Simulation of 24-Pulse Autotransformer Based AC–DC Converter Employing Pulse Multiplication with Direct Torque Controlled Induction Motor Drive Load

In this paper a 24 pulse autotransformer based ac–dc converter has been proposed to improvement power quality at the point of common coupling (PCC). The idea is to use an autotransformer based 12-pulse ac–dc converter using a DC ripple reinjection technique to double its pulse numbers (providing a 24-pulse AC-DC converter). A polygon connected autotransformer is used to produce 12-pulses with flexibility to adjust its voltage ratio for producing DC-link voltage as that of a 6-pulse diode bridge rectifier. The proposed 24-pulse AC-DC converter is utilized to improve the power quality indices at AC mains feeding a direct torque controlled induction motor drive (DTCIMD) load. Simulation results confirmed that the proposed topology has been able to eliminate harmonic currents up to 21st order at the AC mains under different loading conditions. Furthermore, a set of power quality indices at the input AC mains are compared between the simulation results using the proposed topology and the conventional 6-pulse and 12 pulse converters under different loading conditions.

Keywords:

Polygon Autotransformer , Multipulse AC–DC Converters , Pulse Multiplication , DC Ripple Reinjection , Direct Torque Controlled Induction Motor Drive (DTCIMD)