A servo drive is a controller used to control servo motors, similar to a frequency converter for ordinary AC motors. It is part of a servo system and is primarily used in high-precision positioning systems. This article focuses on the function of servo drives and the differences between servo drives and frequency converters.
The role of servo drivers
Servo motor controllers are key components in CNC systems and other related mechanical control fields. They control servo motors through position, speed, and torque to achieve high-precision positioning of transmission systems. As part of a servo system, they are primarily used in high-precision positioning systems.
Mainstream servo drives all use digital signal processors (DSPs) as the control core, which can implement relatively complex control algorithms, achieving digitalization, networking, and intelligence. Power devices generally adopt drive circuits designed around intelligent power modules (IPMs). The IPM integrates the drive circuit and also has fault detection and protection circuits for overvoltage, overcurrent, overheating, and undervoltage.
Servo drives are a crucial component of motion control and are widely used in automated equipment such as industrial robots and CNC machining centers. In particular, servo drives for controlling AC permanent magnet synchronous motors have become a research hotspot both domestically and internationally. Servo drive designs commonly employ a three-loop control algorithm based on vector control, encompassing current, speed, and position.
Difference between servo drives and frequency converters
Servo drives and frequency converters have different definitions
A driver, also known as a servo controller or servo amplifier, is a controller used to control servo motors, functioning similarly to a frequency converter for ordinary AC motors. It is part of a servo system and is primarily used in high-precision positioning systems.
A frequency converter is a power control device that uses the switching function of power semiconductor devices to convert mains frequency power into another frequency. It enables functions such as soft starting of AC asynchronous motors, variable frequency speed regulation, improved operating accuracy, and modification of the power factor.
Servo drives and frequency converters have different overload capabilities.
Generally, the drive has a 3x overload capacity, which can be used to overcome the inertial moment of the inertial load during startup, while the frequency converter generally allows a 1.5x overload.
Servo drives and frequency converters have different control precision.
The control precision of a drive is much higher than that of a frequency converter. Typically, the control precision of a drive motor is guaranteed by a rotary encoder at the rear end of the motor shaft, and some transmission systems even have a control precision as high as 1:1000.
Servo drives and frequency converters have different applications.
Variable frequency drives (VFDs) and drives are two types of control systems; the former belongs to the field of transmission control, while the latter belongs to the field of motion control. One type aims to meet the requirements of general industrial applications, prioritizing low cost and low performance in demanding scenarios. The other type seeks high precision, high performance, and high response.
This article focuses on the role of servo drives and the differences between them and frequency converters. As you can see, servo drives play a significant role and are widely used in automated equipment such as industrial robots and CNC machining centers. Further in-depth understanding of servo drives requires reading more resources.
