Statistical Properties of Initial Spark Path in Short Air Gap With Negative Switching Impulses

The spark discharge path in air gap is tortuous and branch. The random characteristics of spark discharge path is mainly caused by randomness of the number and position of photons in spatial photoelectric process. Space charge and spatial electric field have certain restriction to the development of the discharge path. Negative switching impulses of 250/2500 μs had been applied to three typical air gaps of 0.4~1.2 m. The effect of factors such as gap distance and impulse voltage amplitude were studied in detail with comparison tests. Test results show that the initial direction angle of spark discharge path both in rod-rod and rod-double rods air gaps obey normal distribution respectively, and their normal distributions are influenced by gap distance, rod configure and applied negative switching impulse amplitude. The research in the paper benefits much to get more knowledge of spark discharge process.