Abstract: The present invention discloses an apparatus for damping resonance of an LC type low-pass filter provided on the DC input side of a power converter having a DC input terminal. The apparatus comprises an electric circuit connected in parallel to a reactor constituting the LC type low-pass filter. The electric circuit has an impedance which takes a substantially minimum value at a frequency equal to the resonance frequency of the LC type low-pass filter.

Abstract: A control device for an electric train formed of plural coupled carriages each of which receive power from an overhead power line via a collector, wherein each carriage is provided with a power converter for converting power from the overhead line to a suitable level for a load within the respective carriage. Each carriage also includes an auxiliary power supply device having an input coupled to the output of the power converter of the another carriage and an output coupled to an input of the power converter of the same carriage, so that if the power level from the overhead line to one carriage falls below a predetermined value, the power converter of that carriage is supplied with power from the power converter of another carriage through the intermediary of the auxiliary power supply device of the same carriage.