Voltage vector selection strategy for the interior PMSM DTC system

The direct torque control (DTC) for interior permanent magnet synchronous motor (PMSM) suffers from high current and torque ripple and variable switching frequency. It is due to the use of switching table to control stator flux and torque. In this paper the control of stator flux, torque angle and torque in the interior PMSM DTC system is investigated. A voltage vector selection strategy is proposed which uses stator flux position and torque angle information to determine the applying voltage vector and uses SVM to generate the applying voltage vector. Experimental results for a 15-kW interior PMSM show voltage vector selection strategy can decrease stator current and torque ripple and fix switching frequency against switching table.