But for example if they used PMM squirrel cage motors etc, they would be nice and smooth, cheaper to build, more energy efficient.
On the battery front, using car-style or truck-style EV battery modules would be more robust and would reduce cost by somewhere in the order of 50%.
Instead, most trains still use induction motors (this is the high pitch whine you hear) and many train battery designs use industrial style rack mount batteries, with screw terminals, controlled by a massive PLC cabinet. In eMobility the controls are handled by a small safety-rated microcontroller.
They care a lot more about robustness, maintenance, max continuous power, than cost, volume, or short duration ratings. Commuter trains are used for a decade and half, then sold to developing nation to be used couple more. No surprise that they're choose rack batteries with thick cables to bus bars over plastic packs in trays, if they even consider using degradable batteries at all.
Developing a new train platform takes a lot of time but Siemen’s Velaro Novo platform (in development since 2013 and presented 2018) uses PMM motors[1].
Siemens has been trialing PMM motors since at least 2003[2].
What are you talking about? The noise you hear from trains is the wheels. Battery trains basically don't exist because of this cool invention called a wire and pantograph.
The “nice smooth trains” that commenters are talking about use a pantograph, transformer and small on-board battery, and can go a small distance (few kms) through tunnels and between track segments with the pantograph lowered.
The power system after the battery is similar to older model electric vehicles.
On the battery front, using car-style or truck-style EV battery modules would be more robust and would reduce cost by somewhere in the order of 50%.
Instead, most trains still use induction motors (this is the high pitch whine you hear) and many train battery designs use industrial style rack mount batteries, with screw terminals, controlled by a massive PLC cabinet. In eMobility the controls are handled by a small safety-rated microcontroller.