Regenerative Drive for Subway Trains—Part 2: Overall System Model

The external system (track, vehicle) for the regenerative drive study is modeled from actual construction drawings and performance specifications. A general duty cycle is constructed and found to compare within a few percent of actual measured data; furthermore, the duty cycle simulates all vehicle operational modes (“all out,” cruise, coast, brake). Vehicle dynamics are simulated using current railroad engineering practice; the equivalent mass of rotational elements (transmissions, rotors), about 16 percent of the vehicle curb mass, is accounted for in the accelerated state. The internal d.c. electric drive system is modeled using current industrial design practice; the technique of energy flow-through efficiencies facilitates the determination of vehicle station-station tractive requirements.