A high-gain magnetic integrated dc-dc converter for photovoltaic power generation system

Abstract

A kind of high gain magnetic integrated DC-DC converter for photovoltaic power generation system, it is characterized in that, including CDDC unit, the CDDC unit is connected with power supply V IN Connection, the CDDC unit is connected with magnetic integrated inductance unit, the magnetic integrated inductance unit is connected with fast recovery diode D3, the fast recovery diode D3 is connected with power switch tube Q1, the magnetic integrated inductance unit is connected with fast recovery diode D4, the fast recovery diode D4 is connected with output filter capacitor C3, EE magnetic core upper portion is arranged in the magnetic integrated inductance unit, EE magnetic core lower portion is arranged in the magnetic integrated inductance unit, topology structure is simple, device is less, control is convenient, especially modular design is carried out, the CDDC unit is introduced, so that system obtains higher gain, while the magnetic integrated inductance unit introduced improves the power density of converter, the application helps to promote the performance improvement of high gain magnetic integrated DC-DC converter for photovoltaic power generation system.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems. Background Technology

[0002] Currently, the construction of a new power system based on new energy sources is developing rapidly, and photovoltaic power generation systems have been widely used. However, due to factors such as losses of switching devices, losses of the inductor itself, and current and voltage withstand limitations of switching devices, the efficiency of traditional boost converters is relatively low. Furthermore, in boost converters, if a high gain is to be obtained, the inductance will be very large, which will reduce power density and increase size. To solve the above problems, a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems is proposed. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems. The converter is characterized by comprising a power switch Q1, a CDDC unit, a magnetically integrated inductor unit, a fast recovery diode D3, a fast recovery diode D4, an output filter capacitor C3, and a power supply V. IN The upper part of the EE magnetic core and the lower part of the EE magnetic core, the CDDC unit and the power supply V IN The CDDC unit is connected to the magnetic integrated inductor unit, the magnetic integrated inductor unit is connected to the fast recovery diode D3, the fast recovery diode D3 is connected to the power switch Q1, the magnetic integrated inductor unit is connected to the fast recovery diode D4, the fast recovery diode D4 is connected to the output filter capacitor C3, the upper part of the EE magnetic core is provided in the magnetic integrated inductor unit, and the lower part of the EE magnetic core is provided in the magnetic integrated inductor unit;

[0004] Furthermore, the CDDC unit includes: an energy storage capacitor C1, a fast recovery diode D1, an energy storage capacitor C2, and a fast recovery diode D2, wherein the negative terminal of the energy storage capacitor C1 is connected to the power supply V. IN The positive terminal of the fast recovery diode D1 is connected to the positive terminal of the energy storage capacitor C1; the negative terminal of the fast recovery diode D1 is connected to the negative terminal of the energy storage capacitor C2; the positive terminal of the fast recovery diode D2 is connected to the positive terminal of the energy storage capacitor C1; and the positive terminal of the energy storage capacitor C2 is connected to the negative terminal of the fast recovery diode D2.

[0005] Furthermore, the upper part of the EE core includes the upper half of the core side post I, the upper half of the core middle post III, and the upper half of the core side post II, while the lower part of the EE core includes the lower half of the core side post I, the lower half of the core middle post III, and the lower half of the core side post II.

[0006] Furthermore, the magnetic integrated inductor unit includes an energy storage inductor L1 and an energy storage inductor L2, wherein inductor L1 includes a winding L 11 and winding L 13 Two parts, winding L 11 Winding L is wound on the lower half of the side post I of the magnetic core. 13 Winded in the lower half of the central column III of the magnetic core, the energy storage inductor L1 has the following number of turns as winding L... 11 +L 12 The number of turns and the energy storage inductor L2 include winding L 21 L 22 L 23 L 21 Wound on the upper half of the side post I of the magnetic core, L 22 Wound on the upper half and lower half of core side post II, L 23 Winded on the upper half of the core side post III, the number of turns of L2 is equal to the number of turns of winding L. 21 +L 22 +L 23 The number of turns;

[0007] Furthermore, the input terminal m1 of the energy storage inductor L1 is connected to the power supply V. IN The positive terminal of the power switch Q1 is connected to the positive terminal of the power switch Q3; the output terminal m1' of the power switch Q1 is connected to the negative terminal of the fast recovery diode D1; the input terminal m2 of the power switch L2 is connected to the negative terminal of the fast recovery diode D2; the output terminal m2' of the power switch L1 is connected to the negative terminal of the fast recovery diode D4; the drain D of the power switch Q1 is connected to the negative terminal of the fast recovery diode D3; the positive terminal of the output filter capacitor C3 is connected to the negative terminal of the fast recovery diode D4.

[0008] The beneficial effects of this invention are:

[0009] This invention discloses a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems. It features a simple topology, fewer components, and convenient control. In particular, it incorporates a modular design and introduces a CDDC unit, enabling the system to achieve higher gain. By employing magnetic integration technology, the size and weight of the converter's magnetic components can be effectively reduced, current ripple is also reduced, and core losses are decreased, thereby improving the system's power density. This invention contributes to the performance improvement of high-gain magnetically integrated DC-DC converters for photovoltaic power generation systems. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems according to the present invention;

[0011] Figure 2This is a schematic diagram of the equivalent circuit of a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems according to the present invention.

[0012] Figure 3 This is a schematic diagram of the magnetically integrated inductor structure of a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems according to the present invention;

[0013] Figure 4 This invention provides a magnetic flux vector diagram of a magnetically integrated inductor structure for a high-gain magnetically integrated DC-DC converter designed for photovoltaic power generation systems.

[0014] As shown in the figure: 1-CDDC unit, 2-magnetic integrated inductor unit, 3-magnetic integrated inductor equivalent discrete inductor unit, 41-EE upper part of magnetic core, 42-EE lower part of magnetic core. Detailed Implementation

[0015] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0017] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Example 1

[0019] This invention provides a high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems, characterized by comprising a power switch Q1, a CDDC unit (1), a magnetically integrated inductor unit (2), a fast recovery diode D3, a fast recovery diode D4, an output filter capacitor C3, and a power supply V. IN The upper part (41) and lower part (42) of the EE magnetic core, the CDDC unit (1) and the power supply V IN The CDDC unit (1) is connected to the magnetic integrated inductor unit (2), the magnetic integrated inductor unit (2) is connected to the fast recovery diode D3, the fast recovery diode D3 is connected to the power switch Q1, the magnetic integrated inductor unit (2) is connected to the fast recovery diode D4, the fast recovery diode D4 is connected to the output filter capacitor C3, the upper part (41) of the EE magnetic core is provided in the magnetic integrated inductor unit (2), and the lower part (42) of the EE magnetic core is provided in the magnetic integrated inductor unit (2);

[0020] The magnetic integrated inductor unit (2) is used to reduce the inductor volume and increase the power density. The CDDC unit (1) is used to increase the output gain. Fast recovery diodes D3 and D4 are used for rectification and to prevent reverse current from entering. The output filter capacitor C3 is used for output filtering. The upper part (41) and lower part (42) of the EE core are used to wind the magnetic integrated inductor unit (2). The power supply V IN It is the power supply, providing energy to the converter;

[0021] The CDDC unit (1) includes: an energy storage capacitor C1, a fast recovery diode D1, an energy storage capacitor C2, and a fast recovery diode D2. The negative terminal of the energy storage capacitor C1 is connected to the power supply V. IN The positive terminal of the fast recovery diode D1 is connected to the positive terminal of the energy storage capacitor C1; the negative terminal of the fast recovery diode D1 is connected to the negative terminal of the energy storage capacitor C2; the positive terminal of the fast recovery diode D2 is connected to the positive terminal of the energy storage capacitor C1; and the positive terminal of the energy storage capacitor C2 is connected to the negative terminal of the fast recovery diode D2.

[0022] Figure 1 The CDDC unit (1) and the magnetic integrated inductor unit (2) in the middle are functionally equivalent to Figure 2 The two discrete inductors in the equivalent discrete inductor unit (3) of the magnetic integrated inductor;

[0023] The magnetic integrated inductor unit (2) includes an energy storage inductor L1 and an energy storage inductor L2. The inductor L1 includes a winding L 11 and winding L 13 Two parts, winding L 11 Winding L is wound on the lower half of the side post I of the magnetic core. 13Winded in the lower half of the central column III of the magnetic core, the energy storage inductor L1 has the following number of turns as winding L... 11 +L 12 The number of turns and the energy storage inductor L2 include winding L 21 L 22 L 23 L 21 Wound on the upper half of the side post I of the magnetic core, L 22 Wound on the upper half and lower half of core side post II, L 23 Winded on the upper half of the core side post III, the number of turns of L2 is equal to the number of turns of winding L. 21 +L 22 +L 23 The number of turns;

[0024] Φ 11 Φ 12 Φ 21 Φ 22 Φ 23 These are the windings L 11 L 12 L 21 L 22 L 23 The magnetic flux generated on each segment of the magnetic column;

[0025] Φ 11 =L 11 i1 is the magnetomotive force generated by inductor L1 in the lower half of the magnetic core side post I.

[0026] Φ 13 =L 13 i1 is the magnetomotive force generated by inductor L1 in the lower half of column III in the magnetic core.

[0027] Φ 21 =L 21 i2 is the magnetomotive force generated by inductor L2 in the upper half of the magnetic core side column I.

[0028] Φ 22 =L 22 i2 is the magnetomotive force generated by inductor L2 in the upper half and lower half of core side post II.

[0029] Φ 23 =L 23 i2 is the magnetomotive force of inductor L2 in the lower half of column III in the magnetic core.

[0030] The three magnetic pillars of the integrated inductor have the same air gap;

[0031] The magnetic flux generated by the windings of energy storage inductors L1 and L2 satisfies: Φ 11 +Φ 21 +Φ22 =Φ 13 +Φ 23 Therefore, the magnetic flux decoupling of energy storage inductor L1 and energy storage inductor L2 is achieved inside the magnetic core, which is equivalent to two independent inductors with zero mutual inductance, thus realizing the decoupled integration between the two inductors.

[0032] The input terminal m1 of the energy storage inductor L1 is connected to the power supply V. IN The positive terminal of the power switch Q1 is connected to the positive terminal of the power switch Q3; the output terminal m1' of the power switch Q1 is connected to the negative terminal of the fast recovery diode D1; the input terminal m2 of the power switch L2 is connected to the negative terminal of the fast recovery diode D2; the output terminal m2' of the power switch L1 is connected to the negative terminal of the fast recovery diode D4; the drain D of the power switch Q1 is connected to the negative terminal of the fast recovery diode D3; the positive terminal of the output filter capacitor C3 is connected to the negative terminal of the fast recovery diode D4.

[0033] like Figure 4 As shown, the magnetic flux generated by the windings of the energy storage inductors L1 and L2 in the magnetic integrated inductor unit (2) satisfies: Φ 11 Φ 21 Φ 22 Φ 13 Φ 23 The inductors are evenly distributed, and there is no mutual inductance between the energy storage inductors L1 and L2.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. The various components mentioned in this invention are common technologies in the existing field. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems, characterized in that, The device includes a power switch Q1, a CDDC unit, a magnetic integrated inductor unit, a fast recovery diode D3, a fast recovery diode D4, an output filter capacitor C3, a power supply VIN, an upper part of the EE magnetic core, and a lower part of the EE magnetic core. The CDDC unit is connected to the power supply VIN, the CDDC unit is connected to the magnetic integrated inductor unit, the magnetic integrated inductor unit is connected to the fast recovery diode D3, the fast recovery diode D3 is connected to the power switch Q1, the magnetic integrated inductor unit is connected to the fast recovery diode D4, the fast recovery diode D4 is connected to the output filter capacitor C3, the upper part of the EE magnetic core is located within the magnetic integrated inductor unit, and the lower part of the EE magnetic core is located within the magnetic integrated inductor unit. The CDDC unit includes: an energy storage capacitor C1, a fast recovery diode D1, an energy storage capacitor C2, and a fast recovery diode D2. The negative terminal of the energy storage capacitor C1 is connected to the positive terminal of the power supply VIN; the k-terminal of the fast recovery diode D1 is connected to the positive terminal of the energy storage capacitor C1; the a-terminal of the fast recovery diode D1 is connected to the negative terminal of the energy storage capacitor C2; the a-terminal of the fast recovery diode D2 is connected to the positive terminal of the energy storage capacitor C1; and the positive terminal of the energy storage capacitor C2 is connected to the k-terminal of the fast recovery diode D2. The upper part of the EE magnetic core includes the upper half of the core side post I, the upper half of the core center post III, and the upper half of the core side post II. The lower part of the EE magnetic core includes the lower half of the core side post I, the lower half of the core center post III, and the lower half of the core side post II.

2. A high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems according to claim 1, wherein the magnetically integrated inductor unit includes an energy storage inductor L1 and an energy storage inductor L2. Inductor L1 includes two parts: winding L11 and winding L13. Winding L11 is wound on the lower half of the magnetic core side column I, and winding L13 is wound on the lower half of the magnetic core middle column III. The number of turns of energy storage inductor L1 is the sum of the number of turns of winding L11 + L12. Energy storage inductor L2 includes windings L21, L22, and L23, wherein L21 is wound on the upper half of the magnetic core side column I, L22 is wound on the upper half and lower half of the magnetic core side column II, and L23 is wound on the upper half of the magnetic core side column III. The number of turns of L2 is the sum of the number of turns of windings L21 + L22 + L23.

3. A high-gain magnetically integrated DC-DC converter for photovoltaic power generation systems according to claim 2, wherein the input terminal m1 of the energy storage inductor L1 is connected to the positive terminal of the power supply VIN; the output terminal m1' of the energy storage inductor L1 is connected to the a terminal of the fast recovery diode D1; the input terminal m2 of the energy storage inductor L2 is connected to the k terminal of the fast recovery diode D2; the output terminal m2' of the energy storage inductor L2 is connected to the a terminal of the fast recovery diode D4; the drain D of the power switch Q1 is connected to the k terminal of the fast recovery diode D3; and the positive terminal of the output filter capacitor C3 is connected to the k terminal of the fast recovery diode D4.

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