What types of protection used for generators?

A Generator is the most important and costly equipment in a power system. As it is accompanied by Prime mover, Excitation system, Voltage regulator, Cooling system, etc., its protection becomes very complex and elaborate. It is subjected to more types of troubles than any other equipment.

A modern generating set is generally provided with the following protective schemes: 

(i) Stator Protection

1. Percentage differential protection

2. Protection against stator inter-turn faults

3. Stator overheating protection

(ii) Rotor Protection

1. Field ground-fault protection

2. Loss of excitation protection

3. Protection against rotor overheating

   (due to unbalanced three phase stator currents)

(iii) Miscellaneous

1. Over voltage protection

2. Over speed protection

3. Protection against motoring

4. Protection against vibration

5. Bearing-overheating protection

6. Protection against auxiliary failure

7. Protection against voltage regulator failure

[You can concern to internet for connection diagrams and details of each protection scheme]

Reference Contents ---->

ATS system