Sensorless Self-Commissioning of Synchronous Reluctance Machine with Rotor Self-Locking Mechanism

The paper proposes a sensorless technique for standstill self-commissioning of synchronous reluctance machines. Previous works have demonstrated the potential of simultaneous excitation of $d$ and $q$ axis with hysteresis square-wave voltage injection for the exploration of current plane with insignificant rotor movement. The proposed structure retains the hysteresis control for $q$ axis while $i_d$ is closed loop controlled using a weak PI regulator. Akin to the parking technique, a DC current is imposed in a fixed reference frame to inhibit any rotor movement and realize the self-locking mechanism. This permits systematic inspection of the $dq$ current plane for accurate cross-saturation modeling. In addition, a new approach for the identification of cross-saturation in $d$ axis from the high frequency component in $i_d$ current is developed. The experimental tests on 1.1 kW synchronous reluctance motor test bench prove the validity of proposed technique.