What are the transformer protection classifications of power system relay protection devices?

     1. Longitudinal differential protection: including longitudinal differential, high impedance longitudinal differential, zero sequence longitudinal differential, generator transformer set longitudinal differential, and lead differential protection.

     2. Gas protection.

     3. Overcurrent protection: including negative sequence overcurrent, low voltage overcurrent, composite voltage overcurrent, and directional overcurrent protection, such as the generator transformer group shared, the low voltage overcurrent protection installed on the generator side is counted according to the generator protection.

     4. Grounding protection: including gap grounding protection, zero sequence current voltage, zero sequence current protection.

     5. Impedance protection.

     6. Over-excitation protection and over-voltage protection.

     7. Other protections.

     The above content is organized based on the problems encountered by the students in actual work for reference. If you have any problems, please communicate and correct them in time.