What is the most popular PFC regulated switching p

2022-08-01
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Brief description of PFC regulated switching power supply

among PFC switching power supply, switching regulated power supply is a very important component. The function of switching regulated power supply in PFC is not very different from that of ordinary switching regulated power supply, but it is different in power supply. Ordinary switching regulated power supply needs 220V rectifier power supply, while PFC regulated switching power supply is powered by B + PFC. This article will briefly introduce the PFC power supply

after rectification, no filter capacitor is added, and the unfiltered pulsating positive half cycle voltage is used as the power supply of the chopper. Due to the series of "switching" work of the chopper, the pulsating positive voltage is "chopped" into a current waveform. The characteristics of the waveform are:

1. The current waveform is intermittent, its envelope is the same as the voltage waveform, and the envelope is in phase with the voltage waveform

2. Due to the effect of chopping, the half wave pulsating DC power becomes a high-frequency (determined by the chopping frequency, about 100kHz) "AC" power. The high-frequency "AC" power can only be used by the later stage PWM switching regulated power supply after being rectified again

3. From the perspective of external power supply, the power system achieves that the AC voltage and AC current are in phase and the voltage waveform and current waveform conform to the sinusoidal waveform, which not only solves the problem of power factor compensation, but also solves the problems of electromagnetic compatibility (EMC) and electromagnetic interference (EMI)

the high-frequency "AC" current is rectified by the rectifier diode and filtered into a DC voltage (power supply) to supply power to the backward PWM switching power supply. The DC voltage is called B + PFC (tpw-421 improves fatigue life 1) in some data. The B + PFC voltage output by the chopper is generally higher than + 300V after the original 220 AC rectification and filtering. The reason is that the high voltage is selected, the inductance has small wire diameter, small line voltage drop, small filtering capacitor capacity, good filtering effect, and low requirements for the later stage PWM switch

at present, the chopper (k) of PFC switching power supply has two working modes:

1. Continuous conduction mode (CCM): the switching frequency of gb/t 16989 (1) 997 geotextile joint/joint wide strip tensile test method is certain, and the conduction duty cycle (coefficient) changes with the amplitude of the chopper voltage

2. Discontinuous conduction mode (DCM): the operating frequency of the chopper switch changes with the magnitude of the chopper voltage (the "on" and "off" times in each switching cycle are equal)

the PFC switching power supply part and the PWM switching power supply part of the power factor correction switching power supply are both completed by an integrated circuit, and one IC can complete the design

the 2205 is a brief introduction to the switching regulated power supply PFC. It can be seen that this switching regulated power supply has the characteristics of small inductance path, small line voltage drop and small filter capacitor capacity. Compared with the traditional switching regulated power supply, Bayer has obvious advantages in helping its customers lead the market competition through product differentiation. For those who still don't understand PFC switching regulated power supply, you can spend a few minutes reading this article. I believe there will be unexpected gains

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