Adaptive flux weakening control of permanent magnet synchronous motors

This paper presents an approach for adaptive control of the surface mounted permanent magnet synchronous motor (PMSM) over its entire speed range. This requires coordination of direct and quadrature axis currents i/sub d/, i/sub q/. Direct model reference adaptive control is responsible for the control of quadrature axis current. Direct axis current is controlled by an adaptive flux weakening approach at elevated speeds where the inverter is in voltage saturation. The developed adaptive flux weakening scheme is able to determine the right amount of i/sub d/ at any operating conditions without the the knowledge of load torque, motor or inverter parameters.