Non-isolated boost DC-DC converter

Abstract

The utility model belongs to the technical field of power electronics, and discloses a non-isolated boost DC-DC converter, which comprises an input source Vin, an input inductor Lin, a first switch tube Q1, a second switch tube Q2, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first capacitor C1, a second capacitor C2, a third capacitor C3, a capacitor Co, a diode Do, an input inductor Lin and a coupling inductor. The non-isolated boost DC-DC converter provided by the utility model is provided with the coupling inductor and the converter, can realize significant voltage gain, reduce blocking voltage on a semiconductor and realize continuous input current, and can be suitable for a DC conversion circuit in many occasions.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of power electronics, specifically relates to a non-isolated boost DC-DC converter. BACKGROUND

[0002] With renewable energy has penetrated into the power generation system, due to certain resources, such as photovoltaic (PV), the output voltage is low, the demand for power electronic interface unit, especially DC-DC converter (DC-DC Converter) is essential. Among them, high step converter is suitable for renewable application, because the low voltage generated by renewable energy can be converted into standard voltage level of different applications.

[0003] For the increasing demand of DC-DC converter, although they are simple in structure, but the application occasion is everywhere, in the past design scheme, in order to realize the high performance, the number of active and passive devices is more, therefore, the cost of device rises, and the loss is large. And the subsequently developed high gain DC-DC converter, compared with traditional converter, although some improvement, but also has the problem of stress increase of switching device and low efficiency of converter.

[0004] The patent application with Chinese patent publication No. CN116545221A and the name of a high gain non-isolated DC-DC converter includes DC power supply Vg, switching tube S1, coupling inductance unit, input energy storage inductance L1, first energy storage capacitor C1, second energy storage capacitor C2, third energy storage capacitor C3, fourth energy storage capacitor C4, first diode D1, second diode D2, third diode D3 and load unit, wherein the coupling inductance unit includes first coupling inductance N1, second coupling inductance N2, excitation inductance Lm and leakage inductance Lk, input energy storage inductance L1, first energy storage capacitor C1, first diode D1, second energy storage capacitor C2 and first coupling inductance N1 constitute quasi Z source structure, second diode D2, third energy storage capacitor C3 and first coupling inductance N1 constitute voltage doubling unit. In the process of improving voltage gain, the patent application needs higher duty ratio or adopts complex turn ratio design. UTILITY MODEL CONTENTS

[0005] In order to overcome the problems existing in the prior art, the utility model aims at providing a non-isolated boost DC-DC converter, so as to improve.

[0006] In order to achieve the above purpose, the utility model adopts the technical scheme of:

[0007] A non-isolated boost DC-DC converter, comprising input source V in , input inductance L in, first switch tube Q1, second switch tube Q2, first diode D1, second diode D2, third diode D3, fourth diode D4, first capacitor C1, second capacitor C2, third capacitor C3, capacitor C o , diode D o , input inductor L in , and coupling inductor; the positive pole of the input source V in is connected to the first end of the input inductor L in ; the second end of the input inductor L in is connected to the collector of the first switch tube Q1, the positive pole of the first diode D1, and the first end of the coupling inductor drain inductor L LK ; the negative pole of the first diode D1 is connected to the anti-phase end of the coupling inductor secondary N2, the first end of the third capacitor C3, and the negative pole of the third diode D3; the positive pole of the third diode D3 is connected to the first end of the second capacitor C2 and the negative pole of the second diode D2; the positive pole of the second diode D2 is connected to the collector of the second switch tube Q2, the second end of the first capacitor C1, the anti-phase end of the coupling inductor primary N1, and the second end of the coupling inductor excitation inductor L m ; the second end of the coupling inductor drain inductor L LK is connected to the same-phase end of the transformer primary N1 and the first end of the coupling inductor excitation inductor L m ; the same-phase end of the coupling inductor secondary N2 is connected to the positive pole of the fourth diode D4 and the first end of the first capacitor C1; the second end of the third capacitor C3 is connected to the negative pole of the fourth diode D4 and the positive pole of the diode D o ; the negative pole of the diode D o is connected to the first end of the capacitor C o , and the first end of the capacitor C o is connected to the second end of the capacitor C in , the second end of the input source V in , the emitter of the second switch tube Q2, the second end of the second capacitor C2, and the emitter of the first switch tube Q1.

[0008] Optionally, the negative pole of the input source V in is grounded.

[0009] Optionally, the emitters of the first switch tube Q1 and the second switch tube Q2 are grounded.

[0010] Optionally, the first switch tube Q1 and the second switch tube Q2 are both IGBT type switch tubes.

[0011] Optionally, the first switch tube Q1 and the second switch tube Q2 are both IGBT type switch tubes with model number IKW40N120CS6XKSA1.

[0012] Optionally, the first capacitor C1, the second capacitor C2, the third capacitor C3, and the capacitor C o are all ceramic capacitors.

[0013] Optionally, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the capacitor C o The metal foils of the positive electrode and the negative electrode are all made of conductive materials.

[0014] Optionally, the diode D1 and the diode D2 are both Schottky diodes.

[0015] Optionally, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4 and the diode Do are all STPS745G-TR Schottky diodes.

[0016] Optionally, the input source V in The input voltage is 14V to 60V.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] The non-isolated boost DC-DC converter has a coupling inductor and a current transformer, can realize significant voltage gain, reduce the blocking voltage on the semiconductor, and realize continuous input current. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings described herein are only for the purpose of explanation, and are not intended to limit the scope of the utility model disclosure in any way. In addition, the shape and scale of each component in the drawings are only illustrative, and are used to help understand the utility model, and are not specific limitations on the shape and scale of each component of the utility model. In the drawings:

[0020] Figure 1 It is a non-isolated boost DC-DC converter topology based on the utility model.

[0021] Figure 2 It is a first working state diagram based on the non-isolated boost DC-DC converter of the utility model.

[0022] Figure 3 It is a second working state diagram based on the non-isolated boost DC-DC converter of the utility model.

[0023] Figure 4 It is a third working state diagram based on the non-isolated boost DC-DC converter of the utility model.

[0024] Figure 5The utility model is based on the fourth working state schematic view of non-isolated boost DC-DC converter.

[0025] Figure 6 The utility model is based on the fifth working state schematic view of non-isolated boost DC-DC converter. DETAILED DESCRIPTION

[0026] In order to make the personnel in the technical field better understand the technical scheme in the utility model, the technical scheme in the embodiment of the utility model will be clearly and completely described below in combination with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative labor should belong to the protection scope of the utility model.

[0027] Therefore, the following detailed description of the embodiment of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents the selected embodiment of the utility model. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative labor should belong to the protection scope of the utility model.

[0028] In the description of the embodiment of the utility model, it should be explained that if the orientation or position relationship indicated by the terms "upper", "lower", "horizontal", "inner" and the like is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship of the utility model product when it is usually placed, it is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0029] When an element is referred to as "provided on" another element, it can be directly on the other element or there can be a middle element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a middle element. The terms "vertical", "horizontal", "left", "right" and the like used in this paper are only for the purpose of illustration, and are not the only embodiment. If the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. As "horizontal" only means that its direction is more horizontal than "vertical", it does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0030] It should be noted that like reference numerals and letters refer to like items in the several views, and as such once an item is defined in one view, it is not necessary to further define and explain it in the subsequent views. In the description of the present application, it is to be understood that the terms "including" and "comprising" mean inclusion without restriction and that therefore there is no exclusion of addition of any other feature, integer, step, operation, element, component, or group thereof.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used in the description herein and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0032] The present application will be described in detail below with reference to the drawings.

[0033] The non-isolated boost DC-DC converter of the present application comprises an input source V in , an input inductor L in , a first switch tube Q1, a second switch tube Q2, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first capacitor C1, a second capacitor C2, a third capacitor C3, a capacitor C o , a diode D o , an input inductor L in , and a coupling inductor; the positive pole of the input source V in is connected to the first end of the input inductor L in ; the second end of the input inductor L in is connected to the collector of the first switch tube Q1, the positive pole of the first diode D1, and the first end of the coupling inductor leakage inductor L LK ; the negative pole of the first diode D1 is connected to the anti-phase end of the coupling inductor secondary N2, the first end of the third capacitor C3, and the negative pole of the third diode D3; the positive pole of the third diode D3 is connected to the first end of the second capacitor C2 and the negative pole of the second diode D2; the positive pole of the second diode D2 is connected to the collector of the second switch tube Q2, the second end of the first capacitor C1, the anti-phase end of the coupling inductor primary N1, and the second end of the coupling inductor excitation inductor L m ; the second end of the coupling inductor leakage inductor L LK is connected to the same-phase end of the transformer primary N1 and the second end of the coupling inductor excitation inductor L mThe same end of the coupled inductor secondary N2 is connected with the positive electrode of the fourth diode D4 and the first end of the first capacitor C1. o The positive electrode of the diode D o is connected with the negative electrode of the capacitor C o The first end of the capacitor C o is connected with the negative electrode of the input source V in .

[0034] The non-isolated boost DC-DC converter has a coupled inductor and a current transformer, can realize significant voltage gain, reduce the blocking voltage on the semiconductor, and realize continuous input current.

[0035] Embodiment 1

[0036] As shown in Figure 1 , the embodiment discloses a non-isolated structure high boost DC-DC converter, which comprises an input source V in , the positive electrode of the input source V in is connected with the upper end of an input inductor L in , and the negative electrode is grounded; the input inductor L in is connected with the collector of a first switch tube Q1, the positive electrode of a first diode D1 and the one end of a coupled inductor drain inductor L LK ; the emitter of the first switch tube Q1 is grounded; the negative electrode of the first diode D1 is connected with the different name end of the coupled inductor secondary N2, a third capacitor C3 and the negative electrode of a third diode D3; the positive electrode of the third diode D3 is connected with the one end of a second capacitor C2 and a second diode D2; the positive electrode of the second diode D2 is connected with the collector of a second switch tube Q2, the one end of a first capacitor C1, the different name end of a coupled inductor primary N1 and the one end of a coupled inductor excitation inductor L m ; the emitter of the second switch tube Q2 is grounded; the other end of the coupled inductor drain inductor L LK is connected with the same name end of a transformer primary N1 and the other end of the coupled inductor excitation inductor L m ; the same end of the coupled inductor secondary N2 is connected with the positive electrode of the fourth diode D4 and the other end of the first capacitor C1; the other end of the third capacitor C3 is connected with the negative electrode of the fourth diode D4 and the positive electrode of a diode D o ; the negative electrode of the diode D o is connected with the one end of a capacitor C o and a load in parallel, and the other end in parallel is grounded.

[0037] Preferably, the first switch tube Q1 and the second switch tube Q2 adopt IGBTs with the same duty cycle; by coupling inductance and VMCs to achieve significant voltage gain, reduce the blocking voltage on the semiconductor, and realize continuous input current; while having the advantages of compact structure, small size, high response speed, etc.

[0038] Specifically in the embodiments of the present disclosure, the first switch tube Q1 and the second switch tube Q2 both adopt IGBTs with the model number IKW40N120CS6XKSA1; it should be noted that the IGBTs with the model number IKW40N120CS6XKSA1 have a withstand voltage of 1.2 kV, and can have excellent performance in high-voltage applications; the maximum continuous current Ic of the collector is 80 A, which can withstand the passage of large current; the power dissipation (Pd-power dissipation) is 500 W, the working temperature range is from -40℃ to +175℃, the maximum voltage of the gate / emitter is 20 V, the collector-emitter saturation voltage is 1.85 V, and the gate-emitter leakage current is 600 nA.

[0039] Preferably, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the capacitor C o all adopt electrolytic capacitors; a ceramic capacitor usually uses ceramic material as the dielectric, and has good electrical performance and high working frequency. Specifically, the metal foil of the ceramic capacitor is the electrode, and the electrode layer is usually composed of silver or other conductive metals. After the ceramic capacitor is connected to the power supply, the electrons on the positive electrode will flow from the power supply into the electrode layer, and the electric field inside the ceramic dielectric will promote the storage of electric charge. The flow of electrons forms a potential difference on the electrode, and at the same time, the electric field in the medium forms between the positive and negative electrodes, storing electrical energy. It has a higher dielectric constant, which can store charges between the electrode and the medium. When the capacitor is connected to the circuit, the change of the electric field will cause the release of electric charge, thereby completing the release and absorption of electrical energy. It is usually used in high-frequency applications, filtering, decoupling and voltage stabilization circuits, etc., and has the characteristics of small size, high temperature resistance, good stability, etc., and is suitable for use in various electronic devices.

[0040] Preferably, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4 and the diode Do are all Schottky diodes; in particular, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4 and the diode Do are all Schottky diodes of the type STPS745G-TR; in particular, the STPS745G-TR has a maximum voltage-DC reverse (Vr) of 45 V, a current-average rectification (Io) of 7.5 A, it is fast recovery and has a moderate reverse recovery time; in addition, it has a voltage-forward (Vf) of 840 mV @ 15 A at different If, it is of the surface mount type, and the package form includes TO-263-3, D2Pak, TO-263AB, etc.

[0041] Preferably, the input source V in has an input voltage of 14-60 V.

[0042] Example 2

[0043] The non-isolated high step-up DC-DC converter disclosed in this embodiment includes the following working modes:

[0044] The first working mode and the fourth working mode:

[0045] States 1 and 4 have similar operating characteristics. In these modes, both power switches Q1 and the second switch Q2 are in the on state, causing the input inductor L in to charge and match the inductor V in . At the same time, the current in L in increases. When both switches are in the on state, the voltage on the side of the coupled inductor f drops to zero, causing all diodes to be reverse biased. Therefore, energy is discharged from the output capacitor (C o ) to the load R o . This operating state is shown in Fig. 1. Figure 2

[0046] The second working mode:

[0047] In state 2, the power switch second switch Q2 is off, but Q1 is still in the on state, similar to states 1 and 4, the L in current is still increasing. In this state, the voltage between the leakage inductance and the excitation inductance of the coupled inductor becomes negative, reducing their currents. The second diodes D2 and D o are biased towards the front end, while the other diodes remain off. Energy is transferred through D o ​The input voltage Vin from the secondary side of the coupled inductor and the first capacitors C1 and C3 flow to the output. Figure 3 The current path of the energy flow in this switching state is depicted.

[0048] Third mode of operation:

[0049] When t2 is reached, the second diode D2 is turned off. In this phase, the power switch Q1 remains on, while the second switch Q2 is not conducting. Only the diode Do is conducting, and the voltage over the main line of the coupled inductor is negative, similar to state 2, reducing the current in L k and L m The capacitors C1 and C3 discharge their stored energy and flow to the output port. The operating state is shown in Figure 4 .

[0050] Fifth mode of operation:

[0051] This state is entered after the first switch Q1 is turned off. In this switching state, the power switch second switch Q2 is in the on state. During this time, the fourth diode D4 starts to conduct. In addition, the first diode D1 is in the forward conducting state. The first diode D1 and L k distribute the input current equally. Figure 5 The circuit configuration of switching state 4 is shown.

[0052] Sixth mode of operation:

[0053] At the beginning of state 6, the third diode D3 conducts, increasing its current. The power switch Q1 is still in the off state, while the second switch Q2, the fourth diode D4 and the first diode D1 are in the conducting state. The input inductor L in sees a negative voltage, resulting in a linear decrease. The capacitor C2 and C o discharge, while C1 and C3 charge. Figure 6 The circuit configuration of this state is shown.

[0054] In summary, the load is supplied with electrical energy by the cooperation of the switches and other components, and a higher voltage gain is achieved with fewer components.

[0055] The non-isolated boost DC-DC converter has the characteristics of coupled inductor and current transformer, to achieve significant voltage gain, reduce the blocking voltage on the semiconductor, and realize continuous input current. Higher boost capability, suitable for more occasions of DC conversion circuit, fewer active and passive components required, lower voltage stress on its switch and filter inductor, low cost and high efficiency.

[0056] The device elements involved in the above embodiments are all conventional device elements if not specifically stated, and the structural arrangement, working mode or control mode involved are all conventional arrangement, working mode or control mode in the field if not specifically stated.

[0057] Finally, it is to be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit, and other modifications or equivalent replacements of the technical solutions of the present application made by the ordinary skilled in the art should be covered in the scope of the claims of the present application as long as they do not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A non-isolated boost DC-DC converter, characterized by, The input source V in , the input inductor L in , the first switch Q1, the second switch Q2, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the first capacitor C1, the second capacitor C2, the third capacitor C3, the capacitor C o , the diode D o , the input inductor L in , and the coupling inductor; the positive pole of the input source V in is connected to the first end of the input inductor L in ; the second end of the input inductor L in is connected to the collector of the first switch Q1, the positive pole of the first diode D1, and the first end of the coupling inductor leakage inductor L LK ; the negative pole of the first diode D1 is connected to the anti-phase end of the coupling inductor secondary N2, the first end of the third capacitor C3, and the negative pole of the third diode D3; the positive pole of the third diode D3 is connected to the first end of the second capacitor C2 and the negative pole of the second diode D2; the positive pole of the second diode D2 is connected to the collector of the second switch Q2, the second end of the first capacitor C1, the anti-phase end of the coupling inductor primary N1, and the second end of the coupling inductor excitation inductor L m ; the second end of the coupling inductor leakage inductor L LK is connected to the same-phase end of the transformer primary N1 and the first end of the coupling inductor excitation inductor L m ; the same-phase end of the coupling inductor secondary N2 is connected to the positive pole of the fourth diode D4 and the first end of the first capacitor C1; the second end of the third capacitor C3 is connected to the negative pole of the fourth diode D4 and the positive pole of the diode D o ; the negative pole of the diode D o is connected to the first end of the capacitor C o , the first end of the capacitor C o , the second end of the capacitor C in , the second end of the second capacitor C2, and the emitter of the first switch Q1 are all connected to the negative pole of the input source V in .

2. The non-isolated boost DC-DC converter of claim 1, wherein, The input source V in negative ground.

3. The non-isolated boost DC-DC converter of claim 1, wherein, The first switch tube Q1 and the second switch tube Q2 are both grounded.

4. The non-isolated boost DC-DC converter of claim 1, wherein, The first switch tube Q1 and the second switch tube Q2 are both IGBT switch tubes.

5. A non-isolated boost DC-DC converter according to claim 4, characterized in that, The first switch tube Q1 and the second switch tube Q2 are both IGBT switch tubes of IKW40N120CS6XKSA1.

6. The non-isolated boost DC-DC converter of claim 1, wherein, The first capacitor C1, the second capacitor C2, the third capacitor C3 and the capacitor C o All use ceramic capacitors.

7. A non-isolated boost DC-DC converter according to claim 6, characterized in that, The first capacitor C1, the second capacitor C2, the third capacitor C3 and the capacitor C o The metal foils of the first capacitor C1, the second capacitor C2, the third capacitor C3 and the capacitor C 8. The non-isolated boost DC-DC converter of claim 1, wherein, The diode D1 and the diode D2 are both Schottky diodes.

9. A non-isolated boost DC-DC converter according to claim 8, characterized in that, The first diode D1, the second diode D2, the third diode D3, the fourth diode D4 and the diode Do are all Schottky diodes of STPS745G-TR.

10. The non-isolated boost DC-DC converter of claim 1, wherein, The input source V in The input voltage is 14 to 60 V.

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