×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Negative sequence directional element

Negative sequence directional element

Negative sequence directional element

(OP)
Hello Folks,

I am new to the field of power system protection. I am working on a project where I have to calculate the values of 'Negative sequence directional element' for a radial system. I've successfully calculated the values of various parameters like pick up current, forward and reverse threshold but finding the positive sequence line impedance angle is troubling me. I have Z bus matrix for the line impedances between two buses. I have uploaded image of the single line diagram of the system.Does anybody have any idea how to calculate this?

Thanks

RE: Negative sequence directional element

What type of relay? What is the impedance of a line section?

RE: Negative sequence directional element

(OP)
We are suing SEL 351S relay. They have not given any impedance as such what they have given is Z bus matrices between bus 800-802, 802-803,802-804.....to 806-807.

RE: Negative sequence directional element

How does the Z-bus matrix differ from a table of impedances?

RE: Negative sequence directional element

Hi, By overlapping , you open the first line CB1 and CB2 then , "forward " and " backward " , then you determine the coordination ansi50 / 51 for each each given a value of negative sequence that is tolerable. In my review Appropriate value I2 is the one Who is not Reflected in the secondary of the transformer (in Dy1 for example) or in the case of Determining the voltage (U2 ) IEC 61000 2% or standard IEEE 1159 2%(less accurate ) .

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources