Application of On-line Detection Technology in Shanghai Power Grid

Abstract

The common on-line detection methods are introduced in this paper generally. Additionally, the application of on-line detection in shanghai distribution network is mainly analyzed and its further popularization is well programmed. The Meaning of On-line Detection Distinct from the long-term continuous online monitoring, on-line detection technology is a method that the state variables are acquired in a short period by means of portable measuring devises while the electrical equipments are operating. On-line detection can discover the latent fault of power equipment in advance and then avoid equipment accident by taking critical measures. The comprehensive deep application of the on-line detection enables to save efforts and resources efficiently so as to avert the economic loss that long-time maintenance causes, therefore the overall and high efficient application of this technology can achieve an economy benefits. The method of on-line detection is mainly accorded with the characteristics appeared with electrical equipment fault at first and with the other factors like the capacity of electrical power equipment, structure, volume, price and etc. At present, the common used method of on-line detection in distribution network is the partial discharging detection that mainly contains infrared thermometry, transient grounding voltage and ultrasonic and ultrahigh frequency partial discharge detection technology. Infrared imaging technology is used in the surface temperature measurement and fault heating detection of all the electrical appliances and in the thermal image analysis during the maintenance; Ultraviolet thermometry is used in the examination of corona of power transmission and transformation equipments; Switching on-off current wave analysis technology detects the continuous current of operating arrestor every year before the thunderstorm season; Chromatographic analysis technique of transformer oil of oil-filled equipments develop widely and effectively; Having an analysis of gas's humidity, purity and decomposition products on the SF6 circuit breaker and GIS; Having an oil pressure determination on electric cable and using the oscillation wave location technology to have a state monitoring of electric cable; Detecting the grounding current in the earth loop by using current transformers or clamp ammeters; Flowmeter is used in the flow detection of cycle oil system of large transformers, etc. This essay mainly introduces the application of on-line detection technology in shanghai's distribution network and gives instructive suggestions of this application next according to the current condition.