In CNC machine tools, electric spindles generally use variable frequency speed regulation. There are three main control methods: general variable frequency drive and control, vector control drive drive and control, and direct torque control. The general frequency conversion is scalar driving and control, and its driving control characteristic is constant torque driving, and the output power is proportional to the rotational speed. The dynamic function of the general frequency conversion control is not ambition, and the control function is unsatisfactory at low speed, the output power is not stable, and the C axis function is not available. However, the price is cheap and the structure is simple, and it is generally used for a grinding machine and a general high-speed milling machine. The vector control skills are modeled after the DC motor, oriented by the rotor field, and driven and manipulated using vector changes, with outstanding dynamics. The vector steering drive has a large torque value when it is just started. In addition, the electric spindle itself has a simple structure and a small inertia, so the acceleration is large, and the speed limit can be reached instantaneously after the launch. This kind of driver has two kinds of open loop and closed loop. The latter can complete the azimuth and speed feedback. It not only has better dynamic function, but also can complete the C axis function. The former has poor dynamic function and does not have C axis function. But the price is cheaper. Direct torque control is a new type of high-function communication speed control technology developed after vector control skills. Its control concept is novel, the system structure is simple and clear, it is more suitable for high-speed electric spindle drive, and it is more satisfied with high-speed electric spindle. High speed, wide speed range, high-speed instantaneous quasi-stop dynamic characteristics and static characteristics have become a hot skill in the field of communication transmission. Scope of application: granite, marble, bluestone, sandstone and other stone carvings, such as granite, hard stone can be carved to 5mm...
