The composition of electric vehicles includes: Power Drive and control system, driving power transmission and other mechanical systems, the completion of the task of working devices. Electric power Drive and control system is the core of electric vehicle, and it is also the biggest difference from internal combustion engine car. The Power drive and control system is composed of a drive motor, a power supply and a motor speed control device. Other devices in electric vehicles are basically the same as those of internal combustion engines.
The power supply provides electrical energy for the electric motorcycle's drive motor, which converts the electrical energy of the power supply into mechanical energy, through a transmission device or a direct drive wheel and working device. At present, the most widely used electric power is lead-acid battery, but with the development of the electric vehicle technology, lead-acid battery has been replaced by other batteries because of its low energy, slow charging speed and short life. The main power sources are sodium-sulfur batteries, Ni-CD batteries, lithium batteries, fuel cells, flywheel batteries, and so on, the application of these new power supply for the development of electric vehicles opened up a broad prospect.
The function of the driving motor is to convert the electrical energy of the power supply into mechanical energy, through a transmission device or a direct drive wheel and working device. At present, the electric vehicle is widely used in DC series motor, the motor has a "soft" mechanical characteristics, and the car's driving characteristics are very consistent. But DC motor because of the existence of reversing Spark, less power, lower efficiency, maintenance workload, with the development of motor technology and motor control technology, will gradually be the DC brushless motor (BCDM), switched reluctance Motor (SRM) and AC asynchronous motor to replace.