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Why ngt or ngr used in transformer?
Criteria-in order to protect the stator core from damage during internal earth fault it is necessary to limit the stator earth fault current al low as possible.may be upto 10amp for generator. Basis for selection of ngtr- if generator is connected to the system through generator transformer then generator can be treated as an isolated system which is not influenced by the distribution earthing system. In this case you can select earth fault current as low as possible, but if we use ngr then in order to limit the low earth fault current size of the ngr will be increased.due to big size of ngr we required more space & also its too costly. V = ir means if v constant i is inversely proportional to r exp:-to limit 10amp current , v =11kv/root 3 r = 11/root 3/10*1000=635.10 ohm ( very high value) for overcome on this, general practice to use a ngtr so that we can limit low earth current without any extra cost. Exp:- ngtr 11/240v to limit 10amp current current reflect on secondary side of ngtr will be = (11000/root 3/240)*10=264.6 amp. Resistor value on secondary side r =240/264.6 =0.9 ohm ( approximately) which is much lower than 635.10 ohm. Basis for selection of ngr- if generator is directly connected to the system then we can not limit the earth fault current up to 10 amp. We have to select the earth fault current value above the residual capacitive charging current of system.also we need to check the possibility of relay setting operation with ct ratio. For exmp- if ct ratio is 2000/1amp & earth fault limit current is 100amp relay selected with 10 % setting. Then that relay will see only 200amp earth fault current it will not see 100amp current. Also we can not keep generator solidly grounded because of high earth fault current stator can damage same will happen with ht motor if it is connected to this system. So for this case we need to select the ngr with proper earth fault current
What is pmg stator?
PMG permanent magnet generator is used for excitation or rotor in altrnator
What would happen to the output of an AC generator if one of the stator windings has an open?
There would be a significant decrease in the output of the generator. Depending on the type of generator, it could stop working altogether.
What would happen to the output of an ac generator if one of the stator windings has open?
There would be a significant decrease in the output of the generator. Depending on the type of generator, it could stop working altogether.
How do you calculate 3 phase earth fault loop?
You can't have a three phase earth fault, you can have a phase to phase or a phase to earth fault. If you want the potential phase to earth fault current it will be your voltage times your impedance. If you want the phase to phase potential fault current then you should just double the above result.
What will happen of you give AC supply to stator winding of DC generator?
why the supply is given to the stator of dc generator give answer
Stator earth fault 3 harmonic?
A stator ground fault is a single-phase to ground fault. It is the most common type of fault to which generators are subjected and could be caused by the insulation degradation in the windings as well as environmental influences such us moisture or oil in combination with dirt which settles on the coil surfaces outside the stator slots. This often leads to electrical tracking discharges in the end winding which eventually punctures the groundwall (Finney et al. 2002). Since these faults are short-circuits they are associated with immediate damage to the generator since the resulting short-circuit current would be of devastating.
Why ngt or ngr used in transformer?
Criteria-in order to protect the stator core from damage during internal earth fault it is necessary to limit the stator earth fault current al low as possible.may be upto 10amp for generator. Basis for selection of ngtr- if generator is connected to the system through generator transformer then generator can be treated as an isolated system which is not influenced by the distribution earthing system. In this case you can select earth fault current as low as possible, but if we use ngr then in order to limit the low earth fault current size of the ngr will be increased.due to big size of ngr we required more space & also its too costly. V = ir means if v constant i is inversely proportional to r exp:-to limit 10amp current , v =11kv/root 3 r = 11/root 3/10*1000=635.10 ohm ( very high value) for overcome on this, general practice to use a ngtr so that we can limit low earth current without any extra cost. Exp:- ngtr 11/240v to limit 10amp current current reflect on secondary side of ngtr will be = (11000/root 3/240)*10=264.6 amp. Resistor value on secondary side r =240/264.6 =0.9 ohm ( approximately) which is much lower than 635.10 ohm. Basis for selection of ngr- if generator is directly connected to the system then we can not limit the earth fault current up to 10 amp. We have to select the earth fault current value above the residual capacitive charging current of system.also we need to check the possibility of relay setting operation with ct ratio. For exmp- if ct ratio is 2000/1amp & earth fault limit current is 100amp relay selected with 10 % setting. Then that relay will see only 200amp earth fault current it will not see 100amp current. Also we can not keep generator solidly grounded because of high earth fault current stator can damage same will happen with ht motor if it is connected to this system. So for this case we need to select the ngr with proper earth fault current
How can a stator frie in my eb2200x Honda generator?
the stator is responsible for collecting and delivering all the current to your device or load.
What part of the ac generator produces the rotating magnetic field?
The stator and the magnets.
What is the function of exciter rotor and stator in Generator Operation?
In the operation of a standard generator, the exciter rotor and stator provide DC-type energy to an AC-type supply. This allows the exciter to maintain a constant DC source.
What are the components of a generator?
The rotor, the stator and the voltage regulator are three main components of a generator. If you are talking about a motor generator set then of course the other main component would be the engine to drive the generator.
Why is conductivity important for Generator primary water?
Purpose of maintaining conductivity of primary water in a generator is 1. To avoid earth fault caused by excess conductivity. 2. To avoid corroision of primary water system (including stator windings) as water gets acidic with low conductivity(due to ion exchanger used for reduction of conductivity). P.S. conductivity of PW for a 500 MW generator is usually maintained b/w 1 to 2 micro S/cm.
What is pmg stator?
PMG permanent magnet generator is used for excitation or rotor in altrnator
Why isn't my home power generator working?
check all parts of your generator accordance to release the fault. there may be some difficulties to remove your generator fault because your generator details are not available.
What are the main components of a generator?
The rotor, the stator and the voltage regulator are three main components of a generator. If you are talking about a motor generator set then of course the other main component would be the engine to drive the generator.
Answering Which one is a separately excited generator - ac generator or dc generator?
Excitation is the phenomenon by which you control the excitation of field winding of a generator. In DC generator field winding is placed on stator and this field winding can be self excited or seperately excited depending upon the type on generator used. AC generators can also be self excited or seperately excited type but field winding is placed on rotor nad armature winding on stator.
