The frequency converter of engraving machine generally consists of four parts: rectifier, intermediate dc link, inverter and control. Due to its unique and super performance, the frequency converter can meet the requirements of the spindle for its wide speed adjustment range, high speed stability, strong overload capacity, high low-speed torque, short acceleration and deceleration time and other performance characteristics, occupying a considerable market share in the engraving machine market. Among them, the low-power non-inductance vector frequency converter, which is small in size and cost-effective, is mainly used in the engraving machine system whose spindle power is lower than 3.7kw. General purpose frequency converter and high frequency converter are suitable for high-power spindle with high power and stable torque during cutting. They are widely used in engraving machine and engraving and milling machine systems of 5.5KW and above.

The spindle system is an important component of the engraving machine, and its performance has a crucial influence on the performance of the whole CNC engraving machine. Numerical control engraving machine requires the spindle system to adopt stepless speed change. At present, it mostly USES frequency converter to drive asynchronous ac motor. The main shaft motor adopts the high-speed brushless water-cooled motor at both poles, with small noise and strong cutting force. The operating speed is generally 0 ~ 24000r/min, and the corresponding frequency of converter is 0 ~ 400Hz. In order to improve the machining efficiency, the large carving machine is equipped with multiple spindle heads. Therefore, multiple frequency converters are needed to drive multiple spindle motors at the same time.