Development processes of positive and negative DC corona under needle-plate electrode in air

The characteristics of positive and negative dc corona have been widely studied; however, the development process experienced of dc corona with the voltage is still unclear. This paper carried out dc corona discharge experiments under different dc voltages on the needle-plate model. Results show that positive corona gradually experienced the discharge stages of burst stream, periodic stream, glow and brush in development process; negative corona gradually experienced the Trichel discharge stages of early, middle, zigzag and glow discharge stage. Whatever positive or negative corona, differences exist in pulse amplitude, repetition rate and time interval. The results provide experimental and theoretical basis to set up and improve corona discharge detection technology.