Valley filling and stroboflash-free PFC converter and control method

Abstract

The invention discloses a valley filling and stroboflash-free PFC converter and a control method, and the valley filling and stroboflash-free PFC converter is characterized in that the valley filling and stroboflash-free PFC converter comprises a PFC unit, the PFC unit is provided with an energy storage capacitor and at least one switching tube, the PFC unit is electrically connected in front of a fluctuation circuit or a converter, and the PFC unit is charged through a bus input end and / or winding flyback; the PFC unit is matched with other circuits to be combined with a corresponding control method, peak energy is stored in the PFC unit at a certain moment to increase the PF value, and the PFC unit conducts releasing and valley filling according to needs to prevent output fluctuation; the PFC unit is controlled to carry out energy storage and release control through an internal switch tube and / or a diode, and when a PFC module is added between windings, the energy storage capacitor in the PFC unit can be controlled at a low voltage, and the withstand voltage of the PFC capacitor is reduced; stable output and no stroboflash are realized, internal used components are reduced, the overall size of the converter is further reduced, and the service life is prolonged at the same time.

Description

technical field [0001] The invention relates to the field of converter equipment, in particular to a valley-filling and flicker-free PFC converter and a control method. Background technique [0002] In order to provide stable energy output, the existing converters usually perform filtering after AC rectification, but when the capacitor is directly added, the capacitor voltage decreases with the AC input as the load increases, which reduces the effect of the capacitor; ordinary valley-filling circuits, Valley filling requires capacitors to be charged in series and discharged in parallel. The number of capacitors must be at least two or more, and ordinary valley filling circuits cannot choose the time of valley filling. [0003] Furthermore, in a single-stage PFC circuit, in order to increase the PF value, the current and voltage need to be in the same phase. Therefore, when the sine wave is at a low point in the prior art, the output power of the converter designed is low or ...

AI Technical Summary

Problems solved by technology

[0002] In order to provide stable energy output, the existing converters usually perform filtering after AC rectification, but when the capacitor is directly added, the capacitor voltage decreases with the AC input as the load increases, which reduces the effect of the capacitor; ordinary valley-filling circuits, Valley filling requires capacitors to be charged in series and discharged in parallel. The number of capacitors must be at least two or more, and ordinary valley filling circuits cannot choose the time of valley filling.

[0003] Furthermore, in a single-stage PFC circuit, in order to increase the PF value, the current and voltage need to be in the same phase. Therefore, when the sine wave is at a low point in the prior art, the output power of the converter designed is low or even no output, resulting in a load on the output When the current and voltage ripple is large, there is a strobe when using it on the LED lamp

Moreover, the service life of the components inside the existing converter is relatively short, the overall volume is large, there is less room for capacitor selection, the limited control of the circuit is low, the output efficiency is not high and not stable enough

Images