Using a superconducting magnetic energy storage coil to improve efficiency of a gas turbine powered high speed rail locomotive

The US Federal Railroad Administration has been pursuing the use of locomotives with an on-board prime mover for high speed rail. Such systems would not require the added cost of rail electrification on top of the rail bed modifications. The prime mover runs a synchronous generator, with the output rectified to feed a DC bus. Adjustable speed drives control the traction motors. However, gas turbines run efficiently over a narrow speed range and a relatively narrow power range. The addition of a superconducting magnetic energy storage coil can improve overall system performance. The SMES coil is charged whenever the locomotive is in regenerative braking mode and whenever the prime mover is producing more power than is needed to maintain the desired speed down the track. The chief benefits to such a scheme are: (1) better acceleration at high speeds, (2) reduced prime mover power rating and weight, (3) reduced railbed cost due to reduced weight (4) reduced trip time and (5) improved fuel efficiency