Full Digital Ac Servo Motor Drive Developed

Together with the high-speed development of the microprocessor,power electronics and permanent magnet material manufacturing techniques,the AC servo systems using permanent magnet synchronal motor have beenwidely used in the motion control and drive field, therefore, it is quiteimportant to study and develop AC servo system with high performance andhigh reliability.First of all, this paper presented the development survey of AC servosystem, analyzed the structure character of PMSM, illustrated itsmathematical models, studied the theory of vector control on PMSM furtherdeeply, and then developed a kind of control scheme of the full digital ACservo system.As for hardware, TMS320LF2407A is used as the core of the controlunit. The power circuit makes the intelligent power module (IPM) PS21564for the AC-DC-AC voltage inverter. According to the character of DSP andIPM, current collection circuit, velocity/ position collection circuit, digit toanalog circuit and protection circuit were designed. So a universal hardwareplatform for experiment of AC motors was finished.As for software, the control algorithm of PMSM was implemented byDSP program. It adopted the i_d=0 vector control method to realize thedecoupling control of PMSM. The general PI control method was used inthe position and current loop, a kind of fuzzy PI control method was used inthe speed loop, and SVPWM modulation was used in the inverter.Furthermore, in order to satisfy the requirement of convenient operation andmonitoring, an operation panel and two communication interfaces weredesigned, and the monitor program on PC is also presented. At last, both hardware and software were debugged carefully, thenseveral experiments were conducted and the results were analyzedaccordingly. The results of experiments show that the design of the fullydigital driver of PMSM is reasonable, performance is reliable, and has goodapplication prospect.