Standard eqution of current for this condition,
i(t) = i(0+)*cos(wt)
i(0+) = E/R
For LC circuit,
w = 1/√(LC)
i(t) = (E/R)*cos((1/√(LC))*t) A
The neutral point of a generator is usually earthed to facilitate protection of the stator winding and associated system.
Earthing also prevents damaging transient overvoltages in the event of an arcing earth fault or ferro resonance.
For HV generators, impedance is usually inserted in the stator earthing connection to limit the magnitude of earth fault current.
Buchholz relay is gas operated relay.
It will operate when internal fault occurs in transformer.
It is placed between tank to main conservator.
It has two contacts trip and alarm.
Use of Buchholz relay in distribution transformer is not economical.
1. e = 4.44fφ*Turns
2. V/f ≈ e/f ∝ φ ∝ B
3. Eddy Current loss, Pe ∝ B²f² ∝ f² (as B is constant if V/f is constant)
4. Hysteresis loss, Ph ∝ B^1.6*f ∝ f
If V/f is constant, B is constant, mmf required to create B is constant, Im is constant.