Generator faults and protections

Faults

• Failure of prime mover 
• Failure of field 
• Over current 
• Over speed 
• Over voltage 
• Stator winding fault 
• Unbalanced loading

Protection 

• Stator protection 
• Differential protection (Merz price circulating current scheme) 
• Protection against motoring 
• Negative phase sequence protection against unbalanced loading 
• Field failure protection 
• Reverse power protection 
• Inter turn fault protection 
• Rotor earth fault protection 
• Overcurrent relays in stator and rotor circuit 
• Over voltage protection 
• Over speed protection 
• Rotor fault protection

Fig: GE Power Generator