Analysis of Sensorless Vector Control Scheme of Induction Motor Drive at Zero Frequency Operation

摘要

Induction motor drives without shaft sensor, sensorless drives are increasingly applied in many industrial process involving lower cost and higher performance specification. In this paper we represents sensorless vector control scheme for low speed drive. The sensorless algorithm is based on the estimation of the secondary speed emf that leads the secondary magnetic flux by an angle of π/2. This sensorless algorithm as similar to other algorithms has a problem in zero stator frequency operation. To avoid this problem, the fluctuated reference of secondary flux is used at zero frequency. From this technique the stable estimation of the secondary speed emf is realized.