Torque and power improvement for a variable flux permanent magnet synchronous machine

This paper presents a method to improve the variable flux synchronous machine's performance in the flux weakening region. A dq-model of the machine was used analytically to account for the magnet flux's variation with d-axis current, and the dq-axis inductance variation with dq-axis currents as well. The method was experimentally evaluated on a variable flux syncronous machine and showed a significant improvement of the overall machine's characteristics.