Power converter

Abstract

A power converter capable of realizing soft switching is provided with: a first leg including a first switching element and a second switching element connected in series between a voltage input terminal and a voltage output terminal; a second leg connected in parallel with the first leg between the voltage input terminal and the voltage output terminal, the second leg including a first capacitor and a second capacitor connected in series; a first winding connected between a first node on a line connecting the first switching element and the second switching element in the first bridge arm and a second node on a line connecting the first capacitor and the second capacitor C2 in the second bridge arm; an inductor connected in series with the first winding between the first node and the second node; the second winding and the third winding are connected in series and form a transformer with the first winding; a third switching element connected between the second winding and ground; and a fourth switching element connected between the third winding and ground.

Description

Technical Field

[0001] The present invention relates to a power converter, and in particular to a non-isolated power converter. Background Art

[0002] A power converter is an electronic device that can convert one type of current into another type of current. There are both DC power conversion and AC power conversion. Most intermediate bus converters (IBCs) provide isolation from input to output by using a transformer, and usually also require an inductor for output filtering.

[0003] In existing communication systems, isolated intermediate bus architecture is widely used for safety and power efficiency considerations. In this architecture, the input voltage of the system is first converted into an intermediate voltage by an isolated intermediate bus converter (IBC), and then converted into the voltage required by the load circuit by multiple subsequent non-isolated load point power supplies.

[0004] Since the input voltage range that the load point power supply at the back stage of the intermediate bus converter can adapt to is limited, the intermediate bus converter needs to control the output voltage within a certain range. In order to adapt to a wider input voltage, when the intermediate bus converter transforms the input voltage, the wider input voltage range will cause energy storage components such as inductors to continuously store and release more energy during the voltage conversion process, resulting in an increase in the volume and loss of the energy storage components.

[0005] However, in many new applications, power converters are required to have smaller size, higher efficiency and lower cost. In the face of these requirements, the application of previous isolated power converters is severely restricted due to their large size, high energy consumption and low efficiency. In view of this, a non-isolated intermediate bus converter is proposed. Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a power converter capable of realizing soft switching.

[0008] Technical solutions to solve problems

[0009] A power converter according to one embodiment of the present invention comprises: a first bridge arm connected between a voltage input terminal and a voltage output terminal, comprising a first switching element and a second switching element connected in series, wherein the first switching element is located closer to the voltage input terminal than the second switching element on a line connecting the voltage input terminal and the voltage output terminal; a second bridge arm connected in parallel with the first bridge arm between the voltage input terminal and the voltage output terminal, comprising a first capacitor and a second capacitor connected in series; a first winding connected between a first node and a second node, wherein the first node is a node on a line connecting the first switching element and the second switching element in the first bridge arm, and the second node is a node on a line connecting the first capacitor and the second capacitor C2 in the second bridge arm; an inductor connected in series with the first winding between the first node and the second node; a second winding and a third winding, wherein an opposite-name end of the second winding is connected to a same-name end of the third winding and forms a transformer with the first winding as the primary side with the first winding; a third switching element connected between the same-name end of the second winding and ground; and a fourth switching element connected between the opposite-name end of the third winding and ground.

[0010] Preferably, the first control signal for controlling the on / off of the first switching element is synchronized with the third control signal for controlling the on / off of the third switching element, the second control signal for controlling the on / off of the second switching element is synchronized with the fourth control signal for controlling the on / off of the fourth switching element, and the phases of the first control signal and the third control signal are 180 degrees different from the phases of the second control signal and the fourth control signal.

[0011] Preferably, the capacitances of the first capacitor and the second capacitor are equal.

[0012] Preferably, the first to fourth switching elements are controlled so that their respective on-duty ratios are all 50% without considering a dead time period.

[0013] Preferably, the inductor is formed by line parasitic inductance.

[0014] Preferably, a resonant frequency of a resonant circuit formed by the first capacitor, the second capacitor and the inductor is the same as an operating frequency of the power converter.

[0015] Preferably, the second winding and the third winding have the same number of turns, the number of turns of the first winding is an integer multiple of the number of turns of the second winding, or the number of turns of the first winding is an integer multiple of half the number of turns of the second winding.

[0016] Another embodiment of the present invention relates to a power converter comprising: a first bridge arm connected between a voltage input terminal and a voltage output terminal, comprising a first switching element and a second switching element connected in series, wherein the first switching element is located closer to the voltage input terminal than the second switching element on the line connecting the voltage input terminal and the voltage output terminal; a second bridge arm connected in parallel with the first bridge arm between the voltage input terminal and the voltage output terminal, comprising a first capacitor and a second capacitor connected in series; a first winding connected between a first node and a second node, wherein the first node is a node on the line connecting the first switching element and the second switching element in the first bridge arm, and the second node is a node on the line connecting the first capacitor and the second capacitor C2 in the second bridge arm; and an inductor between the first node and the second node. connected in series with the first winding; a third bridge arm, comprising a third switching element and a fourth switching element connected in series, and connected to the first bridge arm at a third node, the side of the third bridge arm opposite to the third node is connected to the ground, and the third switching element is closer to the third node than the fourth switching element; a fourth bridge arm, comprising a fifth switching element and a sixth switching element connected in series between the fourth node and the ground, the fourth node is a node on the line connecting the third node and the voltage output terminal, and the fifth switching element is closer to the fourth node than the sixth switching element; a second winding, connected between a fifth node and a sixth node, the fifth node is a node on the line connecting the third switching element and the fourth switching element in the third bridge arm, and the sixth node is a node on the line connecting the fifth switching element and the sixth switching element in the fourth bridge arm.

[0017] Preferably, a first control signal for controlling the conduction and disconnection of the first switching element, a third control signal for controlling the conduction and disconnection of the third switching element, and a sixth control signal for controlling the conduction and disconnection of the sixth switching element are synchronized, and a second control signal for controlling the conduction and disconnection of the second switching element, a fourth control signal for controlling the conduction and disconnection of the fourth switching element, and a fifth control signal for controlling the conduction and disconnection of the fifth switching element are synchronized, and a phase of the first control signal, the third control signal and the sixth control signal differs by 180 degrees from a phase of the second control signal, the fourth control signal and the fifth control signal.

[0018] Preferably, the capacitances of the first capacitor and the second capacitor are equal.

[0019] Preferably, the first to sixth switching elements are controlled so that their respective on-duty ratios are all 50% without considering a dead time period.

[0020] Preferably, the inductor is formed by line parasitic inductance.

[0021] Preferably, a resonant frequency of a resonant circuit formed by the first capacitor, the second capacitor and the inductor is the same as an operating frequency of the power converter.

[0022] Preferably, the number of turns of the first winding is an integer multiple of the number of turns of the second winding, or the number of turns of the first winding is an integer multiple of half the number of turns of the second winding.

[0023] Effects of the Invention

[0024] According to the present invention, a power converter capable of realizing soft switching can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a circuit configuration diagram schematically showing a main part of a power converter according to Embodiment 1 of the present invention.

[0026] Figure 2 This is a schematic diagram schematically showing the current flow in the first mode of the power converter according to the first embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram schematically showing the current flow in the second mode of the power converter according to the first embodiment of the present invention.

[0028] Figure 4 This is a timing chart schematically showing control signals in the power converter according to the first embodiment of the present invention.

[0029] Figure 5 This is a circuit configuration diagram schematically showing a main part of a power converter according to Embodiment 2 of the present invention.

[0030] Figure 6 This is a schematic diagram schematically showing the flow of current in the first mode of the power converter according to the second embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram schematically showing the current flow in the second mode of the power converter according to the second embodiment of the present invention.

[0032] Figure 8 This is a timing chart schematically showing control signals in the power converter according to the second embodiment of the present invention.

[0033] Description of Reference Numerals

[0034] 1. 1A: Power converter

[0035] Q1: first switching element;

[0036] Q2: second switching element;

[0037] Q3: third switching element;

[0038] Q4: fourth switching element;

[0039] Q5: fifth switching element;

[0040] Q6: sixth switching element;

[0041] VIN: voltage input terminal;

[0042] VOUT: voltage output terminal;

[0043] Vg1: first control signal;

[0044] Vg2: second control signal;

[0045] Vg3: the third control signal;

[0046] Vg4: fourth control signal;

[0047] Vg5: fifth control signal;

[0048] Vg6: sixth control signal;

[0049] C1: first capacitor;

[0050] C2: second capacitor;

[0051] C3: the third capacitor;

[0052] L1: inductor;

[0053] R1: resistor;

[0054] P1: first winding;

[0055] S1: Second winding;

[0056] S2: tertiary winding;

[0057] N1~N7: nodes. DETAILED DESCRIPTION

[0058] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each figure, the same or corresponding components are marked with the same reference numerals, and repeated descriptions are omitted. In addition, each embodiment described in the present invention is illustrative, and partial replacement or combination of structures can be performed between different embodiments.

[0059] It should be pointed out that the embodiments described below are used to help understand the present invention, but are not used to limit the interpretation of the present invention.

[0060] In addition, in the following description, the terms "first" and "second" are only used to distinguish one component, parameter or value from other components, parameters or values, and the present invention is not limited by these terms. In addition, in the following description, the so-called "connection" includes not only direct connection, but also indirect connection via other elements, and further includes connection by non-direct contact methods such as electromagnetic field coupling.

[0061] (Implementation Method 1)

[0062] Figure 1 This is a circuit configuration diagram schematically showing a main portion of a power converter 1 according to Embodiment 1 of the present invention.

[0063] like Figure 1 As shown, in Embodiment 1, the power converter 1 includes a first switching element Q1, a second switching element Q2, a third switching element Q3, a fourth switching element Q4, a first capacitor C1, a second capacitor C2, an inductor L1, a first winding P1, a second winding S1, and a third winding S2. The first switching element Q1 to the fourth switching element Q4 may be various transistors.

[0064] The first switch element Q1 and the second switch element Q2 are connected in series between the voltage input terminal VIN and the voltage output terminal VOUT to form a first bridge arm. In embodiment 1, the first switch element Q1 is located closer to the voltage input terminal VIN than the second switch element Q2 on the line connecting the voltage input terminal VIN and the voltage output terminal VOUT. An input voltage Vin is provided from the voltage input terminal VIN, and an output voltage Vout is extracted from the voltage output terminal VOUT and the ground. A load can be connected between the voltage output terminal and the ground. The first switch element Q1 is turned on and off according to the first control signal Vgl, and the second switch element Q2 is turned on and off according to the second control signal Vg2.

[0065] The first capacitor C1 and the second capacitor C2 are connected in series to form a second bridge arm, and the second bridge arm is connected between the voltage input terminal VIN and the voltage output terminal VOUT, and is connected in parallel with the first bridge arm. Preferably, the capacitance of the first capacitor C1 and the second capacitor C2 is the same. At this time, the capacitance of the first capacitor C1 and the second capacitor C2 is Cr / 2.

[0066] The first winding P1 and the inductor L1 are connected in series between a node N1 and a node N2, wherein the node N1 is a node on a line connecting the first switching element Q1 and the second switching element Q2 in the first bridge arm, and the node N2 is a node on a line connecting the first capacitor C1 and the second capacitor C2 in the second bridge arm. The inductor L1 may be formed by an independent inductor element, but is not limited thereto. For example, the inductor L1 may also be formed by a parasitic inductance of a line. Let the inductance of the inductor L1 be Lr. The first capacitor C1 and the second capacitor C2 form a resonant circuit with the inductor L1. Let the resonant frequency of the resonant circuit be fr.

[0067] The second winding S1 and the third winding S2 are connected in series. More specifically, the opposite-name end of the second winding S1 and the same-name end of the third winding S2 are connected. The first winding P1, the second winding S1 and the third winding S2 form a transformer, wherein the first winding P1 is the primary side.

[0068] The third switch element Q3 is connected between the same-name end of the second winding S1 and the ground, and is turned on and off according to the third control signal Vg3. The fourth switch element Q4 is connected between the opposite-name end of the third winding S2 and the ground, and is turned on and off according to the fourth control signal Vg4.

[0069] In the power converter 1 of the first embodiment, the second winding S1 and the third winding S2 preferably have the same number of turns. In this case, the number of turns of the first winding P1 is n1, and the number of turns of the second winding S1 and the second winding S2 are both n2.

[0070] The power converter 1 of embodiment 1 may also be provided with a resistor R1 and a third capacitor C3. The resistor R1 and the third capacitor C3 are connected in parallel between a node N3 and grounding. The node N3 is a node on a line connecting the second winding S1 and the second winding S2. The node N3 is connected to the voltage output terminal VOUT. Therefore, it can also be said that the parallel circuit of the resistor R1 and the third capacitor C3 is connected between the voltage output terminal VOUT and grounding.

[0071] According to this structure, in the power converter 1 of the first embodiment, the output voltage Vout and the input voltage Vin satisfy the relationship shown in the following formula (1):

[0072] Vout=Vin*n2 / (2*n1+n2) Formula (1)

[0073] That is to say, the ratio of the output voltage Vout to the input voltage Vin satisfies the relationship shown in the following equation (2):

[0074] Vout / Vin=n2 / (2*n1+n2) Formula (2)

[0075] As can be seen from the above equation (2), in the power converter 1 according to the first embodiment, the conversion ratio between the output voltage Vout and the input voltage Vin can be changed by adjusting n1 and n2.

[0076] In particular, when n1 is an integer multiple of n2, a fixed odd ratio voltage conversion can be reliably achieved between the input voltage Vin and the output voltage Vout. For example, when n1=n2, a fixed conversion ratio of 1:3 can be reliably achieved. For another example, when n1=2n2, a fixed conversion ratio of 1:5 can be reliably achieved.

[0077] In addition, when n1 is an odd multiple of half of n2, a fixed even ratio conversion ratio can be reliably achieved between the input voltage Vin and the output voltage Vout. For example, when n1=0.5n2, a fixed conversion ratio of 1:2 can be reliably achieved. For another example, when n1=1.5n2, a fixed conversion ratio of 1:4 can be reliably achieved.

[0078] Below, refer to Figures 2 to 4 The operation mode of the power converter 1 according to the first embodiment will be described.

[0079] Figure 2 This is a schematic diagram schematically showing the current flow in the first mode of the power converter according to the first embodiment of the present invention. Figure 3 This is a schematic diagram schematically showing the current flow in the second mode of the power converter according to the first embodiment of the present invention. Figure 4 This is a timing chart schematically showing control signals in the power converter according to the first embodiment of the present invention.

[0080] Reference Figure 4 , the first control signal Vg1 is synchronized with the third control signal Vg3, and the second control signal Vg2 is synchronized with the fourth control signal Vg4. The phase of the first control signal Vg1 and the third control signal Vg3 is 180 degrees different from the phase of the second control signal Vg2 and the fourth control signal Vg4. That is, when the first control signal Vg1 and the third control signal Vg3 are at a high level, the second control signal Vg2 and the fourth control signal Vg4 are at a low level, and vice versa. In the following, the first switch element Q1 and the third switch element Q3 are sometimes collectively referred to as the "first switch element group", and the second switch element Q2 and the fourth switch element Q4 are collectively referred to as the "second switch element group".

[0081] Reference Figure 4During the period from t1 to t2, the first control signal Vg1 and the third control signal Vg3 are at high level, the first switch element Q1 and the third switch element Q3 are turned on, the second control signal Vg2 and the fourth control signal Vg4 are at low level, the second switch element Q2 and the fourth switch element Q4 are turned off. At this time, the current flowing through the power converter 1 is as follows: Figure 2 As shown by the dashed arrow and the dotted arrow, the working state at this time is the "first mode".

[0082] During t3-t4, the first control signal Vg1 and the third control signal Vg3 are at low level, the first switch element Q1 and the third switch element Q3 are turned off, the second control signal Vg2 and the fourth control signal Vg4 are at high level, the second switch element Q2 and the fourth switch element Q4 are turned on. At this time, the current flowing through the power converter 1 is as follows: Figure 3 As shown by the dashed arrow and the dotted arrow, the working state at this time is the "second mode".

[0083] During t2-t3, control signals Vg1-Vg4 are all low level, and switch elements Q1-Q4 are all disconnected. In other words, t2-t3 is a dead zone period, and the power converter does not work. By setting the dead zone period, the power converter is protected to smoothly transition from the first mode to the second mode. Similarly, after the working state of the second mode ends, a dead zone period t4-t5 is also provided. Without considering the dead zone period, the duty cycle of the first control signal Vg1 and the third control signal Vg3 is preferably 50%. Similarly, without considering the dead zone period, the duty cycle of the second control signal Vg2 and the fourth control signal Vg4 is also preferably 50%.

[0084] In other words, the first switching element group (including the first switching element Q1 and the third switching element Q3) and the second switching element group (including the second switching element Q2 and the fourth switching element Q4) are preferably controlled so that their respective on-duty ratios are both 50% without considering the dead time period.

[0085] As mentioned above, the capacitances of the first capacitor C1 and the second capacitor C2 are preferably the same, Cr / 2. In addition, the inductance of the inductor L1 is Lr. At this time, the resonant frequency of the resonant circuit composed of the inductor L1, the first capacitor C1 and the second capacitor C2 is fr, which is determined by the following formula (3).

[0086] fr=1 / [2π√(Lr*Cr)] Formula (3)

[0087] Assuming that the operating frequency of the power converter 1 is fs, at this time, it is preferred that fs=fr.

[0088] Thus, in the first mode, the first switching element Q1 and the third switching element Q3 can realize soft switching. Similarly, in the second mode, the second switching element Q2 and the fourth switching element Q4 can also realize soft switching.

[0089] In addition, when the capacitances of the first capacitor C1 and the second capacitor C2 are equal, the midpoint of the resonant capacitance formed by the first capacitor C1 and the second capacitor C2 is connected to the resonant inductor L1 and the primary side of the transformer, thereby reducing the input ripple current.

[0090] (Implementation Method 2)

[0091] Figure 5 This is a circuit configuration diagram schematically showing a main part of a power converter according to Embodiment 2 of the present invention.

[0092] like Figure 5 As shown, the power converter 1A of the second embodiment is different from the power converter 1 of the first embodiment in that the full-wave rectifier circuit of the third switching element Q3 and the fourth switching element Q4 is changed into a full-bridge rectifier circuit. Specifically, in the power converter 1A of the second embodiment, the third winding S2 is not provided. In addition, the power converter 1A also includes a fifth switching element Q5 and a sixth switching element Q6.

[0093] In the power converter 1A, the third switch element Q3 and the fourth switch element Q4 are connected in series to form a third bridge arm, the third bridge arm is connected to the first bridge arm at a node N4, and the third bridge arm is connected to the ground on the side opposite to the node N4. On the line connecting the node N4 and the ground, the third switch element Q3 is located on the node N4 side than the fourth switch element Q4. The fifth switch element Q5 and the sixth switch element Q6 are connected in series between the node N5 and the ground to form a fourth bridge arm. Node N5 is a node on the line connecting the node N4 and the voltage output terminal VOUT. On the line connecting the node N5 and the ground, the fifth switch element Q5 is located on the node N5 side than the sixth switch element Q6. The fifth switch element Q5 is turned on and off according to the fifth control signal Vg5, and the sixth switch element Q6 is turned on and off according to the sixth control signal Vg6. According to the detailed description below Figure 8 It can be seen from the timing diagram of the first control signal Vg1 to the sixth control signal Vg6 that the first control signal Vg1, the third control signal Vg3 and the sixth control signal Vg6 are synchronized, and the second control signal Vg2, the fourth control signal Vg4 and the fifth control signal Vg5 are synchronized. The phases of the first control signal Vg1, the third control signal Vg3 and the sixth control signal Vg6 are 180 degrees different from the phases of the second control signal Vg2, the fourth control signal Vg4 and the fifth control signal Vg5.

[0094] In the second embodiment, the first switching element group includes the first switching element Q1 , the third switching element Q3 , and the sixth switching element Q6 , and the second switching element group includes the second switching element Q2 , the fourth switching element Q4 , and the fifth switching element Q5 .

[0095] The second winding S1 is connected between a node N6 and a node N7, wherein the node N6 is a node on a line connecting the third switch element Q3 and the fourth switch element Q4 in the third bridge arm, and the node N7 is a node on a line connecting the fifth switch element Q5 and the sixth switch element Q6 in the fourth bridge arm. The first winding P1 and the second winding S1 form a transformer, wherein the first winding P1 is a primary side and the second winding S1 is a secondary side.

[0096] The power converter 1A according to the second embodiment may further include a resistor R1 and a third capacitor C3. The resistor R1 and the third capacitor C3 are connected in parallel between the voltage output terminal VOUT and the ground.

[0097] According to the power converter 1A having the above structure, when the number of turns of the first winding P1 is set to n1 and the number of turns of the second winding S1 is set to n2, the ratio of the output voltage Vout to the input voltage Vin satisfies the relationship shown in the following formula (4):

[0098] Vout / Vin=n2 / (2*n1+n2) Formula (4)

[0099] As can be seen from this, in the power converter 1A according to the second embodiment, similarly to the power converter 1 according to the first embodiment, the conversion ratio between the output voltage Vout and the input voltage Vin can be changed by adjusting n1 and n2.

[0100] When n1 is an integer multiple of n2, a fixed odd ratio voltage conversion can be reliably achieved between the input voltage Vin and the output voltage Vout. When n1 is an odd multiple of half of n2, a fixed even ratio voltage conversion can be reliably achieved between the input voltage Vin and the output voltage Vout.

[0101] Below, refer to Figures 6 to 8 The operation mode of the power converter 1A according to the second embodiment will be described.

[0102] Figure 6 This is a schematic diagram schematically showing the flow of current in the first mode of the power converter according to the second embodiment of the present invention. Figure 7 This is a schematic diagram schematically showing the current flow in the second mode of the power converter according to the second embodiment of the present invention. Figure 8 This is a timing chart schematically showing control signals in the power converter according to the second embodiment of the present invention.

[0103] Reference Figure 8 During the period from t1 to t2, the first control signal Vg1, the third control signal Vg3 and the sixth control signal Vg6 are at high level, the first switch element Q1, the third switch element Q3 and the sixth switch element Q6 are turned on, the second control signal Vg2, the fourth control signal Vg4 and the fifth control signal Vg5 are at low level, the second switch element Q2, the fourth switch element Q4 and the fifth switch element Q5 are turned off. At this time, the current flowing through the power converter 1A is as follows: Figure 6 As shown by the dashed arrow and the dotted arrow, the working state at this time is the "first mode" of the power converter 1A.

[0104] During t3-t4, the first control signal Vg1, the third control signal Vg3 and the sixth control signal Vg6 are at a low level, the first switch element Q1, the third switch element Q3 and the sixth switch element Q6 are turned off, the second control signal Vg2, the fourth control signal Vg4 and the fifth control signal Vg5 are at a high level, the second switch element Q2, the fourth switch element Q4 and the fifth switch element Q5 are turned on. At this time, the current flowing through the power converter 1A is as follows: Figure 7 As shown by the dashed arrow and the dotted arrow, the working state at this time is the "second mode" of the power converter 1A.

[0105] In the second embodiment, similarly to the first embodiment, a dead period t2 to t3 is provided between the period t1 to t2 and the period t3 to t4, and a dead period t4 to t5 is provided after the period t3 to t4. In the second embodiment, the duty ratios of the first control signal Vg1, the third control signal Vg3, and the sixth control signal Vg6 are also preferably 50%. Similarly, the duty ratios of the second control signal Vg2, the fourth control signal Vg4, and the fifth control signal Vg5 are also preferably 50%.

[0106] In other words, in embodiment 2, the first switching element group (including the first switching element Q1, the third switching element Q3 and the sixth switching element Q6) and the second switching element group (including the second switching element Q2, the fourth switching element Q4 and the fifth switching element Q5) are also preferably controlled so that their respective on-duty cycles are 50% without considering the dead zone period.

[0107] In Embodiment 2, it is also preferred that the capacitances of the first capacitor C1 and the second capacitor C2 are the same. In addition, by making the resonant frequency of the resonant circuit composed of the inductor L1, the first capacitor C1, and the second capacitor C2 the same as the operating frequency of the power converter 1A, the first switching element Q1, the third switching element Q3, and the sixth switching element Q6 can achieve soft switching in the first mode. Similarly, in the second mode, the second switching element Q2, the fourth switching element Q4, and the sixth switching element Q6 can achieve soft switching.

[0108] In addition, when the capacitances of the first capacitor C1 and the second capacitor C2 are equal, the input ripple current can also be reduced.

[0109] The power converter of the present invention is described in detail above in conjunction with the preferred embodiment, but the present invention is not limited thereto. Those skilled in the art can make various modifications, substitutions and changes to the present invention without departing from the main purpose of the present invention. Other embodiments realized by combining any constituent elements in the above-mentioned embodiments, embodiments obtained by implementing various deformations thought of by those skilled in the art to the above-mentioned embodiments within the scope of the main purpose of the present invention, and various devices with the power converter of the present invention built in are also included in the present invention.

Claims

1. A power converter comprising: A first bridge arm is connected between a voltage input terminal and a voltage output terminal, and includes a first switch element and a second switch element connected in series, wherein the first switch element is located closer to the voltage input terminal than the second switch element on a line connecting the voltage input terminal and the voltage output terminal; A second bridge arm, connected in parallel with the first bridge arm between the voltage input terminal and the voltage output terminal, comprising a first capacitor and a second capacitor connected in series; a first winding connected between a first node and a second node, wherein the first node is a node on a line connecting the first switching element and the second switching element in the first bridge arm, and the second node is a node on a line connecting the first capacitor and the second capacitor C2 in the second bridge arm; an inductor connected in series with the first winding between the first node and the second node; A second winding and a third winding, wherein the opposite-name end of the second winding is connected to the same-name end of the third winding and forms a transformer with the first winding as the primary side together with the first winding; a third switching element connected between the same-name end of the second winding and ground; as well as The fourth switch element is connected between the opposite-name end of the third winding and the ground.

2. The power converter according to claim 1, wherein: A first control signal for controlling the on / off of the first switch element is synchronized with a third control signal for controlling the on / off of the third switch element. A second control signal for controlling the on / off of the second switch element is synchronized with a fourth control signal for controlling the on / off of the fourth switch element. The phases of the first control signal and the third control signal differ by 180 degrees from the phases of the second control signal and the fourth control signal.

3. The power converter according to claim 1 or 2, wherein: The capacitances of the first capacitor and the second capacitor are equal.

4. The power converter according to any one of claims 1 to 3, wherein: The first to fourth switching elements are controlled so that their respective on-duty ratios are all 50% without considering a dead time period.

5. The power converter according to any one of claims 1 to 4, wherein: The inductor is formed by the line parasitic inductance.

6. The power converter according to any one of claims 1 to 5, wherein: A resonant frequency of a resonant circuit formed by the first capacitor, the second capacitor and the inductor is the same as an operating frequency of the power converter.

7. The power converter according to any one of claims 1 to 6, wherein: The second winding and the third winding have the same number of turns, The number of turns of the first winding is an integer multiple of the number of turns of the second winding, or the number of turns of the first winding is an integer multiple of half the number of turns of the second winding.

8. A power converter comprising: A first bridge arm is connected between a voltage input terminal and a voltage output terminal, and includes a first switch element and a second switch element connected in series, wherein the first switch element is located closer to the voltage input terminal than the second switch element on a line connecting the voltage input terminal and the voltage output terminal; A second bridge arm, connected in parallel with the first bridge arm between the voltage input terminal and the voltage output terminal, comprising a first capacitor and a second capacitor connected in series; a first winding connected between a first node and a second node, wherein the first node is a node on a line connecting the first switching element and the second switching element in the first bridge arm, and the second node is a node on a line connecting the first capacitor and the second capacitor C2 in the second bridge arm; an inductor connected in series with the first winding between the first node and the second node; a third bridge arm, comprising a third switch element and a fourth switch element connected in series, and connected to the first bridge arm at a third node, a side of the third bridge arm opposite to the third node being connected to the ground, and the third switch element being closer to the third node than the fourth switch element; a fourth bridge arm, comprising a fifth switch element and a sixth switch element connected in series between a fourth node and ground, the fourth node being a node on a line connecting the third node and the voltage output terminal, the fifth switch element being closer to the fourth node than the sixth switch element; The second winding is connected between a fifth node and a sixth node, wherein the fifth node is a node on the line in the third bridge arm that connects the third switching element and the fourth switching element, and the sixth node is a node on the line in the fourth bridge arm that connects the fifth switching element and the sixth switching element.

9. The power converter according to claim 8, wherein: A first control signal for controlling the on / off of the first switching element, a third control signal for controlling the on / off of the third switching element, and a sixth control signal for controlling the on / off of the sixth switching element are synchronized, A second control signal for controlling the on / off of the second switching element, a fourth control signal for controlling the on / off of the fourth switching element, and a fifth control signal for controlling the on / off of the fifth switching element are synchronized, The phases of the first control signal, the third control signal, and the sixth control signal are 180 degrees different from the phases of the second control signal, the fourth control signal, and the fifth control signal.

10. The power converter according to claim 8 or 9, wherein: The capacitances of the first capacitor and the second capacitor are equal.

11. The power converter according to any one of claims 8 to 10, wherein: The first to sixth switching elements are controlled so that their respective on-duty ratios are all 50% without considering a dead time period.

12. The power converter according to any one of claims 8 to 11, wherein: The inductor is formed by the line parasitic inductance.

13. The power converter according to any one of claims 8 to 12, wherein: A resonant frequency of a resonant circuit formed by the first capacitor, the second capacitor and the inductor is the same as an operating frequency of the power converter.

14. The power converter according to any one of claims 8 to 13, wherein: The number of turns of the first winding is an integer multiple of the number of turns of the second winding, or the number of turns of the first winding is an integer multiple of half the number of turns of the second winding.

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