Study On Discharge Detection System For High Voltage Apparatus Based On Photomultiplier Tube

The discharge detection of the High-Voltage (HV) apparatus as scientific basis for electrical sectors'operation and inspection can be found out effectively and a reliable reference to the insulated condition of apparatus. The flash spotting, especially the Ultraviolet radiation (UV) detecting as a non-electric detecting method has advantages because of non-contacting. But it is hard to use because that it has a poor sensitivity and can not reflect the intensity of the discharge. This paper makes a groping research on the corona discharge from HV apparatus and the technology of UV detecting technology based on photomultiplier tube (PMT), researches the UV detecting technology and characteristics of PMT, designs the discharge UV detection system based on PMT, researches the application status of the system by experiments. The main work and achievements of the research are shown below:①The spectrum of the corona discharge in air from the theory of corona discharge and some experiments were researched The conclusion that the main spectrum of the corona discharge is in UV wave band which should be choose as detecting spectrum in discharge detection.②The characteristic of PMT and its application in Ultraviolet radiation measuring and detection of sun-blind Ultraviolet light were researched. The correlation of discharge from the HV apparatus and its Ultraviolet radiation which is the foundation of UV detecting technology were discussed.③The feasibility of using PMT as detecting sensor from the characteristic of PMT and the detecting circuit were researched. Relative the ultraviolet pulse method and the UV photoelectric cell, ultraviolet power method which fits to the output character of PMT are proposed. The PMT was proved has better linearity than UV photoelectric cell. It could detect the weak UV-light and applied in discharge detection of HV apparatus.④The discharge UV detection system based on PMT and singe-chip was designed. The high speed digital integral circuit was taken to measure the power of UV radiation from discharge. The radiation strength could be inferred as the reference of the intensity of discharge from the relation between the measure results and the UV light got in the surface of the sensor.⑤Detection tests in laboratory included igniter discharge experiment and Tip-Plane Corona discharge experiment and transformer substation were made and the experimental results show that the system could detect the weak UV-light and quantitatively indicate the intensity of UV radiation which could be the reference of the intensity of discharge. The detection system has good sensitivity and linearity, could be used in discharge detection of HV electric equipments.The discharge detection system based on PMT which still has space to ameliorate in reducing noise and keeping the angle of incidence could be applied in actual detection on discharge of HV apparatus. It not only has advantages of good ability on anti-jamming and non- influence on the operation condition of the power system but also could quantitatively indicate the intensity of UV radiation which could be the reference of the intensity of discharge. The detection system has good sensitivity and linearity, could be used in discharge detection of HV electric equipments.