Dual Direct Torque Control of Doubly Fed Induction Machine

The main idea developed in this paper is a novel biconverter structure to supply a doubly fed induction machine (DFIM). Two voltage source inverters (VSIs) feed the stator and rotor windings. The outputs of the two VSIs are combined electromechanically in the machine, and as a result, novel features can be obtained. For example, for high power drive applications, this configuration uses two inverters dimensioned for a half of the DFIM power. A new dual direct torque control is developed with flux model of DFIM. Two switching tables linked to VSI are defined for stator and rotor flux vector control. The satisfactory experimental and simulation results are shown, and they confirm good dynamic behavior in four quadrants of the speed-torque plane. Moreover, experimental results show the correct flux vector control behavior and speed tracking performances.

I. Introduction

This paper is focused on a novel doubly fed induction machine (DFIM) control strategy using direct torque control (DTC) that is linked with two switching tables (STs). This control, which is called dual DTC of DFIM, is based on interaction between two STs that control the stator and rotor flux vector. It can be applied to motor process applications operating in wide variable speed range.