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AC-DC converter

A converter and reactor technology, which is applied in the output power conversion device, the conversion of AC power input to DC power output, the conversion of irreversible AC power input to DC power output, etc., can solve the problem of large switching loss, poor efficiency, etc. problem, to achieve the effect of reducing switching loss and conduction loss

Inactive Publication Date: 2014-04-09
HITACHI LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the conduction loss caused by the current flowing through the diode bridge used in the rectifier circuit; and the switching loss caused by switching while the voltage is applied to the switching element of the power factor improvement circuit is large and the efficiency is not good.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] figure 1 is a circuit configuration diagram of the AC-DC converter according to Embodiment 1 of the present invention.

[0049] The two sets of upper and lower branches respectively connecting the rectifying element Ds1 or Ds2 in series with the main switching element Q1 or Q2 are connected in parallel to form the main switching circuit of the converter. Snubber capacitors C1 and C2 are connected in parallel to these main switching elements, respectively. In addition, diodes and / or body diodes D1 and D2 are respectively connected in antiparallel to each of the above-mentioned main switching elements.

[0050] An AC power supply V1 is connected between series connection points of two sets of upper and lower arms which are AC terminals of the converter via smoothing reactors Ls1 and Ls2 . In addition, a smoothing capacitor Cs and a DC load R1 are connected in parallel between both ends of the main switching circuit as DC terminals of the converter, that is, between the ...

Embodiment 2

[0098] Figure 7 is a circuit configuration diagram of an AC-DC converter according to Embodiment 2 of the present invention. This AC-DC converter 11 is in figure 1 In the AC-DC converter 10 of the first embodiment shown, one end of the resonant capacitor Cr connected to the positive bus LN1 is cut off, and the connection to the negative bus LN0 is replaced.

[0099] The operation of the circuit is the same as that of Embodiment 1, and the operation of sending the energy of the AC power supply V1 to the DC load R1 and the operation of zero-voltage switching can be performed.

[0100] According to the circuit structure of the second embodiment, compared with the first embodiment, the degree of freedom of layout on the substrate may be increased and the size can be reduced.

Embodiment 3

[0102] Figure 8 is a circuit configuration diagram of the AC-DC converter 20 according to Embodiment 3 of the present invention. According to the AC-DC converter 20 of Embodiment 3, the figure 1 The shown AC-DC converter 10 according to Embodiment 1 is changed from being used for a single-phase AC power supply to being used for a three-phase AC power supply.

[0103] exist Figure 8 In, the difference from Example 1 is that the figure 1 The AC power supply V1 of the first embodiment shown is changed to a three-phase AC power supply V2, and a smoothing reactor Ls0, a rectification diode Ds0, a MOSFET Q0, a current sensor 15, and voltage sensors 13, 14, and 16 are added. In addition, a diode and / or a body diode D0 of the MOSFET is connected between the drain and the source of the MOSFET Q0 so that current flows from the source to the drain. In addition, a snubber capacitor C0 is connected between the drain and the source of the MOSFET Q0 .

[0104] The connection point bet...

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Abstract

Disclosed is an AC-DC converter equipped with: a hybrid bridge circuit formed with rectifier elements (Ds 1, 2) and main switching elements (Q1, 2); snubbers (C1, 2) and diodes (D1, 2), connected in parallel to each of the aforementioned elements (Q1, 2); an alternating current power supply (V1) connected between alternating current terminals via (Ls1, 2) used for smoothing; and a (Cs) used for smoothing and a direct current load (R1) which are connected in parallel between the direct current terminals of the bridge circuit; and being further equipped with an auxiliary circuit (1), which includes an (Lr) for resonance use between the direct current terminal (N3) and one end (LN1) of the (Cs) used for smoothing and a series-connected body comprised of an auxiliary switching element (Q3) and a (Cr) for resonance use which are connected to the one end, and with a control means that turns on / off the aforementioned (Q1, 2, 3). After the resonance-use (Cr) is charged with a portion of the energy accumulated in the smoothing-use (Ls1, 2), energy accumulates in the resonance-use (Lr), and the charges of snubbers (C1, 2) are discharged with this energy to achieve zero-voltage switching of MOSFETs Q1-3.

Description

technical field [0001] The present invention relates to an AC-DC converter with zero voltage switching function. Background technique [0002] Conventional AC-DC converters consist of a rectification circuit consisting of a diode bridge; and a power factor improvement circuit consisting of switching elements, smoothing reactors, diodes, and smoothing capacitors, which rectifies AC power and converts it to DC. However, the conduction loss caused by the current flowing through the diode bridge used in the rectifier circuit; and the switching loss caused by switching while the voltage is applied to the switching element of the power factor improvement circuit is large and the efficiency is not good. . [0003] Therefore, Patent Document 1 discloses a bridgeless (hybrid bridge) type AC-DC converter that reduces the conduction loss of the diode bridge and improves efficiency, and Non-Patent Document 1 discloses that the switching loss is reduced and the efficiency is improved. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02M7/12
CPCH02M7/219
Inventor 岛田尊卫塚本创叶田玲彦
Owner HITACHI LTD