Description Of Brushless Motors

(BLDCM) is developed on the basis of brushless DC motors, but its driving current is AC to the letter; Brushless DC motors can also be divided into brushless speed motors and brushless torque motors. Generally, there are two types of driving currents for brushless motors, one is a trapezoidal wave (usually a "square wave"), and the other is a sine wave. Sometimes the former is called a DC brushless motor, while the latter is called an AC servo motor, specifically a type of AC servo motor.
Brushless DC motors usually adopt a "slender" structure to reduce rotational inertia. Brushless DC motors are much smaller in weight and volume than brushless DC motors, and the corresponding rotational inertia can be reduced by about 40-50%. Due to processing issues with permanent magnet materials, the general capacity of brushless DC motors is below 100kW.
This type of motor has good linearity in mechanical and regulatory characteristics, wide speed range, long service life, convenient maintenance, low noise, and no series of problems caused by brushes. Therefore, this type of motor has great potential for application in control systems.
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 asynchronous motor. The rotor of the electric motor is adhered with a magnetized permanent magnet, and 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 function is to receive the start, stop, and brake signals of the motor to control the start, stop, and brake of the 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.
Due to the self controlled operation of brushless DC motors, they do not add additional starting windings to the rotor like synchronous motors that start with heavy loads under variable frequency speed regulation, nor do they generate oscillations and out of step during sudden load changes.
The permanent magnets of small and medium-sized brushless DC motors often use high magnetic energy product rare earth neodymium iron boron (Nd Fe B) material. Therefore, the volume of rare earth permanent magnet brushless motors is reduced by one frame number compared to three-phase asynchronous motors of the same capacity.
In the past thirty years, research on variable frequency speed regulation of asynchronous motors has ultimately been focused on finding methods to control the torque of asynchronous motors. Rare earth permanent magnet brushless DC motors will undoubtedly show 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 due to its characteristics as a DC brushless motor and a frequency changing device, is internationally known as BLDC. The operating efficiency, low-speed torque, and speed accuracy of brushless DC motor are better than any control technology's frequency converter, so it is worth the industry's attention. This product has been produced over 55kW and can be designed up to 400kW, which can meet the needs of the industry for power saving and high-performance driving.