Study On Partial Discharge Detection Technologies And Applications Based On Ultra High Frequency (UHF), Ultrasonic (UV), Transient Earth Voltage (TEV) Methods

With the continuous development of modern power grid, higher standards of the safety and reliability of the power grid operation are put forward. As an effective test method which does not damage the equipment itself, partial discharge (PD) detection has aroused more and more attention.Electrical equipment insulation degradation, even breakdown, occurs because of a variety of reasons, more than 70% of which is partial discharge. For the need of electric power system security, conducting partial discharge detection is a convenient method, which contributes to timely grasping the insulation states of the equipment in transformer substations, completing the track inspection, and avoiding little hidden trouble turned into a big accident.Gas insulated switchgear (GIS) and switch cabinets play an important role in modern substation. However, because of the relatively closed body structure, it is hard to find the potential pitfalls of partial discharge. From the GIS accidents switch cabinets throughout both at home and abroad, internal partial discharge cause the occurrence of major accidents. It was considered that this kind of equipment need less maintenance before, but now how to timely and accurately find the hidden danger of partial discharge has become an important problem facing the electricity workers.There are different typical characteristics of internal partial discharge for GIS and switch cabinets. Therefore, it is significant to study the principles and applications in the field power stations of the several PD detection technologies including high frequency, ultrasound, transient voltage technology.In this paper, the development of PD detection technology in recent years and the prospects for the development is put forward. The characteristics of partial discharge phenomena for several kinds of GIS and switch cabinets is analyzed in detail. By comparison of the principles and performances, the advantages and disadvantages of all kinds of electric testing technology are concluded. A variety of typical graph analysis and diagnosis of partial discharge phenomenon are given. Four typical PD cases are detected by using different technologies. Through qualitative and quantitative analysis of test data, hidden dangers caused by partial discharge are diagnosed. Through application in the actual power grid operation in this paper, valuable experience is obtained for further application of PD detection technologies.