Background:
The output voltage frequency for the previously proposed "phase hopping"
AC-AC frequency conversion technology is determined by the law that the number of output voltage
cycles is reduced by one relative to the power frequency in a large cycle containing six jumps.
According to the law, only a limited number of output frequencies, such as 37.5 Hz, 42.86 Hz and
45 Hz are found. Due to the large spacing between the output frequencies, the "phase hopping" frequency
conversion technology is difficult to put into practical use.
Methods:
In this paper, the law of the output frequency control is generalized so that the number of
output cycles in a large cycle is reduced by n relative to the power frequency. The analysis shows
that the appropriate selection of large cycles, including the number of power frequency cycles and
the value of n, can find more frequencies to be used. Reducing the interval between the output frequencies
within 1Hz.
Results:
The analysis results were verified in simulation by MATLAB, and the harmonics and the
feasibility of the actual application were analyzed.
Conclusion:
Finally, an experimental platform was built and an experimental analysis was carried
out. The experimental results show that the theoretical and simulation analyses are correct.
Wind turbines using self-excited three-phase induction generators: an innovative solution for voltage-frequency control
