Communication and signaling systems on board can be affected by the transient electromagnetic(EM) disturbances induced by a contact sliding between the catenary and the pantograph.In order to verify the immunity of the embedded communication and signaling systems working in these transient EM disturbances environments,the time and amplitude parameters of the transient disturbances on board are characterized.Measurements are performed on a board of the China railways high-speed(CRH) trains to collect a large amount of radiated and conducted transient EM disturbance information both on the train roof and in the radio frequency(RF) cable.With the ultimate goal of generating transient disturbances scenarios,which are representative of those detected by the antennas and the probe,and performing immunity tests in laboratory conditions,statistical distributions of the transient characteristics of the transients,such as rise time(tr),time duration(td),time interval(ti),and peak amplitude(Ap),are studied.As for radiated transient disturbances,several statistical parameters are obtained from probability density functions(PDFs),which were simulated by MTLAB using the probability density and the estimation methods.Test results are estimated by using the maximum likelihood estimation method with 95% confidence intervals(except time interval).In the conducted transient disturbances tests,both tr(common value of 2527 ns) and td(0.10.4 μs) are greater than that in EN 61000-4-4 while ti(4555 μs) is far less than that in EN61000-4-4.
