Direct Torque Control of Two-Phase Induction and Synchronous Motors

In this paper, the direct torque control (DTC) of symmetrical two-phase induction and synchronous motors using different structures of two-phase inverters including two-, three-, and four-leg inverters is studied. Essential equations for controlling both electromagnetic torque and the stator flux modulus are presented and switching tables are derived. Different inverter topologies are compared in terms of the control system operation in high-speed applications and maximum speed of the rotating field deliverable by the drive system. The performance of the DTC of two-phase induction and synchronous motors fed by different inverter topologies is evaluated and the correctness of presented theories is validated by experimental results.