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

Power diode - power semiconductor devices , Power Diode A power diode i...

Power Diode A power diode is a two terminal, anode a and cathode K and  two layer P  and  N  junction devices. A PN  junction normally  formed  by allowing  diffusion and epita

Configured the dual processor architecture, Configured dual processor archi...

Configured dual processor architecture  In centralized SPC, dual processor architecture can be configured to operate in following one of three modes: 1.  Standby mode: In

Describe two ways of correcting the blur, Q. We have discussed three differ...

Q. We have discussed three different color spaces: RGB, HSI and CMY(K). Specify the need for multiple color spaces. Why can we not use only one? Q. A telescope in an observatory

Biomedical question, Find the rms voltage of the given cardiac wave

Find the rms voltage of the given cardiac wave

Find appropriate values of sampling rate - nyquist rate , 1. Find the Nyqu...

1. Find the Nyquist rate for the following signals: (a) x(t) = 5 sin 3000Πt cos 4000Πt (b) A binary channel with bit rate 36000 bps is available for PCM voice transmission.

Briefly explain single mode and multimode fibres, Briefly explain single mo...

Briefly explain single mode and multimode fibres The optical fibres were categorized within two according to the number of modes it passes as: • Single mode fibres • Multi mode

Monostable delay in matlab, how to implement monostable delay in matlab sim...

how to implement monostable delay in matlab simulink environment? [email protected]

Calculate reactive power to be delivered by the capacitor, A single-phase s...

A single-phase source delivers 100 kW to a load operating at 0.8 lagging power factor. In order to improve the system's efficiency, power factor improvement (correction) is achieve

Right-handed coordinate system, The vectors we will use we be refered to ri...

The vectors we will use we be refered to right-handed Cartesian axes. Right handed means that the x,y,z axes are oriented in a particular way (which you must know). See diagrams

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