Multi-phase three-level interleaving Buck circuit

Abstract

The utility model aims to provide a multi-phase three-level interleaving Buck step-down circuit. The step-down circuit comprises a battery UH, a battery UL, a phase circuit, an input end support capacitor circuit and an output end support capacitor circuit. Each phase circuit comprises an upper bridge arm switch tube and a lower bridge arm switch which are connected in series. The positive electrode of the battery UH is connected with the positive electrode of the input end supporting capacitor circuit and the positive electrode of the upper bridge arm switch tube of each phase circuit. The negative electrode of the battery UH is connected with the negative electrode of the input end supporting capacitor circuit and the negative electrode of the lower bridge arm switch tube of each phase circuit. The upper bridge arm switch tube of each phase circuit is connected with the positive electrode of the output end supporting capacitor circuit and the positive electrode of the battery UL through an inductor, and the lower bridge arm switch is connected with the negative electrode of the output end supporting capacitor circuit and the negative electrode of the battery UL through an inductor. According to the utility model, ripples on the input and output sides can be better reduced, and the power density is high.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a multi-phase three-level staggered parallel Buck step-down circuit. Background Art

[0002] The BUCK circuit is a DC-DC converter based on the principle of inductive energy storage, which involves the basic principles of electromagnetic induction and electric energy conversion in physics. In the BUCK circuit, the DC voltage provided by the input power supply is converted into an adjustable low-voltage output by controlling the on and off state of the switch tube by switching the input PWM wave with a variable duty cycle, thereby meeting the power supply requirements of different circuits.

[0003] Traditional energy conversion technology is mainly used in power systems, such as the conversion between AC power and DC power. However, with the rapid development of new energy, especially the widespread application of solar energy and wind energy, integrated converters play an important role in energy conversion. And a key structure in the integrated converter is the BUCK buck circuit. For example, the two-phase two-level staggered parallel Buck buck circuit in the prior art still has problems such as the effect of reducing the ripple on the input and output sides is not ideal, and the power density needs to be further improved. Summary of the invention

[0004] The utility model aims to provide a multi-phase three-level staggered parallel Buck step-down circuit. The device has a scientific structural design, can better reduce input and output side ripples, and has the advantage of higher power density.

[0005] The multi-phase three-level interleaved parallel Buck step-down circuit comprises a battery UH, a battery UL, a phase circuit, an input-end support capacitor circuit, and an output-end support capacitor circuit;

[0006] The phase circuits are provided with a plurality of groups, each group of phase circuits comprises an upper bridge arm switch and a lower bridge arm switch connected in series;

[0007] The positive electrode of the battery UH is respectively connected to the positive electrode of the input-end supporting capacitor circuit and the positive electrode of the upper bridge arm switch of each group of phase circuits, and the negative electrode of the battery UH is respectively connected to the negative electrode of the input-end supporting capacitor circuit and the negative electrode of the lower bridge arm switch tube of each group of phase circuits;

[0008] The upper arm switch of each phase circuit is connected to the positive electrode of the output end supporting capacitor circuit and the positive electrode of the battery UL through the inductor, and the lower arm switch is connected to the negative electrode of the output end supporting capacitor circuit and the negative electrode of the battery UL through the inductor.

[0009] The upper arm switches of each group of phase circuits include an upper arm switch tube Sa1 and an upper arm switch tube Sa2, respectively. The positive electrode of the upper arm switch tube Sa1 is connected to the positive electrode of the battery UH, the negative electrode of the upper arm switch tube Sa1 is connected to the positive electrode of the upper arm switch tube Sa2, the connecting line between the upper arm switch tube Sa1 and the upper arm switch tube Sa2 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the positive electrode of the battery UL.

[0010] The lower arm switches of each group of phase circuits include a lower arm switch tube Sa3 and a lower arm switch tube Sa4, respectively. The positive electrode of the lower arm switch tube Sa3 is connected to the negative electrode of the upper arm switch tube Sa2, the negative electrode of the lower arm switch tube Sa3 is connected to the positive electrode of the lower arm switch tube Sa4, the negative electrode of the lower arm switch tube Sa4 is connected to the negative electrode of the battery UH, the connecting line between the lower arm switch tube Sa1 and the lower arm switch tube Sa2 is connected to one end of the inductor L2, and the other end of the inductor L2 is connected to the negative electrode of the battery UL.

[0011] The input-end supporting capacitor circuit includes a capacitor C1 and a capacitor C2, wherein the positive electrode of the capacitor C1 is connected to the positive electrode of the battery UH, the negative electrode of the capacitor C1 is connected to the positive electrode of the capacitor C2, and the negative electrode of the capacitor C2 is connected to the negative electrode of the battery UH; the connecting line between the capacitor C1 and the capacitor C2 is respectively connected to the connecting line between the upper bridge arm switch and the lower bridge arm switch of each group of phase circuits.

[0012] The output end supporting capacitor circuit includes capacitor C3 and capacitor C4, the positive electrode of capacitor C3 is connected to the positive electrode of battery UL, the negative electrode of capacitor C3 is connected to the positive electrode of capacitor C4, and the negative electrode of capacitor C4 is connected to the negative electrode of battery UL; the connecting line between capacitor C3 and capacitor C4 is respectively connected to the connecting line between the upper bridge arm switch and the lower bridge arm switch of each group of phase circuits.

[0013] The phase circuit is provided with 3-9 groups.

[0014] The working principle of the utility model is as follows:

[0015] The two switch tubes on the upper arm switch or the lower arm switch on each phase circuit are turned on complementary, and the switch tubes at the same position in different phases are turned on successively at intervals of 90 degrees. Then, the output side ripple current is reduced by inductor L1 and inductor L2, and the input end support capacitor circuit and the output end support capacitor circuit are used to stabilize the input and output voltages respectively.

[0016] The beneficial effects of the utility model are as follows:

[0017] The utility model has a scientific and reasonable structural design, and compared with the prior art such as a two-phase two-level staggered parallel Buck step-down circuit, has the advantages of better reducing input and output side ripples and higher power density.

[0018] The structure of the utility model adopts a method of isolating by a three-phase transformer at the grid end, which is more economical and helps to reduce the overall power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a multi-phase three-level interleaved parallel Buck step-down circuit of an embodiment; DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings and embodiments. Example 1

[0021] like Figure 1 As shown, a multi-phase three-level interleaved parallel Buck step-down circuit includes a battery UH, a battery UL, a phase circuit, an input-end support capacitor circuit, and an output-end support capacitor circuit;

[0022] The phase circuit is provided with 4 groups, each group of phase circuits comprises an upper bridge arm switch and a lower bridge arm switch connected in series;

[0023] The positive electrode of the battery UH is respectively connected to the positive electrode of the input-end supporting capacitor circuit and the positive electrode of the upper bridge arm switch of each group of phase circuits, and the negative electrode of the battery UH is respectively connected to the negative electrode of the input-end supporting capacitor circuit and the negative electrode of the lower bridge arm switch tube of each group of phase circuits;

[0024] The upper arm switch of each phase circuit is connected to the positive electrode of the output end supporting capacitor circuit and the positive electrode of the battery UL through the inductor, and the lower arm switch is connected to the negative electrode of the output end supporting capacitor circuit and the negative electrode of the battery UL through the inductor.

[0025] The upper arm switches of each group of phase circuits include an upper arm switch tube Sa1 and an upper arm switch tube Sa2, respectively. The positive electrode of the upper arm switch tube Sa1 is connected to the positive electrode of the battery UH, the negative electrode of the upper arm switch tube Sa1 is connected to the positive electrode of the upper arm switch tube Sa2, the connecting line between the upper arm switch tube Sa1 and the upper arm switch tube Sa2 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the positive electrode of the battery UL.

[0026] The lower arm switches of each group of phase circuits include a lower arm switch tube Sa3 and a lower arm switch tube Sa4, respectively. The positive electrode of the lower arm switch tube Sa3 is connected to the negative electrode of the upper arm switch tube Sa2, the negative electrode of the lower arm switch tube Sa3 is connected to the positive electrode of the lower arm switch tube Sa4, the negative electrode of the lower arm switch tube Sa4 is connected to the negative electrode of the battery UH, the connecting line between the lower arm switch tube Sa1 and the lower arm switch tube Sa2 is connected to one end of the inductor L2, and the other end of the inductor L2 is connected to the negative electrode of the battery UL.

[0027] The input-end supporting capacitor circuit includes a capacitor C1 and a capacitor C2, wherein the positive electrode of the capacitor C1 is connected to the positive electrode of the battery UH, the negative electrode of the capacitor C1 is connected to the positive electrode of the capacitor C2, and the negative electrode of the capacitor C2 is connected to the negative electrode of the battery UH; the connecting line between the capacitor C1 and the capacitor C2 is respectively connected to the connecting line between the upper bridge arm switch and the lower bridge arm switch of each group of phase circuits.

[0028] The output end supporting capacitor circuit includes capacitor C3 and capacitor C4, the positive electrode of capacitor C3 is connected to the positive electrode of battery UL, the negative electrode of capacitor C3 is connected to the positive electrode of capacitor C4, and the negative electrode of capacitor C4 is connected to the negative electrode of battery UL; the connecting line between capacitor C3 and capacitor C4 is respectively connected to the connecting line between the upper bridge arm switch and the lower bridge arm switch of each group of phase circuits.

Claims

1. A multi-phase three-level interleaved parallel Buck step-down circuit, comprising a battery UH, a battery UL, a phase circuit, an input-end support capacitor circuit, and an output-end support capacitor circuit; characterized in that: The phase circuits are provided with a plurality of groups, each group of phase circuits comprises an upper bridge arm switch and a lower bridge arm switch connected in series; The positive electrode of the battery UH is respectively connected to the positive electrode of the input-end supporting capacitor circuit and the positive electrode of the upper bridge arm switch of each group of phase circuits, and the negative electrode of the battery UH is respectively connected to the negative electrode of the input-end supporting capacitor circuit and the negative electrode of the lower bridge arm switch of each group of phase circuits; The upper arm switch of each phase circuit is connected to the positive electrode of the output end supporting capacitor circuit and the positive electrode of the battery UL through the inductor, and the lower arm switch is connected to the negative electrode of the output end supporting capacitor circuit and the negative electrode of the battery UL through the inductor.

2. The multi-phase three-level interleaved parallel Buck step-down circuit according to claim 1, characterized in that: The upper arm switches of each group of phase circuits include an upper arm switch tube Sa1 and an upper arm switch tube Sa2, respectively. The positive electrode of the upper arm switch tube Sa1 is connected to the positive electrode of the battery UH, the negative electrode of the upper arm switch tube Sa1 is connected to the positive electrode of the upper arm switch tube Sa2, the connecting line between the upper arm switch tube Sa1 and the upper arm switch tube Sa2 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the positive electrode of the battery UL.

3. The multi-phase three-level interleaved parallel Buck step-down circuit according to claim 2, characterized in that: The lower arm switches of each group of phase circuits include a lower arm switch tube Sa3 and a lower arm switch tube Sa4, respectively. The positive electrode of the lower arm switch tube Sa3 is connected to the negative electrode of the upper arm switch tube Sa2, the negative electrode of the lower arm switch tube Sa3 is connected to the positive electrode of the lower arm switch tube Sa4, the negative electrode of the lower arm switch tube Sa4 is connected to the negative electrode of the battery UH, the connecting line between the lower arm switch tube Sa1 and the lower arm switch tube Sa2 is connected to one end of the inductor L2, and the other end of the inductor L2 is connected to the negative electrode of the battery UL.

4. The multi-phase three-level interleaved parallel Buck step-down circuit according to claim 1, characterized in that: The input-end supporting capacitor circuit includes a capacitor C1 and a capacitor C2, wherein the positive electrode of the capacitor C1 is connected to the positive electrode of the battery UH, the negative electrode of the capacitor C1 is connected to the positive electrode of the capacitor C2, and the negative electrode of the capacitor C2 is connected to the negative electrode of the battery UH; the connecting line between the capacitor C1 and the capacitor C2 is respectively connected to the connecting line between the upper bridge arm switch and the lower bridge arm switch of each group of phase circuits.

5. The multi-phase three-level interleaved parallel Buck step-down circuit according to claim 1, characterized in that: The output end supporting capacitor circuit includes capacitor C3 and capacitor C4, the positive electrode of capacitor C3 is connected to the positive electrode of battery UL, the negative electrode of capacitor C3 is connected to the positive electrode of capacitor C4, and the negative electrode of capacitor C4 is connected to the negative electrode of battery UL; the connecting line between capacitor C3 and capacitor C4 is respectively connected to the connecting line between the upper bridge arm switch and the lower bridge arm switch of each group of phase circuits.

6. The multi-phase three-level interleaved parallel Buck step-down circuit according to claim 1, characterized in that: The phase circuit is provided with 3-9 groups.

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