A current sharing control method for single-phase Boost type PFC with multiple parallel circuits

Abstract

The invention discloses a current sharing control method for a single-phase Boost type PFC with multiple parallel circuits. The working principle is as follows: 1) the current flowing through a MOS transistor of a PFC rectifier module is converted into a voltage signal ICT by using a current transformer; 2) that ICT signal passe through an RC filter to obtain a current-sharing signal Isense; 3) that digital control performs analog-digital sample on the Isense signal and the current-sharing bus signal ICB, and calculates the difference between the Isense signal and the ICB signal and inputs thedifference into the current-sharing loop control; 4) The current-sharing loop controller controls the reference voltage Vref* of the PFC rectifier module to realize the current-sharing of the PFC rectifier module in parallel. The invention solely samples the current signal of the MOS transistor of the PFC rectifier module to carry out current sharing control, so that the PFC rectifier module canensure a certain current sharing degree of the PFC when the PFC rectifier module is operated in multiple parallel machines, and the sampling circuit design of the current sharing control part of the PFC rectifier module can be simplified. The invention promotes the progress of the single-phase Boost type PFC current sharing technology.

Description

technical field [0001] The invention relates to the technical field of digital power supplies, in particular to a current sharing control method for multi-channel parallel connection of single-phase Boost type PFC. Background technique [0002] as attached figure 1 As shown, in the prior art, the current sharing control of multi-channel parallel connection of single-phase Boost type PFC generally uses a sampling strategy of synthesizing MOS tube current and diode current. In the main power circuit, the current transformer CT1 and the current transformer CT2 respectively detect the magnitude of the current flowing through the MOS tube and the diode. Due to the switching action of the MOS tube, the current flowing through the MOS tube and the diode is a pulse waveform, so it needs to pass through the double diode D F1 、D F2 and the sampling resistor R 1 , to synthesize the current signal into a continuous voltage signal I CT . Voltage signal I CT The waveform is a "stea...

AI Technical Summary

Problems solved by technology

However, in the existing single-phase Boost type PFC multi-channel parallel sampling strategy, two current transformers are required to detect the current of the MOS tube and the diode respectively, which increases the complexity of the current sharing sampling circuit and reduces the aluminum substrate. wiring space

And when the current signal is synthesized, the diode D F1 、D F2 The voltage drop on the voltage signal I CT This will increase the current sharing error of the PFC rectifier module and reduce the stability of the PFC rectifier module

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