Performance Improvement of DTC-SVM of PMSM with Compensation for the Dead Time Effect and Power Switch Loss Based on Extended Kalman Filter

Two algorithms have been extensively studied for motor control: Field Oriented Control (FOC) and Direct Torque Control (DTC). Both control algorithms use a Voltage Source Inverter (VSI) to drive a Permanent Magnet Synchronous Motor (PMSM). To prevent short-arm short-circuit accidents when driving PMSM using VSI, a dead time is used to turn off the TOP and BOTTOM switches of each arm at the same time. However, this dead-time technique causes an unexpected pole voltage to be applied to the PMSM on the VSI output voltage, causing distortion and resulting in control nonlinearity. The disturbance voltage that causes nonlinearity is difficult to measure directly with the sensor. Therefore, this paper analyzes the nonlinearity of the controller due to the distorted voltage caused by the dead time during PMSM operation using the DTC algorithm and predicts the distorted output voltage using the extended Kalman Filter (EKF) to improve control stability. As a result, The algorithm proposed in this paper has verified the improvement of torque ripple and stator flux ripple through experiments and simulations.

Automated summary

This paper studies two algorithms for motor control: Field Oriented Control (FOC) and Direct Torque Control (DTC). Both algorithms utilize a Voltage Source Inverter (VSI) to drive a Permanent Magnet Synchronous Motor (PMSM). However, the use of a dead time in the VSI introduces distortion and control nonlinearity. To address this issue, the paper proposes an algorithm that analyzes and predicts the distorted output voltage using the extended Kalman Filter (EKF) to improve control stability. Experimental and simulation results confirm the improvement in torque ripple and stator flux ripple.