Comparative study of AC and positive and negative DC visual corona for sphere-plane gaps in atmospheric air
PublisherMultidisciplinary Digital Publishing Institute (MDPI)
Rights accessOpen Access
Due to the expansion of high-voltage direct current (HVDC) power systems, manufacturers of high-voltage (HV) hardware for alternating current (ac) applications are focusing their efforts towards the HVDC market. Because of the historical preponderance of ac power systems, such manufacturers have a strong background in ac corona but they need to acquire more knowledge about direct current (dc) corona. Due to the complex nature of corona, experimental data is required to describe its behavior. This work performs an experimental comparative analysis between the inception of ac corona and positive and negative dc corona. First, the sphere-plane air gap is analyzed from experimental data, and the corona inception voltages for different geometries are measured in a high-voltage laboratory. Next, the surface electric ﬁeld strength is determined from ﬁnite element method simulations, since it provides valuable information about corona inception conditions. The experimental data obtained are ﬁtted to an equation based on Peek’slaw,whichallows determining the equivalence between the visual corona surface electric ﬁeld strength for ac and dc supply. Finally, additional experimental results performed on substation connectors are presented to further validate the previous results by means of commercial high-voltage hardware. The results presented in this paper could be especially valuable for high-voltage hardware manufacturers, since they allow determining the dc voltage and electric ﬁeld values at which their ac products can withstand free of corona when operating in dc grids.
CitationRiba, J., Morosini, A., Capelli, F. Comparative study of AC and positive and negative DC visual corona for sphere-plane gaps in atmospheric air. "Energies", 8 Octubre 2018, vol. 11, núm. 10, p. 1-18.