Sir your videos are amazing.. Never learnt all these subjects in a better manner before. Please upload more topics and benefit the students. Thanks and regards
Simple and clear explanation. All my earlier misunderstanding of the alternator reverse power relay stands corrected. With clear understanding of the operational behaviour of a system one can approach his work more confidently.
Thanks for appreciation. We are doing online classes daily on both Engineering and Nautical topics. Please visit www.himtmarine.com for online schedule and topics.
hey jenise, so does that mean that during motoring effect, the generator keeps on running in the same direction and does not change the direction of rotation?
Thank a lot sir for giving a clear instructions and learnt lot from your knowledge and your videos are so helpful to gain my knowledge and clearing my doubts. U are great sir, salute you sir
All the explanation was on point, I only have one doubt that why do we need to go till negative 10% Of rated load to open the breaker and stop the generator why can't we open the breaker at 0kw in case the fuel is reduced to Zero in any trip?
I am more than happy to be able to attain ur class " Sir V.R. Venkatesan" from across the border. Your classes build my confidence and knowledge. HIMT, You are doing a wonderful job of benefiting people around the globe with hard-gained knowledge and years of experience of your intellect teachers. Huge respect for them all. 🤍
Sir., So That means if reverse power trip happens then only the problem is power produced by one gen is consumed by other?? No physical or other damage to gen??
Reverse power happens when the prime mover's developed power falls below the idle power. It will happen when for any reason the fuel supply is cut off or drastically reduced. If there is nothing wrong with the engine , but the fuel filter clogs, the power can go to reverse. This situation will not result in any damage (perhaps running for long periods can damage the fuel pump). If the fuel reduction was due to a safety function,( such as low lub oil pressure), the power will go to reverse. In such case unless the breaker is opened quickly, the engine is going to run and will get damaged severely. It is not the reverse power per se that is causing the damage. It is inability of the engine to stop under failed lub oil condition that will destroy the bearings and crank shaft
Sir, thanks for the wonderful explanation. I am confused as to the reason for maintaining constant speed even after the engine fuel is cut off. Wouldn't there be as speed drop as the alternator is running more like an induction motor? It would be nice if you could clear my doubt.
During reverse power situation, there is also an high chanse of overspeeding of engine if fuel racks of of fuel injection pumps are wrongly adjusted. Make sure whilst the engine goes to stop all of them stays at 0 mm.
wonderful explanation sir. while motoring the generator runs as a synchronous motor, its speed will be much more than engine's rated speed. so while testing the reverse power relay function, aren't we putting generator at risk as far as speed is concerned?
During reverse power condition, the motoring alternator and the other alternator will still run at the same frequency (speed) . There is no danger of over speeding. During motoring as when we test, the fuel from the prime mover is reduced and the reverse power drawn will only compensate for this. Even if the fuel is completely stopped , the alternator (and the engine) will continue to keep rotating, with the reverse power overcoming the resistance. Why should there be any over speeding? Overspeeding can happen only if the fuel to the engine is not reduced and the alternator also turns into a motor . This cannot happen.
Thanks for your interest. We are in the process of developing more videos and in a series. Meanwhile I am writing a series in the Marine Engineer's review .
Thanks for appreciation. We are doing online classes daily on both Engineering and Nautical topics. Please visit www.himtmarine.com for online schedule and topics.
Sry for delay comment ..sir Plz explain what difference between low forward power and reverse active power..at what reason when they two will work??.am more confused plz explain
Reverse power is when the prime mover generates less than the idling power, due to reduction of fuel. Low forward? power only means when the kw load on the alternator is low . The intention is to simulate a fault condition such as Lub oil failure and check whether the engine will shut down.
Professor, I'm hearing that we have a generator in the field that delivers real power properly but is not able to control or deliver reactive power... I'm told it's reverse reactive power...is this possible?
Assuming a generator paralleled with grid. If the AVR voltage is set to the grid voltage and later Should the grid voltage increase above the generator voltage setting, will there be reverse power?
Reverse power is related to KW. Alternator turns to motor only when the KW of the prime move drops. Voltage differences will result in changes in reactive power. Please watch the video on AVR droop in same chaneel
The mechanical power developed by the prime mover has to reduce to a level below the idling power. Fuel to an engine or steam flow to a turbine reduces below the idling level. In such case the power will reverse
Thn wat will this motoring effect cause any danger to alternator part like diodes.... Or this is only for stopping the engine..during parallel operations.can u explain sir..
KW generated by the alternator has to come from the engine which has to produce the mechanical power . When a single alternator is running and is on load if fuel is cut off, (either by stop switch or due to a safety shut down) the engine will stop. ( there will be a blackout). When an alternator is running in parallel , any attempt to stop the engine will fail if the circuit breaker is still connected, as the power to keep rotating will be drawn from the busbar. If the reason for stoppage is a serious engine fault such as LO press failure the engine cannot be saved even of the LO press trip works. Thus to save your engine apart from stopping fuel the breaker has to be opened. That is done through the reverse power relay. The excitation circuit creates a magnetic field to maintain the required EMF so that the terminal voltage is maintained. As the KW on the alternator increases, the field current has to increase. When the alternator is without load, field current will be minimum.' When the alternator is running as a motor, the EMF is less than the terminal voltage, so the field current will be less than the No load condition. In such case how can the excitation circuit get overloaded? There is no risk of damage to those components.
It is for stopping the engine during parallel operation. If an engine runs alone, stopping fuel will stop the engine. If it is connected to another engine , either mechanically (with gears) or electromagnetically ( an in alternators) stopping fuel alone will not work. You need to disconnect the engine.
Sir your videos are amazing.. Never learnt all these subjects in a better manner before.
Please upload more topics and benefit the students.
Thanks and regards
first time in life i got to know about this clearly.....otherwise i was round little knowledge of reverse power...thnx sir
Dear Sir,
Thanks a lot for all your videos sir!
You may have departed this earth, but your videos continue to impart us the correct knowledge.
Simple and clear explanation. All my earlier misunderstanding of the alternator reverse power relay stands corrected. With clear understanding of the operational behaviour of a system one can approach his work more confidently.
Thanks for appreciation. We are doing online classes daily on both Engineering and Nautical topics. Please visit www.himtmarine.com for online schedule and topics.
hey jenise, so does that mean that during motoring effect, the generator keeps on running in the same direction and does not change the direction of rotation?
Thank a lot sir for giving a clear instructions and learnt lot from your knowledge and your videos are so helpful to gain my knowledge and clearing my doubts. U are great sir, salute you sir
crystal clear expertise from your end. This is how colleges should TEACH.
There are no bad marine engineers just Poor Teachers !!!
Respect from Pakistan such a calm And logical teacher!
Explanation superb thank you very much sir.1st time today its clearly understand in my life🎉️🎉️🎉️👍.
The professor knows how to explain things very succinctly.
I've never seen a best explanation than this.. Thanku.
Same here
very nice illustration with different scenarios .....................................thanking you sirrr
All the explanation was on point, I only have one doubt that why do we need to go till negative 10% Of rated load to open the breaker and stop the generator why can't we open the breaker at 0kw in case the fuel is reduced to Zero in any trip?
great sir..very much informative thanks a lot
Fantastic superb Explanation Sir
I am more than happy to be able to attain ur class " Sir V.R. Venkatesan" from across the border. Your classes build my confidence and knowledge. HIMT, You are doing a wonderful job of benefiting people around the globe with hard-gained knowledge and years of experience of your intellect teachers. Huge respect for them all. 🤍
Excellent explaination sir! Very helpful!
Got lot of concept from this, thank you so much sir
Very good and practical explanation, Thank you Sir
EXCELLENT LECTURE SIR.
CONTINUE THIS
Thank u sir ....I had a better understanding of this topic now
Sir., So That means if reverse power trip happens then only the problem is power produced by one gen is consumed by other?? No physical or other damage to gen??
Reverse power happens when the prime mover's developed power falls below the idle power. It will happen when for any reason the fuel supply is cut off or drastically reduced. If there is nothing wrong with the engine , but the fuel filter clogs, the power can go to reverse. This situation will not result in any damage (perhaps running for long periods can damage the fuel pump).
If the fuel reduction was due to a safety function,( such as low lub oil pressure), the power will go to reverse. In such case unless the breaker is opened quickly, the engine is going to run and will get damaged severely.
It is not the reverse power per se that is causing the damage. It is inability of the engine to stop under failed lub oil condition that will destroy the bearings and crank shaft
Sir how to test reverse power
Thank you , I now have a much better understanding of rpp
thank you sir. explanation was very clear.
Hi bro im eto course student plzs one help me sir
Sir, thanks for the wonderful explanation. I am confused as to the reason for maintaining constant speed even after the engine fuel is cut off. Wouldn't there be as speed drop as the alternator is running more like an induction motor? It would be nice if you could clear my doubt.
The alternator runs as a synchronous motor not as an induction motor. So it will continue to run at synchronous speed.
U r just phenomenal....
All this while I had it all wrong😂😂
U might change the way how Indians view marine electrical
It is very useful, Thank you sir.
During reverse power situation, there is also an high chanse of overspeeding of engine if fuel racks of of fuel injection pumps are wrongly adjusted. Make sure whilst the engine goes to stop all of them stays at 0 mm.
how can it be overspeed? when the reversed power is supplied at the same frequency..
Thank you so much sir, very greatful for such endeavour
J8 no words ur knowledge is excellent
wonderful explanation sir. while motoring the generator runs as a synchronous motor, its speed will be much more than engine's rated speed. so while testing the reverse power relay function, aren't we putting generator at risk as far as speed is concerned?
During reverse power condition, the motoring alternator and the other alternator will still run at the same frequency (speed) . There is no danger of over speeding.
During motoring as when we test, the fuel from the prime mover is reduced and the reverse power drawn will only compensate for this.
Even if the fuel is completely stopped , the alternator (and the engine) will continue to keep rotating, with the reverse power overcoming the resistance. Why should there be any over speeding?
Overspeeding can happen only if the fuel to the engine is not reduced and the alternator also turns into a motor . This cannot happen.
thank you for the reply sir. @@vrvenkatesan5825
Awesome sir very good explanation😉😉
Top class explanation sir. Thank you so much if u hav a video series of electrical teachings i would like to buy for study.
Thanks for your interest. We are in the process of developing more videos and in a series. Meanwhile I am writing a series in the Marine Engineer's review .
@@vrvenkatesan5825 sir can i get your articles if possible please share the link or mail paddyinline@gmail.com
Thanks for appreciation. We are doing online classes daily on both Engineering and Nautical topics. Please visit www.himtmarine.com for online schedule and topics.
Useful information..
Veary helpful sir..🙏thanku sir 😊🙏
Sry for delay comment ..sir
Plz explain what difference between low forward power and reverse active power..at what reason when they two will work??.am more confused plz explain
Reverse power is when the prime mover generates less than the idling power, due to reduction of fuel. Low forward? power only means when the kw load on the alternator is low . The intention is to simulate a fault condition such as Lub oil failure and check whether the engine will shut down.
Professor, I'm hearing that we have a generator in the field that delivers real power properly but is not able to control or deliver reactive power... I'm told it's reverse reactive power...is this possible?
thankx for explanation
Thank you very much, Sir!
How its true to avoid alternator become a load during negative (-) Kw..?
which types of relays ,how many types of relays,how many no.of ct&pt are used to protect the generator to reverse power protection
Mechanism of reverse power relay is not explained.Please explained with current coil,voltage coile and non magnetic aluminium plate
Explanation is given in any standard marine electricity book .
Aux engine runs @ MCR or NCR.plz reply sir.
Sir, if alternator side having 500 kw load.what would be load on engine side.
RIP ,,,,Deep condolences
Super Explanation
Assuming a generator paralleled with grid. If the AVR voltage is set to the grid voltage and later Should the grid voltage increase above the generator voltage setting, will there be reverse power?
Reverse power is related to KW. Alternator turns to motor only when the KW of the prime move drops. Voltage differences will result in changes in reactive power. Please watch the video on AVR droop in same chaneel
best video
very nice
Sir what is the exact location of reverse power relay
Between alternator and busbar
What could be the possible reasons of reverse power generation in a generator ?
And ways rectify this?
The mechanical power developed by the prime mover has to reduce to a level below the idling power. Fuel to an engine or steam flow to a turbine reduces below the idling level. In such case the power will reverse
@@vrvenkatesan5825 thank you sir.
Love you from pakistan dear sir
How thermal generator turbine works
Thn wat will this motoring effect cause any danger to alternator part like diodes.... Or this is only for stopping the engine..during parallel operations.can u explain sir..
KW generated by the alternator has to come from the engine which has to produce the mechanical power .
When a single alternator is running and is on load if fuel is cut off, (either by stop switch or due to a safety shut down) the engine will stop. ( there will be a blackout).
When an alternator is running in parallel , any attempt to stop the engine will fail if the circuit breaker is still connected, as the power to keep rotating will be drawn from the busbar. If the reason for stoppage is a serious engine fault such as LO press failure the engine cannot be saved even of the LO press trip works. Thus to save your engine apart from stopping fuel the breaker has to be opened. That is done through the reverse power relay.
The excitation circuit creates a magnetic field to maintain the required EMF so that the terminal voltage is maintained.
As the KW on the alternator increases, the field current has to increase. When the alternator is without load, field current will be minimum.'
When the alternator is running as a motor, the EMF is less than the terminal voltage, so the field current will be less than the No load condition. In such case how can the excitation circuit get overloaded? There is no risk of damage to those components.
It is for stopping the engine during parallel operation. If an engine runs alone, stopping fuel will stop the engine. If it is connected to another engine , either mechanically (with gears) or electromagnetically ( an in alternators) stopping fuel alone will not work. You need to disconnect the engine.
is there any students from HIMT currently studying in either 3rd or 4th year (B.Tech)or just passed ?
Yes, we have B.Tech Marine Engineering Cadets in their 3rd & 4th Years and also passed out Cadets.
You can reach our team at college@himtcollege.com
INFORMATIVE !
why don't we keep setting 0 for reverse power?
Very low or zero reverse power setting will result in unwanted tripping while trying to synchronise the generator to bus bar
I can't understand clearly sir
Any particular doubt?
99
Rip VRV Sir
Please speak french or arabe or written english your speak
Mrglglglgglglglgl is all that I can hear