Design of adaptive bushing based on field grading materials

Abstract

Electrical bushings, as important power system components, are critical to the reliability of power systems. The capacitance-graded bushing is a type of high voltage bushing that is most commonly used in current power systems. However, the limitations of and problems with capacitance-graded bushings are exposed when the operating voltage level increases. A new direct current wall bushing with adaptive field grading materials is proposed, based on the core features of the problem that the bushing is intended to solve. The main insulation structure of the proposed DC wall bushing with adaptive field grading materials comprises three parts: a field grading layer, a current limiting layer and an electrode extension layer. The proposed bushing has characteristics that include a simple structure, small size and environmental friendliness, and it also meets the requirements of existing power systems. The proposed bushing also conforms to the intended development direction for future power equipment and will aid in the development of power systems for operation at higher voltages.