Abstract: Embodiments of the present disclosure provide a direct current (DC) power supply system, comprising: a medium voltage AC switchgear, configured to distribute a medium voltage three-phase AC received from an external supply for a next stage; a phase-shift transformer serving as the next stage, coupled to the medium voltage AC switchgear, and configured to lower the medium voltage three-phase received and output four or more groups of low voltage three-phase AC; and an uncontrolled rectifying circuitry, comprising a plurality of uncontrolled rectifiers configured to receive the four or more groups of low voltage three-phase AC respectively and output a low voltage DC; wherein the four or more groups of low voltage three-phase AC have a predetermined phase difference between each other.

Abstract: The present application provides a mixed control method for a resonant converter, a resonant converter system and a mixed controller. When the resonant converter operates in a case where a voltage gain is less than a predetermined value, the method includes: setting a mixed control start frequency, a mixed control stop frequency and a slope of a phase-shifting angle; detecting an operating frequency of the converter; calculating a time delay of phase shifting according to the slope, the mixed control start frequency, the mixed control stop frequency and a resonant frequency of the resonant converter; and according to the time delay, the mixed control start and stop frequencies, generating a control signal to adjust the operating frequency and the phase-shifting angle of the resonant converter. The present application can realize a relatively low voltage gain and a small circuit loss, thereby the circuit efficiency may be improved.

Abstract: The present application provides a mixed control method for a resonant converter, a resonant converter system and a mixed controller. When the resonant converter operates in a case where a voltage gain is less than a predetermined value, the method includes: setting a mixed control start frequency, a mixed control stop frequency and a slope of a phase-shifting angle; detecting an operating frequency of the converter; calculating a time delay of phase shifting according to the slope, the mixed control start frequency, the mixed control stop frequency and a resonant frequency of the resonant converter; and according to the time delay, the mixed control start and stop frequencies, generating a control signal to adjust the operating frequency and the phase-shifting angle of the resonant converter. The present application can realize a relatively low voltage gain and a small circuit loss, thereby the circuit efficiency may be improved.