current trasnsformer, Electrical Engineering

Assignment Help:
A 13.8 kV feed er circui t breaker has a 600:5 multira tio curr ent
transform er with charact eristics as show n in Figure 5.11. Th e max -
imum load on the feed er is 80 A pri mary. Phase time inve rse overcurrent
relays are connec ted to the CT secon daries. The relay burden
is 3.2 VA at the tap values selected, and the lead burden is 0.38 V.
a. If the 100:5 CT ratio is used, then a relay tap of 5 A is required in order
for the relay pickup to be 125% above the maximum load. With these,
determine the minimum primary current to just operate the relays.
b. For the select ion of part a what is the appro ximate maximu m
symme trical fault curr ent for whi ch the CTs will not saturate
(use the ANS I=IEEE knee point)?
c. If the 200:5 CT ratio is used so that the 2.5 A relay tap can be used,
determine the minimum primary current to just operate the relays.
13.8 kV
Bus Load bus
Equivalent
source
MVASC = 312.5
Z0 = 11.93 ?8 pu
On 100 MVA base
On 100 MVA base
X1 = X2 = j 0.42 pu
X0 = j 1.26 pu
X2 = 0.15 pu
X0 = 8
4 MVA load
@ 0.9 pf
@ 4 MVA
FIGURE P4.3
 2006 by Taylor & Francis Group, LLC.
d. Repeat part b for the selection of part c.
e. Which of thes e two CT and relay select ions would you recommend ?

Related Discussions:- current trasnsformer

Show voltage wave form of rlc series circuit, Q. The voltage wave form of F...

Q. The voltage wave form of Figure is applied to an RLC series circuit with R = 2, L = 2H, and C = 1 F. Obtain i(t) in the series circuit. (Note that the capacitor and inductor va

Surge current - thyristor, Surge Current It is  the maximum admissib...

Surge Current It is  the maximum admissible peak value of  a sinusoidal half  cycle of 10 ms duration at a frequency of 50Hz. The  value is specified at a given junction tem

Biasing clamper, Ask question #Minwhat is biasing of clamper imum 100 words...

Ask question #Minwhat is biasing of clamper imum 100 words accepted#

Types of hazards, The contents of compressed gas cylinders can range from h...

The contents of compressed gas cylinders can range from highly flammable substances, such as hydrogen, propane and ethane (acetylene), to toxic gases, such as chlorine, sulphur dio

Capacitor filter, Capacitor Filter: A capacitor filter is connect...

Capacitor Filter: A capacitor filter is connected directly across the load is displayed in figure. The property of a capacitor is that it permits ac component and blocks

How a nand gate decoder is used for 2716 eprom memory, With neat diagram in...

With neat diagram indicate how a simple NAND gate decoder is used to select a 2716 EPROM memory component for memory locations FF800H-FFFFFH. Simple NAND gate Decoder: As the 2

Calculate the speed of motor when armature current is 25 a, Q. The magnetiz...

Q. The magnetization curve taken at 1000 r/min on a 200-V dc series motor has the following data: Field current, A: 5 10 15 20 25 30 Voltage, A: 80 160 202 222 236 244 Th

Sketch the spectrum of a standard am signal, If the message has a spectrum ...

If the message has a spectrum where K and Wf are positive constants, sketch the spectrum of a standard AM signal that uses the message. Comment on the physical signi?cance

Determine required output power, Q. Two stations (using identical antennas,...

Q. Two stations (using identical antennas, with diameters of 50λ and aperture ef?ciencies of 0.6 at 35 GHz) are separated by 30 km. With negligible antenna losses, antenna connecti

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd