when excitation fails,Reactive power will be supplied by the system to which the generator is connected and generator will work as induction generator and its speed will rise a little. generator which was in over excitation mode will work in underexcitation.but there is under excitation limit which should not be reached so we should detect loss of excitation and trip generator
A loss of excitation will cause the generator to start drawing more and more reactive power over time. Over the first few seconds, and until about thirty seconds after the LOE (depending on the load on the generator before the loss of excitation occurred), active power will stay relatively constant, but reactive power will continue to be absorbed from the rest of the system, and voltage levels will drop. Eventually, the magnetic field between the stator and rotor degrades too much, pole slipping and loss of synchronism will occur. At this point, catastrophic damage will likely have been done to the generator.
loss of field protection is important because when a synchronous generator looses field excitation its acts as an induction generator and draws reactive power from the system which heats and damages rotor so as soon as the loss of field excitation is sensed the generator breaker should be opened as the rotor and the stator would both heat up and could damage. Best Regards, Ayaz Ahmed
The major causes of loss of excitation on generators are due to an open circuit or a short circuit in the field winding. This may also be caused by a breakdown of the insulation system.
stray loss copper loss
when excitation fails,Reactive power will be supplied by the system to which the generator is connected and generator will work as induction generator and its speed will rise a little. generator which was in over excitation mode will work in underexcitation.but there is under excitation limit which should not be reached so we should detect loss of excitation and trip generator
The reverse KVAR relay protects a generator from a loss of excitation. When the excitation system is lost, reactive power will flow from the system back into the generator. When this happens, induced currents at twice the system frequency will flow in the rotor windings and rotor structure.
A loss of excitation will cause the generator to start drawing more and more reactive power over time. Over the first few seconds, and until about thirty seconds after the LOE (depending on the load on the generator before the loss of excitation occurred), active power will stay relatively constant, but reactive power will continue to be absorbed from the rest of the system, and voltage levels will drop. Eventually, the magnetic field between the stator and rotor degrades too much, pole slipping and loss of synchronism will occur. At this point, catastrophic damage will likely have been done to the generator.
loss of field protection is important because when a synchronous generator looses field excitation its acts as an induction generator and draws reactive power from the system which heats and damages rotor so as soon as the loss of field excitation is sensed the generator breaker should be opened as the rotor and the stator would both heat up and could damage. Best Regards, Ayaz Ahmed
Many things are possible. Open circuit or winding. Blown fuse or circuit breaker. Loss of excitation current. Just to name three.
The major causes of loss of excitation on generators are due to an open circuit or a short circuit in the field winding. This may also be caused by a breakdown of the insulation system.
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manly generator engine site lose. Because we know that 1HP=746watt.Formula W=1.732*voltage*current*p.f (this is engine side loss.
Generator power output can be affected by various factors such as mechanical wear and tear, overheating, fuel quality, or improper maintenance practices. These can lead to lower efficiency, reduced output capacity, and potential breakdowns. It is important to regularly monitor and maintain generators to minimize power loss and ensure reliable operation.
Look on the ground! Monitor the coolant reservoir.
Water loss that is difficult to detect and measure is called insensible water loss. This type of loss occurs through processes like evaporation from the skin and exhalation from the lungs, making it challenging to quantify accurately without specialized equipment.
Iron losses (Pi) are independent of of load which occur due to pulsation of flux in the core. Iron losses include both Hysteresis loss and eddy current loss and is same at all the loads.