The model simulates twelve pulse converter for DC motor drive. Wye and Delta converters were connected in series to get the twelve pulses for the DC motor. Any firing angle can be be adjusted for the pulse generating block. The basic concept is that the there exist the angle of 30 degree in voltages of wye and delta connected circuits, so two converters connected with wye and delta windings can provide 12 pulses in the cycle of power frequency; described in this simulation.