When the generator has reverse power (external power is directed to the generator, that is, the generator becomes a motor), the reverse power protection circuit breaker turns on sets off. Three-phase voltage and two-phase current signals must be collected.
Due to the different forms of primary energy, different generators can be made. By using water conservation resources and hydraulic turbine, a hydrogenerator can be made due to the different tank capacity and water head, hydrogenerators with different capacities and rotation speeds can be manufactured. Using coal, oil and other resources, combined with boilers and steam turbines, turbogenerators can be made. Most of these generators are high speed motors (3000 rpm). Additionally, there are different types of gegenerators that use energy such as solar energy, wind energy, atomic energy, geothermal energy, tidal energy and biological energy. In addition, due to different operating principles, generators are divided into DC generators, asynchronous generators and synchronous generators. The most commonly used large generators are synchronous generators.