Thyristorized DC Drives with Regenerative Braking and Speed Reversal

This paper presents a systematic development of the analysis, design, and testing of a thyristor (SCR) controlled separately excited dc motor drive system. The motor armature voltage is supplied from a three-phase fully controlled six-pulse thyristor bridge. Closed loop control is analyzed using transfer function techniques and the necessity of an inner current control loop is demonstrated. Armature reconnection is used to enable regenerative braking and speed reversal. Design of both a proportional and proportional integral controller is outlined and experimental results are given.