High-gain magnetic integrated DC-DC converter for photovoltaic power generation system

Abstract

A high-gain magnetic integrated DC-DC converter for a photovoltaic power generation system is characterized in that the high-gain magnetic integrated DC-DC converter comprises a CDDC unit, the CDDC unit is connected with a power supply VIN, the CDDC unit is connected with a magnetic integrated inductor unit, the magnetic integrated inductor unit is connected with a fast recovery diode D3, the fast recovery diode D3 is connected with a power switch tube Q1, and the power switch tube Q1 is connected with the power supply VIN. The magnetic integrated inductor unit is connected with the fast recovery diode D4, the fast recovery diode D4 is connected with the output filter capacitor C3, the EE magnetic core upper portion is arranged in the magnetic integrated inductor unit, the magnetic integrated inductor unit is internally provided with the EE magnetic core lower portion, the topological structure is simple, the number of devices is small, control is convenient, especially modular design is carried out, the CDDC unit is introduced, and the design is simple. Meanwhile, the power density of the converter is improved through the introduced magnetic integrated inductance unit, and the performance of the high-gain magnetic integrated DC-DC converter for the photovoltaic power generation system is promoted to be improved.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a high-gain magnetic integrated DC-DC converter for a photovoltaic power generation system. Background Art

[0002] At present, the construction of a new power system with new energy as the main body is developing rapidly, and photovoltaic power generation systems have been widely used. Due to the factors such as the loss of switching devices, the loss of the inductor itself, and the current withstand voltage limitation of the switching devices, the efficiency of the traditional boost converter is low. In addition, in the boost converter, if a higher gain is to be obtained, the inductor will be very large, which will reduce the power density and increase the volume. In order to solve the above problems, a high-gain magnetic integrated DC-DC converter for photovoltaic power generation systems is proposed. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a high-gain magnetic integrated DC-DC converter for photovoltaic power generation system, characterized in that it includes a power switch tube Q 1 , CDDC unit, magnetic integrated inductor unit, fast recovery diode D 3 , Fast recovery diode D 4 , output filter capacitor C 3 , Power supply V IN , EE core upper part, EE core lower part, the CDDC unit and the power supply V IN The CDDC unit is connected to the magnetic integrated inductor unit, and the magnetic integrated inductor unit is connected to the fast recovery diode D 3 Connect the fast recovery diode D 3 With power switch tube Q 1 Connect the magnetic integrated inductor unit and the fast recovery diode D 4 Connect the fast recovery diode D 4 With the output filter capacitor C 3 The upper part of the EE core is arranged in the magnetic integrated inductor unit, and the lower part of the EE core is arranged in the magnetic integrated inductor unit;

[0004] Furthermore, the CDDC unit includes: an energy storage capacitor C 1 , fast recovery diode D 1 , energy storage capacitor C 2 , fast recovery diode D 2 , the energy storage capacitor C 1 The - pole is connected to the power supply V IN The + pole is connected; the fast recovery diode D 1 The k-pole and the energy storage capacitor C 1 The + pole is connected; the fast recovery diode D 1The a pole and the energy storage capacitor C 2 The - pole is connected; the fast recovery diode D 2 The a pole and the energy storage capacitor C 1 The + pole is connected; the energy storage capacitor C 2 The + pole of the fast recovery diode D 2 The k pole is connected;

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

[0006] Furthermore, the magnetic integrated inductor unit includes an energy storage inductor L 1 and energy storage inductor L 2 , inductance L 1 Including winding L 11 and winding L 13 Two parts, winding L 11 Wound on the lower half of the core side column Ⅰ, winding L 13 Wound on the lower part of the core column III, the energy storage inductor L 1 The number of turns of winding L 11 +L 12 The number of turns and the energy storage inductor L 2 Including winding L 21 , L 22 , L 23 , where L 21 Wound on the upper part of the core side column Ⅰ, L 22 Wound on the upper part of the core side column II and the lower part of the core side column II, L 23 Wound on the upper part of the core side column III, L 2 The number of turns of winding L 21 +L 22 +L 23 The number of turns and;

[0007] Furthermore, the energy storage inductor L 1 The input terminal m 1 With power supply V IN The + pole is connected; the energy storage inductor L 1 The output terminal m 1 'With fast recovery diode D 1 The a pole of the energy storage inductor L 2 The input terminal m 2 With fast recovery diode D 2 The k pole is connected; the energy storage inductor L 1 The output terminal m 2 'With fast recovery diode D4 The a pole of the power switch tube Q 1 The drain D and the fast recovery diode D 3 The k-pole is connected; the output filter capacitor C 3 The + pole and fast recovery diode D 4 The k pole is connected.

[0008] Beneficial effects of the present invention:

[0009] The present invention discloses a high-gain magnetic integrated DC-DC converter for photovoltaic power generation systems, which has a simple topological structure, fewer devices, and is easy to control. In particular, a modular design is performed, and the CDDC unit introduced enables the system to obtain a higher gain. By introducing magnetic integration technology, the volume and weight of the magnetic components of the converter can be effectively reduced, the current ripple can also be reduced, and the core loss is reduced, thereby improving the power density of the system, which is helpful to promote the performance improvement of the high-gain magnetic integrated DC-DC converter for photovoltaic power generation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the principle of a high-gain magnetic integrated DC-DC converter for a photovoltaic power generation system according to the present invention;

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

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

[0013] Figure 4 A magnetic flux vector diagram of a magnetic integrated inductor structure of a high-gain magnetic integrated DC-DC converter for a photovoltaic power generation system according to the present invention;

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

[0015] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Example 1

[0019] The present invention provides a high-gain magnetic integrated DC-DC converter for photovoltaic power generation system, which is characterized by comprising a power switch tube Q 1 , CDDC unit (1), magnetic integrated inductor unit (2), fast recovery diode D 3 , Fast recovery diode D 4 , output filter capacitor C 3 , Power supply V IN , an EE core upper portion (41), an EE core lower portion (42), the CDDC unit (1) and a power supply V IN The CDDC unit (1) is connected to the magnetic integrated inductor unit (2), and the magnetic integrated inductor unit (2) is connected to the fast recovery diode D 3 Connect the fast recovery diode D 3 With power switch tube Q 1 The magnetic integrated inductor unit (2) is connected to the fast recovery diode D 4 Connect the fast recovery diode D 4 With the output filter capacitor C 3 The magnetic integrated inductor unit (2) is connected to an EE magnetic core upper portion (41) and the magnetic integrated inductor unit (2) is provided with an EE magnetic core lower portion (42);

[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, and the fast recovery diode D 3 And fast recovery diode D 4 Used for rectification and to prevent reverse current injection, the output filter capacitor C 3 For output filtering, the EE core upper part (41) and the EE core lower part (42) are used for winding the magnetic integrated inductor unit (2), the power supply V IN It is the power supply, which provides energy for the converter;

[0021] The CDDC unit (1) comprises: an energy storage capacitor C 1 , fast recovery diode D 1 , energy storage capacitor C 2 , fast recovery diode D 2 , the energy storage capacitor C 1 The - pole is connected to the power supply V IN The + pole is connected; the fast recovery diode D 1 The k-pole and the energy storage capacitor C 1 The + pole is connected; the fast recovery diode D 1 The a pole and the energy storage capacitor C 2 The - pole is connected; the fast recovery diode D 2 The a pole and the energy storage capacitor C 1 The + pole is connected; the energy storage capacitor C 2 The + pole of the fast recovery diode D 2 The k pole is connected;

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

[0023] The magnetic integrated inductor unit (2) comprises an energy storage inductor L 1 and energy storage inductor L 2 , inductance L 1 Including winding L 11 and winding L 13 Two parts, winding L 11 Wound on the lower half of the core side column Ⅰ, winding L 13 Wound on the lower part of the core column III, the energy storage inductor L 1 The number of turns of winding L 11 +L 12 The number of turns and the energy storage inductor L 2 Including winding L 21 , L 22 , L 23 , where L21 Wound on the upper part of the core side column Ⅰ, L 22 Wound on the upper part of the core side column II and the lower part of the core side column II, L 23 Wound on the upper part of the core side column III, L 2 The number of turns of winding L 21 +L 22 +L 23 The number of turns and;

[0024] Φ 11 , Φ 12 , Φ 21 , Φ 22 , Φ 23 Winding L 11 , L 12 , L 21 , L 22 , L 23 The magnetic flux generated on each magnetic column;

[0025] Φ 11 =L 11 i 1 is the inductance L 1 The magnetomotive force generated in the lower half of the core side column I is

[0026] Φ 13 =L 13 i 1 is the inductance L 1 The magnetomotive force generated in the lower part of the core column III is

[0027] Φ 21 =L 21 i 2 is the inductance L 2 The magnetomotive force generated in the upper part of the core side column I is

[0028] Φ 22 =L 22 i 2 is the inductance L 2 The magnetomotive force generated in the upper part of the core side column II and the lower part of the core side column II,

[0029] Φ 23 =L 23 i 2 is the inductance L 2 The magnetomotive force in the lower half of column III in the core is

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

[0031] Energy storage inductor L 1 and energy storage inductor L 2The magnetic flux generated by the winding satisfies: Φ 11 +Φ 21 +Φ 22 =Φ 13 +Φ 23 , so the energy storage inductance L is realized inside the magnetic core 1 and energy storage inductor L 2 The magnetic flux decoupling is equivalent to two independent inductors with zero mutual inductance, which realizes the decoupling integration between the two inductors.

[0032] The energy storage inductor L 1 The input terminal m 1 With power supply V IN The + pole is connected; the energy storage inductor L 1 The output terminal m 1 'With fast recovery diode D 1 The a pole of the energy storage inductor L 2 The input terminal m 2 With fast recovery diode D 2 The k pole is connected; the energy storage inductor L 1 The output terminal m 2 'With fast recovery diode D 4 The a pole of the power switch tube Q 1 The drain D and the fast recovery diode D 3 The k-pole is connected; the output filter capacitor C 3 The + pole and fast recovery diode D 4 The k pole is connected;

[0033] like Figure 4 As shown, the energy storage inductor L in the magnetic integrated inductor unit (2) 1 and energy storage inductor L 2 The magnetic flux generated by the winding satisfies: Φ 11 , Φ 21 , Φ 22 , Φ 13 , Φ 23 , evenly distributed, energy storage inductor L 1 and energy storage inductor L 2 No mutual induction.

[0034] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. The various components mentioned in the present 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 above embodiments and descriptions are only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-gain magnetic integrated DC-DC converter for photovoltaic power generation system, characterized in that: Including power switch tube Q1, CDDC unit, magnetic integrated inductor unit, fast recovery diode D3, fast recovery diode D4, output filter capacitor C3, power supply V IN , EE core upper part, EE core lower part, 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 tube 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, an upper part of the EE core is arranged in the magnetic integrated inductor unit, and a lower part of the EE core is arranged in the magnetic integrated inductor unit.

2. A high-gain magnetic integrated DC-DC converter for photovoltaic power generation system according to claim 1, characterized in that: The CDDC unit includes: a storage capacitor C1, a fast recovery diode D1, a storage capacitor C2, a fast recovery diode D2, and the - terminal of the storage capacitor C1 is connected to the power supply V IN The + pole of the fast recovery diode D1 is connected to the + pole of the energy storage capacitor C1; the a pole of the fast recovery diode D1 is connected to the - pole of the energy storage capacitor C2; the a pole of the fast recovery diode D2 is connected to the + pole of the energy storage capacitor C1; the + pole of the energy storage capacitor C2 is connected to the k pole of the fast recovery diode D2.

3. According to the high-gain magnetic integrated DC-DC converter for photovoltaic power generation systems described in claim 2, the upper part of the EE core includes the upper half of the core side column I, the upper half of the core middle column III, and the upper half of the core side column II, and the lower part of the EE core includes the lower half of the core side column I, the lower half of the core middle column III, and the lower half of the core side column II.

4. According to the high-gain magnetic integrated DC-DC converter for photovoltaic power generation system of claim 3, the magnetic integrated inductor unit comprises an energy storage inductor L1 and an energy storage inductor L2, the inductor L1 comprises a winding L 11 and winding L 13 Two parts, winding L 11 Wound on the lower half of the core side column Ⅰ, winding L 13 Wound on the lower half of the core column III, the number of turns of the energy storage inductor L1 is the same as the winding L 11 +L 12 The number of turns and the energy storage inductor L2 include winding L 21 , L 22 , L 23 , where L 21 Wound on the upper part of the core side column Ⅰ, L 22 Wound on the upper part of the core side column II and the lower part of the core side column II, L 23 Wound on the upper part of the core side column III, the number of turns of L2 is the same as the winding L 21 +L 22 +L 23 The number of turns and .

5. According to the high-gain magnetic integrated DC-DC converter for photovoltaic power generation system of claim 4, the input terminal m1 of the energy storage inductor L1 is connected to the power supply V IN The + pole of the energy storage inductor L1 is connected to the a pole of the fast recovery diode D1; the input terminal m2 of the energy storage inductor L2 is connected to the k pole of the fast recovery diode D2; the output terminal m2' of the energy storage inductor L1 is connected to the a pole of the fast recovery diode D4; the drain D of the power switch tube Q1 is connected to the k pole of the fast recovery diode D3; the + pole of the output filter capacitor C3 is connected to the k pole of the fast recovery diode D4.

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