The Development Of Optoelectronic Detector For The Corona Discharge In GIS

GIS(gas insulated switchgear) is a main equipment of the high-voltage substation system. Because of its complex structure and high integration of switch, the corona discharge phenomenon occurs easily due to the insulation defects, burrs and metal particles and so on, causing the deterioration of equipment insulation performance. Detecting the corona discharge existed in GIS real-time can monitor the working status of the equipment and prevent the accident of discharge deterioration and ensure the stable operation of GIS.The optical pulse method was used to measure the GIS corona discharge in this paper.Not only the optoelectronic detector of corona discharge based on PMT was designed and developed, but also some experiments for the study of the optoelectronic detector were conducted. The main innovative research work of this paper are as follows:The optical detecting principle of corona discharge was analysed and the spectral distribution of the optical signal from corona discharge was obtained by the existing gas corona discharge theory and the high-voltage needle- plate corona discharge simulation.The architecture of detection device is designed to use PMT as the core module. A optical receiving system for increasing the light-sensitive surface and improving the effect of the light gathering by Zemax was designed. A method to receive corona discharge light signal by fluorescent excitation is proposed. A fluorescent glass that matches the spectral distribution and complete the design of the receiving system by fluorescent excitation was produced. The design and production of power module with sensitivity adjustment controlled by SCM and digital potentiometer is completed. The signal processing module of high pass filtering and amplification of the output voltage signal from PMT is designed.The optoelectronic detection device of corona discharge is experimented in the laboratory and field GIS. The optoelectronic detection device is verified to detect the corona discharge in GIS feasibly and accurately through a series of experiments. The parameters results obtained by optoelectronic detection device can effectively reflect the strength of the corona discharge in real time.