In 1832, the French invented a bi kersee DC generator, its principle is through the rotating permanent magnet the magnetic flux change and induced electromotive force generated in the coil, and the electric potential in the form of DC voltage output;
In 1866, Germany's SIEMENS invented the self-excited DC generator;
In 1869, Gram of Belgium made a ring armature, inventing the ring armature generator. The generator rotates the rotor of the generator with hydraulic power. After repeated improvements, the output power of 3.2KW is obtained in 1847.
In 1882, Gordon of the United States made a two - phase giant generator with output power of 447KW, 3 meters high and 22 tons.
In 1896, two phase AC generator Tesla began working operation, 3750KW in Pennsylvania Benitez power plant, 5000V AC has been sent to 40 kilometers outside the city of buffalo.