Research On The Vector-control Converter Technology Of Textile Mchinery

With the quick development of the textile machinery industry, the level of electromechanical integration technology is constantly upgraded in the area of textile machinery. The traditional motor drive technology is replaced by the variable frequency drive system. AC motor is widely applied in this area. Three kinds of converters have been introduced such as V/F control converters, sensorless vector control converters and servo control converters. The research and development of this area appears to be never-ending. However, extensive research and efforts are needed in order to solve a lot of technical problems of the area. For example, Some problems of the control strategy and the hardware-designing should be study further. Therefore, some effective solutions are presented in this paper after many researches on the above problems.AC machine is a multi-variable, time-varying and high order strong coupling system. It is difficult to get high dynamic performance without the vector control strategy. In this paper, the fundamental principle—FOC vector control strategy ,coordinate transformation process of the vector control, AC motor modal and space vector PWM technology firstly are introduced in detail. And then the crucial technology of the closed loop of direct vector control based on the strategy of vector control is discussed. Finally In this paper, the important thing for controlling AC machine using FOC vector control stagey is discussed that how to get the accurate rotor flux. The accurate rotor flux is prerequisite for using the vector control successfully. Some methods to get the accurate rotor flux is also analyzed in this paper.The sensorless vector control converter based on MRAS,which is used widely in the area of textile machinery, is analyzed detailedly. Some problems of the above modal, including the DC initial values accumulation, error accumulation, the parameter of PI regulator determination, the complex of the structure、drift of the AC motor parameter and so on, are studied. Although some interesting methods are presented by the researchers, none of them can solve all above problems. In this paper two methods of improved speed modals and reconstructed speed modals is presented. The incremental speed modal based on MRAS is presented to solve the the DC initial values accumulation and error accumulation problems. However, the problems of the parameter of PI regulator determination and the complex of the structure are not solved because the PI regulator is contained in the above speed modal. Hence, a more promising speed modal named no speed-error direct calculate modal is presented to solve almost all problems involved in the MRAS model. The above point was approved by simulink experiments results. The above new modal is interfered by the drift of AC motor parameters because it contains the reference modal. It is important for the above modal to online identify the parameters of AC motor by the help of traditional Lupberger observer or Kerman filter.In theory, the above method based on MRAS can solve all the issues. But in fact, it is difficult to translate this method to DSP control system directly because there are some defects of large computational algorithm, complex structure and poor real-time characteristics in full-order/reduced-order observer or Kerman filter for online identification of parameters. If a new motor modal that is not sensitive or poor sensitive to the parameters can be found, the above problems will be solved. In this paper, a novel J-M transformation vector modal is proposed. The AC motor modal is converted to a serried excited DC motor modal through J-M coordinate transformation. After the fundamental principle and simulink experiments of J-M control strategy were studied in detail, some simulink experiments are established and the results show that the J-M control modal is not sensitive to the parameters. The close-loop control modal based on J-M strategy needs the rotor speed as feedback signal. More researches on the area are needed to combine J-M control strategy with sensorless vector control system. On the other side, the characteristics of the J-M transformation vector control modal is shown as soft feature of the series excited DC motor by applying different ways with the FOC vector control strategy. The previous control modal can not be applied to the above modal directly. Although some simulink experiments modals based on the J-M control strategy are established in this paper, it needs to do further research to apply the above strategy to the real system.The hardware designing and special functions of textile machinery of the converter is presented, including the inverter circuit, drive circuit, keyboard, display, DSP control circuit, voltage detection, current detection and over voltage, over current, over heat protection circuit, and special functions designing and so on. Finally, more research on the hardware and control strategy problems involved in the textile machinery need to do to design high performance textile converter.