来源：http://www.jnmcd.com 发布时间：2019-01-31 浏览：次
无刷直流电机由电动机主体和驱动器组成，是一种典型的机电一体化产品。 电动机的定子绕组多做成三相对称星形接法，同三相异步电动机十分相似。电动机的转子上粘有已充磁的永磁体 ，为了检测电动机转子的极性，在电动机内装有位置传感器。驱动器由功率电子器件和集成电路等构成，其功能是：接受电动机的启动、停止、制动信号，以控制电动机的启动、停止和制动；接受位置传感器信号和正反转信号，用来控制逆变桥各功率管的通断，产生连续转矩；接受速度指令和速度反馈信号，用来控制和调整转速；提供保护和显示等等。
Brushless DC motor (BLDCM) is a typical mechatronics product, which consists of motor main body and driver. The stator windings of the motor are mostly made into three-phase symmetrical star connection, which is very similar to the three-phase asynchronous motor. 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; to receive the position sensor signals and the positive and negative rotation signals to control the switching on and off of the power transistors of the inverting bridge and to generate continuous torque; to receive speed instructions and speed feedback signals for control and adjustment. Speed; Provide protection and display, etc.
DC motor has fast response, large starting torque, and can provide rated torque from zero to rated speed. But the advantage of DC motor is just its disadvantage. For DC motor to produce constant torque performance under rated load, the armature magnetic field and rotor magnetic field must be maintained at 90 degrees, which needs carbon brush and rectifier.
Carbon brushes and rectifiers produce sparks and powders when the motor rotates. Therefore, in addition to causing damage to components, their use is limited. AC motors have no carbon brushes and rectifiers. They are maintenance-free, robust and widely used. However, complex control techniques are needed to achieve the performance equivalent to that of DC motors. Nowadays, with the rapid development of semiconductor, the switching frequency of power components has been accelerated a lot, which improves the performance of driving motors. The speed of microprocessor is also faster and faster. It can put AC motor control in a rotating two-axis rectangular coordinate system and properly control the current component of AC motor in two axes, so as to achieve the control of similar DC motor and have the same performance as DC motor.
In addition, many microprocessors have made the necessary functions of controlling motors into chips, and the volume is becoming smaller and smaller, such as analog-to-digital converter, pulse width modulation, and so on. Brushless DC motor is an application that controls the commutation of AC motor electronically and obtains the similar characteristics of DC motor without the absence of DC motor mechanism.