| Title |
IPT Characteristics of HCR / ATH Composites for HVDC |
| DOI |
https://doi.org/10.5370/KIEE.2019.68.8.993 |
| Keywords |
HCR/ATH Composites; Super High Voltage Direct Current Insulator; Tracking and Erosion; HVDC Polarity |
| Abstract |
In this paper, we investigated the tracking and erosion properties of HCR / ATH composites using IPT in order to develop insulation materials for HVDC insulators. Samples of two kinds of sample S.A [HCR / ATH_1μm particle (100%)] and S.B [HCR / ATH (fine_1μm_50% + coarse_18μm_50%)] composites were respectively prepared. In accordance with IEC 60587, ± HVDC 4.5k, liquid contaminant velocity of 0.6 ml / min was forced out to perform tracking and erosion tests. The basic physical properties of the samples, namely the mechanical tensile strength (elongation, tensile strength), electrical HVDC positive dielectric breakdown strength and hardness were evaluated. The reason that S.A improves the properties of S.B is that the weakening of the interface due to the size of ATH particles is dominant in the surface degradation tracking and erosion rather than the thermal conductivity enhancement. The effect of polarity also showed much more severe characteristics of the leakage current pulse than the negative polarity. Since the liquid contaminant is forced to flow in large amounts, a sustained conduction current and arc are generated, and an overall increased leakage current is measured over the entire 6 hour period. In the case of positive polarity, the tracking and erosion state from the lower electrode to the upper electrode was shown. In the case of negative polarity, surface discharge occurred at the position of the lower electrode from the beginning to the end. In the evaluation of the thermal conductivity, the density of the HCR / ATH internal structure was high due to the high density of the internal structure, but it could be estimated that the larger the particle size, the weaker the interface |