“Active Flux” Orientation Vector Sensorless Control of IPMSM

This paper presents a novel strategy for the vector control of IPMSM, without signal injection. The overall performance of the motion-sensorless control depends strongly on the accuracy of the rotor position and speed estimation. The proposed state observer is based on the concept of the “active flux” (or “torque producing flux”), which “turns all the salient–pole rotor ac machines into nonsalient–pole ones”. As well as giving a detailed explanation of the concept, the paper demonstrates, through a wide range of experimental results, the effectiveness of the active flux observer under half full rated torque operating conditions in 2 rpm-1000 rpm speed range. Keywords—active flux observer, sensorless control, low speed operation, vector control.