In order to realize the rapid calculation of radio interference values based on physical processes

the statistical regularity of corona current pulse was obtained from experiments and the measured data. Short-time Fourier transform（STFT） was used to calculate the radio interference excitation currents of cylindrical wire and stranded wire under different voltages. The peak and RMS values of the excitation currents were calculated. By using STFT and the method of generating random pulses

frequency spectra along with time of corona currents and dynamic peak and RMS values of excitation currents were calculated. Results show that the corona current pulse amplitudes approximately obey the lognormal distribution

and the time intervals approximately obey an exponential distribution. With the increasing voltage

pulse frequency and the characteristics of excitation current increase accordingly. STFT reflects the dynamic process of spectrum and has a definite corresponding relationship with the time domain waveform of corona current.