Problem in the 132kv Double Circuit Line

6 comments

Rate

Anonymous Poster #1	Problem in the 132kv Double Circuit Line 06/22/2012 3:35 AM
	there are two grid station connected through 132kv double circuit line. on the one circuit the current in the B phase shows zero(sequence is RYB) while the current in the same phase B of the other circuit shows double the current of the other two phase. for example the current on the circuit-1 three phase is 40A,40A, 0A then the current on the circuit-II three phase is 40A,40A & 80A. the problem is at the sending as well as in the receiving end of the grid station. the CT ratio are800-400-200/1A & the earth fault setting are 20%(80A) & the over current setting are 75%(300A). the CT connected at 400/1A. when the load on the two phase reached up to 130A on the first circuit the circuit first tripped on the eaqrth fault. Now when the breaker is on the line is charged & the same process repeated.Also the voltage on the circuit-I is as under RY-132kv, YB-70kv, BR-70kv please tell me what is thr problem.Is the insulatior disc of thr phase B got puncture or the phase B of the line got open(due to damaging of the jumper) or there is the problem in thr CT connection or any other problem. CR4 Admin - email address removed From the CR4 Rules: Do not post phone numbers or email addresses. The CR4 Admin will delete all phone numbers and email addresses posted in threads or comments. You can share this information via the CR4 internal messaging system.
	Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

These comments received enough positive votes to make them "good answers".

JohnDG Guru Join Date: May 2006 Location: Reading, Berkshire, UK. Going under cover. Posts: 9684 Good Answers: 468	#1 Re: problem in the 132kv double circuit line 06/22/2012 5:32 AM
	From what you've said, phase B of circuit 1 is disconnected at the sending end (before the point at which you measured the current and voltage). If the disconnection was at the receiving end, the B phase current would have been zero, but the voltages between the phases would all have been 132kV. __________________ "Love justice, you who rule the world" - Dante Alighieri
	Reply Good Answer (Score 2)

sehdev singh Active Contributor Join Date: Jun 2012 Posts: 11	#2 In reply to #1 Re: problem in the 132kv double circuit line 06/22/2012 9:46 AM
	the same problem occur at recieving end as well at sending end. i donot know about the status of voltage at the sending end. the status of voltage is of recieving end.but the status of current in the B phase is same at the sending as well as recieving end.as at the recieving end there are different 132kv lines.
	Reply

JohnDG Guru Join Date: May 2006 Location: Reading, Berkshire, UK. Going under cover. Posts: 9684 Good Answers: 468	#3 In reply to #2 Re: problem in the 132kv double circuit line 06/22/2012 9:58 AM
	As you don't know the inter-phase voltage at the sending end, all we can say is that there's a disconnection in the B phase somewhere before the receiving end (i.e. it could be a broken cable - tho' I think this is unlikely). __________________ "Love justice, you who rule the world" - Dante Alighieri
	Reply

V.I.Abraham Guru Join Date: May 2007 Location: Pune , India Posts: 875 Good Answers: 42	#4 Re: Problem in the 132kv Double Circuit Line 06/23/2012 7:49 AM
	The voltages at sending and receiving end have to be checked. What I presume is that either a breaker contact of one phase is either not making contact or may be non operative.the other probable fault is the terminal connecting link at sending or receiving end may be broken on the particular feeder in which no current is noticed. The system may be working in parallel so the total load of the phase is carried by the healthy feeder line. The possibility of an earth fault is eliminated as the system is operating when the load is less than the maximum set current.
	Reply

Anonymous Poster #2	#5 Re: Problem in the 132kv Double Circuit Line 07/12/2012 9:26 AM
	Hi there 1. Your problem probably lies with one or both of your Blue phase links at the substations....If a link has for some reason some high resistance the current will flow in the other line and therefor it will double up as you have said..... If you can take out the line that shows 0 amp ask the people to service that blue phase link at both ends (both the subsations) 2. It is also possible that on that line your blue phase conductor might be stolen Cheers Mike
	Reply

MJ Jordaan Active Contributor Join Date: Jul 2011 Posts: 13	#6 Re: Problem in the 132kv Double Circuit Line 07/12/2012 9:41 AM
	Hi there That problem you have indicates to me your line is either stolen or a jumper off at one of the structures....... The current is low for now only 40A and possibly under the earth fault "Pick up" current.... Also the voltages YB and BR indicates low... Let the people drive the line and look for the missing conductor....jumper broken or stolen conductor Cheers Mike
	Reply

These comments received enough positive votes to make them "good answers".

Copy to Clipboard

Anonymous Poster (1); JohnDG (2); MJ Jordaan (1); sehdev singh (1); V.I.Abraham (1)

	Got Something to Say?
	Ask a Question Start a Discussion

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (141 right now) Show Members