Investigation and Wideband Modeling of LCC based ±800 kV UHVDC Converter Station for Electromagnetic Disturbance

The Traditional high voltage direct current (HVDC) grids are equipped with a range of non-linear devices carrying high order of resonance frequencies. The line commutated converter (LCC) based HVDC converters generate a wideband electromagnetic disturbance (EMD) during the switching ON and OFF process of thyristor valves. This EMD is propagated throughout the HVDC system and influences the performance of primary and secondary circuits by conductive and inductive couplings. Line faults, lightning and switching transients further complicate the high frequency (HF) EMD issues. This paper presents the wideband model of LCC module and tower for the insightful analysis of EMD characteristics. The previously ignored wideband parameters along with background and impulsive noise produced from thyristor valves are also modeled and injected in the LCC valve module. The wideband modeling of LCC station will help to overcome the issues of EMD prediction, overvoltage and especially will facilitate to standardize the existing issues of the current relay protection system.