Driver Design Of Permanent Magnet Synchronous Motor In Knitting Machine

Permanent magnet synchronous motor(PMSM) has its outstanding performance compared with other motors. So it is used so widely in every field of industry, especially in high precision servo system. And rare earth which consists the permanent magnet is so rich in our country that it is every important for us to do research in controlling of PMSM. This paper based on knitting machine system and designed a driver of PMSM based on single chip microcomputer. By reading so many datum and document and fully understanding of PMSM controlling technique and actuality, this paper established model of PMSM, and analysed all kinds of features of controlling strategy. The simplest vector control strategy, namely, Id=0 control strategy, was presented. According to the performance requirements of the servo-system in rapid reaction performance, high precision and high stability, a closed-loop control structure that includes three closed-loops: position closed-loop, speed closed-loop and current closed-loop was adopted. Among these control loops, the position control is in the most external. Taking the rapidity of position servo-control into account, a proportion regulator in the position closed-loop was designed. And PI regulator was adopted in the speed closed-loop and the current closed-loop to enhance the fine stability and the rapid reaction performance. The high-precision resolver was connected to PMSM with the same shaft to detect the position and speed of PMSM, and Hall current sensor was adopted to detect current of PMSM. They all had high detection precision. According to the control strategy and the total control method presented, the hardware and software of the whole system were designed. Based on the requirements of driver system, an experiments was done upon the hardware and software. The datum of experiment verified that the driver designed satisfied.