Auxiliary Pulse Tripling Circuit with Low kVA Rating to Reduce Input Current Harmonic Distortion in ۱۲ Pulse Rectifier

In recent years, to increase the number of pulses in ۱۲-pulse autotransformer rectifiers (۱۲-PARs) and reduce the input current total harmonic distortion (IC-THD), without increasing the cost and complexity, the technique of pulse multiplication circuit has been proposed. With this approach in this paper, to upgrade the rectifier structure from ۱۲ pulses to ۳۶ pulses, an auxiliary pulse tripling circuit (APTC) with a very small kilovolt ampere rate (a kilovolt ampere equal to ۱.۳۴% of the rated load power) is presented. The proposed APTC consists of an unconventional interphase transformer (UIPT) with two diodes in the primary winding and a single-phase diode bridge rectifier connected to the secondary winding. Also, the ۱۲-phase autotransformer used in the proposed structure is based on a polygon connection with a very low kilovolt-ampere rate. As a result, the total kilovolt-ampere rate of the proposed ۳۶-pulse autotransformer rectifier (۳۶-PAR) is about ۲۴% of the rated load power, which is much less compared to similar structures. Also, according to the simulation results, the IC-THD in the proposed rectifier is less than ۳%.