Power conversion module

Abstract

The present disclosure is a power conversion module, comprising: an input port, comprising an input positive terminal and an input negative terminal; an output port; a full-bridge switching circuit, comprising: a first bridge arm; a second bridge arm; a magnetic assembly, comprising: a first pair of coupled windings, comprising a first winding and a second winding coupled to each other; a second pair of coupled windings, comprising a third winding and a fourth winding coupled to each other, wherein the first winding and the third winding are connected in series between the first bridge arm and the second bridge arm; an energy storage capacitor combination, partially electrically connected to the input port and electrically connected to the first winding and the third winding; and a rectification circuit, electrically connected to the second winding, the fourth winding and the output port.

Description

Technical Field

[0001] This disclosure relates to the field of power electronic equipment technology, and particularly to a power conversion module. Background Technology

[0002] With the advancement of technologies such as the Internet, cloud computing, electric vehicles, and industrial automation, electricity consumption is increasing, leading to a surge in power demand. This necessitates the development of power conversion devices towards higher power density and efficiency. To meet these demands, the current industry practice is to boost the 12V bus voltage within the power conversion device to 48V to reduce current loss and bus cost. However, to increase the bus voltage from 12V to 48V, a power conversion module must be added to the power conversion device to convert the 48V input voltage to a 12V output voltage for use by other loads.

[0003] In applications with an input voltage of 36V-75V (i.e., a rated voltage of 48V) and an output voltage of 12V or 5V, traditional power conversion modules mostly adopt a half-bridge circuit architecture. This means the power conversion module includes a half-bridge switching circuit, a transformer, and a synchronous rectification circuit. The half-bridge switching circuit includes an upper and lower switching transistor that form the bridge arm, while the synchronous rectification circuit includes two synchronous rectifier transistors. However, in traditional half-bridge circuit architecture power conversion modules, the upper and lower switching transistors are generally controlled to conduct complementaryly. Furthermore, to avoid shoot-through in the bridge arm, the maximum duty cycle of the main switching transistor (e.g., the upper switching transistor) must be less than 0.5. This results in problems such as a narrow voltage gain range, a small primary-to-secondary turns ratio in the transformer, a high effective value of the primary current, high stress on the secondary synchronous rectifier transistors, and low conversion efficiency.

[0004] Therefore, how to develop a power conversion module to solve the problems faced by existing technologies and achieve the goal of optimizing power conversion modules is an urgent issue that needs to be addressed in this field. Summary of the Invention

[0005] The purpose of this disclosure is to provide a power conversion module that solves the problems of narrow voltage gain variation range, small turns ratio of primary and secondary windings of transformer, high effective value of primary current, high stress of secondary synchronous rectifier tube and low conversion efficiency of traditional power conversion modules.

[0006] To achieve the aforementioned objectives, this disclosure provides a power conversion module, comprising: an input port including a positive input terminal and a negative input terminal; an output port including a positive output terminal and a negative output terminal; and a full-bridge switching circuit including: a first power switch including a first terminal and a second terminal, the first terminal being electrically connected to the positive input terminal; a second power switch including a first terminal and a second terminal, the first terminal of the second power switch being electrically connected to the second terminal of the first power switch to form a first midpoint, and the second terminal of the second power switch being electrically connected to the negative input terminal; a third power switch including a first terminal and a second terminal, the first terminal of the third power switch being electrically connected to the positive input terminal; and a fourth power switch including a first terminal and a second terminal, the first terminal of the fourth power switch being electrically connected to the second terminal of the third power switch to form a second midpoint. The system includes: a point where the second terminal of the fourth power switch is electrically connected to the negative input terminal; a magnetic component comprising: a first pair of coupled windings, including a first winding and a second winding coupled to each other; a second pair of coupled windings, including a third winding and a fourth winding coupled to each other, wherein the first winding and the third winding are connected in series between a first midpoint and a second midpoint; an energy storage capacitor assembly, a portion of which is electrically connected to the input port and electrically connected to the first winding and the third winding; and a rectifier circuit electrically connected to the second winding, the fourth winding, and the output port, and including an output capacitor assembly electrically connected between the positive output terminal and the negative output terminal; a first rectifier device, and at least a portion of the second winding and the output capacitor assembly forming a first circuit; and a second rectifier device, and at least a portion of the fourth winding and the output capacitor assembly forming a second circuit. Attached Figure Description

[0007] Figure 1A This is a circuit diagram of the power conversion module according to the first preferred embodiment of this disclosure;

[0008] Figure 1B This is a circuit diagram of the power conversion module according to the second preferred embodiment of this disclosure;

[0009] Figure 1C This is a circuit diagram of the power conversion module according to the third preferred embodiment of this disclosure;

[0010] Figure 2 for Figure 1A The equivalent circuit diagram of the power conversion module shown is shown.

[0011] Figure 3A for Figure 1A A schematic diagram of the magnetic component of the power conversion module shown;

[0012] Figure 3B for Figure 1A A schematic diagram of another preferred embodiment of the magnetic component of the power conversion module shown;

[0013] Figures 4A-4D for Figure 1A The diagram shows the four operating states of the power conversion module.

[0014] Figure 5A for Figure 1A The voltage waveform diagram of the power conversion module is shown below;

[0015] Figure 5B for Figure 1A The diagram shows the current waveform of the power conversion module.

[0016] Figure 6 This is a circuit diagram of the power conversion module according to the fourth preferred embodiment of this disclosure;

[0017] Figure 7 for Figure 1A The power conversion module shown or Figure 6 The diagram shown illustrates the operation of the first to fourth power switches, the first rectifier, and the second rectifier when the power conversion module is started.

[0018] Figure 8A This is a circuit diagram of the power conversion module according to the fifth preferred embodiment of this disclosure;

[0019] Figure 8B This is a circuit diagram of the power conversion module according to the sixth preferred embodiment of this disclosure;

[0020] Figure 8C This is a circuit diagram of the power conversion module according to the seventh preferred embodiment of this disclosure;

[0021] Figure 9 This is a circuit diagram of the power conversion module according to the eighth preferred embodiment of this disclosure;

[0022] Figure 10 This is a circuit diagram of the power conversion module according to the ninth preferred embodiment of this disclosure;

[0023] Figure 11 Power supply for driving Figure 10 The circuit diagram shown is a schematic diagram of the power supply circuit for the floating ground drive circuit of the first rectifier device of the power conversion module.

[0024] Figure 12 This is a circuit diagram of the power conversion module according to the tenth preferred embodiment of this disclosure. Detailed Implementation

[0025] Some typical embodiments embodying the features and advantages of this disclosure will be described in detail in the following description. It should be understood that this disclosure can be varied in different implementations without departing from the scope of this disclosure, and the descriptions and drawings therein are for illustrative purposes only and are not intended to limit this disclosure.

[0026] Figure 1A This is a circuit diagram of the power conversion module according to the first preferred embodiment of this disclosure. Figure 1B This is a circuit diagram of the power conversion module according to the second preferred embodiment of this disclosure. Figure 1C This is a circuit diagram of the power conversion module according to the third preferred embodiment of this disclosure. Figure 2 for Figure 1A The equivalent circuit diagram of the power conversion module shown is as follows. Figure 3A for Figure 1A The diagram shows a structural schematic of the magnetic component of a preferred embodiment of the power conversion module. Figure 3B for Figure 1A A schematic diagram of another preferred embodiment of the magnetic component of the power conversion module is shown. Figure 4A , Figure 4B , Figure 4C and Figure 4D for Figure 1A The diagram shows the four operating states of the power conversion module. Figure 5A for Figure 1A The diagram shows the voltage waveform of the power conversion module. Figure 5B for Figure 1A The diagram shows the current waveform of the power conversion module. In this embodiment, the power conversion module 1 includes an input port, an output port, a full-bridge switching circuit 2, a magnetic component, an energy storage capacitor assembly 4, and a rectifier circuit 5. The input port is used to receive the input voltage V. in It includes a positive input terminal 10 and a negative input terminal 11. The output port is used to provide the output voltage V. o It includes a positive output terminal 12 and a negative output terminal 13. In some embodiments, the input voltage V in The rated value can be, but is not limited to, 48V, and the output voltage V o The rated value can be, but is not limited to, 12V.

[0027] The full-bridge switching circuit 2 includes a first power switch Q1, a second power switch Q2, a third power switch Q3, and a fourth power switch Q4. The first terminal of the first power switch Q1 is electrically connected to the positive input terminal 10; the first terminal of the second power switch Q2 is electrically connected to the second terminal of the first power switch Q1, forming a first midpoint A; the second terminal of the second power switch Q2 is electrically connected to the negative input terminal 11; the first power switch Q1 and the second power switch Q2 constitute the first bridge arm of the full-bridge switching circuit 2. The first terminal of the third power switch Q3 is electrically connected to the positive input terminal 10; the first terminal of the fourth power switch Q4 is electrically connected to the second terminal of the third power switch Q3, forming a second midpoint C; the second terminal of the fourth power switch Q4 is electrically connected to the negative input terminal 11; the third power switch Q3 and the fourth power switch Q4 constitute the second bridge arm of the full-bridge switching circuit 2.

[0028] The magnetic component 3 includes a magnetic core 30, a first pair of coupled windings 36, and a second pair of coupled windings 37 (as shown in Figure 3). The first pair of coupled windings 36 and the second pair of coupled windings 37 may, but are not limited to, share the magnetic core 30 using magnetic integration technology. The first pair of coupled windings 36 includes mutually coupled first windings N. p1 and the second winding N s1 The second pair of coupled windings 37 includes a third winding N that is coupled to each other. p2 and the fourth winding N s2 And the first winding N p1 and the third winding N p2 Electrically coupled, second winding N s1 With the fourth winding N s2 Electrical coupling. Specifically, in Figure 1A In the embodiment, the first winding N p1 The first terminal is electrically connected to the first midpoint A, and the first winding N p1 The second end and the third winding N p2 The first terminal is electrically connected to connection point B, and the third winding N p2 The second end is electrically connected to the second midpoint C, therefore the first winding N p1 With the third winding N p2 It is connected in series between the first midpoint A and the second midpoint C. The second winding Ns1 and the fourth winding Ns1 are connected in series. s2 Each includes a first end and a second end, wherein the second winding N s1 The second terminal is electrically connected to the fourth winding N. s2 The first end makes the second winding N s2 With the fourth winding N s2 Together they form a central tap structure.

[0029] Furthermore, the energy storage capacitor assembly 4 is electrically connected to the input port, for example, electrically connected to the positive input terminal 10, the negative input terminal 11, or simultaneously electrically connected to both the positive input terminal 10 and the negative input terminal 11. Figure 1A In the illustrated embodiment, the energy storage capacitor assembly 4 is electrically connected to the negative input terminal 11. Furthermore, the energy storage capacitor assembly 4 is also electrically connected to the first winding N. p1 and the third winding N p2 In some embodiments, the energy storage capacitor assembly 4 includes at least one energy storage capacitor, wherein each energy storage capacitor may be composed of a single capacitor element or multiple capacitor elements connected in series, parallel or other ways.

[0030] like Figure 1A As shown in the embodiment, the energy storage capacitor assembly 4 includes an energy storage capacitor C1, wherein the first terminal of the energy storage capacitor C1 is electrically connected to the negative input terminal 11 of the input port, and the second terminal of the energy storage capacitor C1 is electrically connected to the first winding N. p1 and the third winding N p2Between, that is, electrically connected to connection point B. Figure 1B As shown in the embodiment, the energy storage capacitor assembly 4 includes an energy storage capacitor C2, wherein the first terminal of the energy storage capacitor C2 is electrically connected to the positive input terminal 10 of the input port, and the second terminal of the energy storage capacitor C2 is electrically connected to the first winding N. p1 and the third winding N p2 Between, that is, electrically connected to connection point B. Figure 1C As shown in the embodiment, the energy storage capacitor assembly 4 includes energy storage capacitor C1 and energy storage capacitor C2, wherein the first terminal of energy storage capacitor C1 is electrically connected to the negative input terminal 11 of the input port, and the second terminal of energy storage capacitor C1 is electrically connected to the first winding N. p1 and the third winding N p2 Between, that is, electrically connected to connection point B; the first end of the energy storage capacitor C2 is electrically connected to the positive input terminal 10 of the input port, and the second end of the energy storage capacitor C2 is electrically connected to the first winding N. p1 and the third winding N p2 Between, that is, electrically connected to connection point B. In addition, any capacitor mentioned in the following content can be similar to the aforementioned energy storage capacitor C1, consisting of a single capacitor element or multiple capacitor elements connected in series, parallel or other ways, so it will not be specifically described thereafter.

[0031] Rectifier circuit 5 and second winding N s1 Fourth winding N s2 The rectifier circuit 5 is electrically connected to the output port, and in this embodiment, the rectifier circuit 5 includes an output capacitor assembly 50, a first rectifier device Q5, and a second rectifier device Q6, and is connected to the second winding N. s1 Fourth winding N s2 Together, they form the full-wave rectifier circuit architecture. The first rectifier device Q5 and the second rectifier device Q6 can be, but are not limited to, as shown below. Figure 1A The power switch shown has a first rectifier Q5 and a second winding N. s1 The output capacitor combination 50 and at least a portion thereof form the first circuit, the second rectifier Q6 and the fourth winding N s2 At least a portion of the output capacitor assembly 50 forms a second circuit. Furthermore, the output capacitor assembly 50 is electrically connected between the positive output terminal 12 and the negative output terminal 13, and includes at least one output capacitor C. o The first terminal of the first rectifier Q5 is electrically connected to the second winding N. s1 The first terminal, the second terminal of the first rectifier Q5, and the output capacitor C o The second terminal and the negative output terminal 13 are electrically connected, and the output capacitor C is connected. o The first end and the first winding N s1 The second end and the second winding N s2 The first terminal is electrically connected, therefore the first rectifier device Q5 and the second winding N are connected. s1and output capacitor C o This can form a first circuit, while the first terminal of the second rectifier Q6 is electrically connected to the fourth winding N. s2 The second terminal of the second rectifier Q6 is connected to the output capacitor C. o The second terminal and the negative output terminal 13 are electrically connected, therefore the second rectifier Q6 and the fourth winding N are connected. s2 and output capacitor C o A second circuit can be formed. Of course, since the first rectifier Q5 and the second rectifier Q6 are composed of power switches, they can be controlled in a synchronous rectification manner. However, in other embodiments, the first rectifier Q5 and the second rectifier Q6 can also be composed of diodes respectively.

[0032] In some embodiments, the power conversion module 1 may further include an input capacitor C. in It is electrically connected between the positive input terminal 10 and the negative input terminal 11. As can be seen from the above, compared to traditional power conversion modules, the power conversion module 1 of this disclosure has a full-bridge switching circuit 2, a first pair of coupling windings 36 and a second pair of coupling windings 37, and an energy storage capacitor assembly 4, with the energy storage capacitor assembly 4 electrically connected to the first winding N. p1 and the third winding N p2 The connection point B between the two terminals and the negative input terminal 11 allows the maximum duty cycle of the power conversion module 1 disclosed herein to be preset through such a circuit topology design, for example, by adjusting the first winding N. p1 and the second winding N s1 The turns ratio between or the third winding N p2 and the fourth winding N s2 The maximum duty cycle of the power conversion module 1 of this disclosure is preset by the turns ratio, so that the maximum duty cycle of the power conversion module of this disclosure can be extended to greater than 0.5, or even close to equal to 1. In this way, the power conversion module 1 of this disclosure can achieve a wide voltage gain variation range and the first winding N p1 and the second winding N s1 Or the third winding N p2 and the fourth winding N s2 Large turns ratio, first winding N p1 Or the third winding N p2 The technology achieves the following effects: low effective current value, lower voltage requirements for the first rectifier Q5 and the second rectifier Q6 in the rectifier circuit 5, and higher conversion efficiency of the power conversion module 1.

[0033] In some embodiments, such as Figures 1A-1C As shown, the first winding N p1 First end and second winding N s1 The first terminal is the same name terminal, and the third winding N p2The first end and the fourth winding N s2 The first end is the same-name end. Furthermore, the first winding N... p1 With the second winding N s1 It can form the primary and secondary windings of a transformer, and the third winding N p2 With the fourth winding N s2 This can form the primary and secondary windings of another transformer. Therefore, based on the first winding N... p1 With the second winding N s1 (or the third winding N) p2 With the fourth winding N s2 Based on the circuit connection relationship, the power conversion module 1 can be divided into the primary side (first winding N). p1 Third winding N p2 The location of the secondary winding (N) and the secondary winding (second winding N) s1 (The location of the fourth winding Ns2).

[0034] In addition, such as Figure 3A , Figure 3B As shown, the magnetic core 30 includes a center post 31 and two side posts (e.g., a first side post 32 and a second side post 33), wherein the air gap of the center post 31 is larger than the air gap of either side post 32 / 33. Furthermore, the first winding N... p1 Second winding N s1 Together they are wound around the first side post 32 (e.g.) Figure 3A As shown, the first winding N p1 Second winding N s1 Wrapped around the two opposing pillars of the first side pillar 32, or as Figure 3B As shown, the first winding N p1 Second winding N s1 Both are wound on the same column of the first side post 32), and the third winding N p2 and the fourth winding N s2 Together they are wound around the second side post 33 (e.g.) Figure 3A As shown, the third winding N p2 and the fourth winding N s2 On the two opposing columns of the second side column 33, or as Figure 3B As shown, the third winding N p2 and the fourth winding N s2 Both are wound on the same column of the second side post 33), and the second winding N s1 and the fourth winding N s2The winding direction causes the DC magnetic flux generated on the two side posts 32 / 33 to be superimposed in the same direction on the middle post 31, while the AC magnetic flux is subtracted on the middle post 31. Furthermore, regarding the construction of the magnetic core 30, the material of the middle post 31 can differ from the rest of the magnetic core 30. For example, the material of the middle post 31 can be iron powder, while the material of the rest of the magnetic core 30 can be ferrite. This results in low core loss for the magnetic core 30, while the core loss of the middle post 31 does not increase significantly. In some embodiments, the cross-sectional area of ​​the middle post 31 can, for example, be equal to the cross-sectional area of ​​the side posts 32 / 33.

[0035] Figure 2 for Figure 1A The equivalent circuit diagram of the power conversion module is shown in the figure. The power conversion module 1 may include an equivalent magnetizing inductance L. m1 L m2 With equivalent leakage inductance L r1 L r2 Equivalent magnetizing inductance L m1 It can be the magnetizing inductance of the first pair of coupled windings 36 itself, and is equivalent to the magnetizing inductance of the first winding N. p1 Parallel connection. Equivalent magnetizing inductance L m2 It can be the magnetizing inductance of the second pair of coupled windings 37 itself, and is equivalent to that of the third winding N. p2 Parallel connection. Equivalent leakage inductance L r1 The leakage inductance can be the leakage inductance of the first pair of coupled windings 36 itself, and the equivalent leakage inductance L r1 Equivalent to the first winding N p1 A series connection is established between connection point A and connection point B. The equivalent leakage inductance L r2 It can be the leakage inductance of the second pair of coupled windings 37 itself, and the equivalent leakage inductance L r2 Equivalent to the third winding N p2 A series connection is made between connection point B and connection point C.

[0036] In some embodiments, the first winding N p1 With the second winding N s1 The turns ratio can be N, or the third winding N. p2 With the fourth winding N s2 The turns ratio can be N, where N is a positive number less than one hundred.

[0037] The following will explain further. Figure 1A The circuit operation mode of the power conversion module 1 shown is as follows, in which... Figures 4A to 4DIn the diagram, solid lines indicate current flow paths, while dashed lines indicate no current flow. Furthermore, since the energy storage capacitor assembly 4 can be electrically connected to the positive input terminal 10, the negative input terminal 11, or both simultaneously, resulting in different implementations, although the circuit operation is similar, to ensure that the following operational descriptions cover implementations corresponding to different connection relationships of the energy storage capacitor assembly 4, when the energy storage capacitor assembly 4 is electrically connected to the negative input terminal 11, the first power switch Q1 and the third power switch Q3 are defined as main power switches; when the energy storage capacitor assembly 4 is electrically connected to the positive input terminal 10, the second power switch Q2 and the fourth power switch Q4 are defined as main power switches. Please refer to [further details omitted]. Figure 5A and Figure 5B and cooperate Figure 1A and Figures 4A to 4D In the power conversion module 1 of this embodiment, the first power switch Q1 and the second power switch Q2 are complementaryly turned on, the third power switch Q3 and the fourth power switch Q4 are complementaryly turned on, and the first power switch Q1 and the third power switch Q3 are turned on 180 degrees out of phase, as are the second power switch Q2 and the fourth power switch Q4. Furthermore, the first rectifier Q5 and the second power switch Q2 are turned on and off synchronously, and the second rectifier Q6 and the fourth power switch Q4 are turned on and off synchronously. Therefore, within one switching cycle, the power conversion module 1 can be divided into the following... Figures 4A to 4D The four operating modes are shown. Figures 5A-5B During the time interval T0-T1 shown, power conversion module 1 enters the following state: Figure 4A In the first operating mode shown, the first power switch Q1 and the third power switch Q3 are turned on, while the second power switch Q2, the fourth power switch Q4, the first rectifier Q5, and the second rectifier Q6 are turned off. If the equivalent leakage inductance L is ignored... r1 The voltage drop across the equivalent magnetizing inductance L m1 Terminal voltage V at both ends AB Equal to input voltage V in Subtract the capacitor voltage V of the energy storage capacitor C1 c1 V AB =V in -V c1 Within this range, and due to the equivalent magnetizing inductance L m1 With equivalent leakage inductance L r1 Series connection, therefore the excitation current i Lm1 Equal to leakage inductance current i Lr1 And it gradually increases, similarly, due to the equivalent magnetizing inductance L m2 With equivalent leakage inductance L r2 Series connection, therefore the excitation current i Lm2 Equal to leakage inductance current i Lr2 And it gradually increases.

[0038] In such Figures 5A-5B During the time interval T2-T3 shown, power conversion module 1 enters as follows: Figure 4B The second operating mode is shown, in which the first power switch Q1, the fourth power switch Q4, and the second rectifier Q6 are turned on, while the second power switch Q2, the third power switch Q3, and the first rectifier Q5 are turned off, and the equivalent magnetizing inductance L... m2 Output voltage V o Clamping, equivalent magnetizing inductance L m2 Terminal voltage V at both ends CB Equal to the capacitor voltage V of the energy storage capacitor C1 c1 Therefore, the capacitor voltage V of the energy storage capacitor C1 c1 Equal to N times the output voltage V o V c1 =N*V o That is, the average voltage V across the energy storage capacitor C1 c1 Combined with the output capacitor C o The ratio of the average voltages is a fixed value N. In addition, the output capacitor C... o The signal is refracted to the primary side of power conversion module 1, i.e., refracted to the third winding N. p2 The position, and its equivalent capacitance is C. o / N 2 And connected in series with the energy storage capacitor C1 and then with the equivalent leakage inductance L r2 The resonance generates an oscillating current and transfers energy to the secondary side of power conversion module 1. Its resonant frequency fr can be expressed as:

[0039]

[0040] Among them, L r2 For equivalent leakage inductance L r2 The inductance value of C1, and the capacitance value of the energy storage capacitor C1. o For the output capacitor C o The capacitance value. And from Figure 5B From the current waveform, it can be seen that in order to prevent the reverse recovery loss caused by the freewheeling current of the body diode of the fourth power switch Q4 after it is turned off, (1-D) / fsw can be controlled to be less than 0.5 / fr, so that the power conversion module 1 operates in over-resonance mode. This ensures that the current of the fourth power switch Q4 is positive when it is turned off (i.e., the current flows from the drain of the fourth power switch Q4 to the source in a positive direction), preventing the freewheeling current of the body diode of the fourth power switch Q4. Here, fsw is the switching frequency of the power switch of the full-bridge switching circuit 2, and D is the duty cycle of the main power switch, corresponding to... Figure 1A This refers to the duty cycle of the first power switch Q1 and the third power switch Q3.

[0041] In such Figures 5A-5BDuring the time interval T4-T5 shown, power conversion module 1 enters as follows: Figure 4C The third operating mode is shown, in which the first power switch Q1 and the third power switch Q3 are turned on, while the second power switch Q2, the fourth power switch Q4, the first rectifier Q5, and the second rectifier Q6 are turned off, and the magnetizing current i Lm1 With excitation current i Lm2 Increase.

[0042] In such Figures 5A-5B During the time interval T6-T7 shown, power conversion module 1 enters as follows: Figure 4D The fourth operating mode is shown, in which the second power switch Q2, the third power switch Q3, and the first rectifier Q5 are turned on, while the first power switch Q1, the fourth power switch Q4, and the second rectifier Q6 are turned off, and the equivalent magnetizing inductance L... m1 Output voltage V o Clamping, equivalent magnetizing inductance L m1 The terminal voltage V at both ends AB Equal to the capacitor voltage V of the energy storage capacitor C1 c1 It is also equal to N times the output voltage V. o And the output capacitor C o The signal is refracted to the primary side of power conversion module 1, that is, refracted to the first winding N. p1 The location, and its equivalent capacitance value is Co / N. 2 And it is connected in series with the energy storage capacitor C1 and then with the equivalent leakage inductance L. r1 The resonance generates an oscillating current and transfers energy to the secondary side of power conversion module 1. Similarly, by controlling power conversion module 1 in the over-resonance state, it is ensured that the current of the second power switch Q2 is positive when it is turned off (i.e., the current flows from the drain of the second power switch Q2 to the source in a positive direction), preventing reverse recovery losses caused by the freewheeling current of the body diode.

[0043] Thus, from the first operating mode to the fourth operating mode, power conversion module 1 has completed one complete switching cycle. During this period, the volt-second balance of the equivalent magnetizing inductance Lm1 can be obtained as follows:

[0044] (V in -V c1 )·D=V c1 ·(1-D) (2)

[0045] And the voltage V across the energy storage capacitor C1 c1 Equal to N times the output voltage V o Therefore, substituting into equation (2) yields the input voltage V. in With output voltage V o The relation is:

[0046]

[0047] Therefore, in the actual operation of power conversion module 1, as the input voltage V... in The power conversion module 1 will adjust the duty cycle D through closed-loop control to achieve the output voltage V in response to changes in voltage. o The voltage is stabilized. In addition, during the change of duty cycle D, the switching frequency fsw can be adjusted synchronously with the duty cycle D to control (1-D) / fsw to be less than 0.5 / fr, so that the power conversion module 1 operates in over-resonance mode to prevent reverse recovery loss caused by the freewheeling current of the body diode of the second power switch Q2 or the fourth power switch Q4.

[0048] like Figure 1A As shown, the first terminal of the energy storage capacitor C1 is electrically connected to the negative input terminal 11 of the input port, and the second terminal of the energy storage capacitor C1 is electrically connected to the first winding N. p1 and the third winding N p2 Between, that is, electrically connected to connection point B, the capacitor voltage V of the energy storage capacitor C1. c1 Equal to N times the output voltage V o V c1 =N*V o That is, the average voltage V of the energy storage capacitor C1 c1 Combined with the output capacitor C o The ratio of the average voltages is a fixed value N. For example... Figure 1B As shown, the first terminal of the energy storage capacitor C2 is electrically connected to the positive input terminal 10 of the input port, and the second terminal of the energy storage capacitor C2 is electrically connected to the first winding N. p1 and the third winding N p2 Between, that is, electrically connected to connection point B, the capacitor voltage V of the energy storage capacitor C2. c2 =V in -N*V o And because Therefore, the average voltage V of the energy storage capacitor C2 c2 Combined with the output capacitor C o The ratio of the average voltages is a fixed value. like Figure 1C As shown, this embodiment of the energy storage capacitor assembly includes energy storage capacitor C1 and energy storage capacitor C2. (See also...) Figure 1A and Figure 1B There is a ratio between the average voltage of each energy storage capacitor and the average voltage of the output capacitor combination, and this ratio is a fixed value.

[0049] In addition, by Figure 5B As shown, the conduction current i flowing through the first rectifier Q5 is... s1 and the on-current i flowing through the second rectifier Q6 s2These can be, but are not limited to, sinusoidal current or partial sinusoidal current.

[0050] As can be seen from the above, compared with the traditional power conversion module using a half-bridge circuit architecture, the power conversion module 1 in this embodiment includes a full-bridge switching circuit 2. Furthermore, compared with the control method where the upper and lower switching transistors of the half-bridge switching circuit in the traditional power conversion module are complementary, the first power switch Q1 and the second power switch Q2 of the full-bridge switching circuit 2 in this embodiment are complementary, as are the third power switch Q3 and the fourth power switch Q4. Moreover, in this embodiment, the energy storage capacitor assembly 4 of the power conversion module 1 is electrically connected to the first winding N. p1 and the third winding N p2 The connection point B between the two terminals is connected to the negative input terminal 11. In this way, the duty cycle of the primary-side switch of the power conversion module 1 disclosed herein can be as close to 1 as possible, resulting in a wider voltage gain range; and the first winding N... p1 and the second winding N s1 Or the third winding N p2 and the fourth winding N s2 The large turns ratio makes the first winding N p1 Or the third winding N p2 The effective value of the primary current is reduced, the loss of the primary switch and the winding loss are reduced, and the stress of the first rectifier device Q5 and the second rectifier device Q6 of the rectifier circuit 5 is lower, and the secondary loss is also reduced, resulting in higher conversion efficiency of the power conversion module 1.

[0051] In some embodiments, by designing the resonant parameters, the current of the first rectifier Q5 or the second rectifier Q6 can be greater than 0 when the first rectifier Q5 or the second rectifier Q6 is turned off.

[0052] Figure 6 This is a circuit diagram of a power conversion module according to a fourth preferred embodiment of the present disclosure. As shown in the figure, the power conversion module 6a of this embodiment is compared to... Figure 1A The power conversion module 1a shown also includes a control unit 6. The control unit 6 outputs six drive signals to control the operation of the first power switch Q1, the second power switch Q2, the third power switch Q3, the fourth power switch Q4, the first rectifier Q5, and the second rectifier Q6, respectively. When the energy storage capacitor assembly 4 is electrically connected to the negative input terminal 11, the drive signal received by the first rectifier Q5 from the control unit 6 is the same as the drive signal received by the second power switch Q2 from the control unit 6 in steady state, and the drive signal received by the second rectifier Q6 from the control unit 6 is the same as the drive signal received by the fourth power switch Q4 from the control unit 6 in steady state.

[0053] exist Figure 1BIn the illustrated embodiment, if the energy storage capacitor assembly 4 is electrically connected to the positive input terminal 10, the drive signal received by the first rectifier Q5 from the control unit 6 is changed to be the same as the drive signal received by the first power switch Q1 from the control unit 6 in the steady state, and the drive signal received by the second rectifier Q6 from the control unit 6 is changed to be the same as the drive signal received by the third power switch Q3 from the control unit 6 in the steady state.

[0054] Even worse, because Figures 1A-1C The power conversion module shown includes a rectifier circuit 5 and a second winding N. s1 Fourth winding N s2 Together they form a full-wave rectifier circuit architecture, which may result in a second winding N. s1 and the fourth winding N s2 The risk of uneven current distribution in the windings makes the second winding N... s1 and the fourth winding N s2 The DC current error will generate a non-zero DC magnetic voltage on the magnetic circuit formed by the first side post 32 and the second side post 33 of the magnetic core 30. The non-zero DC magnetic voltage will cause the DC magnetic flux density on the first side post 32 and the second side post 33 to increase or decrease significantly, thereby bringing the risk of magnetic flux saturation of the side posts 32 / 33. In order to solve the aforementioned shortcomings that may be caused by the full-wave rectifier circuit architecture on the secondary side of the power conversion module, Figure 6 The power conversion module 6a shown also includes a current detection circuit 7, which is electrically connected to the main power switch, for example... Figure 6 In this circuit, the current detection circuit 7 is electrically connected to the first power switch Q1 and the third power switch Q3, which serve as the main power switches, to sample the current flowing through the first power switch Q1 and the current flowing through the third power switch Q3, respectively, and transmits the sampling results to the control unit 6. The control unit 6 further filters the sampling results from the current detection circuit 7 to obtain the DC components of the current flowing through the first power switch Q1 and the third power switch Q3. It then integrates the difference between the DC components of the current flowing through the first power switch Q1 and the third power switch Q3 (i.e., the DC component of the current flowing through the first power switch Q1 minus the DC component of the current flowing through the third power switch Q3), and adjusts the drive signals transmitted to the first power switch Q1 and the third power switch Q3 based on the integration result. By adjusting the duty cycle of these two drive signals, the first winding N of the power conversion module 6a is controlled. p1 The equivalent DC current and the third winding N p2 The equivalent DC current on the winding is in a current-sharing state, which reduces the amount of current in the second winding N. s1 and the fourth winding N s2 To reduce DC current error and prevent saturation of the side posts 32 / 33 of the magnetic core 30.

[0055] Figure 7 for Figure 1A The power conversion module shown or Figure 6 The diagram shown illustrates the operation of the first to fourth power switches, the first rectifier, and the second rectifier when the power conversion module is subjected to pre-bias startup. Figure 1A The power conversion module 1a shown or Figure 6 The power conversion module 6a shown starts up facing pre-bias, that is, before power conversion module 1a or power conversion module 6a starts up, the output capacitor C o If a preset voltage already exists, and the first rectifier Q5 uses the same duty cycle as the second power switch Q2, or the second rectifier Q6 uses the same duty cycle as the fourth power switch Q4, then the output capacitance C of the output capacitor combination 50 will be affected. o The instantaneous charging of energy storage capacitor C1 in energy storage capacitor assembly 4 causes a large inrush current in power conversion module 1 or power conversion module 1a. Therefore, to avoid the output capacitor C... o The instantaneous inrush current to the energy storage capacitor C1, in some embodiments, such as Figure 7 As shown, during the initial startup phase of power conversion module 1a or power conversion module 6a, for example, the capacitor voltage V of energy storage capacitor C1... c1 Less than a voltage threshold V th At this time, the two power switches on the same switching arm of the primary side of power conversion module 1 or power conversion module 1a are complementaryly turned on (i.e., the first power switch Q1 and the second power switch Q2 are complementaryly turned on, and the third power switch Q3 and the fourth power switch Q4 are complementaryly turned on). The first power switch Q1 and the third power switch Q3, which are the main power switches, are first turned on with a small duty cycle, alternating by 180°. As for the first rectifier Q5 and the second rectifier Q6 of power conversion module 1a or power conversion module 6a, they are temporarily turned off (e.g., ...). Figure 7 As shown in (a)). At this time, since the two power switches on the same bridge arm are complementary and conducting, it is equivalent to the synchronous rectification mode of the buck circuit. Therefore, the voltage V on the energy storage capacitor C1 is V. C1 It can be directly expressed as

[0056] V c1 =DV in (3)

[0057] As the duty cycles of the main power switches, namely the first power switch Q1 and the third power switch Q3, gradually expand (e.g. Figure 7 As shown in (b) of the diagram, the voltage V across the energy storage capacitor C1 is... C1 Gradually increase. When the capacitor voltage V C1 Reaching the voltage threshold Vth When the time is right, the first rectifier Q5 and the second rectifier Q6 are controlled to start synchronous rectification operation (e.g., Figure 7 As shown in (c), the first rectifier Q5 and the second power switch Q2 are turned on and off synchronously, and the second rectifier Q6 and the fourth power switch Q4 are turned on and off synchronously. The voltage threshold V... th Based on N times the output voltage V o With a voltage error value V Δ Determine, for example, V th =NV o +V Δ In this way, the output capacitor C can be effectively avoided. o The instantaneous inrush current affects the energy storage capacitor C1. Furthermore, since the primary side of power conversion module 1a or power conversion module 6a is always in synchronous rectification mode, the voltage across the energy storage capacitor C1 can be directly calculated. Therefore, it is not necessary to additionally detect the terminal voltages of the first rectifier Q5 and the second rectifier Q6; only the output voltage V needs to be calculated. o The sample is fed into, for example, control unit 6 and the input voltage V. in By comparing the product of the first rectifier Q5 and the second rectifier Q6 with the duty cycle D of the main power switch, the starting control of the first rectifier Q5 and the second rectifier Q6 can be realized, which greatly simplifies the sampling circuit.

[0058] Of course, in Figure 1B In the embodiment shown, with the energy storage capacitor assembly 4 electrically connected to the positive input terminal 10, in order to avoid the output capacitor C... o The instantaneous surge current to the energy storage capacitor C2 causes a surge in the initial startup phase of the power conversion module 1b, for example, the capacitor voltage V of the energy storage capacitor C2. c2 Less than the voltage threshold V th At this time, the two power switches on the same switching arm of the primary side of the power conversion module 1b are complementaryly turned on (i.e., the first power switch Q1 and the second power switch Q2 are complementaryly turned on, and the third power switch Q3 and the fourth power switch Q4 are complementaryly turned on). The second power switch Q2 and the fourth power switch Q4, which are the main power switches, are initially turned on with a small duty cycle, alternating by 180°. Meanwhile, the first rectifier Q5 and the second rectifier Q6 on the secondary side of the power conversion module 1b are temporarily turned off. As the duty cycle of the main power switches, i.e., the second power switch Q2 and the fourth power switch Q4, gradually increases, the voltage V on the energy storage capacitor C2... C2 Gradually increase. When the capacitor voltage V C2 Reaching the voltage threshold V thThen, the first rectifier Q5 and the second rectifier Q6 are controlled to start synchronous rectification operation, that is, the first rectifier Q5 is synchronously turned on and off with the first power switch Q1, and the second rectifier Q6 is synchronously turned on and off with the third power switch Q3. In this way, the output capacitor C can be effectively avoided. o The instantaneous surge current to the energy storage capacitor C2.

[0059] Figure 8A This is a circuit diagram of the power conversion module according to the fifth preferred embodiment of this disclosure. The power conversion module 8a of this embodiment and... Figure 1A The difference between the power conversion module 1a shown is that the energy storage capacitor combination 4 of the power conversion module 8a is changed to include the first energy storage capacitor C. 1a and the second energy storage capacitor C 1b The first energy storage capacitor C 1a The first terminal is electrically connected to the first winding N p1 The second terminal, the first energy storage capacitor C 1a The second terminal is electrically connected to the negative input terminal 11, and the second energy storage capacitor C 1b The first terminal is electrically connected to the third winding N. p2 The first terminal, the second energy storage capacitor C 1b The second terminal is electrically connected to the negative input terminal 11. Since the operation and technical effects of the power conversion module 8a in this embodiment are similar to those of... Figure 1A The operation of the power conversion module 1a shown and the operations it can perform are not described in detail here. Figure 8B This is a circuit diagram of the power conversion module according to the sixth preferred embodiment of the present disclosure. As shown in the figure, the energy storage capacitor assembly 4 may include a third energy storage capacitor C. 2a and the fourth energy storage capacitor C 2b The third energy storage capacitor C 2a The first terminal is electrically connected to the first winding N p1 The second terminal, the third energy storage capacitor C 2a The second terminal is electrically connected to the positive input terminal 10, and the fourth energy storage capacitor C 2b The first terminal is electrically connected to the third winding N. p2 The first terminal, the fourth energy storage capacitor C 2b The second terminal is electrically connected to the positive input terminal 10. Figure 8C This is a circuit diagram of the power conversion module according to the seventh preferred embodiment of this disclosure. As shown in the figure, the energy storage capacitor assembly 4 may include a first energy storage capacitor C. 1a and the second energy storage capacitor C 1b The first energy storage capacitor C 1a The first terminal is electrically connected to the first winding N p1 The second terminal, the first energy storage capacitor C 1aThe second terminal is electrically connected to the negative input terminal 11, and the second energy storage capacitor C 1b The first terminal is electrically connected to the third winding N. p2 The first terminal, the second energy storage capacitor C 1b The second terminal is electrically connected to the negative input terminal 11; the third energy storage capacitor C 2a and the fourth energy storage capacitor C 2b The third energy storage capacitor C 2a The first terminal is electrically connected to the first winding N p1 The second terminal, the third energy storage capacitor C 2a The second terminal is electrically connected to the positive input terminal 10, and the fourth energy storage capacitor C 2b The first terminal is electrically connected to the third winding N. p2 The first terminal, the fourth energy storage capacitor C 2b The second terminal is electrically connected to the positive input terminal 10.

[0060] Additionally, in some embodiments, the energy storage capacitor assembly 4 may also include an isolation capacitor C. b Among them, the isolation capacitor C b The first end and the first winding N p1 The second terminal and the first energy storage capacitor C 1a The first terminal is electrically connected to the isolation capacitor C. b The second end and the third winding N p2 The first terminal and the second energy storage capacitor C 1b The first terminal is electrically connected, where the isolation capacitor C b Its function is to equalize the current, so that the current flowing through the first winding N p1 and flowing through the third winding N p2 The DC current error is 0, so no additional DC magnetic flux density is generated on the two side posts of the magnetic core, thus avoiding saturation of the two side posts of the magnetic core.

[0061] Figure 9 This is a circuit diagram of the power conversion module according to the eighth preferred embodiment of this disclosure. The power conversion module 9a of this embodiment and... Figure 8A The power conversion module 8a shown differs from the power conversion module 9a in that the magnetic component 3 is replaced with multiple magnetic cores T1 and T2, and the first pair of coupling windings 36 and the second pair of coupling windings 37 do not use magnetic integration technology, but are instead wound on their respective magnetic cores, i.e., the first winding N of the first pair of coupling windings 36 p1 and the second winding N s1 The third winding N of the second pair of coupling windings 37 is wound around the magnetic core T1. p2 and the fourth winding N s2 It is wound around the magnetic core T2.

[0062] Figure 10This is a circuit diagram of a power conversion module according to a ninth preferred embodiment of the present disclosure. The power conversion module 10a of this embodiment is compared to... Figure 8A The difference between the power conversion module 8a shown is that the power conversion module 10a is suitable for high output voltage V. o For example, output voltage V o Input voltage V greater than N points in (i.e. V) o >V in / N). The rectifier circuit 5a of the power conversion module 10a and the second winding N s1 Fourth winding N s2 Together, they form a voltage doubler rectifier circuit architecture, wherein the rectifier circuit 5a includes an output capacitor combination 50a, a first rectifier device Q5, and a second rectifier device Q6. The first rectifier device Q5 and the second rectifier device Q6 can be, but are not limited to, as follows: Figure 10 The power switch shown is connected to the first rectifier Q5 and the second winding N. s1 The first circuit is formed by at least a portion of the capacitors in the output capacitor combination 50a, and the second rectifier Q6 and the fourth winding N s2 The output capacitor combination 50a forms at least a portion of the capacitors to form a second circuit. Furthermore, the first terminal of the first rectifier Q5 is electrically connected to the second winding N. s1 The second terminal of the first rectifier Q5 is electrically connected to the fourth winding N. s2 The first terminal of the second rectifier Q6 is electrically connected to the fourth winding N. s2 The second terminal of the second rectifier Q6 is electrically connected to the negative output terminal 13. The output capacitor assembly 50a includes the first output capacitor C. o1 and the second output capacitor C o2 The first output capacitor C o1 The first terminal and the positive output terminal 12 and the second winding N s1 The first terminal is electrically connected, and the first output capacitor C o1 The second terminal is electrically connected to the second terminal of the first rectifier Q5, therefore the second winding N s1 After being connected in series with the first rectifier Q5, it is connected to the first output capacitor C. o1 They are connected in parallel and electrically connected to the positive output terminal 12 and the output midpoint (located between the first rectifier Q5 and the fourth winding N). s2 Between the output midpoints), and between the first rectifier Q5 and the second winding N. s1 and the first output capacitor C o1 This can form the first circuit. The second output capacitor C o2 The first end and the fourth winding N s2 The first terminal and the first output capacitor C o1 The second terminal is electrically connected to the second output capacitor C.o2 The second terminal is electrically connected to the negative output terminal 13. Therefore, the fourth winding Ns2 is connected in series with the second rectifier Q6 and then with the second output capacitor C. o2 They are connected in parallel and electrically connected between the output midpoint and the output negative terminal 13, while the second rectifier Q6, the fourth winding Ns2, and the second output capacitor C o2 A second circuit can be formed. Since the operating methods of the first power switch Q1 to the fourth power switch Q4, the first rectifier Q5, and the second rectifier Q6 of the power conversion module 10a in this embodiment are all similar... Figure 1A The operation of the first power switch Q1 to the fourth power switch Q4, the first rectifier Q5 and the second rectifier Q6 of the power conversion module 1a shown will not be described in detail here.

[0063] Compared to Figure 1A The secondary side of the power conversion module 1a shown adopts a full-wave rectifier circuit architecture. Since the secondary side of the power conversion module 10a in this embodiment adopts a voltage doubler rectifier circuit architecture, the voltage stress of the first rectifier device Q5 and the second rectifier device Q6 can be effectively reduced. In addition, power switches with low withstand voltage and low on-resistance can be selected, which can effectively improve the conversion efficiency of the power conversion module 10a.

[0064] Figure 11 Power supply for driving Figure 10 The diagram shows the circuit structure of the power supply circuit for the floating ground drive circuit of the first rectifier device in the power conversion module. Because... Figure 10 The first rectifier Q5 is not grounded, so a floating ground drive circuit (not shown) is required to drive it. To supply power to the floating ground drive circuit, a method such as... Figure 11 The power supply circuit 8 shown supplies power to the floating ground drive circuit. The power supply circuit 8 includes a first power supply switch S1, a second power supply switch S2, a first drive capacitor C3, a second drive capacitor C4, a first diode D1, and a second diode D2. The first power supply switch S1 can be an NPN bipolar transistor. The base of the first power supply switch S1 receives a pulse width modulation (PWM) signal, and the collector of the first power supply switch S1 receives a voltage source V. cc The second power supply switch S2 is a PNP bipolar transistor. The base of the second power supply switch S2 receives a pulse width modulation (PWM) signal. The emitter of the second power supply switch S2 is electrically connected to the emitter of the first power supply switch S1. The collector of the second power supply switch S2 is connected to, for example... Figure 10The output negative terminal 13 is electrically connected. The first terminal of the first driving capacitor C3 is electrically connected to the emitter of the second power supply switch S2 and the emitter of the first power supply switch S1. The cathode of the first diode D1 is electrically connected to the second terminal of the first driving capacitor C3. The anode of the second diode D2 is electrically connected to the second terminal of the first driving capacitor C3. The second driving capacitor C4 is electrically connected between the anode of the first diode D1 and the cathode of the second diode D2.

[0065] When the pulse width modulation signal (PWM) is at a low voltage level, the first power supply switch S1 is turned off, and the second power supply switch S2 is turned on. Figure 10 The output capacitor C shown o2 The first driving capacitor C3 is charged, and the voltage across the first driving capacitor C3 is half of the output voltage V. o (i.e. V) o / 2). When the pulse width modulation signal PWM is at a high voltage level, the first power supply switch S1 is turned on, the second power supply switch S2 is turned off, and the potential to ground at the connection point of the first driving capacitor C3 and the first diode D1 is half of the output voltage V. o Add voltage source V cc (i.e. V) o / 2+V cc When the first diode D1 is off and the second diode D2 is on, the first driving capacitor C3 charges the second driving capacitor C4, and the voltage across the second driving capacitor C4 is the voltage source V. cc And it supplies power to the floating drive circuit that drives the first rectifier Q5.

[0066] Figure 12 This is a circuit diagram of a power conversion module according to a tenth preferred embodiment of the present disclosure. The power conversion module 12a of this embodiment and... Figure 10 The difference in the power conversion module 10a shown is that the energy storage capacitor combination 4 in the power conversion module 12a is changed to use a similar... Figure 1A The energy storage capacitor combination 4 is shown. In addition, the power conversion module 12a also includes an active absorption circuit 9, which includes a fifth power switch Q7, a resistor R1, a first absorption capacitor C5, a second absorption capacitor C6, and a third diode D3. The fifth power switch Q7 can be a P-type metal-oxide-semiconductor field-effect transistor (PMOS), and the first terminal of the fifth power switch Q7 is electrically connected to the second terminal of the resistor R1, and the second terminal of the fifth power switch Q7 is electrically connected to the output negative terminal 13. The anode of the third diode D3 is electrically connected to the first terminal of the resistor R1, and the cathode of the third diode D3 is electrically connected to the output negative terminal 13. The first terminal of the first absorption capacitor C5 is electrically connected to the second winding N. s1The second terminal of the first absorption capacitor C5 is connected to the first terminal of the resistor R1 and the anode of the third diode D3. The first terminal of the second absorption capacitor C6 is connected to the cathode of the third diode D3 and the output negative terminal 13. The second terminal of the second absorption capacitor C6 is connected to the second terminal of the first rectifier Q5 and the fourth winding N. s2 The first end.

[0067] When the first rectifier Q5 is reverse-recovery cutoff, the reverse recovery current is absorbed through the first absorption capacitor C5, the third diode D3, and the second absorption capacitor C6. During the period when the first rectifier Q5 is reverse-recovery cutoff or even completely off, the fifth power switch Q7 is turned on, allowing the energy stored in the first absorption capacitor C5 by the reverse recovery current of the first rectifier Q5 to be released through the fifth power switch Q7, resistor R1, and the second winding N. s1 And released to the output voltage V o Therefore, it can be seen that the active absorption circuit 9 of the power conversion module 12a in this embodiment not only solves the voltage stress caused by the reverse recovery of the first rectifier Q5 to maintain the energy balance of the first absorption capacitor C5, but also, since the fifth power switch Q7 is a PMOS to ground, the circuit structure of the driving circuit (not shown) used to drive the fifth power switch Q7 is relatively simple. In other embodiments, the active absorption circuit 9 may not include resistor R1, so the first terminal of the fifth power switch Q7 is instead electrically connected to the second terminal of the first absorption capacitor C5 and the anode of the third diode D3.

[0068] In summary, this disclosure provides a power conversion module comprising a full-bridge switching circuit, a first pair of coupled windings, a second pair of coupled windings, and an energy storage capacitor assembly. The energy storage capacitor assembly is electrically connected to the connection point between the first and third windings and the negative input terminal. Through this circuit topology design and corresponding control method, the maximum duty cycle of the power conversion module of this disclosure can be preset. For example, by adjusting the turns ratio between the first and second windings or between the third and fourth windings, the two power switches on the same bridge arm can be controlled to conduct complementaryly, while the power switches on different bridge arms are staggered by 180°. The secondary rectifier is switched on and synchronized with the main power switch to pre-set the maximum duty cycle of the power conversion module of this disclosure, so that the maximum duty cycle of the power conversion module of this disclosure can be extended to greater than 0.5, or even close to equal to 1. In this way, the power conversion module of this disclosure can achieve technical effects such as a wider voltage gain variation range, a large turns ratio of the first and second windings or the third and fourth windings, a low effective value of the current of the first or third winding, a lower withstand voltage requirement for the first and second rectifier devices of the rectifier circuit, and a higher conversion efficiency of the power conversion module.

Claims

1. A power conversion module, characterized by, The utility model relates to a full-bridge switching circuit, comprising: an input port comprising an input positive terminal and an input negative terminal; an output port comprising an output positive terminal and an output negative terminal; a full-bridge switching circuit comprising: a first power switch comprising a first terminal and a second terminal, the first terminal being electrically connected to the input positive terminal; a second power switch comprising a first terminal and a second terminal, the first terminal of the second power switch being electrically connected to the second terminal of the first power switch and forming a first midpoint, the second terminal of the second power switch being electrically connected to the input negative terminal; a third power switch comprising a first terminal and a second terminal, the first terminal of the third power switch being electrically connected to the input positive terminal; a fourth power switch comprising a first terminal and a second terminal, the first terminal of the fourth power switch being electrically connected to the second terminal of the third power switch and forming a second midpoint, the second terminal of the fourth power switch being electrically connected to the input negative terminal; a magnetic assembly comprising: a first pair of coupled windings comprising a first winding and a second winding coupled to each other; a second pair of coupled windings comprising a third winding and a fourth winding coupled to each other; wherein the first winding and the third winding are connected in series between the first midpoint and the second midpoint; an energy storage capacitor combination, which is electrically connected to the input port and to the first winding and the third winding; and a rectification circuit electrically connected to the second winding, the fourth winding and the output port, comprising: an output capacitor combination electrically connected between the output positive terminal and the output negative terminal, wherein the ratio of the average voltage of the output capacitor combination to the average voltage of the energy storage capacitor combination is a fixed value; a first rectifier device forming a first loop with at least part of the second winding and the output capacitor combination; a second rectifier device forming a second loop with at least part of the fourth winding and the output capacitor combination; wherein the energy storage capacitor combination and the output capacitor combination form an equivalent capacitor, and the equivalent capacitor and a resonant inductance resonate, so that energy is transferred from the input to the output.

2. The power conversion module of claim 1, wherein, The first terminal of the first winding and the first terminal of the second winding are terminals of the same name, and the first terminal of the third winding and the first terminal of the fourth winding are terminals of the same name.

3. The power conversion module of claim 1, wherein, The magnetic assembly further comprises a magnetic core comprising a center column and two side columns, the air gap of the center column being greater than the air gap of any of the side columns, wherein the first winding and the second winding are wound together on one of the two side columns, and the third winding and the fourth winding are wound together on the other of the two side columns; wherein the direct-current magnetic flux generated by the second winding and the fourth winding is superimposed on the center column, and the alternating-current magnetic flux is subtracted on the center column.

4. The power conversion module of claim 1, wherein, The first power switch and the second power switch are complementary to be turned on, the third power switch and the fourth power switch are complementary to be turned on, and the first power switch and the third power switch are turned on 180 degrees out of phase, and the second power switch and the fourth power switch are turned on 180 degrees out of phase.

5. The power conversion module of claim 4, wherein, a turn ratio of the first winding to the second winding is N, or a turn ratio of the third winding to the fourth winding is N, N is a positive number less than 100; an output voltage Vo of the power conversion module is D Vin / N, wherein D is a duty cycle of the first power switch or the second power switch, 0 < D < 1; Vin is an input voltage.

6. The power conversion module of claim 1, wherein, The first rectifier device and the second rectifier device are diodes, respectively.

7. The power conversion module of claim 1, wherein, The first rectifier and the second rectifier are power switches.

8. The power conversion module of claim 7, wherein, The energy storage capacitor combination includes an energy storage capacitor, a first end of the energy storage capacitor is electrically connected to the second end of the first winding and the first end of the third winding, and a second end of the energy storage capacitor is electrically connected to the input negative end.

9. The power conversion module of claim 8, wherein, The driving signal received by the first rectifier is the same as the driving signal received by the first power switch in a steady state, the driving signal received by the second rectifier is the same as the driving signal received by the third power switch in a steady state, and the second power switch and the fourth power switch are main power switches.

10. The power conversion module of claim 9, wherein, In the initial stage of starting of the power conversion module, the first rectifier and the second rectifier are both turned off, the duty cycle of the first power switch and the duty cycle of the third power switch gradually increase from small, and when the capacitor voltage of the energy storage capacitor reaches a voltage threshold, the first rectifier and the second power switch are synchronously turned on and turned off, and the second rectifier and the fourth power switch are synchronously turned on and turned off; wherein the voltage threshold is determined according to N times the output voltage of the power conversion module and a voltage error value.

11. The power conversion module of claim 7, wherein, The energy storage capacitor combination includes an energy storage capacitor, a first end of the energy storage capacitor is electrically connected to the second end of the first winding and the first end of the third winding, and a second end of the energy storage capacitor is electrically connected to the input positive end.

12. The power conversion module of claim 11, wherein, The driving signal received by the first rectifier is the same as the driving signal received by the first power switch in a steady state, the driving signal received by the second rectifier is the same as the driving signal received by the third power switch in a steady state, and the second power switch and the fourth power switch are main power switches.

13. The power conversion module of claim 12, wherein, In the initial stage of starting of the power conversion module, the first rectifier and the second rectifier are both turned off, the duty cycle of the first power switch and the duty cycle of the third power switch gradually increase from small, and when the capacitor voltage of the energy storage capacitor reaches a voltage threshold, the first rectifier and the second power switch are synchronously turned on and turned off, and the second rectifier and the fourth power switch are synchronously turned on and turned off; wherein the voltage threshold is determined according to N times the output voltage of the power conversion module and a voltage error value.

14. The power conversion module of claim 7, wherein, The energy storage capacitor combination includes a first capacitor and a second capacitor, a first end of the first capacitor is electrically connected to the second end of the first winding and the first end of the third winding, a second end of the first capacitor is electrically connected to the input positive end, a first end of the second capacitor is electrically connected to the second end of the first winding and the first end of the third winding, and a second end of the second capacitor is electrically connected to the input negative end.

15. The power conversion module of claim 9 or 12, wherein, The control unit and a current detection circuit are further included, wherein the current detection circuit is electrically connected with the plurality of main power switches to sample currents flowing through the plurality of main power switches and transmit the sampling results to the control unit, the control unit filters the sampling results transmitted by the current detection circuit to obtain direct current components of the currents flowing through the plurality of main power switches, and integrates subtraction values of the direct current components of the currents flowing through the plurality of main power switches to adjust duty cycles transmitted to the plurality of main power switches according to the integration results, so that the equivalent direct currents of the first winding and the third winding are equally distributed.

16. The power conversion module of claim 1, wherein, The second winding and the fourth winding each include a first end and a second end, the second end of the second winding is electrically connected to the first end of the fourth winding, and the output capacitor combination includes an output capacitor, wherein a first end of the first rectifier device is electrically connected to the first end of the second winding, a second end of the first rectifier device is electrically connected to a second end of the output capacitor and the output negative terminal, a first end of the output capacitor is electrically connected to the second end of the second winding and the first end of the fourth winding, a first end of the second rectifier device is electrically connected to the second end of the fourth winding, and a second end of the second rectifier device is electrically connected to the second end of the output capacitor and the output negative terminal.

17. The power conversion module of claim 1, wherein, The energy storage capacitor combination includes a first energy storage capacitor, a second energy storage capacitor, and an isolation capacitor, wherein a first end of the first energy storage capacitor is electrically connected to the second end of the first winding, a second end of the first energy storage capacitor is electrically connected to the input negative terminal or the input positive terminal, a first end of the second energy storage capacitor is electrically connected to the first end of the third winding, a second end of the second energy storage capacitor is electrically connected to the input negative terminal or the input positive terminal, a first end of the isolation capacitor is electrically connected to the second end of the first winding and the first end of the first energy storage capacitor, and a second end of the isolation capacitor is electrically connected to the first end of the third winding and the first end of the second energy storage capacitor.

18. The power conversion module of claim 1, wherein, The output capacitor combination includes a first output capacitor and a second output capacitor, wherein the second winding and the first rectifier device are connected in series and then connected in parallel with the first output capacitor, and are electrically connected between the output positive terminal and an output midpoint, so that the first rectifier device, the second winding, and the first output capacitor form the first loop; the fourth winding and the second rectifier device are connected in series and then connected in parallel with the second output capacitor, and are electrically connected between the output midpoint and the output negative terminal, so that the second rectifier device, the fourth winding, and the second output capacitor form the second loop.

19. The power conversion module of claim 9 or 12, wherein During the period when the first power switch, the fourth power switch and the second rectifier device are turned on and the second power switch, the third power switch and the first rectifier device are turned off, the leakage inductance of the second pair of coupled windings resonates with an equivalent series capacitance, wherein the equivalent series capacitance comprises the energy storage capacitor combination and the output capacitor combination converted to the third winding position; During the period when the second power switch, the third power switch and the first rectifier device are turned on and the first power switch, the fourth power switch and the second rectifier device are turned off, the leakage inductance of the first pair of coupled windings resonates with an equivalent series capacitance, wherein the equivalent series capacitance comprises the energy storage capacitor combination and the output capacitor combination converted to the first winding position.

20. The power conversion module of claim 19, wherein, The current flowing through the first rectifier device and the current flowing through the second rectifier device are respectively sinusoidal current or partial sinusoidal current.

21. The power conversion module of claim 19, wherein, According to the design of the resonance parameters, when the current flowing from the drain to the source of the second power switch is greater than 0 or the current flowing from the drain to the source of the fourth power switch is greater than 0, the first rectifier device or the second rectifier device is turned off correspondingly.

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