12-Pulse Converter for HVDC Transmission Line

12 pulse converter using two 6 pulse converter and ±30° transformer shift to deliver low-ripple,low-harmonic DC output and overall less %THD

This Simulink model implements a complete twelve-pulse controlled rectifier system, formed by combining two six-pulse SCR bridges with a phase-shifting transformer arrangement. The model demonstrates how 12-pulse converters reduce harmonic distortion and improve power quality compared to conventional six-pulse rectifiers.

The setup includes two fully controlled three-phase bridges operating with appropriate firing sequence, a pair of phase-shifted secondary windings (±30°), and a DC output stage that produces smoother voltage with significantly lower ripple. The model allows observation of line currents, AC terminal voltages, individual bridge DC outputs, harmonic content, and the final combined DC waveform.

This design is suitable for studying high-power conversion, HVDC front-end rectification, harmonic minimization, and SCR firing control. All blocks are arranged cleanly, with scopes placed for easy comparison between the two 6-pulse bridges and the resulting 12-pulse DC output.