In the application of automation equipment, the speed adjustment of the load is a common topic. In traditional applications, where the speed adjustment accuracy is relatively high, AC servo motors are generally used to achieve it. In some occasions with low speed, the step It is also a good option to adjust the speed of the motor. However, with the development of brushless DC technology, the speed of brushless motor has become a trend to replace the speed of servo motor and stepper motor. The main reasons are as follows: 1. Brushless DC Although the motor has no code disk and only three Halls are used as feedback, with the development of FOC control technology, the speed change rate of the DC brushless motor under load can already reach a level lower than 0.5%. In terms of accuracy, it is close to the level of the servo motor;
2.The speed regulation unit formed by DC brushless motor + DC brushless motor driver is only about half of the servo motor in cost, which has a natural cost-effective advantage;
3. With the development of control technology, the brushless motor speed control system has added more control functions than servo motors, which makes customers get more technical support in applications and lower costs;
4.Compared with the traditional AC variable frequency speed regulation, the accuracy of brushless motor speed regulation is high, the unit size is small, there are many control methods, there are many ways such as analog quantity, frequency speed regulation, pulse width speed regulation, bus control, etc. The speed ratio range is much higher than the combination of AC motor and inverter, but the current brushless speed regulation is still limited to the range of lower power.The main reason is that the production of DC brushless motors is still based on low power. DC brushless motors above W are already considered very large. At least the situation in China is at present.