> such motors require frequent maintenance for changing the brushes.
"Frequent" is all relative.
The Renault Zoe, 10y ago, was already using a synchronous engine with wired rotor. And most were going over 150kkm without any issues nor brush changes.
> because the electrical currents that circulate through the rotor windings must generate heat
Currently stator heat in wired synchronous engine is less a problem than in SynRMs with permanent magnets.
Most neodymium based permanent magnets start to be irreversibly damaged id they heat up beyond 100°C. That's currently why Tesla has such a good cooling system in their engine.
Wired rotor are bunch of copper coil, as such they are much more resistant to temperature gradients.
"Frequent" is all relative.
The Renault Zoe, 10y ago, was already using a synchronous engine with wired rotor. And most were going over 150kkm without any issues nor brush changes.
> because the electrical currents that circulate through the rotor windings must generate heat
Currently stator heat in wired synchronous engine is less a problem than in SynRMs with permanent magnets.
Most neodymium based permanent magnets start to be irreversibly damaged id they heat up beyond 100°C. That's currently why Tesla has such a good cooling system in their engine.
Wired rotor are bunch of copper coil, as such they are much more resistant to temperature gradients.