DC motor is a machine that converts mechanical energy into DC energy. It is mainly used as DC motor for DC motor, electrolysis, electroplating, electric smelting, charging and excitation power supply of alternator. Although in places where direct current is needed, power rectifier elements are also used to convert alternating current into direct current, but from some aspects of working performance, the alternating current rectifier power supply can not completely replace the direct current generator.
A rotating device that converts direct current electrical energy into mechanical energy. The motor stator provides magnetic field, the DC power supply provides current to the rotor winding, and the commutator keeps the direction of the rotor current and the torque generated by the magnetic field unchanged. According to whether there is a common brush commutator, DC motor can be divided into two categories, including the brush DC motor and the brushless DC motor.
In recent years, with the development of microprocessor technology and the application of new power electronic devices with high switching frequency and low power consumption, as well as the optimization of control methods and the emergence of permanent magnet materials with low cost and high magnetic energy level, BLDCM has developed into a new type of DC motor. The BLDCM not only keeps the good speed regulation performance of the traditional DC motor, but also has the advantages of no sliding contact and reversing spark, high reliability, long service life and low noise, so it has been widely used in aerospace, CNC machine tools, robots, electric vehicles, computer peripherals and household appliances.
According to different power supply modes, BLDCM can be divided into two categories: square wave BLDCM, whose back EMF waveform and power supply current waveform are rectangular wave, also known as rectangular wave permanent magnet synchronous motor; sine wave BLDCM, whose back EMF waveform and power supply current waveform are sine wave.