The stator winding of motor is usually made into three-phase symmetrical star connection, which is very similar to three-phase asynchronous motor. The rotor of the motor is attached with a magnetized permanent magnet. In order to detect the polarity of the motor rotor, a position sensor is installed in the motor.
The driver is composed of power electronic devices and integrated circuits. Its functions are: to receive the starting, stopping and braking signals of the motor to control the starting, stopping and braking of the motor; Receive the position sensor signal and the forward and reverse signals, which are used to control the on-off of each power tube of the inverter bridge to generate continuous torque; Receive speed command and speed feedback signal to control and adjust speed; Provide protection, display, etc.
In the last three decades, the research on variable frequency speed regulation of asynchronous motor is to find a way to control the torque of asynchronous motor in the final analysis. Rare earth permanent magnet brushless DC motor will show its advantages in the speed regulation field with its wide speed regulation, small size, high efficiency and small steady-state speed error.
Brushless DC motor is also called DC frequency conversion because it has the characteristics of DC brushless motor and is also a device for frequency change. The international term is BLDC. The operation efficiency, low speed torque, speed accuracy, etc. of brushless DC motor are better than the frequency converter of any control technology, so it deserves the attention of the industry.
Although the development time of brushless motor in China is short, it has developed rapidly with the increasingly mature and perfect technology. It has been widely used in many fields, such as aircraft models, medical devices, household appliances, electric vehicles, etc., and has formed a large-scale industrial chain in Shenzhen, Changsha, Shanghai, etc. For example, a group of professional manufacturers such as Shenzhen Weiye Motor and Changsha Keda have continuously promoted the development of the industry in technology.
In recent years, brushless motor has become a driving force for rapid development in the field of modeling. Due to the output and price, brushless motors have been mostly used in medium and high-end aviation models in the past few years. Now, due to the rapid development of machining technology, the production cost of brushless motors has dropped a lot. At present, it is entering all levels of the model field, from electric remote control vehicles to electric remote control ships to electric model aircraft, everywhere.