Parallel Operation Of Self Generators With Government Grid

You did not mention PF of 0.65 Inductive or Capacitive.

You are lucky if your set is still operating and alternator has not burnt.

You are Exporting kVAR along with kW, if your power factor is inductive. Otherwise importing power if your power factor is capacitive.

You can control PF by adjusting excitation of the alternator.

If you are generating more inductive power and want to reduce it that means want to bring PF of your power station from 0.65 inductive to 0.8, reduce excitation slowly.

Note that generating more reactive, you are overloading AVR, exciter, main field and stator winding hence do not do it.

Also poor is the power factor of your generating set, poor is the efficiency of your 3 phase alternator hence increasing fuel consumption.

Also do not try to go less than 1 PF. If you go capacitive (importing kVAR from Grid) - will result in poor coupling between revolving fields of rotor and stator - hunting of rotor around stator revolving field and generation of induced voltage in rotor field poles and over heating of poles and failure of field windings.

Protect your machines by installing following:

1. loss of excitation relay based on offset impedance measurement which is set to operate if stator current is in third quarter and exceeds predetermined value.

2. Reverse Power Relay.

3. Power Factor Limiter (this will ensure your alternator will not try to feed heavy reactive current beyond its capability if grid voltage drops).

4. df/dt relay - this is to isolate your power station from Grid in case the grid is unstable or collapses. This relay will trip the Grid Incomer (not your Generator CB)