A full digital control method and control system for light-load intermittent output of a power supply

Abstract

The invention provides an all-digital control method and system for light-load intermittent output of a power supply, which solves the technical problem that the output efficiency and output ripple of the existing power supply cannot be optimized and controlled. The method includes: judging the load state of the power supply according to the output current amplitude of the resonant power supply, switching from continuous output to intermittent output according to the load state; starting intermittent output according to the output voltage amplitude during the intermittent output; forming intermittent output according to the input and output states of the resonant power supply The frequency and phase of the waveform; the intermittent output waveform is formed by determining the number of pulses; the intermittent output is switched to the continuous output according to the load state or the blocking state between adjacent intermittent output waveforms. For half-bridge resonant power supply and full-bridge resonant power supply light-load intermittent output, accurate control of intermittent pulse number, switching frequency and pulse phase difference in the process of frequency modulation, frequency modulation + phase shift control, optimize power supply light-load efficiency, and meet power supply energy output control accuracy , controls the power supply output ripple.

Description

technical field [0001] The invention relates to the technical field of power supply control, in particular to a full-digital control method and control system for a light-load intermittent output of a power supply. Background technique [0002] In the prior art, LLC resonant soft-switching power supplies are widely used in the field of power conversion due to their high conversion efficiency. The full-bridge LLC resonant soft-switching power supply can work not only in pure FM mode, but also in FM+phase-shift mode. However, a major problem with LLC resonant soft-switching power supplies is that light-load regulation is difficult. First, light-load regulation needs to increase the switching frequency to high-frequency, thus significantly reducing the light-load conversion efficiency; secondly, due to the existence of parasitic parameters of the main loop, in some cases, the monotonicity of the power gain curve will be reversed at high frequency, so Makes the power supply lo...

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Problems solved by technology

[0005] In view of the above problems, the embodiment of the present invention provides a light-load intermittent output full digital control method and control system to solve the problem that the existing natural intermittent control process cannot accurately control the switching frequency and the number of intermittent pulses, so that the output efficiency of the power supply and The technical problem that the output ripple cannot be optimized and controlled

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