A single-inductor DC power converter based on switched capacitors

Abstract

The present invention discloses a single-inductor DC power converter based on switched capacitors, which comprises: an input source, a switched-capacitor power conversion section, and a rectification section composed of an inductor and an output capacitor; wherein the switched-capacitor power conversion section includes a switched-capacitor circuit, and this section can be a three-port network with dual inputs and single output, where the output of the three-port network is connected to the input of the rectification section; or a four-port network with dual inputs and dual outputs, where the first output of the four-port network is connected to the input of the rectification section, and the second output is connected to the output of the rectification section. The DC power converter applies the switched-capacitor structure, can provide a high conversion ratio, reduce the voltage stress of devices, and can be flexibly expanded according to application scenarios; uses the dual-path parallel output of the inductor path and the capacitor path to reduce the current stress of devices, improve efficiency and power density; and is suitable for the application scenarios of non-isolated power converters with high conversion ratio and high power density requirements.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly relates to a single-inductor DC power converter based on switched capacitors. Background Art

[0002] In recent years, the rapid development of data centers has been promoted by artificial intelligence and big data technologies, and the power consumption of data centers has increased significantly. The main load of a data center is the processor, and the power supply needs to be converted from a 48V bus to a 12V DC voltage through front-end conversion, and then the power supply voltage of the processor is obtained through conversion by a DC power converter, usually around 1V. How to achieve 12V-1V DC-DC conversion with high efficiency, high step-down ratio, and high power density is a difficult and key problem in the power supply of data centers.

[0003] Document A "5MHz, 12V, 10A, monolithically integrated two-phase series capacitor buck converter" (2016 IEEE Applied Power Electronics Conference and Exposition (APEC), 2016) proposed a buck converter based on a two-stage series capacitor structure, with the power transistors and control fully integrated on the chip. However, its output capacitor is relatively large, and one of the power transistors in the two-stage series capacitor structure needs to withstand the full input voltage, which is not conducive to the use of low-voltage power transistors.

[0004] Document A "Direct 12V / 24V-to-1V 3W 91.2%-Efficiency Tri-State DSD Power Converter with Online VCF Rebalancing and In-Situ Precharge Rate Regulation" (2020 IEEE International Solid-State Circuits Conference (ISSCC), 2020) proposed a two-stage cascaded buck converter, which cascaded a three-level buck converter and a two-stage series capacitor buck converter to achieve a very high step-down gain. However, this structure has a relatively large number of switches, and the system efficiency is relatively low under large load conditions.

[0005] "Literature A: '4A 12-to-1 Flying Capacitor Cross-Connected DC-DC Converter with Inserted D>0.5 Control Achieving >2x Transient Inductor Current Slew Rate and 0.73x Theoretical Minimum Output Undershoot of DSD' (2022 IEEE International Solid-State Circuits Conference (ISSCC), 2022) proposed a buck converter that cross-connected two flying capacitors, enabling each power transistor to withstand a voltage of half the input voltage, thus allowing the use of low-voltage power transistors with better quality factors. Additionally, by changing the control logic, this structure can achieve a duty cycle greater than 50%, thereby enabling a faster transient response."

[0006] "The structures in the above three literatures all require the use of two inductors, which occupy a relatively large volume, thus restricting the improvement of power density. Additionally, to achieve a duty cycle greater than 50%, additional control logic is required, increasing the design difficulty." "Summary of the Invention"

[0007] "In view of this, to solve the problems of limited transient response speed and limited power density caused by the need for multiple inductors in the existing technology structure, the present invention provides a single-inductor DC power converter based on switched capacitors. This structure consists of a first-stage expandable switched-capacitor structure and a rectification part composed of a single inductor and a single capacitor. The switched-capacitor structure reduces the voltage stress of the switching transistors in the first stage and the input voltage of the inductor-capacitor rectification part through a multi-stage flying capacitor structure. The number of switched-capacitor stages can be selected according to the input voltage and conversion ratio, with good scalability, and is suitable for non-isolated DC power converter applications with high power density requirements in large conversion ratio scenarios. The technical solution adopted by the present invention is as follows:"

[0008] "The present invention first provides a single-inductor DC power converter based on switched capacitors, which includes: an input source, a switched-capacitor power conversion part, and an inductor-output capacitor rectification part;"

[0009] The switched-capacitor power conversion section is a three-port network, including 2n + 1 high-side switching transistors, 2n capacitors, 1 low-side switching transistor and three ports. Positive integers are sequentially used to number each high-side switching transistor and each capacitor; the internal connection mode of the switched-capacitor power conversion section is: the drain of the first high-side switching transistor is connected to the first port of the switched-capacitor power conversion section, the source of the i-th high-side switching transistor is commonly connected to the drain of the (i + 1)-th high-side switching transistor and the positive electrode of the i-th capacitor, the negative electrodes of all capacitors numbered odd are commonly connected to the source of the (2n + 1)-th high-side switching transistor, the drain of the low-side switching transistor and the second port of the switched-capacitor power conversion section, and the negative electrodes of all capacitors numbered even are connected to the third port of the switched-capacitor power conversion section, where i and n are both integers, and 1 ≤ i ≤ 2n;

[0010] The inductor-output capacitor rectification section consists of an inductor and an output capacitor. The first port of the switched-capacitor power conversion section is connected to the positive electrode of the input source, the second port of the switched-capacitor power conversion section is connected to the left end of the inductor, the third port of the switched-capacitor power conversion section is connected to the negative electrode of the input source, the negative electrode of the output capacitor and the negative electrode of the load, and the right end of the inductor is connected to the positive electrode of the output capacitor and the positive electrode of the load.

[0011] The control mode of the above single-inductor DC power converter is two-phase control. All high-side switching transistors numbered odd in the switched-capacitor power conversion section are grouped into one group, and all high-side switching transistors numbered even and the low-side switching transistor are grouped into one group. The two groups of switching transistors conduct or turn off alternately, and the conduction times of the two groups of switching transistors can be unequal.

[0012] The present invention also provides another single-inductor DC power converter based on switched capacitors, which also includes: an input source, a switched-capacitor power conversion section and an inductor-output capacitor rectification section

[0013] The first-stage power conversion section is a four-port network, including 2n + 2 high-side switching transistors, 2n capacitors, 2 low-side switching transistors and four ports; its internal connection mode is: the drain of the first high-side switching transistor is connected to the first port of the first-stage power conversion section, the source of the i-th high-side switching transistor is commonly connected to the drain of the (i + 1)-th high-side switching transistor and the positive electrode of the i-th capacitor, the negative electrodes of all capacitors numbered odd are commonly connected to the source of the (2n + 1)-th high-side switching transistor, the drain of the first low-side switching transistor and the second port of the switched-capacitor power conversion section, the negative electrodes of all capacitors numbered even are commonly connected to the drain of the second low-side switching transistor and the source of the (2n + 2)-th high-side switching transistor, the drain of the (2n + 2)-th high-side switching transistor is connected to the third port of the switched-capacitor power conversion section, and the source of the second low-side switching transistor is connected to the fourth port of the switched-capacitor power conversion section, where i and n are both integers, and 1 ≤ i ≤ 2n;

[0014] The inductor-output capacitor rectification part consists of an inductor and an output capacitor. The first port of the switched-capacitor power conversion part is connected to the positive pole of the input source. The second port of the switched-capacitor power conversion part is connected to the left end of the inductor. The third port of the switched-capacitor power conversion part is connected to the right end of the inductor, the positive pole of the output capacitor, and the positive pole of the load. The fourth port of the switched-capacitor power conversion part is connected to the negative pole of the input source, the negative pole of the output capacitor, and the negative pole of the load.

[0015] Furthermore, there is a port in the switched-capacitor power conversion part, which is commonly connected to the positive pole of the load, the positive pole of the output capacitor, and the right end of the inductor.

[0016] The control method of the above single-inductor DC power converter is two-phase control. All the high-side switches with odd numbers and the second low-side switch in the switched-capacitor power conversion part are grouped into one group, and all the high-side switches with even numbers and the first low-side switch are grouped into another group. The two groups of switches conduct or turn off alternately, and the conduction time of the two groups of switches can be unequal.

[0017] According to the preferred embodiment of the present invention, in the single-inductor DC power converter based on switched capacitors, the high-side switches and low-side switches used in the switched-capacitor power conversion part are fully controlled power semiconductor devices.

[0018] Based on the above technical solutions, compared with the existing solutions, the advantages of the present invention are as follows:

[0019] (1) The DC power converter of the present invention utilizes the switched-capacitor structure, taking the switched capacitor as an intermediate voltage source, which is beneficial to reducing the input voltage of the inductor-output capacitor rectification part, reducing the required inductor size to achieve the same ripple, and is beneficial to reducing the system volume and improving the power density.

[0020] (2) The DC power converter of the present invention utilizes the switched-capacitor structure, and the voltage across the switched capacitor can be automatically balanced without additional control, simplifying the control design process.

[0021] (3) The DC power converter of the present invention utilizes a switched-capacitor structure and operates in a two-phase manner. That is, all the switching transistor components in the switched-capacitor power conversion part are divided into two groups, and the two groups of switching transistors conduct or turn off alternately. Taking the three-port switched-capacitor power conversion part as an example, all the high-side switching transistors with odd numbers in the switched-capacitor power conversion part are divided into one group, and all the high-side switching transistors and low-side switching transistors with even numbers are divided into one group; taking the four-port switched-capacitor power conversion part as an example, all the high-side switching transistors with odd numbers and the second low-side switching transistors in the switched-capacitor power conversion part are divided into one group, and all the high-side switching transistors with even numbers and the first low-side switching transistors are divided into one group. Therefore, the control method of the power converter of the present invention is relatively simple, and the duty cycle greater than 50% can be achieved without additional control, which is beneficial to fast transient response.

[0022] (4) The DC power converter of the present invention utilizes a switched-capacitor structure to reduce the voltage stress across the switching transistors, which is beneficial to system design and device selection. By using switching transistors with lower breakdown voltage but better quality factor, the switching loss and conduction loss of the switching transistors can be reduced, which is beneficial to the improvement of efficiency.

[0023] (5) For the switched-capacitor structure adopted by the DC power converter of the present invention, the voltage difference between the positive electrodes of every two adjacent capacitors with odd numbers in the first phase and the voltage difference between the positive electrodes of every two adjacent capacitors with even numbers in the second phase are both fixed values. Under appropriate input voltage, number of stages, and switching transistor drive voltage, this voltage difference can be used as a fixed power supply rail for driving, which simplifies the design of the drive circuit.

[0024] (6) The DC power converter of the present invention can adjust the number of stages of the switched-capacitor circuit according to the magnitude of the input voltage and the required conversion ratio, and has good scalability.

[0025] (7) The DC power converter of the present invention uses a single-inductor structure and can supply power to the load through two paths, namely the inductor path and the capacitor path, which is beneficial to reducing the inductor current stress, thereby beneficial to reducing the inductor volume, improving the power density, and at the same time reducing the loss caused by the inductor winding resistance and improving the efficiency. Description of the Drawings

[0026] Figure 1 is a typical system connection diagram of the single-inductor DC power converter according to an embodiment of the present invention, and the switched-capacitor power conversion part is a three-port network;

[0027] Figure 2 is a typical system connection diagram of the single-inductor DC power converter according to another embodiment of the present invention, and the switched-capacitor power conversion part is a four-port network;

[0028] Figure 3It is the circuit topology diagram of an embodiment of the present invention. The switched-capacitor power conversion part is a three-port network.

[0029] Figure 4 It is the working waveform diagram of an embodiment of the present invention. The switched-capacitor power conversion part is a three-port network.

[0030] Figure 5 It is the circuit topology diagram of another embodiment of the present invention. The switched-capacitor power conversion part is a four-port network.

[0031] Figure 6 It is the working waveform diagram of another embodiment of the present invention. The switched-capacitor power conversion part is a four-port network. Detailed implementation manners

[0032] To more clearly demonstrate the above features and advantages of the present invention, the following will be described in detail in conjunction with the drawings and specific embodiments.

[0033] Figure 1 It is the connection diagram of a single-inductor DC power converter when the switched-capacitor power conversion part of the embodiment of the present invention is a three-port network. It includes an input source, a three-port switched-capacitor power conversion part, and an inductor-output capacitor rectification part. The inductor-output capacitor rectification part consists of an inductor and an output capacitor. The first port A of the switched-capacitor power conversion part is connected to the positive pole of the input source. The second port B of the switched-capacitor power conversion part is connected to the left end of the inductor. The third port C of the switched-capacitor power conversion part is connected to the negative pole of the input source, the negative pole of the output capacitor, and the negative pole of the load. The right end of the inductor is connected to the positive pole of the output capacitor and the positive pole of the load.

[0034] As Figure 3 shown, it schematically shows the circuit topology diagram of a single-inductor DC power converter with n-stage switched capacitors when the switched-capacitor power conversion part is a three-port network. Here, n-stage switched capacitors refer to those internally containing n groups of units each composed of two high-side switching transistors and two capacitors. The switched-capacitor power conversion part internally contains 2n + 1 high-side switching transistors, 2n capacitors, 1 low-side switching transistor, and three ports. Positive integers (1, 2,...) are sequentially used to number each high-side switching transistor and each capacitor. The internal connection method is as follows: The drain of the first high-side switching transistor Q H1 is connected to the first port A of the switched-capacitor power conversion part. The source of the i-th high-side switching transistor Q Hi is commonly connected to the drain of the (i + 1)-th high-side switching transistor Q Hi+1 and the positive pole of the i-th capacitor C i . The negative poles of all capacitors numbered as odd numbers (C1, C3,...) are commonly connected to the source of the (2n + 1)-th high-side switching transistor Q H2n+1 and the source of the low-side switching transistor Q L1The drain is commonly connected to the second port B of the switched-capacitor power conversion section. The negative electrodes of all capacitors numbered even (C2, C4, ……) are connected to the third port C of the switched-capacitor power conversion section, where both i and n are integers, and 1 ≤ i ≤ 2n.

[0035] Figure 4 It is the operating timing diagram of a single-inductor DC power converter with n-stage switched capacitors when the switched-capacitor power conversion section is a three-port network. One period T S contains two phases. All the switching transistors in the switched-capacitor power conversion section are divided into two groups. The first group is switching transistors Q H2i+1 and Q H1 , that is, all the high-side switching transistors with odd numbers. The second group is switching transistors Q H2i (all the high-side switching transistors with even numbers) and Q L1 (low-side switching transistors). The two groups of switching transistors conduct alternately. When the first group of switching transistors Q H2i+1 and Q H1 conduct, the input source V IN charges capacitor C1, and the capacitors C 2i with even numbers charge the capacitors C 2i+1 with odd numbers. The current on inductor L rises, and the second port B of the switched-capacitor power conversion section is at a high level. When the second group of switching transistors Q H2i and Q L1 conduct, the capacitors C 2i-1 with odd numbers charge the capacitors C 2i with even numbers. The current on inductor L drops, and the second port B of the switched-capacitor power conversion section is connected to a low level. The second port B of the switched-capacitor power conversion section changes between high and low levels and is input to the inductor-output capacitor rectification network, and the DC output voltage V O is obtained through rectification. According to the volt-second balance of the inductor and the charge balance of the capacitor, if the negative terminal of the input source is the lowest potential 0 of the circuit, the voltage across the capacitor C 2i with an even number 2i is equal to the voltage across the capacitor C 2i-1 with an odd number 2i - 1, which is (n - i + 1)V IN / (n + 1). The voltage of the positive plate of the capacitor C 2i-1 with an odd number jumps between (n - i + 1)V 2i-1 / (n + 1) and (n - i + 2)V IN / (n + 1), and the voltage of the positive plate of the capacitor C IN with an even number is (n - i + 1)V 2i / (n + 1) and remains unchanged. The second port B of the switched-capacitor power conversion section is at V 2i IN / (n + 1) and remains unchanged. The second port B of the switched-capacitor power conversion section is at V IN ​Jumps between 0 and / (n + 1), within a period T S The conduction duration of the first group of switching transistors Q H2i+1 and Q H1 within the period T is D*T S = [(n + 1)V O / V IN *T S , where D is the duty cycle of the conduction of the first group of switching transistors Q H2i+1 and Q H1 . Where i is an integer and 1 ≤ i ≤ n.

[0036] It can be seen that, compared with the traditional Buck structure, by constructing a multi-level switched-capacitor network, the voltage that each switching transistor needs to withstand when turned off is reduced, making it possible to use low-voltage devices, which is beneficial to the improvement of the overall efficiency; the voltage jump amplitude at the left switching point of the inductor is reduced, and the size of the inductor required to achieve the same ripple is reduced, which is beneficial to the reduction of the system volume and the improvement of the power density. The voltage difference between every two adjacent odd-numbered switching points (SW 2i-1 , SW 2i-3 , ……) and the voltage difference between every two adjacent even-numbered switching points (SW 2i , SW 2i-2 , ……) are both a fixed value V IN / (n + 1). When the working mode is appropriate, this difference can be used as the fixed power supply rail required to drive the switching transistors, simplifying the drive design.

[0037] Figure 2 FIG. shows the connection diagram of a single-inductor DC power converter when the switched-capacitor power conversion part is a four-port network. It includes an input source, a four-port switched-capacitor power conversion part, and an inductor-output capacitor rectification part. The inductor-output capacitor rectification part consists of an inductor, an output capacitor, and a load. The first port A of the switched-capacitor power conversion part is connected to the positive pole of the input source, the second port B of the switched-capacitor power conversion part is connected to the left end of the inductor, the third port C of the switched-capacitor power conversion part is connected to the right end of the inductor, the positive pole of the output capacitor, and the positive pole of the load, and the fourth port D of the switched-capacitor power conversion part is connected to the negative pole of the input source, the negative pole of the output capacitor, and the negative pole of the load.

[0038] Figure 5The circuit topology diagram of the DC power converter with n - stage switched - capacitor when the switched - capacitor power conversion part of an embodiment of the present invention is a four - port network. Here, n - stage switched - capacitor means that it contains n units each composed of two high - side switching transistors and two capacitors. The switched - capacitor power conversion part contains 2n + 2 high - side switching transistors, 2n capacitors, 2 low - side switching transistors and four ports. Positive integers (1, 2, ……) are sequentially numbered for each high - side switching transistor and each capacitor. The internal connection method is as follows: The drain of the first high - side switching transistor Q H1 is connected to the first port A of the switched - capacitor power conversion part. The source of the i - th high - side switching transistor Q Hi is commonly connected to the drain of the (i + 1) - th high - side switching transistor Q Hi+1 , the positive electrode of the i - th capacitor C i . The negative electrodes of all capacitors with odd numbers (C1, C3, ……) are commonly connected to the source of the (2n + 1) - th high - side switching transistor Q H2n+1 , the drain of the first low - side switching transistor Q L1 and the second port B of the switched - capacitor power conversion part. The negative electrodes of all capacitors with even numbers (C2, C4, ……) are commonly connected to the drain of the second low - side switching transistor Q L2 , the source of the (2n + 2) - th high - side switching transistor Q H2n+2 . The drain of the (2n + 2) - th high - side switching transistor Q H2n+2 is connected to the third port C of the switched - capacitor power conversion part. The source of the second low - side switching transistor Q L2 is connected to the fourth port D of the switched - capacitor power conversion part, where both i and n are integers, and 1 ≤ i ≤ 2n.

[0039] Figure 6 is the working timing diagram of the single - inductor DC power converter when the switched - capacitor power conversion part is a four - port network. One period T S contains two phases. All switching transistors in the switched - capacitor power conversion part are divided into two groups. The first group is all high - side switching transistors with odd numbers and the second low - side switching transistor, that is, switching transistors Q H2i+1 , Q H1 and Q L2 . The second group is all high - side switching transistors with even numbers and the first low - side switching transistor, that is, switching transistors Q H2i , Q 2n+2 and Q L1 . The two groups of switches conduct alternately. When the first group of switching transistors Q H2i+1 , Q H1 and Q L2 conduct, the input source V IN charges the capacitor C1, and the capacitors C 2i with even numbers charge the capacitors C 2i+1During charging, the current on inductor L rises, and the second port B of the switched-capacitor power conversion section is at a high level; when the second group of switching transistors Q H2i , Q 2n+2 and Q L1 are conducting, the capacitors C 2i-1 with odd numbers charge the capacitors C 2i with even numbers. At the same time, the charging current of the capacitors flows through the (2n + 2)nd high-side switching transistor Q H2n+2 to the load and serves as part of the load; the current on inductor L drops, and the second port B of the switched-capacitor power conversion section is connected to a low level; the second port B of the switched-capacitor power conversion section alternates between high and low levels and is input to the inductor-output capacitor rectification network, and a DC output voltage V O is obtained after rectification. According to the volt-second balance of the inductor and the charge balance of the capacitors, if the negative terminal of the input source is the lowest potential 0 of the circuit, the voltage across the capacitors C 2i with even numbers 2i is [(n - i + 1)V IN - iV O / (n + 1), the voltage across the capacitors C 2i-1 with odd numbers 2i - 1 is [(n - i + 1)(V IN+ V O )] / (n + 1), the positive plate voltage SW 2i-1 of the capacitors C 2i-1 with odd numbers jumps between [(n - i + 1)(V IN+ V O )] / (n + 1) and [(n - i + 2)V IN - (i - 1)V O / (n + 1), the positive plate voltage SW 2i of the capacitors C 2i with even numbers jumps between [(n - i + 1)(V IN+ V O )] / (n + 1) and [(n - i + 1)V IN - iV O / (n + 1), the second port B of the switched-capacitor power conversion section jumps between V IN - nV O / (n + 1) and 0. Within a period T S , the conduction duration of the first group of switching transistors Q H2i+1 , Q H1 and Q L2 is D*TS = [(n + 1)V IN / V IN - nV O *T S , where D is the duty cycle of the first group of switching transistors Q H2i+1 , Q H1and Q L2 The duty cycle of conduction. When the first group of switching transistors Q H2i+1 , Q H1 and Q L2 are conducting, the voltage difference between the positive plates of every two adjacent odd-numbered capacitors (SW 2i-1 , SW 2i-3 , ……) is all (V IN + V O ) / (n + 1). When the second group of switching transistors Q H2i , Q 2n+2 and Q L1 are conducting, the voltage difference between the positive plates of every two adjacent even-numbered capacitors (SW 2i , SW 2i-2 , ……) is all (V IN + V O ) / (n + 1). Where i is an integer and 1 ≤ i ≤ n.

[0040] It can be seen from this that compared with the embodiment in Figure 3 , in the embodiment in Figure 5 , in addition to using the advantages of the switched-capacitor network to improve efficiency and power density, and there being a fixed voltage difference between the positive plates of adjacent odd / even-numbered capacitors, its load is jointly borne by the inductor current path and the capacitor charge / discharge path. Therefore, the DC component of the inductor current is less than the magnitude of the load current, thereby reducing the loss caused by the inductor winding. At the same time, the inductor current stress is reduced, which is beneficial to using a smaller inductor and further improving the power density.

[0041] The above examples specifically describe the exemplary embodiments of the present invention so that those of ordinary skill in the art can understand and apply the present invention more clearly. Those familiar with the technology in the field can obviously easily apply the solutions in the present invention, or make equivalent replacements for some or all of the technical features in the present invention, or apply the general principles of the present invention to other embodiments without creative labor. Therefore, the present invention is not limited to the detailed structures, setting methods or implementation manners described in the examples, and any modification, improvement or equivalent replacement of the technical features of the present invention should be within the protection scope of the present invention.

Claims

1. A single-inductor DC power converter based on switched capacitors, characterized in that Comprising: An input source, a switched-capacitor power conversion section, and an inductor-output capacitor rectification section; The switched-capacitor power conversion section is a three-port network, including 2n + 1 high-side switching transistors, 2n capacitors, 1 low-side switching transistor, and three ports. Positive integers are sequentially assigned to each high-side switching transistor and each capacitor. The internal connection method of the switched-capacitor power conversion section is as follows: The drain of the first high-side switching transistor is connected to the first port of the switched-capacitor power conversion section. The source of the i-th high-side switching transistor is commonly connected to the drain of the (i + 1)-th high-side switching transistor and the positive electrode of the i-th capacitor. The negative electrodes of all capacitors numbered odd are commonly connected to the source of the (2n + 1)-th high-side switching transistor, the drain of the low-side switching transistor, and the second port of the switched-capacitor power conversion section. The negative electrodes of all capacitors numbered even are connected to the third port of the switched-capacitor power conversion section, where i and n are both integers, and 1 ≤ i ≤ 2n; The inductor-output capacitor rectification section consists of an inductor and an output capacitor. The first port of the switched-capacitor power conversion section is connected to the positive electrode of the input source. The second port of the switched-capacitor power conversion section is connected to the left end of the inductor. The third port of the switched-capacitor power conversion section is connected to the negative electrode of the input source, the negative electrode of the output capacitor, and the negative electrode of the load. The right end of the inductor is connected to the positive electrode of the output capacitor and the positive electrode of the load; The control method of the single-inductor DC power converter is two-phase control. All high-side switching transistors numbered odd in the switched-capacitor power conversion section are grouped into one group, and all high-side switching transistors numbered even and the low-side switching transistor are grouped into another group. The two groups of switching transistors conduct or turn off alternately, and the conduction times of the two groups of switching transistors are not equal to each other.

2. The single-inductor DC power converter based on switched capacitors according to claim 1, wherein The high-side switching transistors and low-side switching transistors used in the switched-capacitor power conversion section are fully controlled power semiconductor devices.

3. A single-inductor DC power converter based on switched capacitors, characterized in that Comprising: An input source, a switched-capacitor power conversion section, and an inductor-output capacitor rectification section; The first-stage power conversion section is a four-port network, including 2n + 2 high-side switching transistors, 2n capacitors, 2 low-side switching transistors, and four ports. Its internal connection method is as follows: The drain of the first high-side switching transistor is connected to the first port of the first-stage power conversion section. The source of the i-th high-side switching transistor is commonly connected to the drain of the (i + 1)-th high-side switching transistor and the positive electrode of the i-th capacitor. The negative electrodes of all capacitors numbered odd are commonly connected to the source of the (2n + 1)-th high-side switching transistor, the drain of the first low-side switching transistor, and the second port of the switched-capacitor power conversion section. The negative electrodes of all capacitors numbered even are commonly connected to the drain of the second low-side switching transistor and the source of the (2n + 2)-th high-side switching transistor. The drain of the (2n + 2)-th high-side switching transistor is connected to the third port of the switched-capacitor power conversion section. The source of the second low-side switching transistor is connected to the fourth port of the switched-capacitor power conversion section, where i and n are both integers, and 1 ≤ i ≤ 2n; The inductor-output capacitor rectification part consists of an inductor and an output capacitor. The first port of the switched-capacitor power conversion part is connected to the positive pole of the input source. The second port of the switched-capacitor power conversion part is connected to the left end of the inductor. The third port of the switched-capacitor power conversion part is connected to the right end of the inductor, the positive pole of the output capacitor, and the positive pole of the load. The fourth port of the switched-capacitor power conversion part is connected to the negative pole of the input source, the negative pole of the output capacitor, and the negative pole of the load; The control method of the single-inductor DC power converter is two-phase control. All the high-side switching transistors with odd numbers and the second low-side switching transistor in the switched-capacitor power conversion part are grouped into one group, and all the high-side switching transistors with even numbers and the first low-side switching transistor are grouped into another group. The two groups of switching transistors conduct or turn off alternately, and the conduction times of the two groups of switching transistors are not equal to each other.

4. A single-inductor DC power converter based on switched capacitors according to claim 3, wherein, The high-side switching transistors and low-side switching transistors used in the switched-capacitor power conversion part are fully controlled power semiconductor devices.

5. A single-inductor DC power converter based on switched capacitors according to claim 3, characterized in that, There is a port in the switched-capacitor power conversion part, which is commonly connected to the positive pole of the load, the positive pole of the output capacitor, and the right end of the inductor.

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