1. For 300MW and above steam turbine generator transformer units, double fast protection shall be installed, that is, generator longitudinal differential protection, transformer longitudinal differential protection and generator transformer unit common longitudinal differential protection; When there is a circuit breaker between the generator and the transformer, double generator longitudinal differential protection shall be installed;

2. Generators above 1MW shall be equipped with longitudinal differential protection;

3. For the generator transformer unit, when there is a circuit breaker between the generator and the transformer, the generator shall be equipped with a single generator of 100MW and below, with independent longitudinal differential protection; When there is no circuit breaker between the generator and the transformer, the generator transformer unit can be installed with common longitudinal differential protection. For generators of 100MW and above, in addition to the generator transformer unit with common longitudinal differential protection, the generator should also be installed with separate longitudinal differential protection. For generator transformer units of 200 ~ 300MW pairs, separate longitudinal differential protection can be added to the transformer, Double fast protection is adopted;

4. For generators with generator transformer unit wiring, if the capacity is less than 100MW, stator grounding protection with protection area less than 90% shall be installed; If the capacity is above 100MW, stator grounding protection with 100% protection area shall be installed;

5. Hydro generators above 1MW shall be equipped with one point grounding protection device;

6. The generator directly connected to the bus shall be equipped with selective grounding protection device when the single-phase grounding fault current is greater than the allowable value;

7. Rotor internal cooling steam turbine generator and steam turbine generator of 100MW and above shall be equipped with one point grounding protection device of excitation circuit, and each generator shall be equipped with one set; In addition, two-point grounding protection devices can be installed, one set for each generator, and one point grounding fault regular detection device shall be installed for the generator excited by rotating rectifier;

8. For generators below 100MW that are not allowed to lose excitation, when semiconductor excitation system is adopted, special loss of excitation protection should be installed;

9. For steam turbine generators below 100MW, periodic detection device can be used for one point grounding fault. For two-point grounding fault, two-point grounding protection device shall be installed;

10. Generators below 100MW but whose loss of excitation has a significant impact on the power system and generators above 100MW shall be equipped with special loss of excitation protection. Dual loss of excitation protection can be installed for 600MW generator.