Single-phase power input circuit based on three-phase Vienna PFC topology and control method

Abstract

The invention provides a single-phase power input circuit based on a three-phase Vienna PFC topology and a control method. Through the adjustment of the duty ratio of a corresponding switching tube suspended in the three-phase Vienna PFC topology, the reverse recovery problem of a low-frequency device in the bidirectional switch is suppressed, the reverse recovery loss of the low-frequency devicein a bidirectional switch of the three-phase Vienna PFC topology is reduced, the heating of the three-phase Vienna PFC topology is reduced, and a solution is provided for the reliable operation of thethree-phase Vienna PFC topology during single-phase power or direct-current input.

Description

technical field [0001] The invention belongs to the technical field of power supply control, and in particular relates to a single-phase electric input circuit and a control method based on a three-phase Vienna PFC topology. Background technique [0002] With the rapid development of the automotive industry in the field of new energy, people have higher and higher requirements for the reliable operation of AC / DC power conversion equipment in various charging scenarios, and PFC (Power Factor Correction) is required to improve the power supply The conversion efficiency of conversion equipment and the reduction of conduction loss; at this stage, Vienna (VIENNA) rectifiers, namely three-phase three-level three-switch PFC rectifiers, are mostly used. The advantages of the Vienna rectifier are: fewer power tubes are needed and the voltage stress is only half of the DC bus voltage, there is no bridge arm output voltage straight-through problem, no need to set the driving dead time,...

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Problems solved by technology

[0006] see Figure 4 , because the equivalent junction capacitance of the third switching tube is pF level, and the third inductance is uF level, so the resonant frequency generated is several hundred kHz; the potential at both ends of the third switching tube changes drastically, which is equal to The voltage of the rectifier bridge stack connected in parallel with the effective junction capacitance produces high-frequency oscillations, which cannot form a strong and stable clamping position for the rectifier bridge stack; the current of the rectifier bridge stack connected in series with the third inductor produces high-frequency oscillations of several hundred kHz; this High-frequency oscillating voltage and current cause reverse recovery problems on the rectifier bridge stack, resulting in dynamic loss of the diodes that make up the rectifier bridge stack, resulting in severe heating of the diodes, which has become a heat dissipation bottleneck for power conversion equipment

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