The Properties and Production of the Insulating Sleeve

As a kind of insulating material, the insulating sleeve includes glass fiber insulating sleeve, PVC sleeve, heat shrinkable sleeve, and so on. The single insulation tube is made of pure porcelain or resin insulation and is used for voltage levels of 35 kV and below; its insulation is tubular, and the middle is fitted or glued to fix it on the perforated wall.

In addition, the insulation structure of a single insulation sleeve is divided into two types: air cavity and air cavity short-circuit type, wherein the air cavity sleeve is used for voltage levels of 10kV and below, and an air cavity is provided between the conductor and the porcelain sleeve as auxiliary insulation, and the sleeve capacitance can be reduced, increasing the corona voltage and the sliding voltage of the tube.

However, when the actual voltage level is high, a corona will occur inside the air cavity of a single insulating sleeve and the above-mentioned effect will be lost. In this case, an air cavity short circuit structure is adopted. The ceramic sleeve of the porcelain sleeve is coated with a semiconductor glaze on the inner wall, and the
spring is connected to the conductor to short the air chamber to eliminate the internal corona and improve the discharge characteristics of the bushing.