All over the world there occur more and more unexpected resonances in railway power grids. They are caused by the steadily growing number of digital power electronic components and regulators in the supply infrastructure. Their numbers and amplitudes are also significantly higher than the amplitudes of the harmonic resonances that were present in traditional infrastructures.

Grid resonances — a serious threat to your railway infrastructure

If these har­mon­ic res­o­nances are undamped, their ampli­tude can be as high as the sig­nal ampli­tude of the base fre­quen­cy of the sup­ply grid. Res­o­nances caused by har­mon­ics could not only dam­age the sup­ply infra­struc­ture itself but also the equip­ment con­nect­ed to it. The band­width of these res­o­nances ranges from a few Hz up to a cou­ple of kHz.

Grid Harmonics Tolerance Test (GHTT) for e‑locomotives

To avoid the mal­func­tion of an e‑locomotive its tol­er­ance against har­mon­ics that may occur in the rail sup­ply grid should be test­ed. EGSTON pro­vides a spe­cif­ic test sys­tem for this task that ensures a sig­nif­i­cant­ly high­er reli­a­bil­i­ty dur­ing oper­a­tion.

IMS method to investigate and avoid harmonic grid resonances

Newest pub­li­ca­tions explain the caus­es of har­mon­ic res­o­nances and pro­vide ana­lyt­i­cal meth­ods how to mea­sure, analyse and avoid them. The Imped­ance Mea­sure­ment Sys­tem (IMS) cre­ates imped­ance plots from e‑locomotives and rail sup­ply grids. With the help of IMS har­mon­ics that are caused by their inter­ac­tion can by pre­dict­ed before they even occur.  This increas­es the avail­abil­i­ty of your rolling stock in your dai­ly oper­a­tion sig­nif­i­cant­ly.

System configuration:

• CSU — Har­mon­ic Injec­tion


IMS Rail
• GHTTS Rail