The research of new insulating liquids having high dielectric strength, good heat transfer, and eco-friendliness is a permanent task for the designers of oil-filled high-voltage equipment. With the development of new energy sources, this equipment must operate under DC. The interest for nanofluids (NFs) is their exceptional cooling property. Recent works showed that the addition of certain nanoparticles (NPs) improves the AC withstand voltage of insulating liquids. This paper investigates the influence of magnetic (Fe₃O₄) and insulating (Al₂O₃ and SiO₂) NPs on DC breakdown voltage (DC-BDV) of MIDEL 1204 natural ester. The experimental values are analysed using both normal and Weibull probabilistic functions. The 1% and 50% DC-BDVs are also deduced. Experimental findings show that the effect of NPs on DC-BDV depends on both their kind and concentration. However, for the concentration of 0.05 g/L, the DC-BDV decreases irrespective of the type of NP. The best improvements are obtained with 0.2 g/L of Fe₃O₄ (50 nm) and with 0.3 g/L of Al₂O₃ (50 nm); these improvements are approximately 10.6% and 9%, respectively. The highest DC-BDV improvement with Al₂O₃ (13 nm), which is 7.6%, is observed with 0.4 g/L. However, the DC-BDV decreases irrespective of the concentration using SiO₂.

具有高介电强度，良好的热传递和生态友好性的新型绝缘液体的研究是充油高压设备设计人员的一项长期任务。随着新能源的发展，该设备必须在直流电下运行。纳米流体（NFs）的兴趣在于其出色的冷却性能。最近的工作表明，添加某些纳米颗粒（NPs）可以提高绝缘液体的AC耐电压。本文研究了磁性（Fe ₃ O ₄）和绝缘（Al ₂ O ₃和SiO ₂）MIDEL 1204天然酯的直流击穿电压（DC-BDV）上的NPs。使用正态和威布尔概率函数分析实验值。还推导了1％和50％的DC-BDV。实验结果表明，NP对DC-BDV的影响取决于其种类和浓度。但是，对于0.05 g / L的浓度，DC-BDV会降低，与NP的类型无关。用0.2 g / L的Fe ₃ O ₄（50 nm）和0.3 g / L的Al ₂ O ₃（50 nm）可获得最好的改善。这些改进分别约为10.6％和9％。Al ₂ O ₃的最高DC-BDV改进观察到0.4g / L的13nm（7.6nm）为7.6％。然而，与使用SiO ₂的浓度无关，DC-BDV降低。