Time-domain virtual EMI receiver model algorithm for corona-originated electromagnetic interference of dc transmission line

A time-domain virtual electromagnetic interference (EMI) receiver model algorithm for corona-originated EMI of dc transmission line is proposed. The presented model is based on short-time fast Fourier transform (FFT) and digital quasi-peak, peak and average detector algorithms together with the measured corona current. The virtual EMI receiver model algorithm is verified by comparing with measurement results of conducted interference of the three regular waveforms. The influences of computational accuracy on the conducted interference are discussed. Through utilising the laboratory-scale corona cage to generate corona current, the 0.5MHz excitation current is calculated by using short-time FFT and excitation function theory. The measured and computational average value, root mean square value, quasi-peak value and peak value of EMI receiver response to corona current sequence are obtained. It is found that computations of radio interference have a good agreement with the measured results.