Multipulse AC-DC Thyristor Converter with DC Bus Current Shaper

This paper proposes an active current shaper for a 12-pulse thyristor converter, termed a load compensator (LSTATCOM). The LSTATCOM injects compensation current through a split winding interphase reactor connected on DC bus of the 12-pulse AC-DC converter. It is desired that the LSTATCOM provides sinusoidal shaping of the source currents for variations in the output load as well as changes in the output voltage requirements. For voltage sensitive DC loads, the LSTATCOM should also be capable of compensating voltage sag and voltage swell. To observe the dynamic and steady state performance of the LSTATCOM based 12-pulse thyristor converter, a detailed mathematical model of the system is derived and the corresponding simulation models are developed. A thorough investigation of the performance results reveals that the proposed LSTATCOM provides sinusoidal shaped source currents for a 12-pulse converter operating under a variety of operating conditions and requirements.