An input voltage signal sampling circuit in a three-phase three-wire PFC circuit

Abstract

An input voltage signal sampling circuit in a three-phase three-wire system PFC circuit, the sampling circuit comprising a module (100) for sampling an input voltage signal of a first phase, a module (200) for sampling an input voltage signal of a second phase and a module (300) for sampling an input voltage signal of a third phase, wherein the module (100) for sampling the input voltage signal of the first phase comprises a first reference ground setting circuit (101), a first voltage division circuit (102), a second voltage division circuit (103), a first operational amplifier (104) and a first output circuit (105); the module (200) for sampling the input voltage signal of the second phase comprises a second reference ground setting circuit (201), a third voltage division circuit (202), a fourth voltage division circuit (203), a second operational amplifier (204) and a second output circuit (205); and the module (300) for sampling the input voltage signal of the third phase comprises a third reference ground setting circuit (301), a fifth voltage division circuit (302), a sixth voltage division circuit (303), a third operational amplifier (304) and a third output circuit (305). The input voltage signal sampling circuit can, without a neutral line, acquire an input voltage signal in a three-phase three-wire system PFC circuit.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to an input voltage signal sampling circuit in a three-phase three-wire PFC circuit. Background technique [0002] At present, the country is vigorously promoting the construction of charging infrastructure, and the three-phase high-power charger is a solution to realize the ground charging device. Generally, a three-phase high-power charger is generally divided into two parts: a front-stage power factor correction (Power Factor Correction, PFC) and a rear-stage DC power supply DCDC. Among them, the pre-stage PFC is an active power factor correction circuit under the condition of three-phase input. The switching device is controlled by an active circuit (such as an active circuit) to make the input current waveform follow the input voltage waveform, thereby improving the power factor and reducing reactive power. Current, line loss, the purpose of improving the quality o...

AI Technical Summary

Problems solved by technology

However, it has been found in practice that many devices do not have a center line, such as: engines

If there is no neutral line in the circuit, the above-mentioned existing sampling method cannot collect the input voltage signal

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