Partial-Discharge-Induced Decomposition and By-Products Properties of Eco-Friendly Insulating Gas HFO-1234ze(E)

HFO-1234ze(E) is nontoxic, environmentally friendly and has good dielectric strength, which has potential to be used in gas-insulated equipment. In this article, the partial discharge characteristics of HFO-1234ze(E) are further studied. The dipole moment, polarizability, and ionization energy of HFO-1234ze(E) under different electric fields are obtained by theoretical calculation to study the effect of the external electric field on stability of the molecular structure. The specific decomposition characteristics of HFO-1234ze(E) under long-term partial discharge are also studied by experiments. The results show that the dipole moment and polarizability of HFO-1234ze(E) are significantly higher than those of SF6, but the ionization energy is slightly lower than that of SF6. With the increase of the external electric field, the stability of molecular structure decreases, and the stability of HFO-1234ze(E) decreases more obviously. Under long-term partial discharge, HFO-1234ze(E) may decompose to produce CF4, C2F6, CHF3, C2F4, and cis–C3H2F4, and the contents increase with time. The quantitative analysis of decomposition products shows that the contents of CF4, C2F6, and CHF3 are less than
$20~\mu \text{L}$
/L. The breakdown voltage of HFO-1234ze(E) does not change significantly after long-term partial discharge, which is mainly due to the low concentration of decomposition and relatively high dielectric strength of C2F6 and cis–C3H2F4.