Researches On Industrial Sewing Machine AC Servo System

With the development of the apparel industry, apparel manufacturing is increasingly complex and requires high production efficiency, so traditional industrial sewing machine has been unable to meet its development needs. At present, microelectronic devices, power electronic devices, computer technology and control technology are developing rapidly, as well as rare earth magnetic materials and manufacturing technology are improved highly, which provide technical support and material basis for power electronic converters-AC permanent magnet synchronous motor servo system. On this basis, the industrial sewing machine intelligent servo system has so many advantages as low noise, high efficiency, accurate positioning and intelligent operation and improves the economic benefits of the apparel industry. Considering this, the project of industrial sewing machine AC PMSM servo control system is taken for the study contents listed as following:According to the modern theme of energy-saving and environmental protection, the permanent magnet synchronous motor drive technology, power electronics transform technology, automatic control technology were analyzed and summarized. In addition, industrial sewing machines on the system structure, function, sewing technology, electrical part were reviewed and discussed. AC servo control system theoretically is analyzed, including traditional SVPWM and non-zero vector SVPWM (that is, minimum common-mode voltage modulation algorithm), PMSM motor vector control algorithm and incremental PI regulator. System simulation model by MATLAB/SIMULINK are also built up, which laid a good foundation for later experimental designing.AC servo control system hardware was designed, including power circuit, the control circuit, as well as serial communications circuits. Power circuit included power rectifier circuit, a bootstrap inverter driven circuit with IRAMX16UP60A, pulse coder circuit, and so on. And control circuit included SPI communications circuits, DSP TMS320F2801, IRMCK201 and its peripheral circuits. By taking cost and EMC into account, PCBs and schematics were drawn. AC servo control system software were programmed and debugged in C and assembler language, Including software design objectives and arrangements of routine structure. Subroutine modules were as follows: the position control module PI subroutine, SPI communications subroutine, A/D testing subroutine, man-machine interface subprogram, and fault handling subroutine.AC servo control system was tested, including hardware and software. A lot of problems were encountered during system debugging, such as PID control parameters matching problem, communication procedures, software Anti-jittering etc. However, after repeated experimenting and researching, these difficulties have been resolved successfully. Finally a 500W industrial sewing machine PMSM AC servo control system was implemented, and a great number of experimental results were achieved.According to high-end industrial sewing machine intelligent servo system, it requires a high input power factor. On the analysis basis of standard IEC61000-3-2 and existing single-phase AC/DC converter power factor correction technologies, a power factor corrector (PFC) was designed to improve the input power factor for AC servo control system. As a result, a one cycle control (OCC) control technology was analyzed for the power factor correction with 750W output power, which was designed and implemented with IR1150 hereafter, which was dedicated for the servo system.