Generator neutral grounding system

Dear Sir As per my understanding following is my observation: 1)The generator neutral is grounded thru NGR where there is distribution at the same voltage level ie the generated voltage level. 2)The gen neutral is grounded thru a NGT when the there is no distribution at the generated voltage level,ie the voltage is stepped up say 11/132kV or 11/33kV or stepped down. 3) The NGT is costlier than NGR. Regards Ravipra

Typically, a high resistance ground is used on lower voltage system where the voltage is 600 volt or less. On higher voltage systems (greater than 1000V), it is more economical to use a transformer which will step down the ground fault voltage so that a low voltage resistor can be used on the secondary of the transformer. In both cases, high resistance grounding is used where it is desired to keep the electrical system operating after one of the power cables has accidently connected to grounded parts. This way, a shut-down of the factory or other facility to repair the fault can be scheduled at a convenient time.