1、 Background information on brushless DC motors: The stator windings of brushless DC motors are mostly made into three-phase symmetrical star connections, which are very similar to three-phase asynchronous brushless DC motors. The rotor of a brushless DC motor is adhered with a magnetized permanent magnet. In order to detect the polarity of the rotor of the brushless DC motor, a position sensor is installed inside the motor. The driver is composed of power electronic devices and integrated circuits, and its function is to receive the start, stop, and brake signals of the brushless DC motor to control the start, stop, and brake of the brushless DC motor; Receive position sensor signals and forward and reverse signals to control the on/off of each power transistor in the inverter bridge, generating continuous torque; Receive speed commands and speed feedback signals to control and adjust the speed; Provide protection and display, etc. In the past thirty years, research on variable frequency speed regulation of asynchronous brushless DC motors has ultimately been focused on finding methods to control the torque of asynchronous brushless DC motors. Rare earth permanent magnet brushless DC motors will undoubtedly demonstrate advantages in the field of speed regulation due to their wide speed regulation, small size, high efficiency, and small steady-state speed error. Brushless DC motor, also known as DC variable frequency, has the characteristics of a DC brushless motor and is also a frequency changing device. It is commonly referred to as BLDC internationally. The operating efficiency, low-speed torque, and speed accuracy of brushless DC motors are better than any control technology of frequency converters, so they are worthy of industry attention. Although the development time of brushless DC motors in China is short, they have developed rapidly with the increasing maturity and improvement of technology. It has been widely applied in various fields such as aviation models, medical devices, household appliances, electric vehicles, and has formed a small-scale industrial chain in Shenzhen, Changsha, Shanghai, and other places. A group of professional manufacturers such as Shenzhen Weiye Motor and Changsha Keda are continuously promoting industry development in terms of technology. In recent years, brushless DC motors have become a rapidly developing driving force in the field of modeling. Due to production and price reasons, brushless DC motors have been mostly used in mid to high-end aviation models in the past few years. Now, due to the rapid development of mechanical processing technology, the production cost of brushless DC motors has decreased significantly. Currently, it is entering various levels of the modeling field, from electric remote-controlled vehicles to electric remote-controlled ships to electric model aircraft, everywhere. 2、 In terms of structural analysis of brushless DC motor, there are similarities between brushless DC motor and brushless motor, as well as rotor and stator, but the structure is opposite to that of brushless motor; The rotor of a brush motor is a coil winding, connected to the power output shaft, and the stator is made of permanent magnet steel; The rotor of a brushless DC motor is made of permanent magnet steel, which is connected to the output shaft along with the casing. The stator is a winding coil, and the commutation brush used by the brushless motor to alternately transform the electromagnetic field is removed. Therefore, it is called a brushless DC motor. Now, there is a problem. How can a brushless DC motor rotate without the transformation of the electromagnetic field?3、 In simple terms, the operating principle of a brushless DC motor is that by changing the alternating frequency and waveform of the current wave input to the stator coil of the brushless DC motor, a magnetic field that rotates around the geometric axis of the motor is formed around the winding coil. This magnetic field drives the permanent magnet steel on the rotor to rotate, causing the motor to rotate. The performance of the motor is related to factors such as the number of magnetic steel, magnetic flux strength of the magnetic steel, and input voltage of the motor, It is also closely related to the control performance of brushless DC motors, as the input is DC, and the current needs to be converted into 3 alternating currents by an electronic governor. It also needs to receive control signals from the remote control receiver to control the motor speed to meet the needs of model use. Overall, the structure of a brushless DC motor is relatively simple, and the real determinant of its performance is the brushless electronic governor. A good electronic governor requires overall control of processes such as microcontroller control program design, circuit design, and complex processing technology, so the price is much higher than that of a brushless motor.