by farecard
lpetrich wrote:Thanks. WMATA started with DC motors with classic cam control in the 1000's, then in the 2000-3000 choppers.farecard wrote:What is the propulsion system of the new cars: VFD's+multiphase motors, chopper+DC, etc?I looked through BART's pages on its new railcars, and there was no mention of any such technical details. Those pages mostly discussed what passengers will experience, like the railcars' floor plans and seats.
The 1000's were rebuilt mid-life with https://en.wikipedia.org/wiki/Variable-frequency_drives & multiphase AC motors.
Newer builds are all AC motors.
I wonder if BART ever rebuilt DC cars with AC?
[AC motors are lighter, smaller diameter & have almost nothing to break. When both systems were born, VFD's just did not exist, especially at these power levels. Now they are off the shelf...]