Re: Very smoky XPT

[matthew@mail.usyd.edu.au (Matthew Geier)]

In article <mauried.200.3692E2B7@commslab.gov.au>,
Maurie Daly <mauried@commslab.gov.au> wrote:
>In article <76ucij$7e3$1@nnrp1.dejanews.com> thalystgv@yahoo.com writes:
>>James
>
>Not totally related to XPT smoke , but does anyone know exactly how the XP 
>power cars provide HEP for the rest of the train.
>I know they use an auxiliary generator which is driven by the main engine,but 
>if this is the case how is the frequency maintained over the rev range of the 
>engine , static invertors possibly.

 I dont know the exact values, but the HEP alternator is connected to
the main engine shaft. The voltage and frequency to the train power line
vary with engine speed. From 100v 25Hz to 300v 60+Hz or there abouts.

 The lights run from a DC battery backed supply with the batteries charged
by a charger connected to the trainline. The Air Con motors have change
over contacts that vary the motor winding connections as the voltage and
frequency of the trainline rises.
 
 The power car end is simple, at the expense of complexity in each car.
30 years ago when the HST was designed, this was probably the best method.
Why the XPT stuck with it im not sure, although solid state frequency 
converters would not have been available in any great power rating when
the XPT was built. A rotary converter on the power cars would have added
to much weight.