A
I am confused as to how the 100% stator E/F with low freq (20Hz) injection principle works. What I could understand is put below, please correct me:-
1. The 20Hz generator, generates low frequency voltage which is applied across the neutral resistance.
2. This injects a low frequency current in the generator stator winding.
3. During normal operation, due to the high impedance (Xc=1/2Pifc) of the stator winding,very small current flows (where?)
4. Under fault the capacitance gets bypassed (????) and the fault current flows to the neutral.
5. This current is reflected to the secondary of the distribution transformer where a CT is placed.
6. This CT current is the input to the relay 64S.
7. The voltage across the voltage divider is another input to the relay.
8. The relay constantly measures the resistance and operates on under resistance.
Above is my totally broken knowledge on this as I could read from the internet & get from my colleagues.
I could not get a complete technical writeup on this protection function.
Request members to contribute on this.
1. The 20Hz generator, generates low frequency voltage which is applied across the neutral resistance.
2. This injects a low frequency current in the generator stator winding.
3. During normal operation, due to the high impedance (Xc=1/2Pifc) of the stator winding,very small current flows (where?)
4. Under fault the capacitance gets bypassed (????) and the fault current flows to the neutral.
5. This current is reflected to the secondary of the distribution transformer where a CT is placed.
6. This CT current is the input to the relay 64S.
7. The voltage across the voltage divider is another input to the relay.
8. The relay constantly measures the resistance and operates on under resistance.
Above is my totally broken knowledge on this as I could read from the internet & get from my colleagues.
I could not get a complete technical writeup on this protection function.
Request members to contribute on this.
