what is vk and imag i
TRANSCRIPT
5/19/2014 What is Vk and Imag i.e Knee point voltage & Magnetising Current? Ho
http://www.allinterview.com/showanswers/70520.html 1/4
Civil Engineering
Interview Questions
(3035)
Mechanical
Engineering
Interview Questions
(3273)
Electrical
Engineering
Interview Questions
(13252)
Electronics
Communications
Interview Questions
(2353)
Chemical
Engineering
Interview Questions
Advertise your Business Here
Browse | Placement Papers | Company | Code Snippets | Certifications | Visa Questions
Post Question | Post Answer | My Panel | Search | Articles | Topics | ERRORS new
Refer this Site Login | Sign Up
Search
Categories >> Engineering >> Electrical Engineering
Question
What is Vk and Imag i.e Knee point voltage & Magnetising Current?How to calculate above values?How to define accuracy class 5P10?
Question Submitted By :: Rajashekar
I also faced this Question!! Rank Answer Posted By
Re: What is Vk and Imag i.e Knee point voltage & Magnetising Current? How to calculate above values?
How to define accuracy class 5P10?
Answer
# 1Vk is knee point of CT it mean when 10% increase in voltage varies the current 50% at that point we determine the knee point voltage. In othe words excitation test of CTs, connect a single phase variable power supply leads to the CT seccondary leads k & l or s1, s2 along with ampere meter & voltage meter & than apply voltage start from zero & raise incremental simultaneously draw a graph on each increments by plotting current on X-axis & voltage on Y-axis.Magnetizing current is those which is used in core & tank of transformer due to leakage flux, which is furthur devided into hysteris losses & eddy current losses.We can find magnetizing current by open circuit test.
1 Zahid Ali
► Interview
► PDF Voltage
► High Voltage
► It Interview
► PDF Voltage
► High Voltage
Electrical Panel &Board
superelmech.in/
Manufacturer & Dealer Of Electrical
Panel & Boards. Enquire Now!
5/19/2014 What is Vk and Imag i.e Knee point voltage & Magnetising Current? Ho
http://www.allinterview.com/showanswers/70520.html 2/4
Interview Questions
(413)
Aeronautical
Engineering
Interview Questions
(77)
Bio Engineering
Interview Questions
(16)
Metallurgy
Interview Questions
(79)
Industrial
Engineering
Interview Questions
(162)
Instrumentation
Interview Questions
(2356)
Automobile
Engineering
Interview Questions
(105)
Mechatronics
Engineering
Interview Questions
(38)
Marine
Engineering
Interview Questions
(43)
Power Plant
Engineering
Interview Questions
(74)
Engineering
AllOther Interview
Questions (1190)
We can find magnetizing current by open circuit test.5P10 means: 5 for composite errors in percentage, P for protection & 10 mean overlaod factor by multiply 10 timesin others words CT will not saturate by passing 10 times higher current.
Is This Answer Correct ? 74 Yes 9 No
Re: What is Vk and Imag i.e Knee point voltage & Magnetising Current? How to calculate above values?
How to define accuracy class 5P10?
Answer
# 2knee point means at which the core tends towards saturation .magnetising current means to produce flux in the core it will take some current it is called magnetising current.before knee point the graph between Vk and Imag will be linear,at which point linear curve getting disturbed .
Is This Answer Correct ? 27 Yes 9 No
3 V .selvakumar
Re: What is Vk and Imag i.e Knee point voltage & Magnetising Current? How to calculate above values?
How to define accuracy class 5P10?
Answer
# 3if it is 5P20 we can calculate from following formula1.2*VA*ALF/rated secondary current.magnetizing current it will be mA it may be .5 or .7 of current
Is This Answer Correct ? 11 Yes 2 No
3 Gunasekaran
Re: What is Vk and Imag i.e Knee point voltage & Magnetising Current? How to calculate above values?
How to define accuracy class 5P10?
Answer
# 4Formula for vk is as follows
vk=if(rct+2*rl)
where if is fault currentrct is ct secondary resistance rl is lead resistance
Is This Answer Correct ? 9 Yes 3 No
0 Savanth
Re: What is Vk and Imag i.e Knee point voltage & Magnetising Current? How to calculate above values?
How to define accuracy class 5P10?
Answer
# 5Dear friend,Knee Point voltage is nothing but a point at which the CT saturates. Thatsy its always better to design the CTs which can operate without saturation even at a voltage appears in the CT during fault condition. Pls find below the following formula for calculating the Knee point voltage.The formula for Knee Point Voltage is:
Vkp = K * If/CTR * (RCT + RL + RR)
in which,
K = Constant, conventionally taken as 2.0
0 Ugrasen ► High Voltage
► AC Voltage
► Winding Core
5/19/2014 What is Vk and Imag i.e Knee point voltage & Magnetising Current? Ho
http://www.allinterview.com/showanswers/70520.html 3/4
Vkp = The minimum Knee Point Voltage
If = Maximum Fault Current at the location, in Amperes
CTR = CT Ratio
RCT = CT Secondary Winding Resistnace, in Ohms
RL = 2-way Lead Resistance, in Ohms
RR = Relay Burden, in [email protected]
Is This Answer Correct ? 2 Yes 0 No
Other Electrical Engineering Interview Questions
Question Asked @ Answers
Dsitrubution transformer minimum IR value 1
show that power dissipated by a pure inductor exited by a sinusoidal voltagesource v = vm sin wt is zero
1
how to increase the power factor in machines 5
how to calculate the current carrying capacity of cable Bhel 2
why we measure ouput of transformers in kva. 1
what happens when back charging of transformer is done for longer period 1
What is the criteria for deciding whther fire wall is required between two power
transformers 1
how to calculate the no. of turns in secondary side of CT? 1
Your B.tech marks is being given in CGPA grade. How is it calculated? 1
Can you any one explain different between instantaneous over current and IDMT 1
How to select a D.G set for calculated load of 110kW..? 5
How to calculate the cable size in sq. mm. when the load is given in KW? 1
For more Electrical Engineering Interview Questions Click Here
5/19/2014 What is Vk and Imag i.e Knee point voltage & Magnetising Current? Ho
http://www.allinterview.com/showanswers/70520.html 4/4
Copyright Policy | Terms of Service | Articles | Site Map | Site Map | Contact Us
Copyright © 2013 ALLInterview.com. All Rights Reserved.
ALLInterview.com :: KalAajKal.com