Method and controller for controlling grid-connected power factor of flyback inverter with dual frequency

Abstract

The present invention discloses a method for dual-frequency control of the grid-connected power factor of a flyback inverter. The grid-connected power factor adjustment method includes: obtaining a working electrical signal of a power grid; obtaining a first sinusoidal modulation wave signal; obtaining a second sinusoidal modulation wave signal; determining a phase angle difference and a time difference corresponding to the phase angle difference according to the power factor; obtaining a sinusoidal correction modulation frequency; generating a sinusoidal correction modulation wave signal having a frequency of the sinusoidal correction modulation frequency; and controlling the flyback inverter to output alternating current through the sinusoidal correction modulation wave signal. The power factor is adjusted by adjusting the phase difference between the target power grid and the sinusoidal correction modulation wave. At the same time, the first sinusoidal modulation wave can work independently when the power supply has only active power, and the sinusoidal correction modulation wave can work independently when the power supply needs reactive power adjustment. By controlling the flyback inverter through the sinusoidal correction modulation wave in the present invention, the flyback inverter can accurately adjust the power factor when connected to the grid, and the harmonic distortion rate is reduced.

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