Online loss minimization based adaptive flux observer for direct torque and flux control of PMSM drive

This paper presents a novel adaptive flux observer based direct torque and flux control (DTFC) of permanent magnet synchronous motor (PMSM) drive. An online loss minimization algorithm (LMA) is developed to estimate the airgap flux so that the motor operates at minimum loss condition while taking the general advantages of DTFC scheme over conventional vector control scheme. The proposed DTFC based PMSM drive incorporating the LMA based flux observer is implemented in real-time using the DSP board DS1104 for a laboratory 5 hp motor. The performance of the proposed LMA based DTFC control of PMSM drive is tested in both simulation and experiment at different operating conditions.