A Comparative Study on Predictive and ISVM Direct Torque Control Methods for a Doubly Fed Induction Machine Fed by an Indirect Matrix Converter

Abstract

This paper presents a comparative study on the Predictive Direct Torque Control method and the Indirect Space Vector Modulation Direct Torque Control method for a Doubly-Fed Induction Machine (DFIM) which its rotor is fed by an Indirect Matrix Converter (IMC). In Conventional DTC technique, good transient and steady-state performances are achieved but it presents a non constant switching frequency behavior and non desirable torque ripples. However, in this paper by using the proposed methods, a fixed switching frequency is obtained. In this model Doubly-Fed Induction Machine is connected to the grid by the stator and the rotor is fed by an Indirect Matrix Converter. Functionally this converter is very similar to the Direct Matrix Converter, but it has separate line and load bridges. In the inverter stage, the Predictive method and ISVM method are employed. In the rectifier stage, in order to reduce losses caused by snubber circuits, the rectifier fourstep commutation method is employed. A comparative study between the Predictive DTC and ISVM-DTC is performed by simulating these control systems in MATLAB/SIMULINK software environments and the obtained results are presented and verified.

Keywords

• Direct Torque Control
• Indirect Matrix Converter
• Indirect Space Vector Modulation
• Predictive DTC