LOUIS JOSEPH KOBIELSKI
Engineers in Sherman, NY

2007004, Mar 1, 2007

Aug 16, 2006

11/465003

Louis Kobielski - Sherman NY, US

H02P 3/14

318376000

A contactor arc suppression system for an electric propulsion vehicle having an on-board diesel-electric power generating system for supplying electric power to a plurality of DC electric traction motors for propelling the vehicle in which the traction motors are operable in an electric power generating mode during electrical braking of the vehicle and the vehicle further has a dynamic braking grid selectively coupled in parallel with the traction motors for absorbing the generated electric power during such electrical braking. The system includes at least one contactor having a pair of contact tips arranged to selectively couple the dynamic braking grid into parallel circuit arrangement with the electric traction motors during electrical braking and a snubber circuit having a diode and a first capacitor connected in series circuit arrangement with the snubber circuit connected in parallel with the contact tips of the contactor. A protection circuit for the diode includes a first resistor and a second capacitor connected in series with the protection circuit connected in parallel with the diode. A second resistor is connected in parallel circuit arrangement with the diode for providing a current discharge path for the first capacitor upon closure of the contact tips.