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

What is terminate and stay resident, What is TSR? TSR: The TPA also as ...

What is TSR? TSR: The TPA also as TSR stand for terminate and stay resident programs which remain in memory in an active state till activated by a hot-key sequence or other eve

What is stored program control, Q. What is Stored Program Control ? Sto...

Q. What is Stored Program Control ? Stored Program Control:Modern digital computers use stored programmed concept. Here, a program or a set of instructions to the computer is s

Explain open loop control systems, Explain Open Loop Control Systems In...

Explain Open Loop Control Systems In an open-loop control system, the controller independently computes exact voltage or current required by the actuator to do the job and send

Arithmetic operations, Arithmetic Operations Various  types of arithmet...

Arithmetic Operations Various  types of arithmetic  operations like addition subtraction increment and  decrement  are performed in 8085 microprocessor. Generally in these  ope

Write a report on various types of diodes, a. write a report (at least  2 p...

a. write a report (at least  2 pages ) on various types of diodes( Show and explain  the theory, symbol, circuit, characteristics, data sheets and applications circuits using the d

Low-pass electronic filter, Low-pass electronic filter: The capacitors...

Low-pass electronic filter: The capacitors and inductors are the reactive elements of the filter. The number of elements ascertains the order of the filter. In this situation,

Ac circuits, AC Circuit: This topic explain the basic concepts of sing...

AC Circuit: This topic explain the basic concepts of single and three-phase ac system. Unit provides the thorough analysis and derivations as required by topics. Here we find

Semiconductors, Charge density In a semiconductor

Charge density In a semiconductor

Image frequency for an fm station, Q. Show that the image frequency for an ...

Q. Show that the image frequency for an FM station does not fall in the range of 88.1-107.9 MHz, regardless of the choice of high- or low-side local oscillator.

Calculate arithmetic mean, a) Get the best linear relationship in accordanc...

a) Get the best linear relationship in accordance with least square analysis for the following data:- X 0.9 2.3 3.3 4.5 5.7 6.7 Y 1.1 1.6 2.6 3.2 4.0 5.0 b) The table belo

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