A hybrid structure LLC power supply

Abstract

The present invention discloses a hybrid structure LLC power supply, which includes an input source, a first power conversion part, and a second power conversion part. The first power conversion part includes a switched-capacitor circuit with a stage number of n, and this part can be a four-port circuit with dual-port input and dual-port output or a three-port circuit with dual-port input and single-port output. The second power conversion part is an LLC resonant circuit with dual-port input and single-port output. The power supply realizes high step-down ratio DC conversion through two-stage step-down of the first power conversion part and the second power conversion part, and the second power conversion part provides isolation. Due to the combination of the switched-capacitor topology, the present invention can be flexibly expanded according to voltage and power levels, can reduce the withstand voltage of switching devices, improve efficiency and power density, and is applicable to power supply applications with high voltage input and low voltage output, high voltage conversion ratio, and isolation requirements.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly relates to a hybrid structure LLC power supply. Background Art

[0002] In recent years, data centers have developed rapidly, and the related power consumption has also increased significantly. To improve the power transmission and distribution efficiency and reduce the transmission line loss, the 48V bus system has become a new standard. The main load in the data center is the processor, and its supply voltage is usually about 1V. How to achieve high-efficiency, high step-down ratio, and high power density isolated DC-DC conversion is a difficult problem in the data center power supply.

[0003] Literature A "48V-to-1V Buck-Assisted Active-Clamp Forward Converter with Reduced Voltage Stress for Datacenter Applications" (2020 IEEE Energy Conversion Congress and Exposition (ECCE), 2020) proposed an active-clamped forward converter, which realizes a high step-down ratio and high voltage isolation through a first-stage Buck part and a first-stage single-switch forward part. However, the maximum voltage stress borne by the switch tube in the topology is still relatively high, which is the input voltage, and the primary-side voltage of the transformer is also relatively high. To achieve a high step-down ratio, it is necessary to increase the number of winding turns, which increases the volume of the transformer.

[0004] Literature "48V to 1V voltage regulator module with magnetic integration" (2018 1st Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia), 2018) uses a full-bridge LLC converter. By designing the transformer, the volume of the magnetic component part in the topology is reduced. However, the voltage stress of all power switch tubes on the primary side of the transformer is still relatively high, and the voltage stress borne by the primary winding is not reduced either, and a large number of winding turns are still required.

[0005] To reduce the voltage stress of the switching device and the volume of the transformer, Reference 18.6 A 92.8%-Peak-Efficiency 60A 48V-to-1V 3-Level Half-Bridge DC-DC Converter with BalancedVoltage on a Flying Capacitor (2020 IEEE International Solid-State CircuitsConference-(ISSCC), 2020) uses a three-level half-bridge converter, making the voltage borne by the primary winding of the transformer only one-fourth of the input voltage. At the same time, the maximum voltage stress borne by the switching tube also drops to one-half of the input voltage. However, its scalability is poor, and the voltage stress borne by the transformer and the switching tube is still relatively high. The impedance of the primary power current path is large, and the system efficiency is low. Summary of the Invention

[0006] In view of the above, to solve the problems in the prior art that the voltage stress borne by the switching tube and the primary winding of the transformer is high, the efficiency and power density are low, and it is not convenient for expansion, the present invention provides a hybrid-structure LLC power supply, which consists of a first-stage expandable switched-capacitor part and a first-stage expandable LLC conversion part. The switched-capacitor part is transformed from the traditional Dickson switched-capacitor topology, and multiple capacitors are used to reduce the voltage stress of the switching tube and the amplitude of the input voltage of the LLC stage. This power supply can flexibly adjust the number of stages of the switched-capacitor part and the number of rectification modules of the LLC part according to the input voltage and power level, with good scalability, and is suitable for high-voltage conversion ratio power supply applications with isolation requirements in low-voltage medium and small power scenarios.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The present invention discloses a hybrid-structure LLC power supply, which includes:

[0009] An input source, a load, a first power conversion part, and a second power conversion part;

[0010] The first power conversion section internally includes n + 1 high-side switching transistors, n capacitors, 2 low-side switching transistors, and four ports. The drain of the first high-side switching transistor is connected to the first port of the first power conversion section. The sources of the first low-side switching transistor, the second low-side switching transistor, and the fourth port of the first power conversion section are commonly connected. The connection methods of the remaining parts are as follows: the source of the i-th high-side switching transistor, the positive electrode of the i-th capacitor, and the drain of the (i + 1)-th high-side switching transistor are commonly connected. The negative electrodes of all capacitors with odd numbers, the drain of the first low-side switching transistor, and the second port of the first power conversion section are commonly connected. The negative electrodes of all capacitors with even numbers, the drain of the second low-side switching transistor, and the third port of the first power conversion section are commonly connected. If n + 1 is odd, the source of the (n + 1)-th high-side switching transistor is commonly connected to the second port of the first power conversion section. If n + 1 is even, the source of the (n + 1)-th high-side switching transistor is connected to the third port of the first power conversion section. Here, i and n are both integers, and 1 ≤ i ≤ n.

[0011] The second power conversion section includes a resonant capacitor, a resonant inductor, k rectification modules, and four ports.

[0012] Each rectification module in the second power conversion section includes a transformer, two rectification switching transistors, and four ports. The internal connection method of the rectification module is as follows: the same-name end of the first winding of the transformer is connected to the first port of the rectification module. The non-same-name end of the first winding of the transformer is connected to the second port of the rectification module. The same-name end of the second winding of the transformer is connected to the source of the first rectification switching transistor. The non-same-name end of the second winding of the transformer, the same-name end of the third winding of the transformer, and the fourth port of the rectification module are commonly connected. The non-same-name end of the third winding of the transformer is connected to the source of the second rectification switching transistor. The drains of the first rectification switching transistor and the second rectification switching transistor are commonly connected to the third port of the rectification module.

[0013] The internal connection method of the second power conversion section is as follows: the positive electrode of the resonant capacitor is connected to the first port of the second power conversion section. The negative electrode of the resonant capacitor is connected to one end of the resonant inductor. The other end of the resonant inductor is connected to the first port of the first rectification module. The second port of the k-th rectification module is connected to the second port of the second power conversion section. The second port of the j-th rectification module is connected to the first port of the (j + 1)-th rectification module. The third ports of all rectification modules are connected to the third port of the second power conversion section. The fourth ports of all rectification modules are connected to the fourth port of the second power conversion section. Here, j and k are positive integers, and 1 ≤ j ≤ k - 1.

[0014] The connection mode between the input source, the first power conversion part, the second power conversion part and the external load is as follows: the first port of the first power conversion part is connected to the positive pole of the input source, the second port of the first power conversion part is connected to the first port of the second power conversion part, the third port of the first power conversion part, the second port of the second power conversion part and the negative pole of the input source are commonly connected, the third port of the first power conversion part is connected to the second port of the second power conversion part, the third port of the second power conversion part is connected to the positive pole of the external load, and the fourth port of the second power conversion part is connected to the negative pole of the external load.

[0015] The present invention also provides another hybrid structure LLC power supply, which includes: an input source, a first power conversion part and a second power conversion part;

[0016] The first power conversion part is an n-stage switched-capacitor circuit, which is a three-port network;

[0017] The first power conversion part internally includes n + 1 high-side switching transistors, n capacitors, 4 low-side switching transistors and three ports. Among them, the drain of the first high-side switching transistor is connected to the first port of the first power conversion part, the source of the i-th high-side switching transistor, the positive pole of the i-th capacitor and the drain of the (i + 1)-th high-side switching transistor are commonly connected. The negative poles of all capacitors numbered as odd numbers, the drain of the first low-side switching transistor and the drain of the third low-side switching transistor are commonly connected. The negative poles of all capacitors numbered as even numbers, the drain of the second low-side switching transistor and the drain of the fourth low-side switching transistor are commonly connected. If n + 1 is odd, the source of the (n + 1)-th high-side switching transistor is commonly connected to the drain of the first low-side switching transistor. If n + 1 is even, the source of the (n + 1)-th high-side switching transistor is commonly connected to the drain of the second low-side switching transistor. The source of the second low-side switching transistor, the source of the second low-side switching transistor and the second port of the first power conversion part are commonly connected. The source of the first low-side switching transistor, the source of the second low-side switching transistor and the third port of the first power conversion part are commonly connected, where i and n are both integers, and 1 ≤ i ≤ n;

[0018] The second power conversion part includes a resonant capacitor, a resonant inductor, k rectification modules and four ports,

[0019] Each rectifier module in the second power conversion section includes a transformer, two rectifier switching tubes, and four ports. The internal connection mode of the rectifier module is that the same-name end of the first winding of the transformer is connected to the first port of the rectifier module, the non-same-name end of the first winding of the transformer is connected to the second port of the rectifier module, the same-name end of the second winding of the transformer is connected to the source electrode of the first rectifier switching tube, the non-same-name end of the second winding of the transformer, the same-name end of the third winding of the transformer, and the fourth port of the rectifier module are commonly connected, the non-same-name end of the third winding of the transformer is connected to the source electrode of the second rectifier switching tube, and the drain electrodes of the first rectifier switching tube, the second rectifier switching tube, and the third port of the rectifier module are commonly connected.

[0020] The internal connection mode of the second power conversion section is that the positive electrode of the resonant capacitor is connected to the first port of the second power conversion section, the negative electrode of the resonant capacitor is connected to one end of the resonant inductor, the other end of the resonant inductor is connected to the first port of the first rectifier module, the second port of the kth rectifier module is connected to the second port of the second power conversion section, the second port of the jth rectifier module is connected to the first port of the (j + 1)th rectifier module, the third ports of all rectifier modules are connected to the third port of the second power conversion section, and the fourth ports of all rectifier modules are connected to the fourth port of the second power conversion section, where j and k are positive integers and 1 ≤ j ≤ k - 1.

[0021] The connection mode between the input source, the first power conversion section, the second power conversion section, and the external load is that the first port of the first power conversion section is connected to the positive electrode of the input source, the second port of the first power conversion section is connected to the first port of the second power conversion section, the third port of the first power conversion section, the second port of the second power conversion section, and the negative electrode of the input source are commonly connected, the third port of the first power conversion section is connected to the second port of the second power conversion section, the third port of the second power conversion section is connected to the positive electrode of the external load, and the fourth port of the second power conversion section is connected to the negative electrode of the external load.

[0022] In an embodiment of the present invention, the switching tubes used are fully controlled power semiconductor devices.

[0023] Based on the above technical solutions, compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The power supply described in the present invention can adjust the number of stages of the switched-capacitor section and the number of rectifier sections according to the voltage and power levels, and is easy to expand.

[0025] (2) The power supply switch tubes of the present invention have low voltage stress, and the primary sides of the first power conversion section and the rectifier module are in an LC resonance state during operation, which can reduce switching losses, improve system efficiency, is beneficial to system design and device selection, and low-voltage power devices can be used.

[0026] (3) The input voltage amplitude of the second power conversion part of the power supply according to the present invention is small, which can reduce the number of turns of the transformer winding and improve the power density of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 One of the two typical system connection diagrams of the hybrid structure LLC power supply according to an embodiment of the present invention;

[0028] Figure 2 One of the two typical system connection diagrams of the hybrid structure LLC power supply according to another embodiment of the present invention;

[0029] Figure 3 (a)-(b) are the circuit topologies of the four-port first power conversion part according to an embodiment of the present invention; wherein (a) is the circuit topology when the number of stages of the first power conversion part is odd, and FIG. (b) is the circuit topology when the number of stages of the first power conversion part is even;

[0030] Figure 4 (a)-(b) are the circuit topologies of the three-port first power conversion part according to an embodiment of the present invention; wherein (a) is the circuit topology when the number of stages of the first power conversion part is odd, and FIG. (b) is the circuit topology when the number of stages of the first power conversion part is even;

[0031] Figure 5 The internal connection diagram of the second power conversion part according to an embodiment of the present invention;

[0032] Figure 6 The circuit topology of a single rectification module inside the second power conversion part according to an embodiment of the present invention;

[0033] Figure 7 One of the system topologies of the hybrid structure LLC power supply according to an embodiment of the present invention;

[0034] Figure 8 One of the system topologies of the hybrid structure LLC power supply according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To more clearly reflect the above features and advantages of the present invention, the following will be described in detail in combination with the drawings and specific power supply embodiments. The technical features of each embodiment of the present invention can be combined correspondingly without conflict.

[0036] Figure 1System connection diagram when the first power conversion part in an embodiment of the present invention is a four-port network, which includes an input source, a four-port first power conversion part, a four-port second power conversion part. The positive pole of the input source is connected to the first port A of the first power conversion part, the negative pole of the input source is connected to the fourth port D of the first power conversion part, the second port B of the first power conversion part is connected to the first port A' of the second power conversion part, the third port C of the first power conversion part is connected to the second port B' of the second power conversion part, the third port C' of the second power conversion part is connected to the positive pole of the external load, and the fourth port D' of the second power conversion part is connected to the negative pole of the external load;

[0037] Figure 2 System connection diagram when the first power conversion part in an embodiment of the present invention is a three-port network, which includes an input source, a three-port first power conversion part, a four-port second power conversion part and an external load. The positive pole of the input source is connected to the first port A of the first power conversion part, the negative pole of the input source, the third port C of the first power conversion part and the second port of the second power part are commonly connected. The second port B of the first power conversion part is connected to the first port A' of the second power conversion part, the third port C' of the second power conversion part is connected to the positive pole of the external load, and the fourth port D' of the second power conversion part is connected to the negative pole of the external load;

[0038] Figure 3 (a)-(b) Circuit topology diagrams of the n-level four-port first power conversion part in an embodiment of the present invention, which internally includes n + 1 high-side switching transistors, n capacitors, 2 low-side switching transistors and four ports. Among them, the drain of the first high-side switching transistor Q H1 is connected to the first port A of the first power conversion part, the source of the first low-side switching transistor Q L1 , the source of the second low-side switching transistor Q L2 and the fourth port D of the first power conversion part are commonly connected. The connection method of the rest is that the source of the i-th high-side switching transistor Q Hi , the positive pole of the i-th capacitor C i and the drain of the (i + 1)-th high-side switching transistor Q Hi+1 are commonly connected. The negative poles of all capacitors numbered as odd numbers (C 1 , C 3 ,...), the drain of the first low-side switching transistor Q L1 and the second port of the first power conversion part are commonly connected to B. The negative poles of all capacitors numbered as even numbers (C 2 , C 4 ,...), the drain of the second low-side switching transistor Q L2 and the third port C of the first power conversion part are commonly connected. If n + 1 is odd, then the (n + 1)-th high-side switching transistor QHn+1 The source electrode of is commonly connected to the second port B of the first power conversion part. If n + 1 is an even number, the (n + 1)-th high-side switch tube Q Hn+1 The source electrode of is connected to the third port C of the first power conversion part, where both i and n are integers, and 1 ≤ i ≤ n.

[0039] Figure 4 (a)-(b) are circuit topologies of the n-level three-port first power conversion part according to an embodiment of the present invention, which internally includes n + 1 high-side switch tubes, n capacitors, 4 low-side switch tubes, and three ports. Among them, the drain electrode of the first high-side switch tube Q H1 is connected to the first port A of the first power conversion part. The source electrode of the i-th high-side switch tube Q Hi , the positive electrode of the i-th capacitor C i , and the drain electrode of the (i + 1)-th high-side switch tube Q Hi+1 are commonly connected. The negative electrodes of all capacitors numbered as odd numbers (C 1 , C 3 ,...), the drain electrode of the first low-side switch tube Q L1 , and the drain electrode of the third low-side switch tube Q L3 are commonly connected. The negative electrodes of all capacitors numbered as even numbers (C 2 , C 4 ,...), the drain electrode of the second low-side switch tube Q L2 , and the drain electrode of the fourth low-side switch tube Q L2 are commonly connected. If n + 1 is an odd number, the source electrode of the (n + 1)-th high-side switch tube Q Hn+1 is commonly connected to the drain electrode of the first low-side switch tube Q L1 . If n + 1 is an even number, the source electrode of the (n + 1)-th high-side switch tube Q Hn+1 is commonly connected to the drain electrode of the second low-side switch tube Q L2 . The source electrode of the third low-side switch tube Q L3 , the source electrode of the fourth low-side switch tube Q L4 , and the second port B of the first power conversion part are commonly connected. The source electrode of the first low-side switch tube Q L1 , the source electrode of the second low-side switch tube Q L2 , and the third port C of the first power conversion part are commonly connected, where both i and n are integers, and 1 ≤ i ≤ n;

[0040] Figure 5 is the internal connection diagram of the second power conversion part according to an embodiment of the present invention, which includes a resonant capacitor, a resonant inductor, k rectification modules, and four ports. The positive electrode of the resonant capacitor C r is connected to the first port A' of the second power conversion part. The negative electrode of the resonant capacitor C r is connected to one end of the resonant inductor L r The resonant inductor Lr The other end and the first port R of the rectification module 1 1-1 are connected. The second port R of the rectification module k k-2 is connected to the second port B' of the second power conversion section. The connection method of the remaining ports is that the second port R of the rectification module j j-2 is connected to the first end R j+1-1 port of the rectification module j + 1. The third ports (R 1-3 , R 2-3 ..., R k-3 ) of all rectification modules are connected to the third port C' of the second power conversion section. The fourth ports (R 1-4 , R 2-4 ..., R k-4 ) of all rectification modules are connected to the fourth port D' of the second power conversion section, where j and k are positive integers and 1 ≤ j ≤ k - 1;

[0041] Figure 6 This is the circuit topology diagram of each rectification module in the second power conversion section of an embodiment of the present invention, including a transformer, two rectification switching tubes, and four ports. Taking the rectification module numbered k as an example, the internal connection method of the rectification module is that the same-name end of the first winding N k of the transformer T k-1 is connected to the first port R of the rectification module k-1 . The non-same-name end of the first winding N k of the transformer T k-1 is connected to the second port R of the rectification module k-2 . The same-name end of the second winding N k of the transformer T k-2 is connected to the source of the first rectification switching tube Q k-1 . The same-name end of the third winding N k of the transformer T k-3 , the same-name end of the third winding N k of the transformer T k-2 and the non-same-name end of the third winding N k-4 of the transformer T k are connected to the fourth port R of the rectification module k-3 . The non-same-name end of the third winding N k-2 of the transformer T k-1 is connected to the source of the second rectification switching tube Q k-2 . The drains of the first rectification switching tube Q k-3 and the second rectification switching tube Q k-2 are commonly connected to the third port R of the rectification module k-3 ,

[0042] Figure 7 This is the system topology of the power supply in a specific embodiment of the present invention, which includes an input source, a first power conversion section with two levels and four ports, and a second power conversion section including two rectification modules;

[0043] Figure 8 The system topology of the power supply for an embodiment of the present invention includes an input source, a first power conversion part with two levels and three ports, and a second power conversion part including two rectification modules;

[0044] The advantages of the present invention will be illustrated through theoretical analysis in combination with specific embodiments. Taking Figure 7 the embodiment in H1 ~ H3 as an example, during steady-state operation, the duty cycles of the driving signals of Q L1 ~Q L2 are the same, and the duty cycles of the driving signals of Q 1 and Q 2 are the same. The voltage on C H1 ~ H3 ~ L2 is 2 / 3 of the input voltage, and the voltage on C H2 ~ L1 is 1 / 3 of the input voltage. There are two modes in the first power conversion part that output power. In the first mode, Q H1 , Q H3 , Q L2 conduct. In the second mode, Q H2 and Q L1 conduct, thereby generating a pair of positive and negative alternating rectangular wave signals with an amplitude of only 1 / 3 of the input voltage at the input end of the second power conversion part. Moreover, the withstand voltage values of Q L1 and Q L2 are also only 1 / 3 of the input voltage. In the traditional solution, the first power conversion part often adopts a full-bridge or half-bridge topology, and the withstand voltage of all switching tubes is equal to the input voltage. Therefore, the present invention allows the use of switching tubes with lower withstand voltage. Moreover, since the amplitude of the input voltage of the second power conversion part is reduced, the volume of the transformer in the second power conversion part can be reduced, and the power density of the system can be increased. Moreover, through the resonant inductor and resonant capacitor in the second power part, the primary switching tubes can work in the zero-current turn-on state, thereby reducing the dead-time loss and switching loss and improving the system efficiency.

[0045] From Figure 7 the specific embodiment shown, it can be seen that each rectification module in the second power part is exactly the same. Therefore, only the parameters of a single module need to be designed to complete the design of the entire power part. Moreover, for different input voltage levels, only the number of modules needs to be adjusted, and there is no need to redesign the module parameters.

[0046] The above examples specifically illustrate and describe the exemplary embodiments of the present invention. The above embodiments are only used to illustrate the technical solutions of the present invention, so as to facilitate the understanding and application of the present invention by ordinary technical personnel in the technical field. The present invention is not limited to the detailed structure, setting method or implementation manner described herein. It should be noted that those skilled in the art can obviously make various modifications to the above embodiments easily, or make equivalent replacements for some or all of the technical features of the present invention, or apply the general principles described herein to other embodiments without creative labor. The modifications, improvements or equivalent replacements of the technical features of the present invention should all be within the protection scope of the present invention.

Claims

1. A hybrid - structure LLC power supply, characterized in that it includes: an input source, a first power conversion part and a second power conversion part; The first power conversion part is an n - stage switched - capacitor circuit, which is a four - port network, The first power conversion part internally includes n + 1 high - side switching transistors, n capacitors, 2 low - side switching transistors and four ports. Among them, the drain of the first high - side switching transistor is connected to the first port of the first power conversion part, the sources of the first low - side switching transistor, the second low - side switching transistor and the fourth port of the first power conversion part are commonly connected. The connection methods of the remaining parts are as follows: the source of the i - th high - side switching transistor, the positive electrode of the i - th capacitor and the drain of the (i + 1) - th high - side switching transistor are commonly connected. The negative electrodes of all capacitors numbered as odd numbers, the drain of the first low - side switching transistor and the second port of the first power conversion part are commonly connected. The negative electrodes of all capacitors numbered as even numbers, the drain of the second low - side switching transistor and the third port of the first power conversion part are commonly connected. If n + 1 is odd, the source of the (n + 1) - th high - side switching transistor is commonly connected to the second port of the first power conversion part. If n + 1 is even, the source of the (n + 1) - th high - side switching transistor is connected to the third port of the first power conversion part, where i and n are both integers, and 1 ≤ i ≤ n, The second power conversion part includes a resonant capacitor, a resonant inductor, k rectification modules and four ports, Each rectification module in the second power conversion part includes a transformer, two rectification switching transistors and four ports. The internal connection method of the rectification module is as follows: the same - name end of the first winding of the transformer is connected to the first port of the rectification module, the non - same - name end of the first winding of the transformer is connected to the second port of the rectification module, the same - name end of the second winding of the transformer is connected to the source of the first rectification switching transistor, the non - same - name end of the second winding of the transformer, the same - name end of the third winding of the transformer and the fourth port of the rectification module are commonly connected, the non - same - name end of the third winding of the transformer is connected to the source of the second rectification switching transistor, and the drains of the first rectification switching transistor, the second rectification switching transistor and the third port of the rectification module are commonly connected, The internal connection method of the second power conversion part is as follows: the positive electrode of the resonant capacitor is connected to the first port of the second power conversion part, the negative electrode of the resonant capacitor is connected to one end of the resonant inductor, the other end of the resonant inductor is connected to the first port of the first rectification module, the second port of the k - th rectification module is connected to the second port of the second power conversion part, the second port of the j - th rectification module is connected to the first port of the (j + 1) - th rectification module, the third ports of all rectification modules are commonly connected to the third port of the second power conversion part, and the fourth ports of all rectification modules are commonly connected to the fourth port of the second power conversion part, where j and k are positive integers and 1 ≤ j ≤ k - 1; The connection mode among the input source, the first power conversion part, the second power conversion part and the external load is as follows: the first port of the first power conversion part is connected to the positive pole of the input source, the second port of the first power conversion part is connected to the first port of the second power conversion part, the third port of the first power conversion part is connected to the second port of the second power conversion part, the fourth port of the first power conversion part is connected to the negative pole of the input source, the third port of the second power conversion part is connected to the positive pole of the external load, and the fourth port of the second power conversion part is connected to the negative pole of the external load.

2. A hybrid structure LLC power supply characterized in that it includes: an input source, a first power conversion part and a second power conversion part; the first power conversion part is an n-stage switched-capacitor circuit, which is a three-port network; The first power conversion part internally includes n + 1 high-side switching transistors, n capacitors, 4 low-side switching transistors and three ports. Among them, the drain of the first high-side switching transistor is connected to the first port of the first power conversion part, the source of the i-th high-side switching transistor, the positive pole of the i-th capacitor and the drain of the (i + 1)-th high-side switching transistor are commonly connected. The negative poles of all capacitors numbered as odd numbers, the drain of the first low-side switching transistor and the drain of the third low-side switching transistor are commonly connected. The negative poles of all capacitors numbered as even numbers, the drain of the second low-side switching transistor and the drain of the fourth low-side switching transistor are commonly connected. If n + 1 is odd, the source of the (n + 1)-th high-side switching transistor is commonly connected to the drain of the first low-side switching transistor. If n + 1 is even, the source of the (n + 1)-th high-side switching transistor is commonly connected to the drain of the second low-side switching transistor. The source of the second low-side switching transistor, the source of the second low-side switching transistor and the second port of the first power conversion part are commonly connected. The source of the first low-side switching transistor, the source of the second low-side switching transistor and the third port of the first power conversion part are commonly connected, where i and n are both integers, and 1 ≤ i ≤ n; the second power conversion part includes a resonant capacitor, a resonant inductor, k rectification modules and four ports, Each rectification module in the second power conversion part includes a transformer, two rectification switching transistors and four ports. The internal connection mode of the rectification module is that the same-name end of the first winding of the transformer is connected to the first port of the rectification module, the non-same-name end of the first winding of the transformer is connected to the second port of the rectification module, the same-name end of the second winding of the transformer is connected to the source of the first rectification switching transistor, the non-same-name end of the second winding of the transformer, the same-name end of the third winding of the transformer and the fourth port of the rectification module are commonly connected. The non-same-name end of the third winding of the transformer is connected to the source of the second rectification switching transistor. The drain of the first rectification switching transistor, the drain of the second rectification switching transistor and the third port of the rectification module are commonly connected. The internal connection method of the second power conversion part is as follows: the positive electrode of the resonant capacitor is connected to the first port of the second power conversion part, the negative electrode of the resonant capacitor is connected to one end of the resonant inductor, the other end of the resonant inductor is connected to the first port of the first rectification module, the second port of the k-th rectification module is connected to the second port of the second power conversion part, the second port of the j-th rectification module is connected to the first port of the (j + 1)-th rectification module, the third ports of all rectification modules are connected to the third port of the second power conversion part, and the fourth ports of all rectification modules are connected to the fourth port of the second power conversion part, where j and k are positive integers and 1 ≤ j ≤ k - 1; The connection method between the input source, the first power conversion part, the second power conversion part and the external load is as follows: the first port of the first power conversion part is connected to the positive electrode of the input source, the second port of the first power conversion part is connected to the first port of the second power conversion part, the third port of the first power conversion part, the second port of the second power conversion part and the negative electrode of the input source are commonly connected, the third port of the first power conversion part is connected to the second port of the second power conversion part, the third port of the second power conversion part is connected to the positive electrode of the external load, and the fourth port of the second power conversion part is connected to the negative electrode of the external load.

3. A hybrid structure LLC power supply according to claim 1 or 2, characterized in that, the switching tubes used are fully controlled power semiconductor devices.

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