Servo drive, also known as "servo amplifier", "servo controller" is used to control the servo motor is a controller, part of the servo system, its role is similar to the inverter acting on the ordinary AC motor, mainly used in high Precision positioning system. Generally through the position, speed and torque of the three ways to control the servo motor to achieve high-precision transmission system positioning, and now is the transmission technology of high-end products. Servo drives are widely used in the field of injection molding machines, textile machinery and other fields.

At present, the mainstream servo drives adopt the digital signal processor (DSP) as the control core, can realize the complicated control algorithm, realize the digitization, the network and the intelligence. Power devices generally use intelligent power module (IPM) as the core design of the drive circuit, IPM internal integrated drive circuit, with over voltage, over current, overheating, undervoltage and other fault detection protection circuit, the main circuit is also added soft Start the circuit to reduce the impact of the boot process on the drive. Power drive unit first through the three-phase full-bridge rectifier circuit input of the three-phase power or electricity to rectify, get the corresponding DC. After a good three-phase rectifier or electricity, and then through the three-phase sinusoidal PWM voltage inverter inverter to drive three-phase permanent magnet synchronous AC servo motor. The whole process of the power drive unit can be simply a process of AC-DC-AC. Rectifier unit (AC-DC) The main topology circuit is a three-phase full-bridge uncontrolled rectifier circuit.

With the large-scale application of servo system, servo drive use, servo drive commissioning, servo drive maintenance are servo drives in today's more important technical issues, more and more industrial technology service providers on the servo drive technology in-depth study.

Servo feed system requirements

1, wide speed range

2, high positioning accuracy

3, there is sufficient transmission rigidity and high speed stability

4, fast response, no overshoot

In order to ensure the productivity and processing quality, in addition to the requirements of a higher positioning accuracy, but also requires a good fast response characteristics, that requires tracking the signal response to the signal faster, because the NC system in the start, brake, The acceleration is large enough to shorten the transition time of the feed system and reduce the contour transition error.

5, low-speed large torque, overload capacity

In general, the servo drive has a load of 1.5 times or more in minutes or even half an hour, and can be overloaded for 4 to 6 times without damage in a short period of time.

6, high reliability

Requirements of CNC machine tool feed drive system reliability, work stability, and has a strong temperature, humidity, vibration and other environmental adaptability and strong anti-interference ability.

Requirements for motors

1, from the lowest speed to the highest speed motor can run smoothly, torque fluctuations to be small, especially at low speeds such as 0.1r / min or lower speed, there is still a smooth speed without crawling phenomenon.

2, the motor should have a large long time overload capacity to meet the requirements of low speed large torque. General DC servo motor requirements in a few minutes overload 4 to 6 times without damage.

3, in order to meet the requirements of rapid response, the motor should have a small moment of inertia and large stall torque, and has as little time constant and start voltage.

4, the motor should be able to withstand frequent Kai, brake and contrarotation.