관측자를 이용한 영구자석형 동기모터의 저속영역 속도리플 개선

Generally, we often use a speed sensor based on a rotary encoder and we can obtain a speed information by counting the increased or decreased number of encoder pulses in a sampling period. However, these speed measurement systems do not inherently produce a true, instanta-neous speed information and then, the speed ripple is generated by speed measurement errors. In order to overcome this problem, speed observer is used for the accurate speed measurement and Improvement of speed ripple for Permancnt Magnet Synchronous Motor (PMSM) in this paper. Speed observer estimates the instantaneous speed at each sampling instant. Tills estimated speed signal is then used as the speed feedback signal for the speed loop control. The proposed speed observer system is proved by simulation using SABER simulation S/W.