What is the frequency of the generator! E.g. what does 50hz means! 

  The synchronous generator is a transforming machinery that can change mechanical energy into electrical energy's machine, alternating current are all supplied by synchronous generator at present. Most of modern synchronous generators are made into revolve- magnetic pole whose rotor is magnetic pole surrounding excitation coil with the direct current excitation and arousing with prime mover to revolve . Be settling three-phase opposited coil on the iron cable and revolving the rotor with magnetic pole, which makes coil in stator incise rotor of magnetic field resulting in three-phase communicate electromotive condition. The frequency of respond electromotive condition is for f=pn/60 ( p=magnetic pole number ; n=generator speed )?

Our country electric power system provise frequency is for 50 Hz, so one couple of generator of magnetic poles requests the speed at 3000 r/min( n=3000r/min), which comply with the speed at 3000r/min(nl=3000r/min) of revolve magnetic field ; two couple of generator of magnetic poles requests the speed at 1500 r/min( n=1500r/min), which comply with the speed at 1500r/min(nl=1500r/min) of revolve magnetic field, it is clear that the "n"speed to be equal to the "nl"in revolve magnetic field, which become the synchronous generators .While generator is manufactured, the magnetic pole number is keeping continually. At this time, the "F"of frequency is proportion in "n"of speed. They are not only the mind character also Frequency modulation principle for synchronous generators.

When the generator run alone, to regulate the speed which can change its frequency, once combining with large charged net. As the frequency of large charged net always keep at 50Hz, the generator also keeps its rated speed running, it is that large charged net of frequency fluctuation will decide its speed. If make the generator running more, that can only let the generators' carry more. Not improve its speed.