High-gain three-mode direct-current converter

Abstract

The utility model discloses a high-gain three-mode DC converter, and belongs to the technical field of power electronics. The high-gain three-mode direct-current converter provided by the utility model comprises a direct-current input power supply Vin, an output load R1, a plurality of diodes, an active switch inductor network and a switch capacitor network, and through a unique dual-duty-ratio design, the direct-current converter can be flexibly switched in various working modes, the flexibility of voltage gain adjustment is effectively improved, and the voltage gain adjustment efficiency is improved. The requirements of different application scenes are met; the active switch inductor network and the switch capacitor network are combined, and through cooperative work of inductors and capacitors, turn-off loss of an input switch is reduced, zero-voltage turn-on of an output switch is realized, and the overall efficiency of the direct-current converter is improved; and meanwhile, the transformer-free design is realized, and the size and the magnetic core loss are reduced.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to a high-gain three-mode DC-DC converter. Background Technology

[0002] With the rapid development of renewable energy systems and DC microgrids, high-gain, high-efficiency DC-DC converters have become a key technology for connecting low-voltage renewable energy to high-voltage DC buses. Although traditional boost converters have a simple structure, their voltage gain is limited by the duty cycle. When high gain is required, an extremely large duty cycle must be used, which leads to extremely high voltage stress on the switching devices, accompanied by serious switching and conduction losses, severely restricting their application in high-voltage scenarios.

[0003] Therefore, how to achieve high-gain, low-voltage-stress, and high-efficiency voltage conversion has become a technical challenge that urgently needs to be overcome by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a high-gain three-mode DC-DC converter, which aims to solve the problems of excessive voltage stress and severe switching losses in existing traditional boost converters due to the voltage gain being limited by the duty cycle.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A high-gain three-mode DC-DC converter includes a DC input power supply V. in The circuit includes an output load R1, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, an active switching inductor network, and a switched capacitor network. The active switching inductor network includes a first inductor L1, a second inductor L2, a first switching transistor S1, a second switching transistor S2, and a third switching transistor S3. The switched capacitor network includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5.

[0007] Input power V in The positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... inThe negative electrodes are respectively connected to the source of the first switching transistor S1 and the negative electrode of the second inductor L2; the negative electrode of the first inductor L1 is respectively connected to the drain of the first switching transistor S1, the anode of the first diode D1, the negative electrode of the first capacitor C1 and the positive electrode of the second capacitor C2; the positive electrode of the second inductor L2 is respectively connected to the cathode of the sixth diode D6, the source of the second switching transistor S2, the source of the third switching transistor S3 and the positive electrode of the fourth capacitor C4; the drain of the third switching transistor S3 is connected to the cathode of the first diode D1; the anode of the second diode D2 is connected to the anode of the sixth diode D6 through the positive electrode of the second capacitor C2, and the cathode of the second diode D2 is respectively connected to the positive electrode of the third capacitor C3 and the anode of the third diode D3, and the negative electrode of the third capacitor C3 is connected to the positive electrode of the fourth capacitor C4; the cathode of the third diode D3 is respectively connected to the positive electrode of the output load R1 and the positive electrode of the first capacitor C1; the anode of the fourth diode D4 is respectively connected to the cathode of the fifth diode D5 and the negative electrode of the fourth capacitor C4, and the cathode of the fourth diode D4 is respectively connected to the positive electrode of the fifth capacitor C5 and the anode of the sixth diode D6; the anode of the fifth diode D5 is respectively connected to the negative electrode of the output load R1 and the negative electrode of the fifth capacitor C5;

[0008] The first switching transistor S1 and the second switching transistor S2 share the first driving signal with a duty cycle of d1, and the third switching transistor S3 uses the second driving signal with a duty cycle of d2.

[0009] A further improvement of the present invention lies in that: the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5 and the sixth diode D6 adopt low-rated voltage diodes with low forward voltage drop.

[0010] A further improvement of the present invention lies in that: the first switching transistor S1, the second switching transistor S2 and the third switching transistor S3 adopt low-rated voltage switches with low on-resistance.

[0011] A further improvement of the present invention lies in that: the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 are all selected to have capacitance values that keep the terminal voltages of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 constant during operation.

[0012] A further improvement of the present invention lies in that: the first inductor L1 and the second inductor L2 adopt inductors with the same specifications, and the range of the inductance value is 60 uH ≤ L1 = L2 ≤ 200 uH.

[0013] A further improvement of the present invention lies in that: the duty cycles satisfy the following relationship 0 < d1 + d2 < 1, and under different duty cycle combinations, the high-gain three-mode DC converter has three operating modes.

[0014] A further improvement of this invention is that the three operating modes are Mode 1, Mode 2, and Mode 3; when the high-gain three-mode DC-DC converter is in Mode 1, the input power supply V... in The positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... in The negative terminals of the first inductor L1 and the second inductor L2 are connected to the source of the first switching transistor S1 and the negative terminal of the second inductor L2, respectively. The negative terminal of the first inductor L1 is connected to the drain of the first switching transistor S1, the negative terminal of the first capacitor C1, and the positive terminal of the second capacitor C2, respectively. The positive terminal of the second inductor L2 is connected to the source of the second switching transistor S2 and the positive terminal of the fourth capacitor C4, respectively. The positive terminal of the third capacitor C3 is connected to the anode of the third diode D3, and the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4, respectively. The cathode of the third diode D3 is connected to the positive terminal of the output load R1 and the positive terminal of the first capacitor C1, respectively. The anode of the fourth diode D4 is connected to the negative terminal of the fourth capacitor C4, and the cathode of the fourth diode D4 is connected to the positive terminal of the fifth capacitor C5, respectively. The negative terminal of the output load R1 is connected to the negative terminal of the fifth capacitor C5, respectively.

[0015] The first switch S1 and the second switch S2 are in the ON state, and the third switch S3 is in the OFF state; the third diode D3 and the fourth diode D4 are in the ON state, and the first diode D1, the second diode D2, the fifth diode D5, and the sixth diode D6 are in the OFF state; the first inductor L1 and the second inductor L2 are connected in parallel to the DC input power supply V. in The first capacitor C1 and the fourth capacitor C4 are in the charging state, while the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in the discharging state.

[0016] A further improvement of this invention is that when the high-gain three-mode DC-DC converter is in mode two, the input power supply V... in The positive terminal of the first inductor L1 is connected in sequence to the positive terminal of the first inductor L1, the anode of the first diode D1, the cathode of the first diode D1, the drain of the third switch S3, the source of the third switch S3, the positive terminal of the second inductor L2, and the negative terminal of the second inductor L2 to the input power supply V. in The negative terminal of the output load R1 is connected in sequence to the negative terminal of the fifth capacitor C5, the positive terminal of the fifth capacitor C5, the negative terminal of the second capacitor C2, the positive terminal of the second capacitor C2, the negative terminal of the first capacitor C1, and the positive terminal of the first capacitor C1 to the positive terminal of the output load R1, forming a circuit.

[0017] The first switch S1 and the second switch S2 are in the off state, and the third switch S3 is in the on state; the first diode D1 is in the on state, and the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 are in the off state; the first inductor L1 and the second inductor L2 are connected in series to the DC input power supply V.in The capacitor is in a charging state, while the first capacitor C1, the second capacitor C2, and the fifth capacitor C5 are in a discharging state.

[0018] A further improvement of this invention is that: when the high-gain three-mode DC-DC converter is in mode three, the input power supply V... in The positive terminal is connected to the positive terminal of the first inductor L1, and the input power supply V is... in The negative terminal of the first inductor L1 is connected to the negative terminal of the second inductor L2; the negative terminal of the first inductor L1 is connected to the negative terminal of the first capacitor C1 and the positive terminal of the second capacitor C2; the positive terminal of the second inductor L2 is connected to the cathode of the sixth diode D6 and the positive terminal of the fourth capacitor C4; the anode of the second diode D2 is connected to the anode of the sixth diode D6 via the positive terminal of the second capacitor C2, the cathode of the second diode D2 is connected to the positive terminal of the third capacitor C3, and the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4; the positive terminal of the output load R1 is connected to the positive terminal of the first capacitor C1; the cathode of the fifth diode D5 is connected to the negative terminal of the fourth capacitor C4, and the positive terminal of the fifth capacitor C5 is connected to the anode of the sixth diode D6; the anode of the fifth diode D5 is connected to the negative terminal of the output load R1 and the negative terminal of the fifth capacitor C5.

[0019] The first switch S1, the second switch S2, and the third switch S3 are in the off state; the second diode D2, the fifth diode D5, and the sixth diode D6 are in the on state; the first diode D1, the third diode D3, and the fourth diode D4 are in the off state; the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in the charging state; and the first capacitor C1 and the fourth capacitor C4 are in the discharging state.

[0020] A further improvement of this invention is that when the high-gain three-mode DC-DC converter is in mode one, the voltage of the fourth capacitor C4 is equal to the voltage of the second capacitor C2 and the DC input power supply V. in The sum of the voltages of the first capacitor C1 and the second capacitor C2 is equal to the sum of the voltages of the third capacitor C3 and the fourth capacitor C4. When the high-gain three-mode DC-DC converter is in mode two, the output voltage of the output load R1 is the sum of the voltages of the first capacitor C1, the second capacitor C2, and the fifth capacitor C5. When the high-gain three-mode DC-DC converter is in mode three, the output voltage of the first inductor L1 is the DC input power supply V. in The voltage difference between the second capacitor C2 and the voltage of the third capacitor C3 is half that of the fourth capacitor C4. The voltage of the fourth capacitor C4 is equal to the voltage of the fifth capacitor C5.

[0021] Compared with the prior art, the positive and progressive effects of this utility model are as follows:

[0022] The high-gain three-mode DC-DC converter provided by this utility model includes a DC input power supply V.in The DC-DC converter, consisting of an output load R1, multiple diodes, an active switching inductor network, and a switched capacitor network, employs a unique dual duty cycle design. This allows for flexible switching between various operating modes, effectively improving the flexibility of voltage gain adjustment and meeting the needs of different application scenarios. The combination of the active switching inductor network and the switched capacitor network, through the coordinated operation of inductors and capacitors, reduces the turn-off losses of the input switches and achieves zero-voltage turn-on of the output switches, improving the overall efficiency of the DC-DC converter. Simultaneously, it achieves a transformerless design, reducing size and core losses. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0024] Figure 1 This is a topology diagram of a high-gain three-mode DC-DC converter according to the present invention;

[0025] Figure 2 This is a timing diagram of a high-gain three-mode DC-DC converter according to the present invention;

[0026] Figure 3 This is a structural diagram of mode one of a high-gain three-mode DC-DC converter according to this utility model;

[0027] Figure 4 This is a structural diagram of mode two of a high-gain three-mode DC-DC converter according to this utility model;

[0028] Figure 5 This is a structural diagram of mode 3 of a high-gain three-mode DC-DC converter according to this utility model;

[0029] Among them, V GS1 V GS2 V GS3 These are the voltages between the gate and source of the first switch S1, the second switch S2, and the third switch S3, respectively; T S One period; d1T S d2T represents the conduction duration of the first switch S1 and the second switch S2 within one cycle. S The on-time of the third switch S3 within one cycle;

[0030] V L1 V L2 The voltages of the first inductor L1 and the second inductor L2 are respectively; i L1 i L2 These are the currents of the first inductor L1 and the second inductor L2, respectively;

[0031] V S1 V S2 V S3 These are the voltages of the first switch S1, the second switch S2, and the third switch S3, respectively; i S1 i S2 i S3 These are the currents of the first switch S1, the second switch S2, and the third switch S3, respectively. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] Definitions:

[0035] Low rated voltage switch: refers to a switch with a lower safe voltage allowed during normal operation, and is usually used in low voltage circuits.

[0036] Low on-resistance: This refers to the low resistance between the contacts of a switch when it is in the on state, which facilitates the smooth flow of current.

[0037] Low forward voltage drop: This refers to the low voltage drop across a diode when it is forward-biased.

[0038] Low rated voltage: This means that the diode can withstand a relatively low maximum reverse voltage (i.e., rated voltage).

[0039] The present invention will be further described in detail below with reference to the accompanying drawings. The description is intended to explain the present invention and not to limit it.

[0040] See Figure 1 A high-gain three-mode DC-DC converter, including a DC input power supply V inThe circuit includes an output load R1, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, an active switching inductor network, and a switched capacitor network. The active switching inductor network includes a first inductor L1, a second inductor L2, a first switching transistor S1, a second switching transistor S2, and a third switching transistor S3. The switched capacitor network includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5.

[0041] Input power V in The positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... in The negative terminals of the first inductor L1 and the second inductor L2 are connected to the source of the first switching transistor S1 and the negative terminal of the second inductor L2, respectively. The negative terminal of the first inductor L1 is connected to the drain of the first switching transistor S1, the anode of the first diode D1, the negative terminal of the first capacitor C1, and the positive terminal of the second capacitor C2, respectively. The positive terminal of the second inductor L2 is connected to the cathode of the sixth diode D6, the source of the second switching transistor S2, the source of the third switching transistor S3, and the positive terminal of the fourth capacitor C4, respectively. The drain of the third switching transistor S3 is connected to the cathode of the first diode D1. The anode of the second diode D2 is connected to the anode of the sixth diode D6 via the positive terminal of the second capacitor C2. The cathode of the second diode D2 is connected to the positive terminal of the third capacitor C3 and the anode of the third diode D3, respectively; the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4; the cathode of the third diode D3 is connected to the positive terminal of the output load R1 and the positive terminal of the first capacitor C1, respectively; the anode of the fourth diode D4 is connected to the cathode of the fifth diode D5 and the negative terminal of the fourth capacitor C4, respectively; the cathode of the fourth diode D4 is connected to the positive terminal of the fifth capacitor C5 and the anode of the sixth diode D6, respectively; the anode of the fifth diode D5 is connected to the negative terminal of the output load R1 and the negative terminal of the fifth capacitor C5, respectively.

[0042] The first switch S1 and the second switch S2 share the first driving signal with a duty cycle of d1, while the third switch S3 uses the second driving signal with a duty cycle of d2.

[0043] The unique dual duty cycle design enables the DC-DC converter to switch flexibly between multiple operating modes, effectively improving the flexibility of voltage gain adjustment and meeting the needs of different application scenarios. The combination of active switching inductor network and switched capacitor network, through the coordinated work of inductor and capacitor, reduces the turn-off loss of input switch and realizes zero-voltage turn-on of output switch, improving the overall efficiency of DC-DC converter. At the same time, it realizes transformerless design, reducing size and core loss.

[0044] Specifically, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5 and the sixth diode D6 employ low-rated voltage diodes with a low forward voltage drop.

[0045] The diode models can be selected as BYY32E-200, SBR3000CT. These diodes all belong to Schottky diodes or ultrafast recovery diodes, having a low forward voltage drop and fast switching characteristics. Selecting such diodes can reduce conduction losses and improve the overall efficiency.

[0046] Specifically, the first switch S1, the second switch S2 and the third switch S3 employ low-rated voltage switches with a low on-resistance.

[0047] The switch models can be selected as IRF3205, Si4468DY. These switches all belong to N-channel MOSFETs, having faster switching speeds and better dynamic characteristics. Selecting such switches can meet circuits with extremely high efficiency requirements and low working voltages.

[0048] Specifically, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 are all selected to have capacitance values that keep the terminal voltages of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 constant during operation.

[0049] The capacitance values of the capacitors cannot be increased infinitely. Instead, on the basis of meeting the minimum capacitance value, a moderate capacitance value should be selected to optimize performance and economy. Specifically: the minimum capacitance value of the first capacitor C1 is 10 uF, the minimum capacitance value of the second capacitor C2 is 6.8 uF, the minimum capacitance value of the third capacitor C3 is 4.5 uF, the minimum capacitance value of the fourth capacitor C4 is 4.5 uF, and the minimum capacitance value of the fifth capacitor C5 is 3.2 uF;

[0050] The maximum capacitance values of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 are all 1.5 to 2 times the corresponding minimum capacitance values.

[0051] Specifically, the first inductor L1 and the second inductor L2 employ inductors with the same specifications, and the range of the inductance value is 60 uH ≤ L1 = L2 ≤ 200 uH.

[0052] Specifically, the duty cycle satisfies the following relationship 0 < d1 + d2 < 1. Under different duty cycle combinations, the high-gain three-mode DC converter has three operating modes.

[0053] Specifically, the three operating modes are Mode 1, Mode 2 and Mode 3; when the operating mode of the high-gain three-mode DC converter is in Mode 1, the input power supply V inThe positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... in The negative terminals of the first inductor L1 and the second inductor L2 are connected to the source of the first switching transistor S1 and the negative terminal of the second inductor L2, respectively. The negative terminal of the first inductor L1 is connected to the drain of the first switching transistor S1, the negative terminal of the first capacitor C1, and the positive terminal of the second capacitor C2, respectively. The positive terminal of the second inductor L2 is connected to the source of the second switching transistor S2 and the positive terminal of the fourth capacitor C4, respectively. The positive terminal of the third capacitor C3 is connected to the anode of the third diode D3, and the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4, respectively. The cathode of the third diode D3 is connected to the positive terminal of the output load R1 and the positive terminal of the first capacitor C1, respectively. The anode of the fourth diode D4 is connected to the negative terminal of the fourth capacitor C4, and the cathode of the fourth diode D4 is connected to the positive terminal of the fifth capacitor C5, respectively. The negative terminal of the output load R1 is connected to the negative terminal of the fifth capacitor C5, respectively.

[0054] The first switch S1 and the second switch S2 are in the ON state, and the third switch S3 is in the OFF state; the third diode D3 and the fourth diode D4 are in the ON state, and the first diode D1, the second diode D2, the fifth diode D5, and the sixth diode D6 are in the OFF state; the first inductor L1 and the second inductor L2 are connected in parallel to the DC input power supply V. in The first capacitor C1 and the fourth capacitor C4 are in the charging state, while the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in the discharging state.

[0055] Specifically, when the high-gain three-mode DC-DC converter is operating in mode two, the input power supply V in The positive terminal of the first inductor L1 is connected in sequence to the positive terminal of the first inductor L1, the anode of the first diode D1, the cathode of the first diode D1, the drain of the third switch S3, the source of the third switch S3, the positive terminal of the second inductor L2, and the negative terminal of the second inductor L2 to the input power supply V. in The negative terminal of the output load R1 is connected in sequence to the negative terminal of the fifth capacitor C5, the positive terminal of the fifth capacitor C5, the negative terminal of the second capacitor C2, the positive terminal of the second capacitor C2, the negative terminal of the first capacitor C1, and the positive terminal of the first capacitor C1 to the positive terminal of the output load R1, forming a circuit.

[0056] The first switch S1 and the second switch S2 are in the off state, and the third switch S3 is in the on state; the first diode D1 is in the on state, and the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 are in the off state; the first inductor L1 and the second inductor L2 are connected in series to the DC input power supply V. in The capacitor is in a charging state, while the first capacitor C1, the second capacitor C2, and the fifth capacitor C5 are in a discharging state.

[0057] Specifically, when the high-gain three-mode DC-DC converter is operating in mode three, the input power supply V in The positive terminal is connected to the positive terminal of the first inductor L1, and the input power supply V is... in The negative terminal of the first inductor L1 is connected to the negative terminal of the second inductor L2; the negative terminal of the first inductor L1 is connected to the negative terminal of the first capacitor C1 and the positive terminal of the second capacitor C2; the positive terminal of the second inductor L2 is connected to the cathode of the sixth diode D6 and the positive terminal of the fourth capacitor C4; the anode of the second diode D2 is connected to the anode of the sixth diode D6 via the positive terminal of the second capacitor C2, the cathode of the second diode D2 is connected to the positive terminal of the third capacitor C3, and the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4; the positive terminal of the output load R1 is connected to the positive terminal of the first capacitor C1; the cathode of the fifth diode D5 is connected to the negative terminal of the fourth capacitor C4, and the positive terminal of the fifth capacitor C5 is connected to the anode of the sixth diode D6; the anode of the fifth diode D5 is connected to the negative terminal of the output load R1 and the negative terminal of the fifth capacitor C5.

[0058] The first switch S1, the second switch S2, and the third switch S3 are in the off state; the second diode D2, the fifth diode D5, and the sixth diode D6 are in the on state; the first diode D1, the third diode D3, and the fourth diode D4 are in the off state; the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in the charging state; and the first capacitor C1 and the fourth capacitor C4 are in the discharging state.

[0059] Specifically, when the high-gain three-mode DC-DC converter is operating in mode one, the voltage across the fourth capacitor C4 is equal to the voltage across the second capacitor C2 and the DC input power supply V. in The sum of the voltages of the first capacitor C1 and the second capacitor C2 is equal to the sum of the voltages of the third capacitor C3 and the fourth capacitor C4. When the high-gain three-mode DC-DC converter is in mode two, the output voltage of the output load R1 is the sum of the voltages of the first capacitor C1, the second capacitor C2, and the fifth capacitor C5. When the high-gain three-mode DC-DC converter is in mode three, the output voltage of the first inductor L1 is the DC input power supply V. in The voltage difference between the second capacitor C2 and the voltage of the third capacitor C3 is half that of the fourth capacitor C4. The voltage of the fourth capacitor C4 is equal to the voltage of the fifth capacitor C5.

[0060] Specifically, when the high-gain three-mode DC-DC converter operates in Mode 1:

[0061] V C4 =V C2 +V in

[0062] V c1 +V c2 =V C3+V c4

[0063] In the formula, V c1 V is the voltage across the first capacitor C1. C2 V is the voltage across the second capacitor C2. C3 The voltage across the third capacitor C3; V C4 This is the voltage across the fourth capacitor, C4.

[0064] When the high-gain three-mode DC-DC converter is operating in mode two:

[0065] V o =V C1 +V C2 +V C5

[0066] In the formula, V o V is the output voltage of the output load R1. C5 This is the voltage across the fifth capacitor, C5.

[0067] When the high-gain three-mode DC-DC converter is operating in mode three:

[0068] V L =(V in -V C2 ) / 2

[0069] V c2 =V c3

[0070] V C4 =V c5

[0071] In the formula, V L This is the output voltage of the first inductor L1.

[0072] Output voltage of output load R1 With DC input power supply V in The relationship between them is:

[0073] .

[0074] Example 1

[0075] A high-gain three-mode DC-DC converter includes an active switched inductor network, a switched capacitor network, and a DC input power supply V. inThe system includes: a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, and a load R1; an active switching inductor network including a first inductor L1, a second inductor L2, a first switching transistor S1, a second switching transistor S2, and a third switching transistor S3; and a switched capacitor network including a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5; and an input power supply V. in The positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... in The negative terminals of the first inductor L1 and the second inductor L2 are connected to the source of the first switching transistor S1 and the negative terminal of the second inductor L2, respectively. The negative terminal of the first inductor L1 is connected to the drain of the first switching transistor S1, the anode of the first diode D1, the negative terminal of the first capacitor C1, and the positive terminal of the second capacitor C2, respectively. The positive terminal of the second inductor L2 is connected to the cathode of the sixth diode D6, the source of the second switching transistor S2, the source of the third switching transistor S3, and the positive terminal of the fourth capacitor C4, respectively. The drain of the third switching transistor S3 is connected to the cathode of the first diode D1. The anode of the second diode D2 is connected to the anode of the sixth diode D6 via the positive terminal of the second capacitor C2. The cathode of the second diode D2 is connected to the positive terminal of the third capacitor C3 and the anode of the third diode D3, respectively. The negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4. The cathode of the third diode D3 is connected to the positive terminal of the output load R1 and the positive terminal of the first capacitor C1, respectively. The anode of the fourth diode D4 is connected to the cathode of the fifth diode D5 and the negative terminal of the fourth capacitor C4, respectively. The cathode of the fourth diode D4 is connected to the positive terminal of the fifth capacitor C5 and the anode of the sixth diode D6, respectively. The anode of the fifth diode D5 is connected to the negative terminal of the output load R1 and the negative terminal of the fifth capacitor C5, respectively.

[0076] In the active switched-inductor network, L1 and L2 play crucial roles in energy storage and energy transfer during circuit operation. The three power MOSFET switches S1, S2, and S3 control the charging and discharging processes of the inductors and the direction of the current through different combinations of conduction and cutoff states. In Mode 1, S1 and S2 are simultaneously turned on, and L1 and L2 are connected in parallel to the input source for charging. When entering Mode 2, S1 and S2 are turned off, S3 is turned on, and L1 and L2 become connected in series to the input source to continue charging. The switched-capacitor network includes the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5. They cooperate with the actions of the inductors and switches in different operating modes of the circuit to achieve energy storage, transfer, and regulation of the output voltage. In Mode 1, D3 and D4 are turned on, C1 and C4 are charged, and C2, C3, and C5 are discharged. In Mode 2, only D1 is turned on, and C1, C2, and C5 are discharged to supply power to the output load. In Mode 3, D2, D5, and D6 are turned on, and C2, C3, and C5 are charged, while C1 and C4 are discharged to supply power to the output load. The active switched-inductor network and the switched-capacitor network cooperate with each other. In different operating modes, through the charging and discharging of the inductors and the energy storage and release processes of the capacitors, the function of converting a low input voltage into a high output voltage is achieved. The current paths are different in different modes, and the operating states of each component also change accordingly, ultimately achieving performance advantages such as high voltage gain and reduced voltage stress of the components.

[0077] For the high-gain three-mode DC converter of the present utility model, without considering the parasitic parameters and losses of the devices, as Figure 2 shown, the red and blue vertical coordinates in each coordinate system correspond one-to-one with the waveforms of the same color in that coordinate system, and the time is from t0 to t3. The following will be gradually analyzed according to different timing diagrams. In each switching cycle, the converter operates in three different modes. d1 and d2 are the duty cycles of the converter, so the relationship 0 < d1 + d2 < 1 must always be satisfied. The circuits corresponding to each mode, including the current flow paths, are as Figure 1 shown, Figure 3 Figure 4 and <> Figure 5 shown.

[0078] The high-gain three-mode DC converter has three operating modes. At the time of [t0 - t1], the operating mode of the high-gain three-mode DC converter is Mode 1: The first switch S1 and the second switch S2 are simultaneously turned on through the same control signal, thereby connecting the first inductor L1 and the second inductor L2 in parallel to the DC input power supply V in , and the inductors are in the charging state V L = V in , resulting in a linear increase in their currents. As Figure 3As shown, the third switch S3, the first diode D1, the second diode D2, the fifth diode D5, and the sixth diode D6 are off, while only the third diode D3 and the fourth diode D4 are on. This causes the first capacitor C1 and the fourth capacitor C4 to be in a charging state, while the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in a discharging state, and V C4 =V C2 +V in Meanwhile, V c1 +V c2 =V C3 +V c4 .

[0079] At time [t1-t2], the high-gain three-mode DC-DC converter operates in mode two: at t = t1, the first switch S1 and the second switch S2 are off, the third switch S3 is on, and the first inductor L1, the second inductor L2, and the DC input power supply V are connected. in In series, the voltage across each inductor is half the input voltage (V). L =V in / 2, therefore, the inductor is in charging mode, although the rate of current increase is halved compared to the previous mode. Since the turn-off voltage between the first switch S1 and the second switch S2 is relatively low in this mode, equal to half the input voltage, the switching turn-off loss is significantly reduced. Furthermore, as... Figure 2 As shown, activating the third switch S3 under ZVS (Zero-Voltage Switching) conditions can significantly reduce switching losses. Figure 4 As shown, the third capacitor C3 and the fourth capacitor C4 are not working, so the current does not pass through capacitor C3 and the fourth capacitor C4. The first capacitor C1, the second capacitor C2, and the fifth capacitor C5 are all discharged and provide energy to the output load R1. The voltage V across the output load R1 is... o =V C1 +V C2 +V C5 .

[0080] At time [t2-t3], the high-gain three-mode DC-DC converter operates in mode three:

[0081] At t = t2, the third switch S3 and the first diode D1 are off, while the third diode D3 and the fourth diode D4 are on. For example... Figure 5 As shown, the second diode D2, the fifth diode D5, and the sixth diode D6 are conducting, and the DC input power supply V... in The energy stored in the first inductor L1 and the second inductor L2 is then transferred to the second capacitor C2, the third capacitor C3, and the fifth capacitor C5. At this time, V L =(Vin -V C2 ) / 2, thus causing the DC input power supply V in Current I in The current i of the first inductor L1 L1 and the current i of the second inductor L2 L2 It decreases linearly. At this time, the first capacitor C1 and the fourth capacitor C4 are turned on, providing voltage to the output load R1, and V c2 =V c3 V C4 =V c5 .

[0082] The structure proposed in this invention can flexibly achieve high voltage gain through various duty cycle combinations, based on the relationship between the output voltage and the input voltage. The duty cycle can be flexibly adjusted to regulate the output. In addition, the structure significantly reduces the voltage stress on the components. The three operating modes of the high-gain three-mode DC-DC converter reduce the switching and turn-off losses of the input switch, realize soft switching, and improve the overall efficiency.

[0083] The above content is only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed in this utility model shall fall within the scope of protection of the claims of this utility model.

Claims

1. A high-gain three-mode DC-DC converter, characterized in that, Including DC input power supply V in The circuit includes an output load R1, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, an active switching inductor network, and a switched capacitor network. The active switching inductor network includes a first inductor L1, a second inductor L2, a first switching transistor S1, a second switching transistor S2, and a third switching transistor S3. The switched capacitor network includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. Input power V in The positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... in The negative terminals of the first inductor L1 and the second inductor L2 are connected to the source of the first switching transistor S1 and the negative terminal of the second inductor L2, respectively. The negative terminal of the first inductor L1 is connected to the drain of the first switching transistor S1, the anode of the first diode D1, the negative terminal of the first capacitor C1, and the positive terminal of the second capacitor C2, respectively. The positive terminal of the second inductor L2 is connected to the cathode of the sixth diode D6, the source of the second switching transistor S2, the source of the third switching transistor S3, and the positive terminal of the fourth capacitor C4, respectively. The drain of the third switching transistor S3 is connected to the cathode of the first diode D1. The anode of the second diode D2 is connected to the anode of the sixth diode D6 via the positive terminal of the second capacitor C2. The cathode of the second diode D2 is connected to the positive terminal of the third capacitor C3 and the anode of the third diode D3, respectively; the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4; the cathode of the third diode D3 is connected to the positive terminal of the output load R1 and the positive terminal of the first capacitor C1, respectively; the anode of the fourth diode D4 is connected to the cathode of the fifth diode D5 and the negative terminal of the fourth capacitor C4, respectively; the cathode of the fourth diode D4 is connected to the positive terminal of the fifth capacitor C5 and the anode of the sixth diode D6, respectively; the anode of the fifth diode D5 is connected to the negative terminal of the output load R1 and the negative terminal of the fifth capacitor C5, respectively. The first switch S1 and the second switch S2 share the first driving signal with a duty cycle of d1, while the third switch S3 uses the second driving signal with a duty cycle of d2.

2. A high-gain three-mode DC-DC converter according to claim 1, characterized in that, The first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 are low-rated voltage diodes with low forward voltage drop.

3. A high-gain three-mode DC-DC converter according to claim 1, characterized in that, The first switch S1, the second switch S2, and the third switch S3 are low-rated voltage switches with low on-resistance.

4. A high-gain three-mode DC-DC converter according to claim 1, characterized in that, The first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are all selected to maintain a constant capacitance value at their terminals during operation.

5. A high-gain three-mode DC-DC converter according to claim 1, characterized in that, The first inductor L1 and the second inductor L2 are inductors of the same specifications, with inductance values ​​ranging from 60uH to L1 to L2 to 200uH.

6. A high-gain three-mode DC-DC converter according to claim 1, characterized in that, The duty cycle satisfies the following relationship: 0 < d1 + d2 < 1. Under different combinations of duty cycles, the high-gain three-mode DC-DC converter has three operating modes.

7. A high-gain three-mode DC-DC converter according to claim 6, characterized in that, The three operating modes are Mode 1, Mode 2, and Mode 3; when the high-gain three-mode DC-DC converter is in Mode 1, the input power supply V... in The positive terminals are connected to the positive terminal of the first inductor L1 and the drain of the second switching transistor S2, respectively, and the input power supply V... in The negative terminals of the first inductor L1 and the second inductor L2 are connected to the source of the first switching transistor S1 and the negative terminal of the second inductor L2, respectively. The negative terminal of the first inductor L1 is connected to the drain of the first switching transistor S1, the negative terminal of the first capacitor C1, and the positive terminal of the second capacitor C2, respectively. The positive terminal of the second inductor L2 is connected to the source of the second switching transistor S2 and the positive terminal of the fourth capacitor C4, respectively. The positive terminal of the third capacitor C3 is connected to the anode of the third diode D3, and the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4, respectively. The cathode of the third diode D3 is connected to the positive terminal of the output load R1 and the positive terminal of the first capacitor C1, respectively. The anode of the fourth diode D4 is connected to the negative terminal of the fourth capacitor C4, and the cathode of the fourth diode D4 is connected to the positive terminal of the fifth capacitor C5, respectively. The negative terminal of the output load R1 is connected to the negative terminal of the fifth capacitor C5, respectively. The first switch S1 and the second switch S2 are in the ON state, and the third switch S3 is in the OFF state; the third diode D3 and the fourth diode D4 are in the ON state, and the first diode D1, the second diode D2, the fifth diode D5, and the sixth diode D6 are in the OFF state; the first inductor L1 and the second inductor L2 are connected in parallel to the DC input power supply V. in The first capacitor C1 and the fourth capacitor C4 are in the charging state, while the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in the discharging state.

8. A high-gain three-mode DC-DC converter according to claim 7, characterized in that, When the high-gain three-mode DC-DC converter is operating in mode two, the input power supply V in The positive terminal of the first inductor L1 is connected in sequence to the positive terminal of the first inductor L1, the anode of the first diode D1, the cathode of the first diode D1, the drain of the third switch S3, the source of the third switch S3, the positive terminal of the second inductor L2, and the negative terminal of the second inductor L2 to the input power supply V. in The negative terminal of the output load R1 is connected in sequence to the negative terminal of the fifth capacitor C5, the positive terminal of the fifth capacitor C5, the negative terminal of the second capacitor C2, the positive terminal of the second capacitor C2, the negative terminal of the first capacitor C1, and the positive terminal of the first capacitor C1 to the positive terminal of the output load R1, forming a circuit. The first switch S1 and the second switch S2 are in the off state, and the third switch S3 is in the on state; the first diode D1 is in the on state, and the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 are in the off state; the first inductor L1 and the second inductor L2 are connected in series to the DC input power supply V. in The capacitor is in a charging state, while the first capacitor C1, the second capacitor C2, and the fifth capacitor C5 are in a discharging state.

9. A high-gain three-mode DC-DC converter according to claim 8, characterized in that, When the high-gain three-mode DC-DC converter is operating in mode three, the input power supply V in The positive terminal is connected to the positive terminal of the first inductor L1, and the input power supply V is... in The negative terminal of the first inductor L1 is connected to the negative terminal of the second inductor L2; the negative terminal of the first inductor L1 is connected to the negative terminal of the first capacitor C1 and the positive terminal of the second capacitor C2; the positive terminal of the second inductor L2 is connected to the cathode of the sixth diode D6 and the positive terminal of the fourth capacitor C4; the anode of the second diode D2 is connected to the anode of the sixth diode D6 via the positive terminal of the second capacitor C2, the cathode of the second diode D2 is connected to the positive terminal of the third capacitor C3, and the negative terminal of the third capacitor C3 is connected to the positive terminal of the fourth capacitor C4; the positive terminal of the output load R1 is connected to the positive terminal of the first capacitor C1; the cathode of the fifth diode D5 is connected to the negative terminal of the fourth capacitor C4, and the positive terminal of the fifth capacitor C5 is connected to the anode of the sixth diode D6; the anode of the fifth diode D5 is connected to the negative terminal of the output load R1 and the negative terminal of the fifth capacitor C5. The first switch S1, the second switch S2, and the third switch S3 are in the off state; the second diode D2, the fifth diode D5, and the sixth diode D6 are in the on state; the first diode D1, the third diode D3, and the fourth diode D4 are in the off state; the second capacitor C2, the third capacitor C3, and the fifth capacitor C5 are in the charging state; and the first capacitor C1 and the fourth capacitor C4 are in the discharging state.

10. A high-gain three-mode DC-DC converter according to claim 9, characterized in that, When the high-gain three-mode DC-DC converter is operating in mode one, the voltage across the fourth capacitor C4 is equal to the voltage across the second capacitor C2 and the DC input power supply V. in The sum of the voltages of the first capacitor C1 and the second capacitor C2 is equal to the sum of the voltages of the third capacitor C3 and the fourth capacitor C4. When the high-gain three-mode DC-DC converter is in mode two, the output voltage of the output load R1 is the sum of the voltages of the first capacitor C1, the second capacitor C2, and the fifth capacitor C5. When the high-gain three-mode DC-DC converter is in mode three, the output voltage of the first inductor L1 is the DC input power supply V. in The voltage difference between the second capacitor C2 and the voltage of the third capacitor C3 is half that of the fourth capacitor C4. The voltage of the fourth capacitor C4 is equal to the voltage of the fifth capacitor C5.

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