Questions on some Etap :D (basics)

[sysy]

Hi all, i am trying to create a power system one line diagram for analysis on ETAP Star.

May i ask what are the typical values for a power system for the components such as generators, power transformers, current transformers, circuit breakers(high,low), fuse and motor. I search the net but its either i can't understand the diagram or there is not much information as to what to key in for the values. Would appreciate any help so that i can start on my project

 

[davidbeach]

There are no typical values. Every system is different. If you want a standard test case, google up the IEEE 30 bus system.

 

[sysy]

hello thanks! it looks really complicated for me haha, is there a power system that u could recommend me to look up to even if there are no typical values?

 

[davidbeach]

"google up the IEEE 30 bus system"

 

[sysy]

Hi, i did search after you told me to the first time. Could u briefly explain to me how i can make use of the IEEE 30 bus system for my STAR Protection analysis in ETAP? thank you.

 

[LionelHutz]

You'd use it as an example to learn how to model your system.

 

[sysy]

Hi LionelHutz,

Thanks! I want to ask if i can use this circuit

http://article.sapub.org/image/10.5923.j.instrument.20120102.03_001.gif

to do a Star- protective device coordination analysis?

 

[LDKGR]

Hi sysy,

my recommendation is to start with a very basic diagram (Grid - MV switch - Trafo - LV switch - Load). After that you can add more and more items in your diagram according to your background.

 

[LionelHutz]

I don't think anyone is clear on what you're trying to do.

You should have the data on the sources, transformers, CT's etc when you're going to model an actual system. Most components really don't require that much data points to do basic simulations. For example, a transformer requires the winding configuration, grounding, voltages, impedance and X/R ratio.

If you are just playing around, then do as LDKGR suggested and start with a very basic power system. Etap will supply many default values and you could just use those.

 

[LDKGR]

Hi LionelHutz,

sysy is student

 

[sysy]

Yes, sorry i didn't make it clear to you. I am working on my final year project and am requested to develop a protection scheme that will keep electrical power system stable by isolating the faulted parts from the rest of the electrical network and my basic skills in engineering is burdening me.

I have to Investigate
1. Current and voltage transformers to step down the high voltages and currents.
2. Protective relays to sense the faults and initiate trips or disconnections.
3. Circuit breakers to open/close the systems based on inputs from relays.

I have a lot of doubts and i just want to try to clear it out here because i have seen most tutorials and i know how to create a graph and how to use the tools but what i am confused with is how the components react in the OLD as i place them and how the settings of values would affect them.

Sorry to bother but can i ask if the way i place the relays and circuit breakers are correct in the attached file. Thanks a lot!