Study On Application Technology Of On-line Monitoring Of Insulated Fault Of Capacitive Equipments

Along with the quick development of the electric power business, the people have more and more high request for dependability of electric power running. The traditional prevention test has already not satisfied the request that the electric power system develop quickly. It is inevitable trend of the electric equipment maintain that condition-based maintenance is gradually replace prevention maintenance; Technology of on-line monitoring and diagnose of power equipment insulation is inevitable trend for development of condition-based maintenance.This paper introduces the significance and status que of on-line detection of insulation of capacitance electric equipments, based on study and application of engineering; we analyzed the impact of many factors for influence measure precision. Considering the characteristics and requirements of detecting the dielectric loss of the capacitive equipment, we presents the harmonic analysis theory and the implement scheme for on-line monitoring the insulation performance of the electrical equipment at substation, which the method uses mainly software technique to fulfils. Designs, manufacture and test for hardware and software of the whole system are finished. The whole on-line monitoring system has been capable of fringe running.Current sensor, signal expanding and filter circuit, digital signal collecting and processing circuit etc. are designed; Adopt two identical circuit of A/D transform, frequency trace and data sampling/holding circuits, and use PLD to control time sequence of sampling transform, speed and precision of sampling are all satisfied request of on-line monitoring of the dielectric loss, we point out the action of each unit circuit at explaining the principal of each unit circuit; Structure of the system adopt principal and subordinate model, we established an on-line monitoring mathematics model of insulation of capacitance electric equipments through stronger data analyze and disposal ability of computer; Program to data processing with perfect function are compiled, and satisfy demand of monitoring.The results of the system show that it is effective to use this on-line detecting system to detect the dielectric loss of the capacitive equipment, and the system possesses a high stability and precision.