In the process of industrial development, the emergence of the motor can be said to be the revolutionary achievements, because of the motor drive is the foundation of industrial development, the dc motor is the most frequently used, a dc motor is dc to dc motor, dc motor of the electric energy into mechanical energy. In dc motor, depending on the field winding connection mode can be divided into separately excited, shunt, series and compound four types of motors, and in the speed control system with the most is separately excited motor. In recent years, our country small and medium-sized motor and micro &special motor industry is developing rapidly, the brushless dc motor with its characteristics of high efficiency low noise gradually replace brush motor, become a new star of industry applications. This, in China's leading outsourcing service platform has a more prominent reflect fast. It is understood that the fast packet + motor control task, brushless motor with % accounted for more than a near monopoly platform of motor control task requirements. Knowledge dc motor can be classified into several categories: compound dc motor, series dc motor, shunt dc motor, separately excited dc motor. Knowledge and the widely use of brushless dc motor is developed on the basis of dc motor, the traditional dc motor developed on the basis of the permanent magnet brushless dc motor, the structure of the basic are the same, different is the permanent magnet brushless dc motor armature winding on the stator, which is similar to the ac motor winding, generally takes the form of multiphase, at the same time, the current situation of the application of three-phase most; The rotor of permanent magnet, and USES the electronic commutation, the interaction between the stator magnetic field with permanent magnet rotor magnetic field produces electromagnetic torque. Permanent magnet brushless dc motor based on the shape of the permanent magnet and the magnetic circuit structure is different, the air-gap magnetic field waveform three square wave, trapezoidal wave, sine wave, the back emf waveform corresponding to the same. Knowledge point the difference between the brushless dc motor and stepping motor. Stepper motor is the electrical pulse signal into angular displacement or linear displacement of open loop control stepping motor. In the case of the overload, motor speed, stop position depends only on the pulse signal frequency and pulse number, and not affected by load change. Brushless dc motor is a kind of high performance motor, its the biggest characteristic is the external characteristic of dc motor without brush of the structure of the mechanical contact, it USES the permanent magnet rotor, no excitation loss, fever and installed on the outside of the stator, armature winding heat easily. Difference between the two is as follows: a, the different control precision based on the driving principle is different, so the general brushless dc motor is used to control the accuracy is not high, stepper motor is used to control the accuracy is higher. Different brushless dc motor, drive principle and principle of stepper motor driver is different, inductive brushless dc motor is provided by hall element positioning alternating power control. Stepper motor is driven by single pulse voltage directly, don't need a hall element, can be added to the motor by controlling the number of pulses to precise positioning rotation Angle; , different brushless dc motor speed higher than the speed of the stepper motor; Knowledge of the brushless dc motor using range: electric cars, household appliances, industrial equipment, medical equipment, automobile motor drive the main trend of the market: the biggest trend in the field of motor drive and control is to adopt the brushless direct current (刷)The control of the motor and drive them. In the presence of the motor and contribution to the development of course is needless to say too much, after all, as a strong support of industrial development, motor for many industrial related aspects of modern plays a decisive role.
