Study on the mechanism and characteristics of pulsed corona discharge in water

Plasma pulse is a safe and environmentally friendly unconventional technology for enhancing oil and gas production. However, during the pulsed discharge process, an abnormal discharge phenomenon often occurs, which severely affects the performance of the equipment and is referred to as corona discharge. This paper combines laboratory discharge test data to theoretically analyze and validate through COMSOL simulation the mechanism of corona discharge generation under the same electrode gap distance. A comparative analysis with arc discharge is also conducted to further examine its characteristics, and nonlinear regression analysis is used to study the impedance variation of the plasma channel during corona discharge. Results indicate that the decrease in switch breakdown voltage in the later stages of continuous discharge leads to the generation of corona discharge. The impedance of the plasma channel can be characterized by a time-varying resistance model based on a double exponential function. Finally, validation through theoretical calculations and Simulink simulations achieves a fitting rate of over 99%. The research provides significant guidance for further analysis of corona discharge and the development of suppression methods in plasma pulse technology, contributing to the optimization of the equipment and enhancing its operational performance.