Background and development of brushless motors.
The stator winding of an electric motor is often made into a three-phase symmetrical star connection, which is very similar to a three-phase induction motor. The rotor of the electric motor is coated with magnetized permanent magnets. In order to detect the polarity of the motor rotor, a position sensor is installed inside the motor. The driver is composed of power electronic devices and integrated circuits, and its functions are: to receive start, stop, and brake signals from the motor to control its start, stop, and brake; to receive position sensor signals and forward/reverse rotation signals to control the on/off state of each power transistor in the inverter bridge and generate continuous torque; to receive speed commands and speed feedback signals to control and adjust the speed; and to provide protection and display, etc.
Over the past three decades, research on variable frequency speed regulation for asynchronous motors has ultimately been aimed at finding methods to control the torque of asynchronous motors. Rare earth permanent magnet brushless DC motors are bound to demonstrate their advantages in the field of speed regulation due to their characteristics of wide speed regulation range, small size, high efficiency, and small steady-state speed error.
Brushless DC motors, due to their characteristics of DC brushed motors and their function as frequency-variable devices, are also known as DC inverters, with the internationally recognized term BLDC. The operational efficiency, low-speed torque, and speed accuracy of brushless DC motors surpass those of frequency converters using any control technology, making them worthy of industry attention.
Although brushless motors have only been developed in China for a short time, they have experienced rapid growth as technology has become increasingly mature and refined. They have been widely applied in various fields such as model airplanes, medical devices, household appliances, and electric vehicles, and have formed a preliminary industrial chain in places like Shenzhen, Changsha, and Shanghai. Professional manufacturers like Shenzhen TOPBAND MOTOR have continuously pushed forward technological advancements in the industry. In recent years, brushless motors have become a rapidly developing driving force in the model field. Due to production volume and price considerations, brushless motors were previously mainly used in mid-to-high-end model airplanes. However, with the rapid development of mechanical processing technology, the production cost of brushless motors has decreased significantly. Currently, they are entering various levels of the model field, from electric remote-controlled cars to electric remote-controlled boats and even electric model airplanes, making them ubiquitous.
