Very well explained about the differential protection relay actually it works on the same principle the two C.T installed on primary and secondary side of Power Transformer are paired and the sensing Relay is connected across them in case of faults the Net Current or Total current attains some value which leads to trip command to Master Trip Relay no. 86. The differential relay is also helpful in finding if there is any kind of short circuit between primary and secondary windings.But there is no such thing like Generator Transformer it is just Step Up Transformer it is not generating any power .
If the CTs are configured in opposite direction, I am thinking the 87 element will operate not only during the thru fault or the fault in the other transformer but during the normal load operation too.
it should be mentioned that ct connection differs to accomodate vector change of transformers. otherwise incorrectly wired ct would result in faulty tripping.
Very good explanation. But why is it necessary to occur fault for tripping transformer, when the 33KV side CT connection is in reversed condition? In this situation during initial charging itself the secondary CT's current will be in reverse polarity such way that it will get added up in the 87 relay and trip the transformer.
Hi .. Thanks for Your videos.. I have a question about the stability test transformer for Power Distribution Transformers 126MVA ( 220Kv / 33 Kv) , please can you share information for this
Very good but ... The TR diff scheme includes bais current and slope and I diff in present numerical relays . So concept is correct but how to calculate these three thing with formula ... Slope , bais currents , I diffe currents with formulas
yes they will. but that is not desirable so we have to check all these things in the beginning itself when the transformer is being commissioned, so that these problems don't arise afterwards. And in numerical relays we rectify some errors of ct connection internally without changing the connection.
Good videos. Thanks. I have a silly question- why the current in Ct secondary is opposite to direction of the current flow from GT to feeder. (What do you mean by to balance the current, it flows in opposite direction) Thanks in advance
CTs primary coil is the line where CT is fixed and the voltage is induced in the secondary of CT, so the current in the secondary coil of CT always flows opposite to that of the current in the primary because as per the law induced current always opposes the cause which produced it. So in short, current in secondary of CT always flows opposite to current in primary coil or lines. Hope it is clear for you now.
No Tr1 will see it as a fault outside it's differential zone. So differential protection will never operate. But if CB of LV SIDE of TR2 fails to open TR1 will trip through back up over current protection
In first two cases u hv shown the current flow as same ...i.e. opposing each othr...then hwcom in first case(33kv fdr side fault) u say I0 but not trip....and also for second case in trafo area fault....I0 but trip ? confused....can u xplain ?
restraining coils are only the difference.diff protection is basic scheme which is having disadvantages of operating for through fault also this problem is recovered by the help of %diff protection which is having restraining coils
Please make vedio by taking 15 mva transformer 132 kv / 11 kv YD TF with 100 /1 amp hv CT and 1250 /1 amp lv CT PLEASE DO A VEDIO WITH THIS EXAMPLE USING AN ALSTOM RELAY TO GET THE DIFF SETTING ..
Now days we have all numerical relay for advanced system protection . So there is no use if you teach old electro magnetic relay concepts .. So please make vedio with example to get I DIFF SETTING
During faults in the feeder, the feeder relay would operate first. But if it fails to operate then the over-current relay and earth fault relays of transformer would operate.
I have seen many videos for understanding the diff protection... And this is the best one ... Keep posting more videos..
simple and nice one sir
good nice,
and easy of explanation
it was just a awesome video lecture... thank you sir, i will see it over and over...
Nice explanation.
mate, this is some beautiful explanation
Very well explained about the differential protection relay actually it works on the same principle the two C.T installed on primary and secondary side of Power Transformer are paired and the sensing Relay is connected across them in case of faults the Net Current or Total current attains some value which leads to trip command to Master Trip Relay no. 86. The differential relay is also helpful in finding if there is any kind of short circuit between primary and secondary windings.But there is no such thing like Generator Transformer it is just Step Up Transformer it is not generating any power .
very nice video...
sir please post a video on impedance or distance relays also
very nice explanation!!
very thorough treatise
Super helpful thanks a lot
How I can add malticontroller to the circuit? and is it matter to have a specific transistor value before and after the step down transformer
sir please make video on reverse reactive power relay...
If the CTs are configured in opposite direction, I am thinking the 87 element will operate not only during the thru fault or the fault in the other transformer but during the normal load operation too.
yes. but it also depends on the loading of the transformer and the pick up value of the relay
it should be mentioned that ct connection differs to accomodate vector change of transformers. otherwise incorrectly wired ct would result in faulty tripping.
Immidiate trip will accur
Pls add distance protection, backup protection in details also add all vector group of transformer,also add circuit breaker
Well explained sir
boss could u plz elaborate the basics of slope characteristics for diff relays .. thnx
Very good explanation. But why is it necessary to occur fault for tripping transformer, when the 33KV side CT connection is in reversed condition?
In this situation during initial charging itself the secondary CT's current will be in reverse polarity such way that it will get added up in the 87 relay and trip the transformer.
thanks sir, i was very easy to understand your explanation
Hi .. Thanks for Your videos.. I have a question about the stability test transformer for Power Distribution Transformers 126MVA ( 220Kv / 33 Kv) , please can you share information for this
How connect and protect two transformers with a single breaker relay please?
how feeder one breaker will trip? from where it fed tripping signal?
for feeders we have different set of overcurrent and earth fault relays
can you send me links of yours all videos about protection and CT PT
Very good but ... The TR diff scheme includes bais current and slope and I diff in present numerical relays .
So concept is correct but how to calculate these three thing with formula ... Slope , bais currents , I diffe currents with formulas
Even Under Normal Conditions if the CT Connections r wrong they will give trip signel continously
yes they will. but that is not desirable so we have to check all these things in the beginning itself when the transformer is being commissioned, so that these problems don't arise afterwards. And in numerical relays we rectify some errors of ct connection internally without changing the connection.
🤚🤚🙏🙏💝
Thank you very much.sir
thank you, I wish you could upload a video about the 3phase differential protection diagrams with their calculations.
ya sure. soon I will be uploading videos on those topics
i need solution manual of power system protection by pathikar please
czcams.com/video/gSyqe8_fHto/video.html
Thank you so much, just in time for my exams.
Welcome
Thanks👌🏻👌🏻
Good videos. Thanks. I have a silly question- why the current in Ct secondary is opposite to direction of the current flow from GT to feeder. (What do you mean by to balance the current, it flows in opposite direction) Thanks in advance
CTs primary coil is the line where CT is fixed and the voltage is induced in the secondary of CT, so the current in the secondary coil of CT always flows opposite to that of the current in the primary because as per the law induced current always opposes the cause which produced it. So in short, current in secondary of CT always flows opposite to current in primary coil or lines. Hope it is clear for you now.
thanks for vedio ,,i think if there is a fault onTR2 both CBs of TR2 should open same time otherwise TR1 will also trip, correct me if im wrong
No Tr1 will see it as a fault outside it's differential zone. So differential protection will never operate. But if CB of LV SIDE of TR2 fails to open TR1 will trip through back up over current protection
Many thanks for valuable information. but I still not full understand polarity of CT circuit.
Current the flows into the dot on the primary flows out of the dot on the secondary side.
In first two cases u hv shown the current flow as same ...i.e. opposing each othr...then hwcom in first case(33kv fdr side fault) u say I0 but not trip....and also for second case in trafo area fault....I0 but trip ? confused....can u xplain ?
SuperPosker a bit confusing on the current flowing in the diff relay
Thank you
Your lecture is fine but could you explain me percentage differential relay
yeah soon will be uploading a video on this topic.
what if only One TF is there??
What is the difference between Percentage Differential protection and Differential Prrotection
soon I will be uploading a video on this topic also.
restraining coils are only the difference.diff protection is basic scheme which is having disadvantages of operating for through fault also this problem is recovered by the help of %diff protection which is having restraining coils
Please make vedio by taking 15 mva transformer 132 kv / 11 kv YD TF with 100 /1 amp hv CT and 1250 /1 amp lv CT
PLEASE DO A VEDIO WITH THIS EXAMPLE USING AN ALSTOM RELAY TO GET THE DIFF SETTING ..
Now days we have all numerical relay for advanced system protection . So there is no use if you teach old electro magnetic relay concepts ..
So please make vedio with example to get I DIFF SETTING
Sound is too low.
is there any oter relay operating?
During faults in the feeder, the feeder relay would operate first. But if it fails to operate then the over-current relay and earth fault relays of transformer would operate.
Pen paper use kr liyo , wo jyada better rhegea😔😔
jone!!!!
You are Mr.Pandi rajan
No I am not Mr. Pandi Rajan
Can u please speak loud ?