Kilovolt Amps and Horse Power?

[Ian]

I have been given some coursework which has rather puzzled me, and I'm not sure how to tackle the probem:

Any tips that would get me started would be ideal! I think I'm going to have to get this question clarified by the lecturer, as no-one else seems to understand this either - we haven't done much electronics on the course yet.

 

[Me__2001]

i dont know if this is right but it sound good

shaft HP = 45Kva / 0.75 and HP = 60Kva/0.75

maybe?

 

[Ian]

It could be, but I think its going to be fairly complicated to work out, as there is the other load on each channel aswell. Still working on it, eek!

 

[ChristopherP]

I think Flops may be the one to help out here?

He's into electronics isn't he?

Chris

 

[floppybootstomp]

The AC volts' horse power is easy enough to work out. Presumably for 200 Amps worth of 28V DC you'd have to convert that to Kva?

What's baffling me is how to work out the power dissipated during generation and conversion. I'd guess you need some reference figures and a formula (equation?) to work that one out. Are all these power convertors the same in real life or do they have individual characteristics?

Heat dissipation - have not a clue. Ditto with overall efficiencies.

Again, I'm assuming this question ties in with similar course topics where these devices have been examined and discussed. Without some form of reference or knowing the correct mathematical formula, I just don't know.

My Electronics experience only goes to City & Guilds Part III Electronic Servicing - Colour TV Reception and Digital Techniques. That was in 1987 and I've forgotten most of it though obviously some parts are ensconced in me noggin. Were I to look at my exam papers from that time, I expect I'd be flummoxed.

edit: Just noted each device has an efficiency figure - 85% so we have 15% inefficiency. Thinking on it...

 

[Ian]

Cheers Floppy I've never dealt with kVA and Horsepower before, so I'll see how I can convert them now I've got the heat dissipated question done, but the rest I still cant figure out.

We haven't been given any other formulae or data apart from this, that is why I was puzzled too. We have mainly been getting computing based electronics work but this was a "one off" coursework - I think I'll have to get the lecturer to go through this, as I don't know anyone who has managed to do it.

 

[ChrisIMRIE]

I might print the convo out and give it to Andy this afternoon, my electronics teacher.

Should get him thinking instead of teaching us

I will see if he might help.

Chris.

 

[Ian]

Thanks Chris, only just noticed this reply