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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.
What else can I help you with?
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.
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 are the constructional features of a 3 phase induction motor?
stator,roto
What is the frequency of the second harmonic if the fundamental frequency is 1000 Hertz?
If the first harmonic of 1 kHz is 2 kHz, then the second harmonic is the odd order harmonic of 3 kHz.
What are the 3 fault's?
normal fault, reverse fault, strike-slip fault,
What are the 3 types of faults found on the earth?
i know that one of them is the san Andreas fault in the USA but i don't know the other two
How do you remove a crankshaft pulley on a 67 Chevelle?
The crankshaft pulley unbolts from the harmonic balancer. The harmonic balancer can be removed from the crankshaft with a 3 bolt puller.
Can you change the stator direction of 3 phase squirrel case motor?
yes by reversing phases
How many stator poles are used for battry charging when using thev 3 a stator assembly given as an?
The number of stator poles used for battery charging in a 3-phase stator assembly typically depends on the design and application of the generator or alternator. However, in many cases, a 3-phase generator will have either 6 or 12 poles, which allows for effective charging of batteries by generating alternating current (AC) that can be rectified to direct current (DC) for charging. The specific number of poles can vary based on factors like the desired output voltage and frequency.
What is the name principle of 3 phase induction motor?
Transformer action. There is no electrical connection between the stator and the rotor, and voltages get induced into the rotor bars when they are swept by lines of magnetic flux created by the stator windings.
Is Total harmonic distortion important when selecting a UPS?
Total Harmonic Distortion is an important phenomenon while selecting a UPS. AC Harmonic content (THD-Voltage) shall be <= 3% for linear load and <=5% for non linear load.
What is the problem if your 2001 Olds Intrigue has a new battery and alternator but the battery is not charging back up?
the answer could be 3 fold ,either your new battery is faulty,or your alternator is faulty ,,or the logical problem could be an earth fault ,clean down all earth points properly ,if that doesnt cure your fault ,you may have a wiring fault, could be a open circuit I.E broken wire inside harness.
