At present, most servo drivers use digital signal processor (DSP) as the control core, which can achieve more complex control algorithm, digitalization, networking and intellectualization. The drive circuit based on intelligent power module (IPM) is widely used in power devices. IPM has integrated drive circuit, fault detection and protection circuit for over-voltage, over-current, overheat and under-voltage, and soft-start circuit is added in the main circuit to reduce the impact of starting process on the driver. Firstly, the power driving unit rectifies the input three-phase or commercial power through the three-phase full bridge rectifier circuit to get the corresponding DC power. The three-phase permanent magnet synchronous AC servo motor is driven by three-phase sinusoidal PWM voltage source inverter. The whole process of power driving unit can be simply said as AC-DC-AC process. The main topology circuit of rectifier unit (AC-DC) is three-phase full bridge uncontrolled rectifier circuit.


With the large-scale application of servo system, the use, debugging, maintenance of servo driver are important topics in today's servo driver technology. More and more industrial control technology service providers have conducted in-depth research on servo driver technology.


Servo driver is an important part of modern motion control, which is widely used in industrial robots, CNC machining centers and other automation equipment. In particular, the servo driver used to control AC permanent magnet synchronous motor has become a hot topic at home and abroad. At present, the current, speed and position closed-loop control algorithm based on vector control is widely used in the design of AC servo driver. Whether the speed closed-loop design is reasonable or not plays a key role in the whole servo control system, especially in the performance of speed control.