what is difference between differential protection and
distance protection and how we calculate the sloop?
- 5 Answers
- 43632 Views
- OPS, Power Grid, I also Faced
- E-Mail Answers
Answer Posted / raju t
Differential Protection:
1. It simultaneously compares the phaser difference & magnitude of the current entering & leaving the protected zone.
2. It works on kirchoff's current law
3. It is a unit protection scheme i.e. it needs current inputs from minimum two different sources.
4. Differential current = |I1+I2| --> Vector sum
5. It cannot be used to provide backup to other relays
6. %Slope = (Id2-Id1)/(Ib2-Ib1)
Distance Protection:
1. It calculates the apparent impedance of a line with the help of voltage & current input connected to the relay. If measured impedance falls below set impedance trip command is issued to clear the fault.
2. It works on impedance measuring principle
3. It is a non-unit protection but can be easily used as an unit protection by co-ordinating distance protection with PLCC
4. Z=V/I
5. It can be set to provide backup to adjoining lines & bus bar depending on the requirement.
| Is This Answer Correct ? | 30 Yes | 0 No |
Post New Answer View All Answers
Write the force balance equation of ideal spring element.
What is gain margin?
How we can change the direction of rotation of Induction motor? Prove it using graphical
What is the physical significance of phase.. i.e. what is exactly the meaning in layman's language.. 1 phase, 3 phase etc ???
when we decide to use soft starter drive or vfd drive in mcc to operate apump?
what is the value of combined earthing in general electrical circiut?
What kind of socket shall be provided for window type air conditioner with cooling capacity upto 18000 BTU/hr
Why the power generated in dams is complex power? Why the generators in dams cannot produce Real power directly (i.e power which has zero reactive part)?
what is difference between 5A and 100A CT constructional wise and operation?
Why cables and busbar both needed in LT Panels?
we have provided 30 nos. relay contacts in panel.I want to know how do we do the numbering for the relay contacts as per any applicable standards
What is the maximum No. of out going mccbs permitted from an LV distribution paqnel? What is the ampere relation between incomer and out going switch gears/mccbs?
What are the advantages of autotransformer?
what are the application of over current relay?
Which level of the Transformer oil got dielectric strengh? And why?
