Metro-North/GE AC propulsion system retrofit program

Two DC-powered 1100 Series cars were retrofitted with an AC propulsion system. Extensive tests were conducted on the propulsion system and the cars are currently in revenue service. The cars selected are 85-ft painted steel multiple-unit cars built by Pullman Standard in 1965. The braking system is a 26CMUE-80 electric pneumatic straight air pipe system supplied by New York Air Brake. The AC inverter propulsion packaging is a three-phase, variable-voltage, variable-frequency, gate turn-off thyristor, voltage-source inverter driving two three-phase, asynchronous traction motors. Each propulsion inverter is a microprocessor controlled, variable voltage, variable-frequency, voltage-source inverter using pulsewidth modulation (PWM) and square-wave regulation techniques. The propulsion inverter control strategy is derived to drive two asynchronous motors operating in parallel