Example 35.1

[nmjwolf]

I am having a bit of trouble following this example....I am missing something how they are calculating the bases.

Why when the Sbase and Vbase are calculated are they shown as 15MVA and 13.9K? Shouldn't the Sbase be 15/3 and the Vbase be 13.9/sqrt(3) when calculated for a 3-phase system?

Thanks,

Jason

 

[Flyer_PE]

Is this in Camara's book? I'm away from home and don't have the EERM with me. I'll take a shot at this though. Typically, the power base is the full three-phase value. The base voltage can be expressed on either a phase or line basis depending on the problem statement. On a pu basis both the line voltage and the phase voltage will be 1.0 if they are at the base value.

Hopefully, I haven't just caused more confusion.

Jim

 

[mudpuppy]

Dang Jim, 11 minute response--on a Saturday! Do you get paged every time a question is posted?

wolf--it is good you are having trouble following example 35.1, because it is flawed. Be sure to get the errata for all the P P I materials you may have <a href="http://ppi2pass.com/"the other board"/PPIInfo_pg_Errata-Errata.html" target="_blank">here</a>.

EDIT: Ok, the link doesn't work because of the replacement the EB software automatically does between P P I and "the other board". But the errata are available on P P I's website if you look hard enough. Or replace "the other board" with P P I (with no spaces) in the link text above.