Gary Allen Vincent

A Guide to Testing Liquid Dielectrics In Simple Combination with Solid Dielectrics

This guide reviews tests, standards, and guidelines in the characterization of dielectric liquid/solid systems for voltage and thermal endurance.

The effects of water and silanol on the electrical properties of silicone fluids

Based on many research investigations and much practical experience, it is well established that the performance capabilities of organic insulating oils are impaired by the presence of contaminants, such as water.1 Recent proposals to use silicone fluids as insulating oils have raised many questions about the effect of contaminants on the electrical properties of these materials.

The behavior of silicone fluids and other insulating oils under a sustained arc

Polydimethylsiloxanes fluids, by virtue of their inorganic, siloxane backbone rapidly form solid bridges on breakdown which effectively extinguish any arcs. If this solid material is continuously removed from the electrode gap, an arc can be sustained, in which case, the “arc power” and volume of gas evolved per unit time are dependent upon molecular structure, molecular weight, and molecular weight distribution of the fluid. Judicious blending of these controllable variables should lead to a silicone insulating fluid having optimum characteristics.

Structure property relationships in silicone fluid dielectrics

In his 1971 Whitehead Memorial Lecture,1 Hyde discussed the versatility of silicone fluids, resins, and elastomers with emphasis on the potential of these materials in new insulation systems.