Research On AC Variable Frequency Drive Technology Of Machine Tool Spindle

As the basis of mechanical equipment, CNC machine represent the level of a country’s machinery manufacturing. Spindle drive is one of the key components of CNC machine. This paper studies the spindle drive technology.After review the spindle drive technology, discussed the requirement of spindle motor driving control. And on this basis, refines three scientific problems: rotor flux observation,closed-loop flux-weakening and current decoupling. Select current model as the basis, after analysis the mechanism of the observation error, propose the flux oriented correction method to improve the accuracy of the flux orientation.With the target of maximum torque output to assignment of magnetizing current and torque current, propose closed-loop flux weakening scheme using the reference voltage. In terms of current decoupling, using PI parameter to instead the coupling term.In this paper, Matlab / Simulink has been used to design a simulation model of the spindle drive system. Simulation research is carried out on the simulation platform, including double closed-loop system operation and rotor flux observation,closed-loop flux-weakening, current decoupling simulation. The establishment of the simulation model and the simulation experiment are discussed in detail.On the basis of theoretical analysis and simulation research, this paper designed a spindle AC motor drive devices for the laboratory prototype. Design hardware and software of the control board with TMS320F2812 as controller and design panel hardware with ATmega32A-AVR as control chip. The inverter hardware prototype consist of the transducer power board by a Frequency converter product. Develop embedded software for the hardware and build this experimental platform finally. On this platform, lots of experiment has been designed,such as the current closed-loop experiment, current and speed double closed loop experiment, flux observation experiment, closed-loop flux-weakening experiment and so on. In this paper, the experimental equipment, experimental parameters, experimental scheme, experimental process and experimental results are introduced in detail.