Variation Law of Spatial Electric Field During the Development of Streamer Under Positive Switching Impulse Voltage

The streamer discharge process has typical characteristics such as weak luminescence and high ionization. It is of great significance for deepening the mechanism of streamer discharge process and improving the gap insulation performance to quantitatively analyze the optical signal and spatial electric field distortion law during the development of streamer. Consequently, we adopted photoelectric integrated electric field sensor, photomultiplier tube, Rogowski coil and other equipment to build a photoelectric combined detection system so as to measure the instantaneous optical power, space electric field, and ground electrode discharge current during the discharge development of the 10 cm needle-ball gap under positive standard switching impulse voltage. The test results show that, at the beginning of corona, the ultraviolet light generated by the streamer will cause the distortion of the electric field; the more intense the light of streamer of the needle electrode is, the larger the electric field established in the space will be. When the breakdown occurs in the gap, the spatial electric field distortion is obvious, the streamer is observed by the photomultiplier tube before breakdown, and a negative current flows through the ball electrode. Comparison and analyses of the instant optical power and electric field under different voltages reveal that the electric field sensor can be ultized to judge the moment of initiation of the streamer and the intensity of the streamer. © 2019, High Voltage Engineering Editorial Department of CEPRI. All right reserved.