Research On High Performance AC Variable Frequency Device For CNC Spindle

Numerical control technology, numerical control equipment is the important basis of manufacturing industry modernization, directly related to the country’s national comprehensive power and economic development, having respect to C hina’s strategic economic status. N umerical control system, as the kernel part of NC machine tool, which is composed of machine tool body and numerical control system, is a key factor in function, reliability, performance and cost of the machine tool. Moreover, the spindle shaft driving control system is the key part of the numerical control system, whose performance directly affects the machining efficiency, processing material range and processing quality. Modern CNC machine tool with high performance spindle drive system is mainly used in three-phase AC asynchronous motor as the main engine, though AC asynchronous motor is a high order, strong coupling, nonlinear multivariable object, many frequency conversion device manufacturers spend lots of energy and talents on the research and control of it.On the basis of analyzing AC speed regulation and current situation and development trend of its related technologies, also the theoretical knowledge of the mathematical model and coordinate transformation of the asynchronous motor, analyze the speed control mode of asynchronous motor and select the vector control strategy, Then, through the coordinate transformation, the asynchronous motor is equivalent to the DC motor. Realize the control of decoupling and design out the general scheme of the vector control system of AC asynchronous motorStudy the way to realize the hardware circuit design and related control program of vector control system. this paper mainly introduces the design of the spindle control frequency conversion system with TMS320F2812 as the main controller, including the hardware part of the frequency conversion device, mostly the design of these circuit, such as the main power circuit, signal acquisition circuit, control board circuit, panel circuit, switching power supply circuit and so on. In the aspects of software design, analyze the general flow of the software and the communication between the panel and the control panel, further to verify the correctness and rationality of the design of the device with plate, welding, debugging, experimental testing including motor no- load test, on the hardware of the control system, and evaluate the performance of the device. Finally, this paper makes a summary on the research work, analyze and forecast the future research work.