Direct Torque Control (DTC) of Multi-phase Induction Motor using TMS320F2407 Digital Signal Processor

In this paper, direct torque control (DTC) of five-phase induction motor is implemented using TMS320LF2407A digital signal processor (DSP). Multi-phase motors are usually designed to have the concentrated winding and non-sinusoidal air-gap flux density distribution in order to maximize the torque per ampere. This means that the phase voltage of a multiphase motor has the non-sinusoidal waveform. Accordingly, the conventional analysis on a multi-phase Space Vector Pulse Width Modulation (SVPWM), which is confined to a sinusoidal phase voltage, should be extended to a non-sinusoidal phase voltage. A DTC scheme is proposed, where fast torque response with low ripple in the stator flux and torque of five-phase induction motor can be achieved. In comparison with DTC for three phase induction motor, the five-phase DTC system has thirty-two space voltage vectors, which provide greater flexibility in selecting the inverter switching states thus accomplishing a more precise control of the stator flux and torque. Simulation and experimental results clearly demonstrate a better dynamic and steady state performance with DTC for five-phase induction motor, which suggest that the combination of DTC with multi-phase induction motor have a great practical prospect in motor drives.