the development of technology, with the application of new drive motors, the application of the speed control of electric vehicles to the application of DC inverter technology will become an inevitable trend.
In the rotary direction control of the drive motor, the DC motor relies on the contactor to change the direction of the current of the armature or the magnetic field, thereby realizing the direction change of the motor, which makes the hole-ha circuit complicated and reliable. When driven by an AC asynchronous motor, the change of the steering of the motor only needs to change the phase sequence of the three-phase current of the magnetic field, so that the control circuit can be simplified. In addition, the AC motor and its variable frequency speed control technology make the braking energy recovery control of the electric vehicle more convenient and the control circuit is simpler.
Traveling device
The function of the traveling device is to drive the driving torque of the electric motor to the ground through the wheel and drive the wheel to travel. It is identical to the composition of other cars and consists of wheels, tires and suspensions.