×
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

Asymmetry voltage level IEC60034-1

Asymmetry voltage level IEC60034-1

Asymmetry voltage level IEC60034-1

(OP)
Hello to all. I want to ask about the voltage level of assymetry at 400kV grid which is specified on IEC 60034-1 standard and for which a generator should be kept synchronized to the grid.

RE: Asymmetry voltage level IEC60034-1

What do you want to ask about it?

Voltage assymetry will manifest itself as negative phase sequence currents in the generator stator, which in turn lead to high frequency currents in the rotor forging causing the rotor to overheat. Each machine is different in its ability to handle NPS currents. Machines connected to a large system will usually be required to remain in service with a certain level of voltage assymetry; the grid operator will specify the requirements which may or may not reference the IEC standard.

Per the UK's grid code:

CC.6.1.5

.......

(b)
Under Planned Outage conditions, the maximum Phase (Voltage)
Unbalance on the GB Transmission System should remain, in England and Wales, below 1%, and in Scotland, below 2%, unless abnormal conditions prevail.

CC.6.1.6

In England and Wales, under the Planned Outage conditions stated in CC.6.1.5(b) infrequent short duration peaks with a maximum value of 2% are permitted for Phase (Voltage) Unbalance, subject to the prior agreement of NGET under the
Bilateral Agreement. NGET will only agree following a specific assessment of the impact of these levels on Transmission Apparatus and other Users Apparatus with which it is satisfied.

Other systems will have similar requirements.

----------------------------------
  Sometimes I only open my mouth to swap feet...

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