Partial Discharge Performance of HFO-1336mzz(E)/CO₂: An Eco-friendly Insulating Gas

HFO-1336mzz(E) (HFO-butene) is regarded as a promising eco-friendly insulating gas to replace sulfur hexafluoride (SF₆) used in medium-voltage gas insulated equipment (MV-GIE). In this paper, we systematically explored partial discharge properties of HFO-butene/CO₂ gas mixture by revealing partial discharge inception voltage (PDIV), partial discharge extinction voltage (PDEV), and phase resolved partial discharge (PRPD) pattern under different mixing ratios, and gas pressure conditions. Meanwhile, the action and influence mechanism of “space charge layer” on PD distribution properties of HFO-butene/CO₂ is proposed. We found PDIV of HFO-butene/CO₂ demonstrated linear-saturation increase trend with mixing ratio and gas pressure, which is equivalent to that of SF₆ as HFO-butene content reaches 25%~30%. In addition, there showed “double peak” phenomenon in the n-φ spectrum of HFO-butene/CO₂ with low HFO-butene content and gas pressure, which is ascribed to the shielding effect of the stable “space charge layer” nearby the needle electrode that improves non-uniformity of the electric field. Corresponding results revealed PD characteristics of HFO-butene/CO₂ gas mixture and brought guidance to development of brought guidance based MV-GIE.