Testing the Frame-Angle-Based Direct Torque Control for 3? Induction Motor Drives

In this project, the performance evaluation of the frame-angle-based (FAB) direct torque controller (DTC) for 3φ induction motor drives (IMDs), which are fed by 3φ sixpulse wavelet-modulated (WM) dc–ac power electronic converters (PECs). The tested DTC is designed to adjust the de- and qe-axis components of the voltages (ve ds and ve qs) applied to a 3φ IMD. The adjustments in ve ds and ve qs are created in response to changes in the load torque, command torque, drive speed, and/or system parameters. Desired adjustments in ve ds and ve qs are set by regulating the angle ϑ of the frame created by ve ds and ve qs. This frame produces reference modulating signals that are required to generate WM switching pulses for operating the 3φ dc–ac PEC in the IMD.

The complete IMD system, incorporating the FAB-DTC, is implemented for a 10-hp IMD system for performance evaluation. Tests of the FAB-DTC for the 10-hp IMD are conducted for various changes in the load torque, command torque, drive speed, and system parameters. Simulation and experimental test results demonstrate fast, accurate, reliable, and dynamic responses with minor sensitivity to variations in system parameters.

Keywords: Digital signal processing, direct torque controller (DTC) methods, frame angle controller, wavelet modulation, 3φ induction machines.