A wide input range high gain three-port dc-dc converter

Abstract

The application discloses a wide input range high-gain three-port DC-DC converter, and belongs to the field of power electronic converters. The converter is provided with three ports of a fuel cell FC, a storage battery Bat and a resistance load R, the FC port to the Bat port is a four-switch Buck-Boost converter, the wide input range of the FC is realized, and a switch capacitor unit composed of a switch tube, a capacitor and a diode is combined, the on-off of the switch tube is controlled, the connection mode of the inductor and the capacitor in the circuit and the on-off state of the diode are changed, and therefore the voltage gain of the FC port to the R port and the Bat port to the R port is improved. The application has the advantages of wide input range, high voltage gain, high integration degree and high stability, and is suitable for a new energy hybrid power generation system of fuel cells, photovoltaic cells and the like.

Description

Technical Field

[0001] This invention belongs to the field of power electronic converters, specifically relating to a wide input range, high-gain three-port DC-DC converter. Background Technology

[0002] With the development of modern society, human demand for energy is increasing daily. However, traditional fossil fuels are facing depletion and environmental pollution, forcing humanity to vigorously develop new energy sources such as solar, wind, and hydrogen energy. However, new energy sources suffer from intermittency and slow dynamic response, often making them unsuitable for direct power supply to loads. To effectively utilize new energy sources and improve the stability of new energy power supply systems, it is necessary to add auxiliary energy storage devices to form a hybrid power supply system with new energy as the primary source and auxiliary energy storage devices as a secondary source. Traditional hybrid power supply systems use multiple discrete power conversion units to achieve energy flow between the new energy port, auxiliary energy storage port, and load port, which has disadvantages such as large size, high cost, and difficulty in control. In contrast, a hybrid power supply system based on a three-port DC-DC converter achieves energy flow between the three ports using only a single integrated three-port DC-DC converter, offering advantages such as small size, low cost, high integration, and convenient control.

[0003] Three-port DC-DC converters can be broadly classified into three categories: isolated, partially isolated, and non-isolated. Isolated and partially isolated three-port DC-DC converters can achieve higher voltage gain due to the use of transformers, but they suffer from problems such as large size and electromagnetic losses. In low-power renewable energy applications, non-isolated three-port DC-DC converters have unparalleled advantages. To address the low voltage gain of traditional non-isolated three-port DC-DC converters, technologies such as cascading, coupled inductors, switched inductors, and switched capacitors can improve voltage gain. Cascading technology involves many components and is costly, while coupled inductors and switched inductors suffer from high magnetic component losses. Furthermore, voltage constraints exist between the renewable energy port and the auxiliary energy storage port in many three-port DC-DC converters, limiting their application. For example, the three-port DC-DC converter proposed by Liu Junfeng in "High-Gain Non-Isolated Three-Port Converters" can only be used when the photovoltaic port voltage V... pv Greater than the battery terminal voltage V b In this scenario, the three-port DC-DC converter proposed by PENG LUO in "Analysis and Design of a New Non-Isolated Three-Port Converter With High Voltage Gain for Renewable Energy Applications" can only be applied when the port voltage is V in new energy applications. in Less than the battery terminal voltage Vb In this scenario. Summary of the Invention

[0004] The purpose of this invention is to provide a wide input range, high-gain three-port DC-DC converter. A four-switch Buck-Boost converter is applied between the two power ports, allowing for unconstrained voltage at both ports and achieving a wide input range. Simultaneously, by controlling the on / off state of the power switches, the connection method of the inductors and capacitors in the circuit, and the switching status of the diodes, the voltage gain and charging / discharging effects are improved.

[0005] The technical solution to achieve the purpose of this invention is: a wide input range, high gain three-port DC-DC converter, including a first input source V fc Second input source V b First inductor L1, second inductor L2, first diode D1, second diode D2, third diode D3, fourth diode D4, fifth diode D5, sixth diode D6, seventh diode D7, first power switch S1, second power switch S2, third power switch S3, fourth power switch S4, third power switch S5, fourth power switch S6, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, load R;

[0006] Wherein, the first input source V fc The positive terminal is connected to the anode of the first diode D1 and the third diode D3 via the seventh diode D7, and the first input source V fc The negative terminal is connected to the second input source V. b The cathode of the first diode D1 is connected to the drain of the third power switch S3, and one end of the first inductor L1 is connected to the first input source V. fc The positive terminal of the first inductor L1 is connected to the drain of the first power switch S1, and the source of the first power switch S1 is connected to the first input source V. fc The negative terminal of the first power switch S1 is connected to the source of the third power switch S3, which is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to the drain of the second power switch S2, and the source of the second power switch S2 is connected to the drain of the first power switch S1. The drain of the fourth power switch S4 is connected to the source of the third power switch S3, and the source of the fourth power switch S4 is connected to the second input source V. b The negative terminal of the second inductor L2 is connected to the drain of the fourth power switch S4, and the other end of the second inductor L2 is connected to the drain of the fifth power switch S5. The source of the fifth power switch S5 is connected to the second input source V. b The negative terminal of the sixth power switch S6 is connected to the source of the fifth power switch S5, and the drain of the sixth power switch S6 is connected to the second input source V. bThe positive terminal of the first capacitor is connected to the cathode of the second power switch S2, one end of the fourth capacitor C4 is connected to the cathode of the third diode D3, the anode of the fourth diode D4 is connected to the cathode of the third diode D3, the anode of the fifth diode D5 is connected to the cathode of the fourth diode D4, the anode of the sixth diode D6 is connected to the cathode of the fifth diode D5, one end of the first capacitor C1 is connected to the anode of the fourth diode D4, the other end of the first capacitor C1 is connected to the anode of the sixth diode D6, one end of the second capacitor C2 is connected to the cathode of the sixth diode D6, the other end of the second capacitor C2 is connected to the anode of the fifth diode D5, one end of the third capacitor C3 is connected to the anode of the fifth diode D5, and the other end of the third capacitor C3 is connected to the second input source V. b The negative terminal of the first input source V is connected to one end of the load R, and the other end of the load R is connected to the cathode of the sixth diode D6; fc First diode D1, third power switch S3, fourth power switch S4, second inductor L2, fifth power switch S5, sixth power switch S6, second input source V b Construct a four-switch Buck-Boost converter to satisfy the first input source V fc When greater than or less than the second input source V b Working within the range, eliminating the first input source V fc Port and second input source V b Voltage constraint between ports; the third diode D3, the fourth diode D4, the fifth diode D5, the sixth diode D6, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the load R together constitute a switched capacitor unit. By controlling the opening and closing of the first power switch S1, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 can be controlled to conduct and be cut off at different times.

[0007] Compared with the prior art, the significant advantages of this invention are:

[0008] (1) The present invention realizes the energy flow of two power sources and one load through an integrated three-port DC-DC converter, which reduces the number of devices, lowers the cost, and improves the integration of the system.

[0009] (2) The two power ports of the present invention are connected by a four-switch Buck-Boost converter, which can eliminate the voltage constraint between the two power supplies and has a wider range of applications.

[0010] (3) This invention achieves the effect of increasing voltage gain and charging / discharging by controlling the on and off of the power switching transistor, changing the connection method of the inductor and capacitor in the circuit, and the on and off state of the diode. Attached Figure Description

[0011] Figure 1 This is a circuit diagram of the wide input range, high gain three-port DC-DC converter of the present invention.

[0012] Figure 2 shows the equivalent circuit diagrams of the wide input range, high gain three-port DC-DC converter of the present invention in different modes of single-input single-output mode. Figure 2(a) is the equivalent circuit diagram with the first power switch S1 turned on and all other power switches turned off, and Figure 2(b) is the equivalent circuit diagram with all power switches turned off.

[0013] Figure 3 shows the first input source voltage V of the wide input range high gain three-port DC-DC converter of the present invention in dual-input single-output mode. fc Greater than the second input source voltage V b Equivalent circuit diagrams for different modes. Figure 3(a) is the equivalent circuit diagram with the first power switch S1, the fourth power switch S4, and the sixth power switch S6 turned on, and all other power switches turned off. Figure 3(b) is the equivalent circuit diagram with the fourth power switch S4 and the sixth power switch S6 turned on, and all other power switches turned off. Figure 3(c) is the equivalent circuit diagram with the second power switch S2 and the sixth power switch S6 turned on, and all other power switches turned off.

[0014] Figure 4 shows the first input source voltage V of the wide input range high gain three-port DC-DC converter of the present invention in dual-input single-output mode. fc Less than the second input source voltage V b Equivalent circuit diagrams for different modes. Figure 4(a) is the equivalent circuit diagram when the first power switch S1 is turned on and all other power switches are turned off. Figure 4(b) is the equivalent circuit diagram when the first power switch S1, the second power switch S2, and the sixth power switch S6 are turned on and all other power switches are turned off. Figure 4(c) is the equivalent circuit diagram when the second power switch S2 and the sixth power switch S6 are turned on and all other power switches are turned off.

[0015] Figure 5 shows the first input source voltage V of the wide input range high gain three-port DC-DC converter of the present invention in single-input dual-output mode. fc Greater than the second input source voltage V b Equivalent circuit diagrams for different modes. Figure 5(a) is the equivalent circuit diagram with the first power switch S1 and the sixth power switch S6 turned on and all other power switches turned off. Figure 5(b) is the equivalent circuit diagram with the first power switch S1, the third power switch S3 and the sixth power switch S6 turned on and all other power switches turned off. Figure 5(c) is the equivalent circuit diagram with the third power switch S3 and the sixth power switch S6 turned on and all other power switches turned off.

[0016] Figure 6 shows the first input source voltage V of the wide input range high gain three-port DC-DC converter of the present invention in single-input dual-output mode. fc Less than the second input source voltage V b Equivalent circuit diagrams for different modes. Figure 6(a) is the equivalent circuit diagram with the first power switch S1, the third power switch S3, and the sixth power switch S6 turned on, and all other power switches turned off. Figure 6(b) is the equivalent circuit diagram with the third power switch S3 and the sixth power switch S6 turned on, and all other power switches turned off. Figure 6(c) is the equivalent circuit diagram with the third power switch S3 and the fifth power switch S5 turned on, and all other power switches turned off.

[0017] Figure 7 shows the main waveforms of the wide input range, high gain three-port DC-DC converter of the present invention in three operating modes. Specifically, Figure 7(a) shows the waveform in single-input single-output mode; Figure 7(b) shows the first input source voltage V when operating in dual-input single-output mode. fc Greater than the second input source voltage V b The waveform diagram; Figure 7(c) shows the first input source voltage V when operating in dual-input single-output mode. fc Less than the second input source voltage V b The waveform diagram; Figure 7(d) shows the first input source voltage V when operating in single-input dual-output mode. fc Greater than the second input source voltage V b The waveform diagram; Figure 7(e) shows the first input source voltage V when operating in single-input dual-output mode. fc Less than the second input source voltage V b The waveform diagram. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] Combination Figure 1 This invention proposes a wide input range, high-gain three-port DC-DC converter, characterized by including a first input source V. fc Second input source V b First inductor L1, second inductor L2, first diode D1, second diode D2, third diode D3, fourth diode D4, fifth diode D5, sixth diode D6, seventh diode D7, first power switch S1, second power switch S2, third power switch S3, fourth power switch S4, third power switch S5, fourth power switch S6, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, load R;

[0020] Wherein, the first input source V fcThe positive terminal is connected to the anode of the first diode D1 and the third diode D3 via the seventh diode D7, and the first input source V fc The negative terminal is connected to the second input source V. b The cathode of the first diode D1 is connected to the drain of the third power switch S3, and one end of the first inductor L1 is connected to the first input source V. fc The positive terminal of the first inductor L1 is connected to the drain of the first power switch S1, and the source of the first power switch S1 is connected to the first input source V. fc The negative terminal of the first power switch S1 is connected to the source of the third power switch S3, which is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to the drain of the second power switch S2, and the source of the second power switch S2 is connected to the drain of the first power switch S1. The drain of the fourth power switch S4 is connected to the source of the third power switch S3, and the source of the fourth power switch S4 is connected to the second input source V. b The negative terminal of the second inductor L2 is connected to the drain of the fourth power switch S4, and the other end of the second inductor L2 is connected to the drain of the fifth power switch S5. The source of the fifth power switch S5 is connected to the second input source V. b The negative terminal of the sixth power switch S6 is connected to the source of the fifth power switch S5, and the drain of the sixth power switch S6 is connected to the second input source V. b The positive terminal of the first capacitor is connected to the cathode of the second power switch S2, one end of the fourth capacitor C4 is connected to the cathode of the third diode D3, the anode of the fourth diode D4 is connected to the cathode of the third diode D3, the anode of the fifth diode D5 is connected to the cathode of the fourth diode D4, the anode of the sixth diode D6 is connected to the cathode of the fifth diode D5, one end of the first capacitor C1 is connected to the anode of the fourth diode D4, the other end of the first capacitor C1 is connected to the anode of the sixth diode D6, one end of the second capacitor C2 is connected to the cathode of the sixth diode D6, the other end of the second capacitor C2 is connected to the anode of the fifth diode D5, one end of the third capacitor C3 is connected to the anode of the fifth diode D5, and the other end of the third capacitor C3 is connected to the second input source V. b The negative terminal of the first input source V is connected to one end of the load R, and the other end of the load R is connected to the cathode of the sixth diode D6; fc First diode D1, third power switch S3, fourth power switch S4, second inductor L2, fifth power switch S5, sixth power switch S6, second input source V b Construct a four-switch Buck-Boost converter to satisfy the first input source V fc When greater than or less than the second input source V b Working within the range, eliminating the first input source V fc Port and second input source V bVoltage constraint between ports; the third diode D3, the fourth diode D4, the fifth diode D5, the sixth diode D6, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the load R together constitute a switched capacitor unit. By controlling the opening and closing of the first power switch S1, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 can be controlled to conduct and be cut off at different times.

[0021] This invention can be divided into three working modes according to the number of input / output ports: single-input single-output, dual-input single-output, and single-input dual-output. Assume the first input source V... fc The voltage across the two ends is Second input source V b The voltage across the two ends is The voltage across the load R is The voltage across the first inductor is The voltage across the second inductor is The voltage across the first capacitor C1 is The voltage across the second capacitor C2 is The voltage across the third capacitor C3 is The voltage across the fourth capacitor C4 is The duty cycle of the first power switch S1 is The duty cycle of the second power switch S2 is The duty cycle of the third power switch S3 is The duty cycle of the fourth power switch S4 is The duty cycle of the fifth power switch S5 is The duty cycle of the sixth power switch S6 is The switching cycle is The three working modes are described in detail below:

[0022] When the converter operates in single-input single-output mode, the main waveform is shown in Figure 7(a). Within one switching cycle, this mode has two operating modes. The equivalent circuit for the t0~t1 stage is shown in Figure 2(a). The first power switch S1 is turned on, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively, and the third capacitor C3 charges the first capacitor C1. At the same time, the third capacitor C3 and the second capacitor C2 provide energy to the load R. The equivalent circuit for the t1~t2 stage is shown in Figure 2(b). The first power switch S1 is turned off, and the first input source V fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 work together to provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3.

[0023] The following relationship can be obtained for the t0~t1 stage:

[0024] (1)

[0025] The following relationship can be obtained from t1 to t2:

[0026] (2)

[0027] In one switching cycle, the inductor volt-second balance yields:

[0028] (3)

[0029] Combining equations (1) and (3), the input-output voltage relationship is obtained as follows:

[0030] (4)

[0031] When the converter operates in dual-input single-output mode:

[0032] When the first input source voltage V fc Greater than the second input source voltage V b The main waveform is shown in Figure 7(b). Within one switching cycle, this mode has three operating modes. The equivalent circuit for the t0~t1 stage is shown in Figure 3(a). The first power switch S1 and the fourth power switch S4 are turned on, and the first input source V fc The first inductor L1 and the fourth capacitor C4 are charged respectively, and the second input source V b The second inductor L2 is charged, and the third capacitor C3 charges the first capacitor C1. Simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R. The equivalent circuit for the t1~t2 stage is shown in Figure 3(b), where only the fourth power switch S4 is turned on, and the first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3. The second input source V b The second inductor L2 is charged; the equivalent circuit for the t2~t3 stage is shown in Figure 3(c), where only the second power switch S2 is turned on, and the first input source V fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R, and the second input source V b The second inductor L2, the first capacitor C1, and the fourth capacitor C4 work together to provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3.

[0033] The following relationship can be obtained for the t0~t1 stage:

[0034] (5)

[0035] The following relationship can be obtained for the t1~t2 stage:

[0036] (6)

[0037] The following relationship can be obtained for the t2~t3 stage:

[0038] (7)

[0039] In one switching cycle, the inductor volt-second balance yields:

[0040] (8)

[0041] Combining equations (5) and (8), the input-output voltage relationship is obtained as follows:

[0042] (9)

[0043] When the first input source voltage V fc Less than the second input source voltage V b The main waveform is shown in Figure 7(c). Within one switching cycle, this mode has three operating modes. The equivalent circuit for the t0~t1 stage is shown in Figure 4(a), where only the first power switch S1 is turned on, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively, and the third capacitor C3 charges the first capacitor C1. At the same time, the third capacitor C3 and the second capacitor C2 provide energy to the load R. The equivalent circuit for the t1~t2 stage is shown in Figure 4(b). The first power switch S1, the second power switch S2 and the sixth power switch S6 are turned on, and the first input source V fc The first inductor L1 and the fourth capacitor C4 are charged respectively, and the second power supply V is charged. b The second inductor L2 is charged, and the third capacitor C3 charges the first capacitor C1. Simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R. The equivalent circuit for stage t2~t3 is shown in Figure 4(c). The second power switch S2 and the sixth power switch S6 are turned on, and the first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R, and the second input source V b The second inductor L2, the first capacitor C1, and the fourth capacitor C4 work together to provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3.

[0044] Relation (1) can be obtained from stage t0 to t1, relation (6) can be obtained from stage t1 to t2, and relation (7) can be obtained from stage t2 to t3.

[0045] In one switching cycle, the inductor volt-second balance yields:

[0046] (10)

[0047] Combining equations (1), (6), (7), and (10), the input-output voltage relationship is obtained as follows:

[0048] (11)

[0049] When the converter operates in single-input dual-output mode:

[0050] When the first input source voltage V fc Greater than the second input source voltage V b The main waveform is shown in Figure 7(d). Within one switching cycle, this mode has three operating modes. The equivalent circuit for the t0~t1 stage is shown in Figure 5(a). The first power switch S1 and the sixth power switch S6 are turned on, the third power switch S3 is turned off, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively. The current of the second inductor L2 freewheels through the body diode of the fourth power switch S4 and supplies power to the second input source V. b During charging, the third capacitor C3 charges the first capacitor C1, and simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R. The equivalent circuit for the t1~t2 stage is shown in Figure 5(b). The first power switch S1, the third power switch S3, and the sixth power switch S6 are turned on, and the first input source V... fc These are the first inductor L1, the fourth capacitor C4, the second inductor L2, and the second power supply V, respectively. b During charging, the third capacitor C3 charges the first capacitor C1, and simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R. The equivalent circuit for stage t2~t3 is shown in Figure 5(c). The first power switch S1 is off, and the third power switch S3 and the sixth power switch S6 are on. The first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3. The first input source V fc Also for the second inductor L2 and the second power supply V b Charge.

[0051] According to the volt-second balance principle of inductors, the input-output voltage relationship can be obtained as follows:

[0052] (12)

[0053] When the first input source voltage V fc Less than the second input source voltage V bThe main waveform is shown in Figure 7(e). Within one switching cycle, this mode has three operating modes. The equivalent circuit for the t0~t1 stage is shown in Figure 6(a). The first power switch S1, the third power switch S3, and the sixth power switch S6 are turned on, the fifth power switch S5 is turned off, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively, while the first input source V is charged. fc The second inductor L2 is used as the second input source V b During charging, the third capacitor C3 charges the first capacitor C1, and simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R. The equivalent circuit for stage t1~t2 is shown in Figure 6(b). The third power switch S3 and the sixth power switch S6 are turned on, while the first power switch S1 and the fifth power switch S5 are turned off. The first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R and charge the second capacitor C2 and the third capacitor C3, while the first input source V... fc The second inductor L2 is used as the second input source V b Charging. The equivalent circuit for stage t2~t3 is shown in Figure 6(c). The third power switch S3 and the fifth power switch S5 are turned on, while the first power switch S1 and the sixth power switch S6 are turned off. The first input source V fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R and charge the second capacitor C2 and the third capacitor C3, while the first input source V... fc Charge the second inductor L2.

[0054] According to the volt-second balance principle of inductors, the input-output voltage relationship can be obtained as follows:

[0055] (13)

[0056] Analysis of the three converter modes reveals that this invention achieves energy flow between two power supply ports and one load port through an integrated three-port DC-DC converter. The dual-input single-output mode realizes the first input source V. fc Second input source V b For power supply to the load, the single-input dual-output mode realizes the first input source V fc Power supply to the load and power supply to the second input source V b The charging process. As can be seen from the input-output voltage relationship, this invention improves the voltage gain by applying a switched capacitor unit, while the first input source V... fc Second input source V b There are no voltage constraints between them, making them suitable for a wider range of applications.

Claims

1. A wide input range, high gain three-port DC-DC converter, characterized in that, Including the first input source V fc Second input source V b First inductor L1, second inductor L2, first diode D1, second diode D2, third diode D3, fourth diode D4, fifth diode D5, sixth diode D6, seventh diode D7, first power switch S1, second power switch S2, third power switch S3, fourth power switch S4, third power switch S5, fourth power switch S6, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, load R; Wherein, the first input source V fc The positive terminal is connected to the anode of the first diode D1 and the third diode D3 via the seventh diode D7, and the first input source V pe The negative terminal is connected to the second input source V. b The cathode of the first diode D1 is connected to the drain of the third power switch S3, and one end of the first inductor L1 is connected to the first input source V. fc The positive terminal of the first inductor L1 is connected to the drain of the first power switch S1, and the source of the first power switch S1 is connected to the first input source V. fc The negative terminal of the first power switch S1 is connected to the source of the third power switch S3, which is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to the drain of the second power switch S2, and the source of the second power switch S2 is connected to the drain of the first power switch S1. The drain of the fourth power switch S4 is connected to the source of the third power switch S3, and the source of the fourth power switch S4 is connected to the second input source V. b The negative terminal of the second inductor L2 is connected to the drain of the fourth power switch S4, and the other end of the second inductor L2 is connected to the drain of the fifth power switch S5. The source of the fifth power switch S5 is connected to the second input source V. b The negative terminal of the sixth power switch S6 is connected to the source of the fifth power switch S5, and the drain of the sixth power switch S6 is connected to the second input source V. b The positive terminal of the first capacitor is connected to the cathode of the second power switch S2, one end of the fourth capacitor C4 is connected to the cathode of the third diode D3, the anode of the fourth diode D4 is connected to the cathode of the third diode D3, the anode of the fifth diode D5 is connected to the cathode of the fourth diode D4, the anode of the sixth diode D6 is connected to the cathode of the fifth diode D5, one end of the first capacitor C1 is connected to the anode of the fourth diode D4, the other end of the first capacitor C1 is connected to the anode of the sixth diode D6, one end of the second capacitor C2 is connected to the cathode of the sixth diode D6, the other end of the second capacitor C2 is connected to the anode of the fifth diode D5, one end of the third capacitor C3 is connected to the anode of the fifth diode D5, and the other end of the third capacitor C3 is connected to the second input source V. b The negative terminal of the first input source V is connected to one end of the load R, and the other end of the load R is connected to the cathode of the sixth diode D6; fc First diode D1, third power switch S3, fourth power switch S4, second inductor L2, fifth power switch S5, sixth power switch S6, second input source V b Construct a four-switch Buck-Boost converter to satisfy the first input source V fc When greater than or less than the second input source V b Working within the range, eliminating the first input source V fc Port and second input source V b Voltage constraint between ports; the third diode D3, the fourth diode D4, the fifth diode D5, the sixth diode D6, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the load R together constitute a switched capacitor unit. By controlling the opening and closing of the first power switch S1, the third diode D3, the fourth diode D4, the fifth diode D5, and the sixth diode D6 can be controlled to conduct and be cut off at different times.

2. The wide input range, high gain three-port DC-DC converter according to claim 1, characterized in that, When the power required by the load is less than the first input source V fc The maximum power provided, and the second input source V b When charging is not required, the first input source V fc This wide-input-range, high-gain three-port DC-DC converter supplies power to the load R independently and operates in single-input, single-output mode. When the power required by the load exceeds the first input source V... fc When the maximum power is provided, the first input source V fc Second input source V b Simultaneously supplying power to the load R, the wide-input-range, high-gain three-port DC-DC converter operates in dual-input, single-output mode; when the power required by the load is less than the first input source V... fc The maximum power provided, and the second input source V b When charging is needed, the first input source V fc Simultaneously supplying load R and the second input source V b Powered by a wide input range, high-gain three-port DC-DC converter operating in single-input dual-output mode.

3. The wide input range, high gain three-port DC-DC converter according to claim 2, characterized in that, In single-input single-output mode, the first input source V fc The supplied power flows through the first inductor L1 and the switched capacitor to the load R, supplying power to the load R; in dual-input single-output mode, the first input source V fc The supplied power flows through the first inductor L1 and the switched capacitor to the load R, supplying power to the load R. The second input source V b The supplied power flows through the second inductor L2 and the switched capacitor to the load R, supplying power to the load R; in single-input dual-output mode, the first input source V fc The supplied power flows to the load R through the first inductor L1 and the switched capacitor unit, supplying power to the load R. The first input source V fc The supplied power flows through the second inductor L2 to the second input source V. b , give the second input source V b Charge.

4. The wide input range, high gain three-port DC-DC converter according to claim 2, characterized in that, Within one switching cycle, the single-input single-output mode has two operating modes. The second power switch S2, the third power switch S3, the fourth power switch S4, the fifth power switch S5, and the sixth power switch S6 are always off. Specifically: in the first mode, the first power switch S1 is on, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively, and the third capacitor C3 charges the first capacitor C1. At the same time, the third capacitor C3 and the second capacitor C2 provide energy to the load R. In the second mode, the first power switch S1 is turned off, and the first input source V fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 work together to provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3.

5. The wide input range, high gain three-port DC-DC converter according to claim 2, characterized in that, When the first input source voltage V fc Greater than the second input source voltage V b During one switching cycle, the single-input dual-output mode has three operating modes. The third power switch S2 and the fifth power switch S5 are always off, while the sixth power switch S6 is always on. Specifically: In the first mode, the first power switch S1 is on, the third power switch S3 is off, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively. The current of the second inductor L2 freewheels through the body diode of the fourth power switch S4 and supplies power to the second input source V. b During charging, the third capacitor C3 charges the first capacitor C1, and simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R; in the second mode, the first power switch S1 and the third power switch S3 are turned on, and the first input source V... fc These are the first inductor L1, the fourth capacitor C4, the second inductor L2, and the second power supply V, respectively. b During charging, the third capacitor C3 charges the first capacitor C1, and simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R; in the third mode, the first power switch S1 is turned off, the third power switch S3 is turned on, and the first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R, while simultaneously charging the second capacitor C2 and the third capacitor C3. The first input source V fc Also for the second inductor L2 and the second power supply V b Charging; when the first input source voltage V fc Less than the second input source voltage V b During one switching cycle, the single-input dual-output mode has three operating modes. The second power switch S2 and the fourth power switch S4 are always off, the third power switch S3 is always on, and the fifth power switch S5 and the sixth power switch S6 are complementary in conduction. Specifically: In the first mode, the first power switch S1 and the sixth power switch S6 are on, the fifth power switch S5 is off, and the first input source V... fc The first inductor L1 and the fourth capacitor C4 are charged respectively, while the first input source V is charged. fc The second inductor L2 is used as the second input source V b During charging, the third capacitor C3 charges the first capacitor C1, and simultaneously, the third capacitor C3, together with the second capacitor C2, provides energy to the load R; in the second mode, the sixth power switch S6 is turned on, and the first power switch S1 and the fifth power switch S5 are turned off, and the first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R and charge the second capacitor C2 and the third capacitor C3, while the first input source V... fc The second inductor L2 is used as the second input source V b Charging; in the third mode, the fifth power switch S5 is turned on, the first power switch S1 and the sixth power switch S6 are turned off, and the first input source V... fc The first inductor L1, the first capacitor C1, and the fourth capacitor C4 together provide energy to the load R and charge the second capacitor C2 and the third capacitor C3, while the first input source V... fc Charge the second inductor L2.

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