Mounting base for rotating rectifiers - Aluminum or Copper? 2

[edison123]

I have seen many rotating rectifiers (3 phase, bridge type) for generators mounted on aluminum plates, which also act as heat sinks.

Given that copper has a better thermal conductivity, wouldn't it make more sense to use it than aluminum?

Muthu

http://www.edison.co.in

 

[3DDave]

I would expect a tradeoff if air is on both sides of the plate - at some point the lateral movement of heat, which favors thicker plates, is balanced by the transverse movement, which favors thinner plates. Without careful (and for me, unpracticed) analysis, it's tough to be sure. Fortunately FEA methods can handle some parts of it, but it's always the transfer to air and by radiation that make it a chore.