Current transformer insulated by pressurized gas

摘要

A current transformer for outdoor high-voltage installations which is insulated by pressurized gas includes a metallic top housing mounted to a hollow porcelain insulator. The top housing contains a primary conductor which is surrounded by coils of the secondary circuit. The secondary terminal leads are installed in a grounded lead-through tube which is disposed within the hollow porcelain insulator. In order to increase the dielectric strength of the current transformer, the space which is enclosed by the top housing and the porcelain insulator is divided into a high-pressure region and a low-pressure region, the former region including zones which are exposed to high voltages, in particular the interior of the top housing, and which are bounded throughout by metal and a mechanically strong insulating material, such as a casting region. The partition between the high-pressure region and the low-pressure region preferably is a conical sleeve which surrounds the lead-through tube in the upper portion of the porcelain insulator.