Research On Fiber-optic Digital On-site Detection System For High-voltage Capacitance Equipments

Capacitance equipment is an important equipment of substation whose secure and stable running is an important factor to ensure the power system’s normal operation. So it is important to realize the capacitance equipments’ reliable monitoring of insulating. In the past years, the power system uses precautionary experience to test the capacitance equipments’ insulation. As precautionary experience is carried out at low voltage, so the test’s results can’t reflect the real insulation of the capacitance equipment sometimes. Based on the defect of preventive test, the article develops a system of fiber-optic digital on-site detection in order to finish capacitance equipments’insulating on-site detection of substation. The article’s finished work is as follows.The article develops a hardware system of fiber-optic digital on-site detection which is based on light technology. It solves the problem of active current sensors and remote module for energy supply. At the same time, it exploits fiber-optic transmission signals which have great anti-electromagnetic capability to ensure reliable signal transmission. Besides, this system also introduces the PCI-1761relay card to change the on-off condition of the power supply of local module with failure, which helps to improve the stability of data communications. Finally, optical switch is embedded in the system to achieve the transform of the different optic paths, which helps to reduce the number of local modules to reduce the system cost.The article develops a software system of fiber-optic digital on-site detection. This system uses graphical programming of Lab VIEW to achieve the relative measurement for equipments of the same type for the same phase in substation, which includes data communication based on USB virtual serial port, PCI-1761’s controlling, optical switch’s controlling based on RS-232serial port, algorithm implementation, data storing and the webpage reporting.The article verifies the feasibility of on-site detection system using comparison test of fiber-optic digital on-site detection designed by this paper and RCD-1B on-line detector through three110KV current transformers of the lab.