Oil-immersed transformers are the core equipment of power systems for energy transfer. The thermal characteristic of a transformer immediately affects its operational reliability and service life. Therefore, analyzing the hot spot temperature of transformers is highly important. Currently, researchers worldwide have achieved substantial research results in this field. This paper reviews the research status of the transformer hot spot temperature. First, the calculation method of transformer loss, the forms of heat transfer and its calculation method, the characteristics of the cooling method, and its application occasions are summarized. Second, the methods used to research the transformer hot spot temperature are presented in detail. From the perspective of transformer heat production and heat dissipation, research results on the factors influencing transformer hot spot temperature are summarized. Last, the research direction of the transformer hot spot temperature is indicated.

Probody^™ therapeutics (Pb‐Tx) are protease‐activatable prodrugs of monoclonal antibodies (mAbs) designed to target tumors where protease activity is elevated while avoiding normal tissue. They are comprised of a parental mAb, a mask that inhibits antibody binding to target, and a protease‐cleavable substrate between the mask and the mAb. We report a quantitative systems pharmacology (QSP) model for the rational design and clinical translation of Pb‐Tx. The model adequately described monkey pharmacokinetic data following administration of six anti‐CD166 Pb‐Tx of varying mask strength and substrate cleavability, and captured the trend of decreasing Pb‐Tx systemic clearance with increasing mask strength. Projections to humans suggested both higher levels of Pb‐Tx in tumor relative to parental mAb and an optimal mask strength for maximizing tumor receptor‐mediated uptake. Simulations further suggested the majority of circulating species in humans would be intact/masked Pb‐Tx, with no significant flux of cleaved/activated species from tumor to the systemic compartment.

HFO1234zeE is an environmental-friendly gas with the potential to replace sulfur hexafluoride (SF₆). Therefore, research on the breakdown and decomposition characteristics of the HFO1234zeE gas mixture was conducted. The breakdown experiments of the 20% HFO1234zeE/80% N₂ gas mixture under different electric fields were performed, and the feasibility of replacing SF₆ with HFO1234zeE was verified in terms of insulation strength. Based on the density functional theory, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) wave function distributions of the HFO1234zeE molecule were obtained. According to the frontier orbital theory, the possible position of reaction in the molecule may occur at the carbon-carbon double bond and carbon-hydrogen bond. Moreover, reaction force field-molecular dynamics (ReaxFF-MD) was used to simulate the decomposition of the 20% HFO1234zeE/80% N₂ gas mixture, the effect of the temperature and pressure on the decomposition reaction was studied, and the main decomposition paths were analyzed. The research results show that the main decomposition products are C₂F₂, CN, CNF, H, N, F, and HN₂. With the increase in temperature and pressure, the number of molecules decomposed increases. The conclusions provide the theoretical basis for the application of HFO1234zeE.

Octafluorocyclobutane (c-C₄F₈) is one of the environmentally friendly gases with the potential to replace SF₆. In this paper, the AC breakdown characteristics of c-C₄F₈/N₂ mixture in an extremely non-uniform electric field were studied; the effects of the gas pressure, electrode distance, and c-C₄F₈ volume fraction on the breakdown voltage were analyzed; and the feasibility of replacing SF₆ with c-C₄F₈/N₂ was verified. The results show that the breakdown voltage of c-C₄F₈ /N₂ increases with an increase in pressure, electrode spacing, and volume fraction of c-C₄F₈ in an extremely non-uniform electric field. Under the same conditions, the breakdown voltage of 20%c-C₄F₈/80%N₂ is 46–90% that of 20%SF₆/80%N₂. When the pressure is 0.3 MPa, the 20%c-C₄F₈/80%N₂ breakdown voltage can reach over 57% that of SF₆. Taking into consideration the environment, liquefaction temperature, and insulation strength, 20%c-C₄F₈/80%N₂ may replace SF₆ used for medium- and low-voltage equipment.

Hydrofluoroolefin HFO1234zeE ( trans ‐1,3,3,3‐tetrafluoroprop‐1‐ene) is an environmentally friendly gas insulating medium that has the potential to replace SF ₆ . To clarify the decomposition paths and products of an HFO1234zeE/N ₂ gas mixture under partial discharge, the decomposition mechanism is explored with density functional theory. The results indicate that only HFO1234zeE molecules decompose in the range of low‐temperature plasma, and electrons with different energies interact with molecules and cause them to decompose through different paths. Then, products are generated by free radical recombination, addition reactions and internal configurational conversions of the molecule. An experimental investigation of decomposition of the HFO1234zeE/N ₂ gas mixture with different discharge modes is carried out, and it is found that the products calculated with density functional theory are consistent with those seen experimentally. The results show the decomposition mechanism of the insulating gas under partial discharge and provide a theoretical basis for the application of HFO1234zeE.

Trans-1, 3, 3, 3-tetrafluoroprop-1-ene (HFO) is an environmentally friendly gas that has the potential to replace sulfur hexafluoride (SF6). In this work, the breakdown characteristics of a HFO/N2 gas mixture were studied under an extremely nonuniform electric field, and the effects of pressure and mixing ratio on breakdown characteristics were analyzed. In the test, a SF6/N2 gas mixture was used as the control group for comparative analysis. The results show that when the electric field nonuniformity coefficient is high, the breakdown voltage of pure HFO gas shows an “N” type curve with an increasing pressure due to the homogenization of the electric field by the corona. Because of a change in the mixing ratio and electric field nonuniformity coefficient, the breakdown voltage of the HFO/N2 gas mixture varies linearly or peaks with pressure. The breakdown voltage of the HFO/N2 gas mixture shows a synergistic effect with the mixing ratio at low pressure and a positive synergistic effect at high pressure. Considering the liquefaction temperature and insulation strength of the gases, HFO/N2 gas with a 40% volume fraction has the potential to replace SF6.