Effect of Relative Humidity on DC Corona Pulse Characteristics at Different Air Pressure

It has been investigated that the effect of relative humidity on statistical parameters of negative corona pulses at different air pressure conditions. A rod-plane electrode configuration has been used. The range of air pressure and relative humidity is 0.06 MPa~0.10 MPa and 30%~90% respectively. The variation of average amplitude and standard deviation of negative corona pulses is illustrated. Average amplitude and standard deviation of negative corona pulses are lowered, as the air pressure or relative humidity rises. It is demonstrated by the ratios of average amplitude under different conditions that the degree of influence of air pressure (or relative humidity) on average amplitude becomes more pronounced at higher relative humidity (or air pressure). The linear relationship exists between average amplitude and the square root of the product of air pressure and relative humidity. While between standard deviation and the product of air pressure and the square root of relative humidity are the second order relationship. It means that the degree of influence of air pressure and relative humidity is the same on average amplitude, but different on standard deviation