Four level decoupled SVPWM based direct torque control (DTC) of open end induction motor drive

In this present paper, a decoupled method for a fixed switching frequency direct torque control (DTC) using four level inverter is discussed. In this approach the four level voltages are generated by using cascaded connection of two conventional two level inverters which are fed with the unequal dc link voltages. Controlling of the two inverters feeding the open end winding induction motor is easier than compared to the controlling of inverter voltages in the other multi level inverters. However, the proposed DTC scheme does not require the sector information of the estimated fundamental stator voltage vector and its relative position with respect to the stator flux vector. Simulation results clearly demonstrate a better dynamic and simplicity in numerical calculations of the proposed method.