STEADY-STATE MODEL OF DIRECT CONNECTED GENERATOR-HVDC CONVERTER UNITSIN THE HARMONIC DOMAIN

A new twelve-pulse unit connection model is formulated and solved in t he harmonic domain. The model takes into account the effects of genera tor saliency and saturation, interaction of the converter with the DC system, and variation in the firing and end of commutation angles caus ed by AC voltage and DC current harmonics. The reactive power control by generator excitation in the absence of converter transformer on-loa d tap-changers is also modelled. The solution of a test system is vali dated by means of time domain simulations.