New integration algorithms for estimating motor flux over a wide speed range

This paper proposes three new integration algorithms for motor flux estimation. The algorithms are developed to solve the problems associated with a pure integrator. Of the proposed integration algorithms, one with adaptive control has the best performance. This algorithm can effectively eliminate the nonlinear distortion produced by amplitude limiters used in the other two. The DC drift problem associated with the pure integrator is also solved. The adaptive algorithm can accurately estimate the motor flux over a wide speed range (100:1, i.e., 60 to 0.6 Hz). The performance of the algorithms is investigated and compared. Experiments on a PWM CSI-fed synchronous motor drive have been carried out to verify the proposed algorithms