Answer / sanset

Partial discharge (Pd) fault detection is a well proven
test method that relies on the detection of small electrical
discharges generated in faulty areas of electrical
insulation. It is also a method under consideration for
future on-line monitoring systems particularly in the area
of asset management of transformers. Much of the fundamental
principles of capturing Pd pulses were developed in academic
environments. However the limitations of Pd fault detection
is that it requires considerable operator skill in detecting
Pd pulses and interpreting results. It has been estimated
there are less than 200 operators in the world, capable of
correctly conducting and interpreting Pd testing.
Consequently, to-date Pd test has largely been limited to
the laboratory and low electrical noise environments.

The theme of more contemporary work has been the
identification of Pd pulses in extremely electrically noisy
environments requiring a rare combination of expertise, HV
technology and intelligent systems. Several concepts through
industrial collaboration have been identified that have lead
to the development of algorithms permitting recognition of
Pd pulses barely discernible with traditionally applied
visual analysis. Finding that the successful recognition of
Pd and the ability to accurately predict Pd pulse shapes
under fault conditions; requires substantial historical
behaviour details, based on a knowledge of localised
background noise indigenous to the subject equipment.
Currently work is being undertaken, researching techniques
to predict the unique nature of Pd pulses generated within
particular electrical environments, by sophisticated
analysis (feature specific) of local conditions.

In A.C systems, fuse is placed in phase-in order to disconnect the circuit during faulty condition. But, what is the reason for putting "LINK" in neutral istead of connecting through (same) wire.

3 Answers  

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what are the main parts of DG? explian thier functions?

8 Answers   Apollo Power, Tata DoCoMo, Tyco, Vizag Steel,

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what is through fault?

0 Answers   KSEB,

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how many frequent start/stop operation possible in case of HT MOTORS.

5 Answers   DVC, Steel Plant,

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Transmission lines usually use a.3 phase b.2 phase c. Single phase

1 Answers   K Tech Electrical,

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Hi,Any one has idea regarding the KPTCL Recuirtments for AE'e & JE's for the year of 2009-10???Kindly help in regards..

1 Answers  

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my question is Megger of cable insulation or swgr board meggerring some values in one day 50mohms,some other day checking different values(20Mohms). this tell that some person tell that that values ok. how to identify the megger value is correct. pls tell me the answer.

2 Answers  

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why some transformer without breather.

1 Answers   GTS,

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In one village i have seen Earthing transformer's earthing line was also connected to the Transformer body to ground the transformer,can it be possible to maintain 0Volt reutral line this way?

2 Answers  

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what kn of disc is used in 33kv,132kv,220kv,400kv,800kv transmission line

0 Answers   Jindal, Power Grid,

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what is the difference between current voltage transformer and current transformer and where it is used?

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When we use air circuit breaker, it has O/L protection ,time delay SC protection, Instataneous SC protection & ground fault protection. They all have some setting range. But what is the suitable/allowable setting for the above protection which will be safe for the equipment? For example-O/L protection setting have a range of (0.4,0.45,0.5,0.55,0.6,0.65,0.7,0.8,0.9,1.0)xIn Time delay SC protection have a range of (1.25,1.5,2,3,4,6,8,10,12)xIn Time delay setting is 0.02,0.1,0.2,0.3,0.4 Instataneous setting is fixed to 20xIn Gound fault setting is given 100A,300A,600A,900A,1200A This setting are for 2500A ACB. So what will be the basic allowable setting for the above protection? is there any formulae to calculate this<

0 Answers   Lupin,

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