New Sensorless Vector Control Methods Based on a New Minimum-Order Flux State-Observer in the "D-Module" for Permanent Magnet Synchronous Motors

This paper proposes new sensorless vector control methods that can be applied to both of salient-pole and non-salient-pole permanent magnet synchronous motors (PMSM). The proposed method estimates the phase of rotor flux by the “D-module observer”, which is newly developed for sensorless vector controls of PMSM. The “D-module observer” has the following attractive features. 1) It is a new state observer requiring no additional approximation to the motor mathematical model. 2) It is a minimum order state observer. 3) Observer gain guaranteeing proper estimation in four quadrants wide operating range except singular zero-speed can be a simple constant, and can be easily designed. 4) It utilizes motor parameters in the simplest manner. 5) Its structure is very simple and realized at the minimum computing cost. 6) It can be applied to both of salient-pole and non-salient-pole PMSM. 7) It can be realized in both rotor and stator reference frames. Detailed designs and analyses for the “D-module observer” and “D-module observer” based sensorless vector control systems in both rotor and stator reference frames are given. Their validity and usefulness are examined and confirmed through extensive experiments.