[ausev] DC or AC motors - which make the best generators?

[Gil Dawson]

Here's my impression:

Choosing a design with AC vs DC generators is very similar to the 
design choice of Alternator vs Generator in an ICE car.  An 
alternator's AC output is rectified with diodes to drive the charging 
buss.

The reason DC motors don't show up with regen very often might be 
because the controller for a DC motor is relatively simple, and so 
appeals to the individual car builder.  The controller for an AC 
motor, howevr, is relatively sophisticated yet permits more precise 
control of the car's handling.  AC controllers, therefore, would 
appeal more to designers in a competitive market who can recover 
their engineering costs over thousands of units sold.

You could theoretically add regen features to the design of a DC 
Controler, but then the controler would cost more, pricing it out of 
the homebrew market.  Adding regen capability to an AC controller 
would presumably add a smaller proportion to the cost, yet produce a 
feature that is known to the public and can be used in marketing the 
car.

Regen isn't worth a whole lot, anyway.  Individuals can build a fine 
car without it.

It's interesting how this division between AC and DC favoring 
distinct design goals echoes the arguments between Tesla and Edison 
between AC and DC for electrical distribution standards.  Edison 
favored DC, which would have led to an industry of many independent 
local power plants each with its own distribution system.  Tesla 
favored AC, which led to an integrated transmission system, and power 
plants could be located practically anyplace.  Edison wanted 
customers for his products.  Tesla wanted to light up the world.

--Gil