ETAP PowerStation Sequence of Operations

[croudk]

All right everyone, here's a pretty focused question. Has anyone out there had much experience with the new Sequence of Operations module in ETAP PowerStation? This module is supposed to allow you to simulate a fault (3-phase or line-to-ground) anywhere in a system model and it will evaluate and report device clearing times in sequence. I played with it a bit when it first came out, but I wanted to see if anyone else has any experience with it - good or bad. My experience with it was not real positive, but the system I tried it on had a very complicated protection scheme. I am getting ready to analyze a loop system and I am trying to decide if I should try ETAP's Sequence of Operations or not.

 

[dpc]

I saw a report that was produced with this tool and it did not match up too well with what I came up using traditional TCC evaluation. The report I saw didn't really provide me enough information to be able to figure out why it was getting different results.

It's a nice idea and moves into the realm of fault simulation. But it's important to be able to verify the results somehow.

Seems like it could be helpful for a looped system - it's difficult to use TCCs to evaluate and display results for loops since the relays often see very different of fault current for any one fault.

 

[croudk]

Thanks. That was my take on it also. The clearing times that were reported seemed almost arbitrary when evaluated manually using TCCs and breaker opening times. I wasn't sure if the problem was arising simply because I had a system with Schweitzer multifunction relays and several levels of differential protection. But it sounds like it may be a more common problem. Hopefully I'll get some more replies to compare with.