Development of computational design for reliable prediction of dielectric strengths of perfluorocarbon compounds

Abstract

The development of robust computational protocols capable of accurately predicting the dielectric strengths of eco-friendly insulating gas candidates is crucial; however, it lacks relevant efforts significantly. Consequently, a series of computational protocols are employed in this study to enable the computational prediction of polarizability and ionization energy of eco-friendly, perfluorinated carbon-based candidates, followed by the equation-based prediction of their dielectric strength. The validation process associated with the prediction of the afore-mentioned variables for selected datasets confirms the suitability of the B3LYP-based prediction protocol for reproducing experimental values. Subsequently, the validation of dielectric strength prediction outlines the following three conclusions. (1) The referenced equation adopted from a previous study is incapable of predicting the dielectric strengths of 137 organic compounds present in our database. (2) Parameterization of the coefficients in the referenced equation leads to the accurate prediction of the dielectric strengths. (3) Incorporation of a novel variable, viz. molecular weight, into the referenced equation combined with the parameterization of the coefficients leads to a robust protocol capable of predicting dielectric strengths with high efficiencies even with a significantly smaller fitting dataset. This implies the development of a comprehensive solution capable of accurately predicting the dielectric strengths of a substantially large dataset.

Computational Insights into Degradation Probability of Small Fluorocarbon Compounds

“…Beyond their environmental benefits, a substantial number of these compounds also demonstrate comparable insulating properties. Specifically, in our previous studies, we highlighted that one key parameter to evaluate the insulating performance of fluorocarbon compounds could be their dielectric strength, with candidates exhibiting dielectric strengths close to that of SF 6 being particularly noteworthy. , Besides, other essential factors, such as electron affinity and dielectric constant, can be adopted to assess the insulating properties of these compounds. However, it is crucial to underscore that structural durability must be a fundamental consideration for their application in electrical transmission systems.…”

“…Among potential candidates, perfluorocarbon (PFC) compounds have emerged as promising alternative insulating gases to replace SF 6 in various electrical applications primarily owing to the probability of identifying PFC compounds with relatively low GWP. − Additionally, PFCs exhibit excellent thermal and electrical performances under a wide range of operating conditions, ensuring the reliability and efficiency of electrical systems . Extensive efforts have been therefore dedicated to improving the other core insulating properties, such as dielectric strength, dielectric constant, and electron affinity, which should meet the guidelines for practical applications. − For instance, the dielectric strengths of various PFC compounds have been identified to range from 8.0 to 12 kV/mm with the lowest (highest) values for C 10 F 18 (C 2 F 6 ) . Recently, the 3M company developed various NOVEC gases with the aim of replacing the conventional SF 6 , represented by NOVEC-4710 gas (C 3 F 7 CN) .…”

“…Conversely, General Electric has pioneered a grid-friendly ecoconscious gas known as g 3 , comprising a blend of Novec 4710 and CO 2 gases. In our previous studies, the dielectric strengths of PFC and non-PFC compounds could be accurately predicted by computational chemistry. , While these efforts have led to significant advances in identifying PFC compounds with great insulating properties, a fundamental understanding of their structural durability has not been fully discussed despite its importance for a stable implication.…”

Rational Design of Reliable Computational Protocols for Predicting Dielectric Constants of Gaseous Molecules

“…The Clausius−Mossotti equation, which describes the relation between the polarizability (α) and the dielectric constant (ε r ), can be defined as follows. 15,16…”

“…19,20 Note that the DFT-calculated polarizability and ionization energy were validated for 54 and 48 organic compounds in our previous study, respectively. 15 Computational Parameterization of Designed Protocols. Each computational protocol was parametrized considering two different metrics, namely, root-mean-squared deviation (RMSD) and Spearman's rank correlation coefficient (SRCC).…”