A Highly Effective Modified Direct Torque Control for Five Phase Induction Motor without AC Phase Current Sensors

Abstract

The Direct Torque Control (DTC) technique requires stator currents and DC bus voltage, as well as inverter switch states, in order to estimate stator flux and electromagnetic torque values. Measurement of phase currents in real time with current sensors is a common method of gathering this data. To control a Five-Phase Induction Motor (FPIM), the DTC needs at least four alternating current (AC) sensors and one voltage sensor. When utilized in a global training system, this number has disadvantages due to cost, size, and non-linearity. The purpose of this article is to show how to remove the alternating current sensors from an FPIM's DTC. This is accomplished by reconstructing the phase currents using a simple DC current sensor placed at the voltage inverter's input and modifying the classical DTC control technique by using a good choice of certain allowable switching vectors of a five-phase voltage inverter, the 18° zone offset strategy of the stator flux, and developing a new commutation table for the stator currents construction. The proposed control approach is supported by simulation results.