Buck topology circuit and power supply
By adopting a buck topology circuit of parallel three-level bridge arm module and anti-coupled inductor module in high-frequency power supply, the problem of high cost of switching tubes and inductors in Buck topology is solved, and the low cost and high cost of high-frequency power supply is achieved reliability.
Patent Information
- Application Number
- CN202420840914.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-22
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-04-22
AI Technical Summary
The Buck topological design in existing high-frequency power supplies leads to high cost of switching tubes and large inductor volume, making it difficult to meet economic requirements.
The buck topology circuit of the parallel three-level bridge arm module and the reverse coupling inductor module is adopted. By reducing the withstand voltage level and inductance value of the switching tube, the inductor volume is reduced and the switching frequency is increased.
It significantly reduces the cost of the power system, improves the power density and stability and reliability of high-frequency power supplies, and avoids the use of high-cost, high-volume switching tubes and inductors.
Smart Images
Figure CN222147426U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of power electronics, in particular to a step-down topology circuit and a power supply. Background Art
[0002] With the continuous development of social industrialization, high-frequency power supplies are widely used in the industrial field. Under the premise of meeting the reliability of high-frequency power supplies, users have put forward higher requirements for the economy of high-frequency power supplies.
[0003] The DC-DC part of the high-frequency power supply is the core part of the power supply, which determines the main characteristics of the high-frequency power supply. Usually, a buck topology circuit is integrated in the DC-DC to maintain the high reliability of the high-frequency power supply, and the buck topology circuits integrated in the DC-DC in the prior art are mostly Buck topology. The existing Buck topology generally adopts a switch tube with a high withstand voltage level and an independent inductor design. However, this Buck topology design has great defects. On the one hand, in the high-frequency power supply, since the high-withstand voltage switch tube of the existing Buck topology design is a hard switch, not only the switching loss is large and the switching frequency is difficult to increase, but also the switch tube with a high withstand voltage level also means large switching loss, and the cost of the switch tube is also higher. On the other hand, the inductor in the Buck topology generally adopts an independent inductor design, but in the high-frequency power supply, since the switching frequency of the switch tube is generally low, the inductance value of the independent inductor is large, and the volume of the independent inductor with a large inductance value is also larger, and the cost of the inductor is also higher.
[0004] In other words, how to reduce the volume of the inductor in the buck topology circuit to save the system cost of the power supply is a technical problem that urgently needs to be solved. Utility Model Content
[0005] The main purpose of the utility model is to provide a buck topology circuit and a power supply, aiming to reduce the volume of the inductor in the buck topology circuit to save the system cost of the power supply.
[0006] To achieve the above object, the utility model provides a buck topology circuit, the buck topology circuit comprising: n three-level bridge arm modules connected in parallel with each other, and an anti-coupling inductor module paired with each of the three-level bridge arm modules, where n is a natural number greater than 1;
[0007] The three-level bridge arm module is electrically connected to a paired reverse coupling inductor module;
[0008] The three-level bridge arm module is provided with an upper bridge arm unit and a lower bridge arm unit connected in series with the upper bridge arm unit;
[0009] The reverse coupling inductor module includes an upper inductor and a lower inductor, wherein the upper inductor is electrically connected to the midpoint of the upper bridge arm of the upper bridge arm unit, and the lower inductor is electrically connected to the midpoint of the lower bridge arm of the lower bridge arm unit; wherein each of the upper bridge arm units respectively controls the corresponding upper inductor electrically connected to the midpoint of the upper bridge arm and the aggregate output after reverse coupling with the adjacent upper inductor as a positive output, and each of the lower bridge arm units respectively controls the corresponding lower inductor electrically connected to the midpoint of the lower bridge arm and the aggregate output after reverse coupling with the adjacent lower inductor as a negative output.
[0010] Optionally, a driving phase difference between an upper bridge arm unit and a lower bridge arm unit in the same three-level bridge arm module is 180°;
[0011] When n>2, the driving phase shift between the upper bridge arm units in different three-level bridge arm modules is 180° / n;
[0012] When n=2, the driving phases between the upper bridge arm units in different three-level bridge arm modules are shifted by 90°.
[0013] Optionally, the buck topology circuit includes a busbar midpoint, and the upper bridge arm unit includes a first switch tube and a first diode;
[0014] The collector of the first switch tube is electrically connected to a preset positive power supply terminal, the emitter of the first switch tube is electrically connected to the cathode of the first diode, and the anode of the first diode is electrically connected to the busbar midpoint and the lower bridge arm unit respectively.
[0015] Optionally, the lower bridge arm unit includes a second switch tube and a second diode;
[0016] The collector of the second switch tube is electrically connected to the anode of the second diode, the cathode of the second diode is electrically connected to the midpoint of the busbar and the anode of the first diode respectively, and the emitter of the second switch tube is electrically connected to a preset negative power supply terminal.
[0017] Optionally, the emitter of the first switch tube and the cathode of the first diode are connected together to form the upper bridge arm midpoint of the upper bridge arm unit;
[0018] The collector of the second switch tube and the anode of the second diode are connected together to form the lower bridge arm midpoint of the lower bridge arm unit.
[0019] Optionally, the buck topology circuit further includes a power supply capacitor module, and the busbar midpoint is the capacitor midpoint of the power supply capacitor module;
[0020] The first end of the power supply capacitor module is electrically connected to the upper bridge arm unit in different three-level bridge arm modules and the positive power supply end;
[0021] The second end of the power supply capacitor module is electrically connected to the lower bridge arm unit in the different three-level bridge arm modules, and the negative power supply end;
[0022] The capacitor midpoint of the power supply capacitor module is electrically connected to the full bridge arm midpoint of each of the three-level bridge arm modules; wherein,
[0023] In the same three-level bridge arm module, the anode of the first diode in the upper bridge arm unit and the cathode of the second diode in the lower bridge arm unit are connected together to form the full bridge arm midpoint of the three-level bridge arm module.
[0024] Optionally, the power supply capacitor module includes a first capacitor unit and a second capacitor unit connected in series with the first capacitor unit; wherein,
[0025] The power supply capacitor module includes a first capacitor unit and a second capacitor unit connected in series with the first capacitor unit; wherein,
[0026] The connection point of the first capacitor unit and the second capacitor unit in series is the capacitor midpoint of the power supply capacitor module;
[0027] One end of the first capacitor unit that is not connected to the second capacitor unit is electrically connected to the collector of the first switch tube in each of the upper bridge arm units and the positive power supply end;
[0028] One end of the second capacitor unit that is not connected to the first capacitor unit is electrically connected to the emitter of the second switch tube in each lower bridge arm unit and the negative power supply end.
[0029] Optionally, the first capacitor unit includes M power capacitors connected in series, and the second capacitor unit includes X power capacitors connected in series, wherein M and X are both natural numbers greater than 0, and M=X.
[0030] Optionally, the buck topology circuit further includes a DC capacitor module;
[0031] Each of the upper inductors is electrically connected to the positive output terminal of the DC capacitor module, and each of the lower inductors is electrically connected to the negative output terminal of the DC capacitor module.
[0032] In addition, to achieve the above-mentioned purpose, the present application also provides a power supply, which also includes a rectifier module and a DC-DC converter electrically connected to the rectifier module, wherein the DC-DC converter includes at least the buck topology circuit described in any one of the above items.
[0033] The present application provides a buck topology circuit and a power supply, the circuit comprising n three-level bridge arm modules connected in parallel with each other, and an anti-coupling inductor module paired with each three-level bridge arm module, n being a natural number greater than or equal to 1; wherein the three-level bridge arm module is electrically connected to the paired anti-coupling inductor module; the three-level bridge arm module is provided with an upper bridge arm unit, and a lower bridge arm unit connected in series with the upper bridge arm unit; the anti-coupling inductor module comprises an upper inductor and a lower inductor, and the upper inductor is electrically connected to the upper bridge arm midpoint of the upper bridge arm unit, and the lower inductor is electrically connected to the lower bridge arm midpoint of the lower bridge arm unit, in addition, each upper bridge arm unit respectively controls the upper inductor electrically connected to the corresponding upper bridge arm midpoint and the adjacent upper inductor to obtain a total output after anti-coupling as a positive output, and each lower bridge arm unit respectively controls the lower inductor electrically connected to the corresponding lower bridge arm midpoint and the adjacent lower inductor to obtain a total output after anti-coupling as a negative output.
[0034] Different from the existing Buck topology, the present application provides n three-level bridge arm modules in parallel for use in small and medium power supplies in the buck topology circuit. Since the voltage resistance level of the three-level bridge arm module used in small and medium power supplies is much lower than the voltage resistance level of the switch tube in the existing Buck topology, this also means that the lower voltage resistance level can bring lower switching loss and conduction loss to the buck topology circuit, which not only avoids the use of bulky and costly switch tubes, but also significantly improves the switching frequency in the buck topology circuit; then, the present application electrically connects each three-level bridge arm module to a paired anti-coupling inductor module respectively. The three-level bridge arm module provided according to the present application has the characteristic of high switching frequency, which can effectively reduce the inductance value of the anti-coupling inductor module. In addition, the present application adopts a reverse coupling inductor module to replace the large independent inductor with two low-cost small upper and lower inductors; then, the upper inductor electrically connected to the midpoint of the upper bridge arm is reversely coupled with the adjacent upper inductor by using the upper bridge arm unit, and the lower inductor electrically connected to the midpoint of the lower bridge arm is reversely coupled with the adjacent lower inductor by using the lower bridge arm unit, so that the winding directions of the upper inductor and the adjacent upper inductor, and the winding directions of the lower inductor and the adjacent lower inductor are opposite, thereby generating a reverse coupling effect. This reverse coupling effect makes the inductance values cancel each other out between adjacent inductors, significantly reducing the overall inductance value in the buck topology circuit, thereby effectively reducing the cost of the power supply system. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 This is a schematic diagram of the structure of the high-frequency power supply of this application;
[0036] Figure 2 This is a schematic diagram of a single-phase buck with a commonly used diode bottom tube;
[0037] Figure 3 This is a schematic diagram of a single-phase buck with a commonly used switch tube.
[0038] Figure 4 This is a schematic diagram of a commonly used two-phase buck cascade;
[0039] Figure 5 This is a schematic diagram of a commonly used three-phase buck cascade;
[0040] Figure 6 A schematic diagram of a buck topology circuit of the present application;
[0041] Figure 7 A schematic diagram of a multi-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application;
[0042] Figure 8 A schematic diagram of another multi-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application;
[0043] Fig. 9 This is another schematic diagram of a multi-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application;
[0044] Fig.10 Schematic diagram of waveforms involved in a two-phase interleaved cascaded three-level buck topology;
[0045] Fig.11 This is a schematic diagram of a multi-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application.
[0046] Description of Figure Numbers:
[0047] Label name Label name 100 Buck topology circuit 10 Three-level bridge module 20 Anti-coupled inductor module 11 Upper arm unit 12 Lower arm unit Lu Upper inductor Ld Lower Inductor Q1 The first switch Q2 The second switch D1 The first diode D2 The second diode 30 Power supply capacitor module 40 DC capacitor module C3 The third power supply capacitor 301 The first capacitor unit 302 The second capacitor unit
[0048] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0049] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0050] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0051] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0052] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0053] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.
[0054] With the continuous development of power electronics technology, high-frequency power supplies (i.e., high-frequency power supplies) are becoming more and more widely used, especially in the production of hydrogen by electrolysis of water and arc drawing in crucibles. The requirements for high-frequency power supplies in such occasions are mainly concentrated on low cost, high reliability, and high power density. Moreover, low cost, high reliability, and high power density have always been the key indicators for the development of the power supply field.
[0055] At present, the main components of high-frequency power supply are as follows Figure 1 As shown in the figure, the three-phase power is converted into direct current after non-rectifier or controllable rectification, and then outputted as the required voltage after DC-DC step-down. Among them, the DC-DC part is the core part of the power supply, which determines the main characteristics of the high-frequency power supply. The existing technology often uses Buck topology in DC-DC to maintain the high reliability of the high-frequency power supply, and the existing Buck topology used in the high-frequency power supply has various forms, most of which are single-phase, two-phase or three-phase cascade Buck topology, refer to Figure 2-Figure 5 As shown, Figure 2 For a single-phase buck with a diode under the diode, Figure 3 is a single-phase buck at the bottom of the switch tube, and Figure 2 and Figure 3 The single-phase buck equivalent shown. Figure 4 For two-phase buck cascade, Figure 5It is a three-phase buck cascade. That is, although the existing Buck topology is stable and reliable, the existing Buck topology generally adopts a switch tube with a high withstand voltage level and an independent inductor design. The switch tube with a high withstand voltage level not only has the defects of large device size and high cost, but also the switching frequency of the switch tube in the high-frequency power supply is generally low, which leads to a large inductance value of the independent inductor, and the volume of the independent inductor with a large inductance value is also larger, and the cost of the inductor is also higher, which leads to a large volume, high cost, and low efficiency of the entire high-frequency power supply. Therefore, based on the above problems, the buck topology circuit and power supply of the utility model are proposed.
[0056] The utility model provides a buck topology circuit 100, referring to Figure 6 , Figure 6 The buck topology circuit 100 includes: n three-level bridge arm modules 10 connected in parallel, and a reverse coupling inductor module 20 paired with each of the three-level bridge arm modules 10, where n is a natural number greater than 1;
[0057] The three-level bridge arm module 10 is electrically connected to a paired reverse coupling inductor module 20;
[0058] The three-level bridge arm module 10 is provided with an upper bridge arm unit 11 and a lower bridge arm unit 12 connected in series with the upper bridge arm unit 11;
[0059] The reverse coupling inductor module 20 includes an upper inductor Lu and a lower inductor Ld, wherein the upper inductor Lu is electrically connected to the midpoint of the upper bridge arm of the upper bridge arm unit 11, and the lower inductor Ld is electrically connected to the midpoint of the lower bridge arm of the lower bridge arm unit 12; wherein each of the upper bridge arm units 11 respectively controls the corresponding upper inductor Lu electrically connected to the midpoint of the upper bridge arm and the adjacent upper inductor Lu to reversely couple the summed output as a positive output, and each of the lower bridge arm units 12 respectively controls the corresponding lower inductor Ld electrically connected to the midpoint of the lower bridge arm and the adjacent lower inductor Ld to reversely couple the summed output as a negative output.
[0060] In this embodiment, the buck topology circuit 100 designed in this application is a multi-phase cascade three-level buck bracket structure. Figure 6, the buck topology circuit 100 may include n three-level bridge arm modules 10 connected in parallel to each other, and an anti-coupling inductor module 20 paired with each three-level bridge arm module 10. And each three-level bridge arm module 10 is electrically connected to the paired anti-coupling inductor module 20. That is, the present application adopts a three-level bridge arm module 10 applied to small and medium power supplies, and the buck topology circuit formed by the n three-level bridge arm modules 10 connected in parallel to each other significantly improves the switching frequency and power density of the entire high-frequency power supply. In addition, the withstand voltage level of the three-level bridge arm module 10 applied to small and medium power supplies is much lower than the withstand voltage level of the switch tube in the existing Buck topology. For example, for the high-frequency power supply involved in the 380V rectification application, the two-level buck in the existing high-frequency power supply needs to select a switch tube with a withstand voltage level of 1200V, but the three-level bridge arm module 10 designed in the present application can be a withstand voltage level of 600V or 650V. That is, the three-level bridge arm module 10 with a low withstand voltage level in the present application not only means that it can bring lower switching loss and conduction loss to the high-frequency power supply, but also can effectively reduce the device volume of the high-frequency power supply and save the system cost of the high-frequency power supply. In addition, the present application adopts the reverse coupling inductor module 20 to replace the large-volume independent inductor with two smaller-volume upper inductors and lower inductors, that is, the reverse coupling inductor module 20 effectively compresses the volume of the inductor device to achieve the purpose of saving the system cost of the high-frequency power supply, and each upper bridge arm unit 11 controls the corresponding upper inductor Lu electrically connected to the midpoint of the upper bridge arm and the adjacent upper inductor Lu to reversely couple the aggregate output as the positive output, and each lower bridge arm unit 12 controls the corresponding lower inductor Ld electrically connected to the midpoint of the lower bridge arm and the adjacent lower inductor Ld to reversely couple the aggregate output as the negative output, thereby further improving the stability and reliability of the high-frequency power supply.
[0061] It should be noted that the upper inductor Lu and the lower inductor Ld in each anti-coupling inductor module 20 are both output inductors of the anti-coupling inductor design.
[0062] In addition, it should be noted that, referring to Figure 6When the number of the three-level bridge arm modules 10 is n, the number of the anti-coupling inductor modules 20 paired with the three-level bridge arm modules 10 is also n, and the number of the upper bridge arm units 11 and the lower bridge arm units 12 in the n three-level bridge arm modules 10 is also n, and the number of the upper inductor Lu and the lower inductor Ld in the n anti-coupling inductor modules 20 is also n, wherein the n three-level bridge arm modules 10 can be expressed by a three-level bridge arm module 10-1, a three-level bridge arm module 10-2, ..., and a three-level bridge arm module 10-n; the n anti-coupling inductor modules 20 can be expressed by an anti-coupling inductor module 20-1, an anti-coupling inductor module 10-2, ..., and a three-level bridge arm module 10-n. Inductor modules 20-2, ..., and anti-coupling inductor modules 20-n are used to express; n upper bridge arm units 11 can be expressed by upper bridge arm unit 11-1, upper bridge arm unit 11-2, ..., and upper bridge arm unit 11-n; n lower bridge arm units 12 can be expressed by lower bridge arm unit 12-1, lower bridge arm unit 12-2, ..., and lower bridge arm unit 12-n; n upper inductors Lu can be expressed by upper inductor Lu-1, upper inductor Lu-2, ..., and upper inductor Lu-n; n lower inductors Ld can be expressed by lower inductor Ld-1, lower inductor Ld-2, ..., and lower inductor Ld-n.
[0063] In a specific embodiment, refer to Figure 6 , Figure 6 The upper inductor Lu-2 is the adjacent inductor of the upper inductor Lu-1, the upper inductor Lu-3 is the adjacent inductor of the upper inductor Lu-2, ..., the upper inductor Lu-(n-1) is the adjacent inductor of the upper inductor Lu-n; Figure 6The lower inductor Ld-2 is the adjacent inductor of the lower inductor Ld-1, the lower inductor Ld-3 is the adjacent inductor of the lower inductor Ld-2, ..., the lower inductor Ld-(n-1) is the adjacent inductor of the lower inductor Ld-n. The present application sequentially electrically connects the opposite-name end of the upper inductor Lu-1 with the same-name end of the upper inductor Lu-2, the same-name end of the upper inductor Lu-2 with the opposite-name end of the upper inductor Lu-3, ..., and the same-name end of the upper inductor Lu-(n-1) with the opposite-name end of the upper inductor Lu-n, thereby forming a structure in which adjacent upper inductors in different anti-coupling inductor modules 20 are coupled and connected to each other, thereby making the winding directions of the upper inductor and the adjacent upper inductor opposite, generating a reverse coupling effect to cancel out the inductance values between the upper inductor and the adjacent lower inductor; the present application electrically connects the opposite-name end of the lower inductor Ld-1 with the lower inductor Ld-2. The same-name end of the inductor Ld-2 is electrically connected, the same-name end of the lower inductor Ld-2 is electrically connected to the opposite-name end of the lower inductor Ld-3, ..., and the same-name end of the lower inductor Ld-(n-1) is electrically connected to the opposite-name end of the lower inductor Ld--n, thereby forming a structure in which adjacent lower inductors in different anti-coupling inductor modules 20 are coupled and connected to each other, so that the winding direction of the lower inductor is opposite to that of the adjacent lower inductor, and a reverse coupling effect is generated to offset the inductance value between the lower inductor and the adjacent lower inductor, thereby reducing the overall inductance value in the buck topology circuit, thereby effectively saving the system cost of the high-frequency power supply. In addition, the present application not only provides a filter inductor for buck output through the above-mentioned adjacent upper and lower inductor anti-coupling connection method, but also outputs consistent impedance on the positive and negative sides, reduces the EMC problem caused by inconsistent impedance, and can also play a filtering role, thereby further improving the stability and reliability of the high-frequency power supply.
[0064] In another embodiment, referring to Figure 6 , when there are n upper inductors Lu and n lower inductors Ld, the present application can design the upper inductor Lu-1, the upper inductor Lu-2, ..., and the upper inductor Lu-n in a stacked design, and also design the lower inductor Ld-1, the lower inductor Ld-2, ..., and the lower inductor Ld-n in a stacked design. In addition, the upper inductor Lu-1, the upper inductor Lu-2, ..., and the upper inductor Lu-n can also be designed in parallel stacking, or / and the lower inductor Ld-1, the lower inductor Ld-2, ..., and the lower inductor Ld-n can be designed in parallel stacking, that is, the present application arranges the n upper inductors Lu and the n lower inductors Ld in the space where the same upper inductor Lu and the lower inductor Ld are located, which can effectively reduce the circuit area of the high-frequency power supply, thereby effectively saving the design cost of the high-frequency power supply.
[0065] In summary, the present application provides n three-level bridge arm modules in parallel for use in small and medium power supplies in the buck topology circuit. Since the voltage resistance level of the three-level bridge arm module used in the small and medium power supply is much lower than the voltage resistance level of the switch tube in the existing Buck topology, this also means that the lower voltage resistance level can bring lower switching loss and conduction loss to the buck topology circuit, which not only avoids the use of bulky and costly switch tubes, but also significantly improves the switching frequency in the buck topology circuit; then, the present application electrically connects each three-level bridge arm module to a paired anti-coupling inductor module, and effectively reduces the inductance value of the anti-coupling inductor module based on the high switching frequency characteristic of the three-level bridge arm module. In addition, the present application adopts a reverse coupling inductor module to replace the large independent inductor with two low-cost small upper and lower inductors; then, the upper inductor electrically connected to the midpoint of the upper bridge arm is reversely coupled with the adjacent upper inductor by using the upper bridge arm unit, and the lower inductor electrically connected to the midpoint of the lower bridge arm is reversely coupled with the adjacent lower inductor by using the lower bridge arm unit, so that the winding directions of the upper inductor and the adjacent upper inductor, and the winding directions of the lower inductor and the adjacent lower inductor are opposite, thereby generating a reverse coupling effect. This reverse coupling makes the inductance values cancel each other out between adjacent inductors, significantly reducing the overall inductance value in the buck topology circuit, thereby effectively reducing the cost of the power supply system.
[0066] Further, in another embodiment of the buck topology circuit of the present application, the driving phase difference between the upper bridge arm unit 11 and the lower bridge arm unit 12 in the same three-level bridge arm module 10 is 180°;
[0067] When n>2, the driving phase shift between the upper bridge arm units in different three-level bridge arm modules is 180° / n;
[0068] When n=2, the driving phases between the upper bridge arm units in different three-level bridge arm modules are shifted by 90°.
[0069] In the embodiment, when n=2, that is, for a two-phase staggered cascaded buck topology circuit, the driving phase between the upper bridge arm unit 11 and the lower bridge arm unit 12 in the same three-level bridge arm module 10 is different by 180°, and the driving phase between the upper bridge arm units in different three-level bridge arm modules is shifted by 90°; when n>2, that is, for an N-phase staggered cascaded buck topology circuit, the present application makes a driving phase difference of 180° between the upper bridge arm unit 11 and the lower bridge arm unit 12 in the same three-level bridge arm module 10, and the driving phase between the upper bridge arm units 11 in different three-level bridge arm modules 10 is shifted by 180° / n. That is, the present application can realize current sharing control between different three-level bridge arm modules 10 through the above-mentioned phase-shift control strategy applied to the buck topology circuit, and prevent the flux saturation between the upper inductance Lu and the lower inductance Ld of the anti-coupling inductor through current sharing control. It can also realize that the inductor current frequency corresponding to the paired anti-coupling inductor module 20 is 2*fs*N. That is to say, since the bridge arm module designed in the present application is a three-level bridge arm module 10, the current frequency on the paired anti-coupling inductor module 20 is twice the same buck switching frequency under the prior art.
[0070] It should be noted that the inductor current frequency expression is: 2*fs*N, wherein fs is the switching frequency of the three-level bridge arm module 10 paired with the anti-coupled inductor module 20; N refers to n, that is, the total number of the three-level bridge arm modules 10.
[0071] Further, in some feasible embodiments, the buck topology circuit includes a busbar midpoint, and the upper bridge arm unit 11 includes a first switch tube Q1 and a first diode D1;
[0072] The collector of the first switch tube Q1 is electrically connected to a preset positive power supply terminal, the emitter of the first switch tube Q1 is electrically connected to the cathode of the first diode D1, and the anode of the first diode D1 is electrically connected to the busbar midpoint and the lower bridge arm unit 12 respectively.
[0073] Furthermore, in some other feasible embodiments, the lower bridge arm unit 12 includes a second switch tube Q2 and a second diode D2;
[0074] The collector of the second switch tube Q2 is electrically connected to the anode of the second diode D2, the cathode of the second diode D2 is electrically connected to the bus midpoint and the anode of the first diode respectively, and the emitter of the second switch tube Q2 is electrically connected to a preset negative power supply terminal.
[0075] In this embodiment, the first switch tube Q1 and the second switch tube Q2 may be power switch tubes of the same type, and the power switch tubes may be IGBTs or MOS tubes.
[0076] Further, in some feasible embodiments, the emitter of the first switch tube Q1 and the cathode of the first diode D1 are connected together to form the upper bridge arm midpoint of the upper bridge arm unit 11;
[0077] The collector of the second switch tube Q2 and the anode of the second diode D1 are connected together to form the lower bridge arm midpoint of the lower bridge arm unit.
[0078] In this embodiment, refer to Figure 7 , Figure 7 This is a schematic diagram of a multi-phase interleaved cascade three-level buck topology involved in an embodiment of the present application. When the number of upper bridge arm units 11 is n, the number of first switch tubes Q1 and first diodes D1 is also n respectively; when the number of lower bridge arm units 12 is n, the number of second switch tubes Q2 and second diodes D2 is also n respectively; wherein, n first switch tubes Q1 can be expressed by first switch tube Q1-1, first switch tube Q1-2, ..., and first switch tube Q1-n; n second switch tubes Q2 can be expressed by second switch tube Q2-1, second switch tube Q2-2, ..., and second switch tube Q2-n; n first diodes D1 can be expressed by first diode D1-1, first diode D1-2, ..., and first diode D1-n; n second diodes D2 can be expressed by second diode D2-1, second diode D2-2, ..., and second diode D2-n.
[0079] In another embodiment, referring to Figures 8 to 9 , Figure 8 Schematic diagram of another multi-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application. Fig. 9 Schematic diagram of another multi-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application. Figure 8 The anti-coupled inductor module 20 shown may only include n upper inductors Lu, Fig. 9 The anti-coupling inductor module 20 shown may only include n lower inductors Ld. That is, when the anti-coupling inductor module 20 only includes the upper inductor Lu or the lower inductor Ld, the corresponding waveforms and effects are the same.
[0080] In a specific embodiment, refer to Fig.10 , Fig.10Schematic diagram of a two-phase interleaved cascaded three-level buck topology involved in an embodiment of the present application. When the buck topology circuit designed in the present application is a two-phase interleaved cascaded three-level buck topology, there are two three-level bridge arm modules 10 in parallel, and each three-level bridge arm module 10 is electrically connected to a paired anti-coupling inductor module 20. Specifically, the upper bridge arm midpoints of the upper bridge arm units 11 in the two three-level bridge arm modules 10 are respectively electrically connected to the upper inductor Lu in the paired anti-coupling inductor module 20, and the lower bridge arm midpoints of the lower bridge arm units 12 in the two three-level bridge arm modules 10 are respectively electrically connected to the lower inductor Ld in the paired anti-coupling inductor module 20, and the windings between the two upper inductors Lu are reversely coupled, and the windings between the two lower inductors Ld are reversely coupled. In addition, in order to increase the frequency of the inductor output current, the present application will Fig.10 The first switch tube Q1-1 driving and the first switch tube Q1-2 driving phase difference is 180°, the second switch tube Q2-1 driving and the second switch tube Q2-2 driving phase difference is 180°, and the first switch tube Q1-1 driving and the second switch tube Q2-1 driving are out of phase by 90°. The waveforms of the upper inductance Lu and the lower inductance Ld under this configuration and the driving waveforms between the switches in the two three-level bridge arm modules 10 are as follows: Fig.11 As shown, Fig.10 This is a waveform diagram of the two-phase interleaved cascaded three-level buck topology. Fig.11 The waveform in the figure shows that the present application realizes the current sharing control between the two three-level bridge arm modules 10 through the above-mentioned phase shift control strategy, thereby effectively preventing the magnetic flux saturation between the upper inductor and the lower inductor of the anti-coupling inductor.
[0081] Further, in some feasible embodiments, referring to Figure 7-Figure 10 , the buck topology circuit further includes a power supply capacitor module 30, and the busbar midpoint is the capacitor midpoint of the power supply capacitor module 30;
[0082] The first end of the power supply capacitor module 30 is electrically connected to the upper bridge arm unit 11 in the different three-level bridge arm modules 10 and the positive power supply end;
[0083] The second end of the power supply capacitor module 30 is electrically connected to the lower bridge arm unit 12 in the different three-level bridge arm modules 10, and the negative power supply end;
[0084] The capacitor midpoint of the power supply capacitor module 30 is electrically connected to the midpoint of all bridge arms of each of the three-level bridge arm modules 10; wherein,
[0085] In the same three-level bridge arm module 10 , the anode of the first diode D1 in the upper bridge arm unit 11 and the cathode of the second diode D2 in the lower bridge arm unit 12 are connected together to form the full bridge arm midpoint of the three-level bridge arm module.
[0086] It should be noted that the power supply capacitor module 30 can be understood as the high voltage side.
[0087] Further, in some other feasible embodiments, referring to Figure 7-Figure 10 , the power supply capacitor module 30 includes a first capacitor unit 301, and a second capacitor unit 302 connected in series with the first capacitor unit 301; wherein,
[0088] The connection point of the first capacitor unit 301 and the second capacitor unit 302 in series is the capacitor midpoint of the power supply capacitor module 30;
[0089] The end of the first capacitor unit 301 that is not connected to the second capacitor unit 302 is the first end of the power supply capacitor module 30, which is electrically connected to the collector of the first switch tube Q1 in each of the upper bridge arm units 11 and the positive power supply end;
[0090] The second end of the power supply capacitor module 30 , which is one end of the second capacitor unit 302 not connected to the first capacitor unit 301 , is electrically connected to the emitter of the second switch tube Q2 in each lower bridge arm unit 12 and the negative power supply end.
[0091] Further, in some feasible embodiments, the first capacitor unit 301 includes M power capacitors connected in series, and the second capacitor unit 302 includes X power capacitors connected in series, wherein M and X are both natural numbers greater than 0, and M=X.
[0092] Furthermore, in some other feasible embodiments, the buck topology circuit further includes a DC capacitor module 40;
[0093] Each of the upper inductors Lu is electrically connected to the positive output terminal of the DC capacitor module 40 , and each of the lower inductors Ld is electrically connected to the negative output terminal of the DC capacitor module 40 .
[0094] It should be noted that the DC capacitor module 40 may include a third power supply capacitor C3.
[0095] In summary, the multi-phase three-level interleaved cascade and anti-coupled inductor application topology proposed in this application, as well as the phase-shift control strategy applied in the topology, can significantly improve the power density of high-power high-frequency power supplies, reduce the size of the power supply, and also reduce the system cost of the power supply.
[0096] In addition, the present application also provides a power supply, which also includes a rectifier module and a DC-DC converter electrically connected to the rectifier module, wherein the DC-DC converter at least includes the above-mentioned buck topology circuit.
[0097] It should be noted that the power supply of the present application can be understood as a high-frequency power supply, and the high-frequency power supply designed in the present application includes but is not limited to a high-power special power supply.
[0098] In another embodiment, the high frequency power supply further includes an ACDC module, and the ACDC module at least includes the above-mentioned rectifier module and a DC-DC converter.
[0099] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the technical concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.
Claims
1. A buck topology circuit, It is characterized in that The buck topology circuit comprises: n three-level bridge arm modules connected in parallel with each other, and an anti-coupling inductor module paired with each of the three-level bridge arm modules, where n is a natural number greater than 1; The three-level bridge arm module is electrically connected to a paired reverse coupling inductor module; The three-level bridge arm module is provided with an upper bridge arm unit and a lower bridge arm unit connected in series with the upper bridge arm unit; The reverse coupling inductor module includes an upper inductor and a lower inductor, wherein the upper inductor is electrically connected to the midpoint of the upper bridge arm of the upper bridge arm unit, and the lower inductor is electrically connected to the midpoint of the lower bridge arm of the lower bridge arm unit; wherein each of the upper bridge arm units respectively controls the corresponding upper inductor electrically connected to the midpoint of the upper bridge arm and the aggregate output after reverse coupling with the adjacent upper inductor as a positive output, and each of the lower bridge arm units respectively controls the corresponding lower inductor electrically connected to the midpoint of the lower bridge arm and the aggregate output after reverse coupling with the adjacent lower inductor as a negative output.
2. The buck topology circuit according to claim 1, It is characterized in that The driving phase difference between the upper bridge arm unit and the lower bridge arm unit in the same three-level bridge arm module is 180°; When n>2, the driving phase shift between the upper bridge arm units in different three-level bridge arm modules is 180° / n; When n=2, the driving phases between the upper bridge arm units in different three-level bridge arm modules are shifted by 90°.
3. The buck topology circuit according to claim 1, It is characterized in that The buck topology circuit includes a busbar midpoint, and the upper bridge arm unit includes a first switch tube and a first diode; The collector of the first switch tube is electrically connected to a preset positive power supply terminal, the emitter of the first switch tube is electrically connected to the cathode of the first diode, and the anode of the first diode is electrically connected to the busbar midpoint and the lower bridge arm unit respectively.
4. The buck topology circuit according to claim 3, It is characterized in that The lower bridge arm unit includes a second switch tube and a second diode; The collector of the second switch tube is electrically connected to the anode of the second diode, the cathode of the second diode is electrically connected to the midpoint of the busbar and the anode of the first diode respectively, and the emitter of the second switch tube is electrically connected to a preset negative power supply terminal.
5. The buck topology circuit according to claim 4, It is characterized in that The emitter of the first switch tube and the cathode of the first diode are connected together to form the upper bridge arm midpoint of the upper bridge arm unit; The collector of the second switch tube and the anode of the second diode are connected together to form the lower bridge arm midpoint of the lower bridge arm unit.
6. The buck topology circuit according to claim 4, It is characterized in that The buck topology circuit further includes a power supply capacitor module, and the busbar midpoint is the capacitor midpoint of the power supply capacitor module; The first end of the power supply capacitor module is electrically connected to the upper bridge arm unit in different three-level bridge arm modules and the positive power supply end; The second end of the power supply capacitor module is electrically connected to the lower bridge arm unit in different three-level bridge arm modules and the negative power supply end; The capacitor midpoint of the power supply capacitor module is electrically connected to the full bridge arm midpoint of each of the three-level bridge arm modules; wherein, In the same three-level bridge arm module, the anode of the first diode in the upper bridge arm unit and the cathode of the second diode in the lower bridge arm unit are connected together to form the full bridge arm midpoint of the three-level bridge arm module.
7. The buck topology circuit according to claim 6, It is characterized in that The power supply capacitor module includes a first capacitor unit and a second capacitor unit connected in series with the first capacitor unit; wherein, The connection point of the first capacitor unit and the second capacitor unit in series is the capacitor midpoint of the power supply capacitor module; One end of the first capacitor unit that is not connected to the second capacitor unit is the first end of the power supply capacitor module, which is electrically connected to the collector of the first switch tube in each of the upper bridge arm units and the positive power supply end; The end of the second capacitor unit that is not connected to the first capacitor unit is the second end of the power supply capacitor module, which is electrically connected to the emitter of the second switch tube in each lower bridge arm unit and the negative power supply end.
8. The buck topology circuit according to claim 7, It is characterized in that The first capacitor unit includes M power capacitors connected in series, and the second capacitor unit includes X power capacitors connected in series, wherein M and X are both natural numbers greater than 0, and M=X.
9. The buck topology circuit according to claim 1, It is characterized in that The buck topology circuit also includes a DC capacitor module; Each of the upper inductors is electrically connected to the positive output terminal of the DC capacitor module, and each of the lower inductors is electrically connected to the negative output terminal of the DC capacitor module.
10. A power source, It is characterized in that The power supply further includes a rectifier module and a DC-DC converter electrically connected to the rectifier module, wherein the DC-DC converter at least includes the buck topology circuit according to any one of claims 1-9.