Power conversion device

Abstract

An embodiment discloses a power conversion device including: a first power conversion unit including a first inductor, a second inductor, and a first switching unit; a first connection unit and a second connection unit connected to the first power conversion unit; and a second power conversion unit connected to the first connection unit and the second connection unit, wherein the first inductor is connected to the first connection unit, and the second inductor is connected to the second connection unit.

Description

Technical Field

[0001] The embodiment relates to a power conversion device. Background Technology

[0002] Recently, there has been increasing interest in fast chargers for electric vehicles, energy storage systems (ESS), and photovoltaic power generation. Power conversion devices used in conjunction with batteries in these applications require a wide output voltage range to cover a broad range of battery voltages. Furthermore, high current is also required due to the high power capacity demands of these applications. Therefore, there is a need to develop power conversion devices with a wide output voltage range.

[0003] The problem with traditional power conversion circuits is that they are subject to high voltage and current stresses and it is difficult to ensure output voltage gain. Summary of the Invention

[0004] Technical issues

[0005] The embodiment provides a power conversion device with a wide output voltage range.

[0006] In addition, a power conversion device with a wide output current range is provided.

[0007] In addition, a power conversion device capable of simultaneously expanding the output voltage range or the output current range is provided.

[0008] In addition, a power conversion device is provided that can extend the output voltage range or output current range while maintaining continuous power transmission.

[0009] The purpose of the embodiments is not limited thereto, and may include purposes or effects that can be understood from the technical solutions or embodiments described below.

[0010] Technical solution

[0011] The power conversion device according to an embodiment may include: a first power conversion unit, the first power conversion unit including a first inductor, a second inductor and a first switching unit; a first connection unit and a second connection unit, the first connection unit and the second connection unit being connected to the first power conversion unit; and a second power conversion unit, the second power conversion unit being connected to the first connection unit and the second connection unit, wherein the first inductor may be connected to the first connection unit and the second inductor may be connected to the second connection unit.

[0012] The first connection unit may include a first electrode and a second electrode with opposite polarities, and the first inductor may be connected to either the first electrode or the second electrode.

[0013] The second connection unit may include a first electrode and a second electrode with opposite polarities, and the second inductor may be connected to either the first electrode or the second electrode.

[0014] The first inductor can be connected between the first connection unit and the first switch unit, and the second inductor can be connected between the second connection unit and the first switch unit.

[0015] The first switching unit may include a first switch to a third switch, and the second switch may be disposed between the first switch and the third switch.

[0016] The first inductor can be connected between the second switch and the third switch, and the second inductor can be connected between the first switch and the second switch.

[0017] The first switching unit may also include a fourth switch, and the fourth switch may be connected to the third switch.

[0018] The first inductor can be connected between the third and fourth switches, and the second inductor can be connected between the first and second switches.

[0019] The second power conversion unit may include a second switching unit, and the second switching unit can transmit power to the first connection unit and the second connection unit.

[0020] The second power conversion unit may further include a second switching unit and a third switching unit connected in series or in parallel with the second switching unit.

[0021] The second switching unit can transmit power to the first connection unit, and the third switching unit can transmit power to the second connection unit.

[0022] The second power conversion unit may include a third inductor and a first transformer unit disposed between the second switching unit and the first connection unit.

[0023] The second power conversion unit may include: a third inductor and a first transformer unit, the third inductor and the first transformer unit being disposed between the second switching unit and the first connection unit; and a fourth inductor and a second transformer unit, the fourth inductor and the second transformer unit being disposed between the third switching unit and the second connection unit.

[0024] The first inductor can be connected between the first electrode of the first connection unit and the first switch, and the second inductor can be connected between the second electrode of the second connection unit and the third switch.

[0025] The second power conversion unit may include a first rectifier circuit and a second rectifier circuit. The first rectifier circuit may be disposed between the first transformer unit and the first connection unit, and the second rectifier circuit may be disposed between the second transformer unit and the second connection unit.

[0026] The power conversion device may further include an output unit connected to the first power conversion unit, and the first power conversion unit may include a first capacitor unit and a second capacitor unit connected between the first switching unit and the output unit.

[0027] Beneficial effects

[0028] According to the embodiments, a power conversion device with a wide output voltage range can be provided.

[0029] In addition, it is possible to provide power conversion devices with a wide output current range.

[0030] In addition, it is possible to provide a power conversion device that can simultaneously extend the output voltage range or the output current range.

[0031] In addition, it is possible to provide a power conversion device that can extend the output voltage range or output current range while maintaining continuous power transmission.

[0032] The various advantages and effects of the present invention are not limited to those described above, and can be more easily understood in the process of describing specific embodiments of the present invention. Attached Figure Description

[0033] Figure 1 This is a block diagram of a power conversion device according to an embodiment. Figure 2 This is a block diagram of the first power conversion unit according to an embodiment. Figure 3 This is a circuit diagram of the inductor according to an embodiment. Figure 4 and Figure 5 This is a circuit diagram of the first switching unit according to the embodiment. Figures 6a to 6d This is a circuit diagram of the first power conversion unit according to the embodiment. Figures 7a to 7d This is a circuit diagram of the first power conversion unit according to another embodiment. Figures 8a to 8c This is a block diagram of the second power conversion unit according to an embodiment. Figures 9a to 9c as well as Figure 10a and Figure 10b This is a circuit diagram of the second switching unit according to the embodiment. Figures 11a to 11c , Figures 12a to 12c and Figures 13a to 13c This is a circuit diagram of the second and third switching units according to the embodiment. Figure 14 This is a circuit diagram of the transformer unit according to an embodiment. Figures 15a to 15d This is a circuit diagram of the power conversion device according to an embodiment. Figure 16a and Figure 16b This is a circuit diagram showing the power conversion device in its first mode. Figure 17a and Figure 17b This is a circuit diagram showing the power conversion device in the second mode, and Figures 18a to 18c This is an image showing the drive of each switch when the power conversion device is in the third mode. Detailed Implementation

[0034] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0035] However, the technical concept of the present invention is not limited to the embodiments described, but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more components in the embodiments can be selectively combined or substituted.

[0036] Furthermore, unless clearly and specifically defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that is generally understood by one of ordinary skill in the art to which the invention pertains, and commonly used terms (such as terms defined in dictionaries) may be interpreted taking into account their contextual meaning in the relevant field.

[0037] Furthermore, the terminology used in the embodiments of the present invention is for describing the embodiments and is not intended to limit the invention.

[0038] In this specification, unless specifically mentioned in the phrase, the singular form may also include the plural form, and when described as “at least one (or one or more) of A and B, C”, it may include one or more of all combinations that can be combined with A, B and C.

[0039] Furthermore, when describing the components of embodiments of the present invention, terms such as first, second, A, B, (a) and (b) may be used.

[0040] These terms are used only to distinguish one component from another, and the nature, order, sequence, etc. of the corresponding components are not limited by these terms.

[0041] Furthermore, when a component is described as being “connected,” “joined,” or “engaged” to another component, this can include not only cases where the component is directly connected, joined, or engaged to another component, but also cases where the component is “connected,” “joined,” or “engaged” to the other component via yet another component between the component and the other component.

[0042] Furthermore, when a component is described as being formed or disposed "above" or "below" another component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or disposed between the two components. Additionally, when expressed as "above or below," the meaning relative to a component can include not only an upward direction but also a downward direction.

[0043] Figure 1 This is a block diagram of a power conversion device according to an embodiment.

[0044] Reference Figure 1 According to the embodiment, the power conversion device 1000 may include a first power conversion unit 1100, a second power conversion unit 1200, a first connection unit 1300, a second connection unit 1400, an input unit 1500, and an output unit 1600.

[0045] The power conversion device 1000 can receive power, convert the received power, and output the converted power. The power conversion device 1000 can convert the voltage or current of the received power and output the converted voltage or current. The power conversion device 1000 can convert direct current (DC) power to DC power. The power conversion device 1000 can decrease or increase the DC voltage.

[0046] The power conversion device 1000 can receive DC voltage through the input unit 1500. The received voltage can reach the first power conversion unit 1100 through the second power conversion unit 1200 via the first connection unit 1300 and the second connection unit 1400, and can be output from the first power conversion unit 1100 through the output unit 1600. The direction of current flow through the power conversion device 1000 is not restricted; for example, current can be input to the first power conversion unit 1100 via the first connection unit 1300 and the second connection unit 1400 and output through the second power conversion unit 1200.

[0047] Figure 2 This is a block diagram of the first power conversion unit according to an embodiment.

[0048] Reference Figure 1 and Figure 2The power conversion device 1000 according to an embodiment may include a first power conversion unit 1100. The first power conversion unit 1100 may include a first inductor 1110, a second inductor 1120, and a first switching unit 1130. The first power conversion unit 1100 may receive power from a first connection unit 1300 and a second connection unit 1400 and convert the voltage or current. The first power conversion unit 1100 may convert the power and output the converted power through an output unit 1600. The first power conversion unit 1100 may include a non-isolated power conversion circuit that receives power and generates a single output power. Furthermore, the power transmission direction of the first power conversion unit 1100 is not limited to forward, and may be bidirectional or reverse.

[0049] The power conversion device 1000 according to an embodiment may include a first connection unit 1300 and a second connection unit 1400. The first connection unit 1300 and the second connection unit 1400 may be disposed between a first power conversion unit 1100 and a second power conversion unit 1200. The first connection unit 1300 and the second connection unit 1400 may be disposed between the first power conversion unit 1100 and the second power conversion unit 1200 and electrically connected to both. The first connection unit 1300 and the second connection unit 1400 may receive power from the second power conversion unit 1200 and transmit power to the first power conversion unit 1100. Furthermore, the first connection unit 1300 and the second connection unit 1400 may receive power from the first power conversion unit 1100 and transmit power to the second power conversion unit 1200. Each of the first connection unit 1300 and the second connection unit 1400 may each include a first electrode (+) and a second electrode (-). The first electrode (+) and the second electrode (-) may have opposite polarities. The first electrode (+) of the first connection unit 1300 can be connected to point a of the first switching unit 1130 via the first inductor 1110. The second electrode (-) of the first connection unit 1300 can be connected to point c of the first switching unit 1130 via the first inductor 1110. The first electrode (+) of the second connection unit 1400 can be connected to point b of the first switching unit 1130 via the second inductor 1120. The second electrode (-) of the second connection unit 1400 can be connected to point d of the first switching unit 1130 via the second inductor 1120.

[0050] A capacitor C can be connected between the first connection unit 1300 and the first inductor 1110, and a capacitor C can also be connected between the second connection unit 1400 and the second inductor 1120. Because capacitors are included between the first connection unit 1300 and the first inductor 1110, and between the second connection unit 1400 and the second inductor 1120, noise and ripple reduction are achieved. Furthermore, a capacitor can be connected between the first switching unit 1130 and the output unit 1600. Because a capacitor is included between the first switching unit 1130 and the output unit 1600, noise and ripple reduction are also achieved.

[0051] Figure 3 This is a circuit diagram of an inductor according to an embodiment.

[0052] Reference Figure 2 and Figure 3 The first power conversion unit 1100 may include a first inductor 1110 and a second inductor 1120. The first inductor 1110 and the second inductor 1120 can generate power based on the change in current flowing through them over time. As the current change in the first inductor 1110 and the second inductor 1120 increases, the generated power level can increase. The first inductor 1110 and the second inductor 1120 can generate power in the direction opposite to the current flow direction. The first inductor 1110 and the second inductor 1120 can receive individual power inputs.

[0053] The first inductor 1110 can be connected to the first connection unit 1300. The first inductor 1110 can be connected in series with the first connection unit 1300. The first inductor 1110 can be connected to the first connection unit 1300 and generate power according to changes in the current supplied from the first connection unit 1300. Furthermore, the first inductor 1110 can be connected to the first switching unit 1130. The first inductor 1110 can be electrically connected to the first switching unit 1130 and transmit the output voltage to the first switching unit 1130.

[0054] The second inductor 1120 can be connected to the second connection unit 1400. The second inductor 1120 can be connected in series with the second connection unit 1400. The second inductor 1120 can be connected to the second connection unit 1400 and generate power according to changes in the current supplied from the second connection unit 1400. Furthermore, the second inductor 1120 can be connected to the first switching unit 1130. The second inductor 1120 can be electrically connected to the first switching unit 1130 and transmit the output voltage to the first switching unit 1130.

[0055] Reference Figure 3The first inductor 1110 and the second inductor 1120 may each include a single inductor or multiple inductors.

[0056] Reference Figure 3 In (a), the first inductor 1110 and the second inductor 1120 may each include two inductors. In this case, the two inductors may each be connected to a corresponding one of the first and second electrodes of the connection unit. (Refer to...) Figure 3 (b) and Figure 3 (c) The first inductor 1110 and the second inductor 1120 may each include one inductor. In this case, the inductors may be connected to either the first electrode or the second electrode of the connection unit. See reference [link to reference]. Figure 3 (d) The first inductor 1110 and the second inductor 1120 may each comprise a combination of two inductors. In this case, each of the two inductors may be connected to one of the first and second electrodes of the connection unit, and the two inductors may be connected and combined. When the combination of two inductors is included, there may be an effect of reducing the ripple of the inductor current.

[0057] Figure 4 and Figure 5 This is a circuit diagram of the first switching unit according to an embodiment.

[0058] Reference Figure 2 , Figure 4 and Figure 5 The first power conversion unit 1100 may include a first switching unit 1130. The first switching unit 1130 may include multiple switches to allow or block current flow. The first switching unit 1130 may allow or block current flow from the first inductor 1110 and the second inductor 1120, thereby allowing current output to the output unit. Depending on the type of the multiple switches, the first switching unit 1130 may allow current to flow in two directions or allow current to flow in only one direction. The multiple switches may include diodes or semiconductor switches.

[0059] Reference Figure 4(a) The first switching unit 1130 may include three switches. The first switching unit 1130 may include first to third switches S1, S2, and S3. The first to third switches S1, S2, and S3 may be sequentially connected in the direction from point a to point d, and the second switch S2 may be located between the first switch S1 and the third switch S3. Furthermore, the first switching unit 1130 may include multiple connection points a, b, c, and d. a may be a point connected to the first switch S1. b may be a point connected between the first switch S1 and the second switch S2. c may be a point connected between the second switch S2 and the third switch S3. d may be a point connected to the third switch S3. (See reference...) Figure 4 (b) The first switching unit 1130 may include a bidirectional switch. In this case, current can flow either from the input unit to the output unit or from the output unit to the input unit. (See reference...) Figure 4 (c) The first switching unit 1130 may include a positive switch. In this case, current can flow in the direction from the input unit to the output unit. (Refer to...) Figure 4 (d) The first switching unit 1130 may include a reverse switch. In this case, current can flow in the direction from the output unit to the input unit. When the first switching unit 1130 includes three switches, namely the first switch to the third switches S1, S2 and S3, there may be an effect that requires a small number of switches.

[0060] Reference Figure 5 (a) The first switching unit 1130 may include four switches. The first switching unit 1130 may include first switches to fourth switches S1, S2, S3, and S4. The first switches to fourth switches S1, S2, S3, and S4 may be sequentially connected in the direction from point a to point d. A second switch S2 may be located between the first switch S1 and the third switch S3, and the third switch S3 may be located between the second switch S2 and the fourth switch S4. Furthermore, the first switching unit 1130 may include multiple connection points a, b, c, and d. a may be a point connected to the first switch S1. b may be a point connected between the first switch S1 and the second switch S2. c may be a point connected between the third switch S3 and the fourth switch S4. d may be a point connected to the fourth switch S4. Additionally, the first switching unit 1130 may include a first capacitor unit C1 and a second capacitor unit C2. The first capacitor unit C1 may be connected to one side of the first switch S1 and the second switch S2, and the second capacitor unit C2 may be connected to one side of the third switch S3 and the fourth switch S4. The first capacitor unit C1 and the second capacitor unit C2 may include capacitors. The first capacitor unit C1 and the second capacitor unit C2 may have the effect of suppressing voltage spikes from the first to the fourth switches S1, S2, S3, and S4. (Refer to...) Figure 5 (b) The first switching unit 1130 may include a bidirectional switch. In this case, current can flow either from the input unit to the output unit or from the output unit to the input unit. (See reference...) Figure 5 (c) The first switching unit 1130 may include a positive switch. In this case, current can flow in the direction from the input unit to the output unit. (Refer to...) Figure 5 (d) The first switching unit 1130 may include a reverse switch. In this case, current can flow in the direction from the output unit to the input unit. When the first switching unit 1130 includes four switches, namely the first to the fourth switches S1, S2, S3 and S4, there may be an effect of reducing the withstand voltage required for the switches.

[0061] Figures 6a to 6d This is a circuit diagram of the first power conversion unit according to an embodiment.

[0062] Figures 6a to 6d The diagram illustrates a first switching unit 1130 comprising three switches, namely, switches S1, S2, and S3. A capacitor C may be disposed between the first switching unit 1130 and the output unit 1600.

[0063] Reference Figure 6a The first inductor 1110 can be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 can be connected to the first electrode (+) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point c between the second switch S2 and the third switch S3. The second inductor 1120 can be connected to point b between the first switch S1 and the second switch S2.

[0064] Reference Figure 6b The first inductor 1110 can be connected to the first electrode (+) of the first connection unit 1300, and the second inductor 1120 can be connected to the second electrode (-) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point a between the first switch S1 and the first electrode (+) of the first connection unit 1300. The second inductor 1120 can be connected to point d between the third switch S3 and the second electrode (-) of the second connection unit 1400.

[0065] Reference Figure 6cThe first inductor 1110 and the second inductor 1120 may each include two inductors. Each of the two inductors may be connected to one of the first electrode (+) and the second electrode (-) of the first connection unit 1300 and the second connection unit 1400. Furthermore, the two inductors of the first inductor 1110 and the two inductors of the second inductor 1120 may be combined with each other. When the two inductors are combined, there is an effect of reducing the ripple of the inductor current. One inductor of the first inductor 1110 may be connected to point a between the first switch S1 and the first electrode (+) of the first connection unit 1300, and the other inductor may be connected to point c between the second switch S2 and the third switch S3. Similarly, one inductor of the second inductor 1120 may be connected to point d between the third switch S3 and the second electrode (-) of the second connection unit 1400, and the other inductor may be connected to point b between the first switch S1 and the second switch S2.

[0066] Reference Figure 6d The first inductor 1110 can be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 can be connected to the first electrode (+) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point c between the second switch S2 and the third switch S3. The second inductor 1120 can be connected to point b between the first switch S1 and the second switch S2. Furthermore, the first inductor 1110 and the second inductor 1120 can be combined with each other. When the two inductors are combined, there is an effect of reducing the ripple of the inductor current.

[0067] Figures 7a to 7d This is a circuit diagram of a first power conversion unit according to another embodiment.

[0068] Figures 7a to 7d The diagram illustrates a first switching unit 1130 comprising four switches, namely, first switches to fourth switches S1, S2, S3, and S4. A first capacitor unit C1 may be disposed between the first switch S1 and the second switch S2 and the output unit 1600, and a second capacitor unit C2 may be disposed between the third switch S3 and the fourth switch S4 and the output unit 1600.

[0069] Reference Figure 7aThe first inductor 1110 can be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 can be connected to the first electrode (+) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point c between the third switch S3 and the fourth switch S4. The second inductor 1120 can be connected to point b between the first switch S1 and the second switch S2.

[0070] Reference Figure 7b The first inductor 1110 can be connected to the first electrode (+) of the first connection unit 1300, and the second inductor 1120 can be connected to the second electrode (-) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point a between the first switch S1 and the first electrode (+) of the first connection unit 1300. The second inductor 1120 can be connected to point d between the fourth switch S4 and the second electrode (-) of the second connection unit 1400.

[0071] Reference Figure 7c The first inductor 1110 and the second inductor 1120 may each include two inductors. Each of the two inductors may be connected to one of the first electrode (+) and the second electrode (-) of the first connection unit 1300 and the second connection unit 1400. Furthermore, the two inductors of the first inductor 1110 and the two inductors of the second inductor 1120 may be combined with each other. When the two inductors are combined, there is an effect of reducing the ripple of the inductor current. One inductor of the first inductor 1110 may be connected to point a between the first switch S1 and the first electrode (+) of the first connection unit 1300, and the other inductor may be connected to point c between the third switch S3 and the fourth switch S4. Similarly, one inductor of the second inductor 1120 may be connected to point d between the fourth switch S4 and the second electrode (-) of the second connection unit 1400, and the other inductor may be connected to point b between the first switch S1 and the second switch S2.

[0072] Reference Figure 7dThe first inductor 1110 can be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 can be connected to the first electrode (+) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point c between the third switch S3 and the fourth switch S4. The second inductor 1120 can be connected to point b between the first switch S1 and the second switch S2. Furthermore, the first inductor 1110 and the second inductor 1120 can be combined with each other. When the two inductors are combined, there is an effect of reducing the ripple of the inductor current.

[0073] Figures 8a to 8c This is a block diagram of the second power conversion unit according to an embodiment.

[0074] Reference Figure 1 and Figures 8a to 8c According to the embodiment, the power conversion device 1000 may include a second power conversion unit 1200.

[0075] The second power conversion unit 1200 can receive power from the input unit 1500, generate two power outputs, and transmit these two power outputs to the first connection unit 1300 and the second connection unit 1400. The second power conversion unit 1200 may include a single power conversion unit or multiple power conversion units. When the second power conversion unit 1200 includes multiple power conversion units, it may include multiple switching units, which may be connected in series, parallel, or series-parallel. The single or multiple power conversion units included in the second power conversion unit 1200 can generate one or two link voltages and transmit these one or two link voltages to the first connection unit 1300 and the second connection unit 1400. A unidirectional converter can be used as the second power conversion unit 1200 and may include, for example, a resonant inductor-inductor-capacitor (LLC) converter and a phase-shifted full-bridge (PSFB) converter. In addition, the bidirectional converter can be used as a second power conversion unit 1200 and can include, for example, a resonant capacitor-inductor-inductor-capacitor (CLLC) converter, a resonant capacitor-inductor-inductor-capacitor (CLLLC) converter, and a dual active bridge (DAB).

[0076] Reference Figure 8a The second power conversion unit 1200 may include a single power conversion unit. In this case, the single power conversion unit can receive power from the input unit 1500, generate two link power outputs, and transmit the two link power outputs to the first connection unit 1300 and the second connection unit 1400.

[0077] Reference Figure 8b The second power conversion unit 1200 may include two power conversion units. These two power conversion units may be connected in parallel to the input unit 1500. In this case, the two power conversion units can generate a link power output and each transmit power to the first connection unit 1300 and the second connection unit 1400. Alternatively, in another embodiment, each of the two power conversion units can transmit power to both the first connection unit 1300 and the second connection unit 1400 (not shown). When multiple power conversion units are connected in parallel as described above, the load can be distributed, thereby reducing the current stress on the second power conversion unit 1200 and facilitating heat management.

[0078] Reference Figure 8c The second power conversion unit 1200 may include two power conversion units. These two power conversion units may be connected in series to the input unit 1500. In this case, each power conversion unit may independently deliver power to both the first connection unit 1300 and the second connection unit 1400. Alternatively, in another embodiment, each power conversion unit may independently deliver power to both the first connection unit 1300 and the second connection unit 1400 (not shown). When multiple power conversion units are connected in series as described above, the voltage stress on the second switching unit can be reduced, thereby providing the effect of allowing the use of switches with lower withstand voltages.

[0079] Furthermore, in another embodiment, multiple power conversion units can be connected in series-parallel to the input unit (not shown). Each of the multiple power conversion units can transfer power to both the first connection unit and the second connection unit, or can transfer power to either the first connection unit or the second connection unit. In this case, current stress can be reduced, and voltage stress on the second switching unit can be decreased. Therefore, it is possible to achieve a high capacity while applying SiC metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0080] Figures 9 and 10 are circuit diagrams of the second switching unit according to an embodiment.

[0081] Referring to Figures 9 and 10, the second power conversion unit according to the embodiment may include a second switching unit 1210.

[0082] The second switching unit 1210 can receive power from the input unit 1500.

[0083] Figure 9a The diagram illustrates the case where the second switching unit is a two-level full-bridge. In this case, the second switching unit may include four switches. Figure 9b and Figure 9cThis illustrates the case where the second switching unit is a two-level half-bridge. In this case, the second switching unit may include two switches.

[0084] Figure 10a The diagram illustrates a case where the second switching unit is a three-level full-bridge. In this case, the second switching unit may include 12 switches. Figure 10b The diagram illustrates a case where the second switching unit is a three-level half-bridge. In this case, the second switching unit may include six switches. Additionally, the second switching unit may include two capacitors.

[0085] Figures 11 to 13 are circuit diagrams of the second and third switching units according to the embodiments.

[0086] Referring to Figures 11 to 13, the second power conversion unit according to the embodiment may further include a third switching unit 1220. The third switching unit 1220 may be connected in series or in parallel to the second switching unit 1210. The third switching unit 1220 may have the same structure as the second switching unit 1210. The third switching unit 1220 may receive power from the input unit 1500. The second switching unit 1210 and the third switching unit 1220 may each supply power to the first connection unit 1300 or the second connection unit 1400, or may simultaneously supply power to both the first connection unit 1300 and the second connection unit 1400.

[0087] Figures 11a to 11c The second power conversion unit according to the embodiment is shown to be a two-level full-bridge. Figure 11a This illustrates the case where the second switch unit 1210 and the third switch unit 1220 are connected in parallel. Figure 11b This illustrates the case where the second switch unit 1210 and the third switch unit 1220 are connected in series. Figure 11c The second switch unit 1210 and the third switch unit 1220 are shown in series-parallel connection.

[0088] Figures 12a to 12c The second power conversion unit according to the embodiment is shown to be a two-level half-bridge. Figure 12a This illustrates the case where the second switch unit 1210 and the third switch unit 1220 are connected in parallel. Figure 12b This illustrates the case where the second switch unit 1210 and the third switch unit 1220 are connected in series. Figure 12c The second switch unit 1210 and the third switch unit 1220 are shown in series-parallel connection.

[0089] Figures 13a to 13c The second power conversion unit according to another embodiment is shown to be a two-level half-bridge. Figure 13aThis illustrates the case where the second switch unit 1210 and the third switch unit 1220 are connected in parallel. Figure 13b This illustrates the case where the second switch unit 1210 and the third switch unit 1220 are connected in series. Figure 13c The second switch unit 1210 and the third switch unit 1220 are shown in series-parallel connection.

[0090] Figure 14 This is a circuit diagram of a transformer unit according to an embodiment.

[0091] Reference Figure 14 The second power conversion unit according to an embodiment may include a transformer unit. The transformer unit can receive power and convert voltage. The transformer unit can be connected to a second switch. The transformer unit can be disposed between the second switch and the first and second connection units.

[0092] Figure 14 (a) illustrates a transformer unit in which the second power conversion unit according to an embodiment transmits power to a connection unit via a switching unit. When the second power conversion unit includes a second switching unit and a third switching unit, and the second switching unit and the third switching unit are connected in series or in parallel, the second switching unit and the third switching unit can each be connected to a transformer unit.

[0093] Figure 14 (b) and Figure 14 (c) shows a transformer unit in which the second power conversion unit according to the embodiment transmits power to two connection units through a switching unit. Figure 14 The transformer unit of (b) includes a transformer and can be connected with a center tap structure. Figure 14 The transformer unit of (c) includes two transformers, and the transformers can be connected in series on the primary side (the side adjacent to the input unit). The transformer unit can be connected to the first and second connection units when the second power conversion unit includes a second switching unit and the second switching unit transmits power to the first and second connection units.

[0094] Figures 15a to 15d This is a circuit diagram of a power conversion device according to an embodiment.

[0095] Reference Figures 15a to 15dThe second power conversion unit 1200 may include a third inductor 1240 and a third capacitor unit 1250. The third inductor 1240 and the third capacitor unit 1250 may be disposed between the second switching unit 1210, the third switching unit 1220, and the first transformer unit 1230. The second power conversion unit 1200 may include the third inductor 1240 to achieve zero-voltage switching (ZVS). Furthermore, the second power conversion unit 1200 may include two rectifier circuits. The second power conversion unit 1200 may include a first rectifier circuit 1260 and a second rectifier circuit 1270. The first rectifier circuit 1260 and the second rectifier circuit 1270 may be connected to the first transformer unit 1230. The first rectifier circuit 1260 may be connected to the first connection unit 1300. The second rectifier circuit 1270 may be connected to the second connection unit 1400. The first rectifier circuit 1260 and the second rectifier circuit 1270 may be connected in series or in parallel with each other.

[0096] Figure 15a This is a circuit diagram of the power conversion device according to the first embodiment.

[0097] Reference Figure 15aThe second power conversion unit 1200 can generate two link power outputs using a full-bridge LLC converter, and the first switching unit 1130 of the first power conversion unit 1100 can include three switches. The transformer unit can wind a transformer into a center-tapped structure. The first power conversion unit 1100 can include a first inductor 1110, a second inductor 1120, and a first switching unit 1130. The first switching unit 1130 can include first switches to third switches S1, S2, and S3. The first inductor 1110 can be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 can be connected to the first electrode (+) of the second connection unit 1400. A capacitor can be included between the first inductor 1110 and the first connection unit 1300, and a capacitor can be included between the second inductor 1120 and the second connection unit 1400. The first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point c between the second switch S2 and the third switch S3. The second inductor 1120 can be connected to point b between the first switch S1 and the second switch S2. Furthermore, the first inductor 1110 and the second inductor 1120 can be combined with each other. When the two inductors are combined, the ripple of the inductor current can be reduced. The second power conversion unit 1200 may include a second switching unit 1210, a third inductor 1240, a third capacitor unit 1250, a first transformer unit 1230, a first rectifier circuit 1260, and a second rectifier circuit 1270. The first rectifier circuit 1260 can be connected to the first connection unit 1300. The second rectifier circuit 1260 can be connected to the second connection unit 1300. The first rectifier circuit 1260 and the second rectifier circuit 1270 may each include four switches. The first rectifier circuit 1260 and the second rectifier circuit 1270 can be connected to the first transformer unit 1230. The third inductor 1240 may be disposed between the second switching unit 1210 and the third capacitor unit 1250. The third capacitor unit 1250 can be disposed between the third inductor 1240 and the first transformer unit 1230. The first transformer unit 1230 can be disposed between the third capacitor unit 1250 and the first rectifier circuit 1260 and the second rectifier circuit 1270. The second switching unit 1210 may include four switches.

[0098] Figure 15b This is a circuit diagram of a power conversion device according to the second embodiment.

[0099] Reference Figure 15bThe second power conversion unit 1200 can generate two link power outputs using a full-bridge LLC converter, and the first switching unit 1130 of the first power conversion unit 1100 can include four switches. The transformer unit can include two transformers. The first power conversion unit 1100 can include a first inductor 1110, a second inductor 1120, and a first switching unit 1130. The first switching unit 1130 can include first switches to fourth switches S1, S2, S3, and S4. The first inductor 1110 can be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 can be connected to the first electrode (+) of the second connection unit 1400. A capacitor can be included between the first inductor 1110 and the first connection unit 1300, and a capacitor can be included between the second inductor 1120 and the second connection unit 1400. The first inductor 1110 and the second inductor 1120 can each include one inductor. The first inductor 1110 can be connected to point c between the third switch S3 and the fourth switch S4. The second inductor 1120 can be connected to point b between the first switch S1 and the second switch S2. Furthermore, the first inductor 1110 and the second inductor 1120 can be combined with each other. When the two inductors are combined, the ripple of the inductor current can be reduced. The first capacitor unit C1 and the second capacitor unit C2 can be disposed between the first switch unit 1130 and the output unit 1600. The second power conversion unit 1200 may include a second switch unit 1210, a third inductor 1240, a third capacitor unit 1250, a first transformer unit 1230, a first rectifier circuit 1260, and a second rectifier circuit 1270. The first rectifier circuit 1260 can be connected to the first connection unit 1300. The second rectifier circuit 1260 can be connected to the second connection unit 1300. The first rectifier circuit 1260 and the second rectifier circuit 1270 may each include four switches. The first rectifier circuit 1260 and the second rectifier circuit 1270 can be connected to the first transformer unit 1230. A third inductor 1240 can be disposed between the second switching unit 1210 and the third capacitor unit 1250. The third capacitor unit 1250 can be disposed between the third inductor 1240 and the first transformer unit 1230. The first transformer unit 1230 can be disposed between the third capacitor unit 1250 and the first rectifier circuit 1260 and the second rectifier circuit 1270. The second switching unit 1210 may include four switches.

[0100] Figure 15c This is a circuit diagram of a power conversion device according to the third embodiment.

[0101] Reference Figure 15cThe second power conversion unit 1200 may use two full-bridge LLC converters (transformers) connected in parallel to the input unit 1500. Each LLC converter can generate a link power output, and the first switching unit 1130 of the first power conversion unit 1100 may include four switches. The transformer unit may include two separate transformers. The first power conversion unit 1100 may include a first inductor 1110, a second inductor 1120, and a first switching unit 1130. The first switching unit 1130 may include first switches to fourth switches S1, S2, S3, and S4. The first inductor 1110 may be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 may be connected to the first electrode (+) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 may each include one inductor. The first inductor 1110 may be connected to point c between the third switch S3 and the fourth switch S4. The second inductor 1120 may be connected to point b between the first switch S1 and the second switch S2. The second power conversion unit 1200 may include a second switching unit 1210, a third switching unit 1220, a third inductor 1240, a fourth inductor 1241, a third capacitor unit 1250, a fourth capacitor unit 1251, a first transformer unit 1230, a second transformer unit 1231, a first rectifier circuit 1260, and a second rectifier circuit 1270. The first rectifier circuit 1260 may be connected to a first connection unit 1300. The second rectifier circuit 1260 may be connected to a second connection unit 1300. The first rectifier circuit 1260 and the second rectifier circuit 1270 may each include four switches. The first rectifier circuit 1260 may be connected to the first transformer unit 1230, and the second rectifier circuit 1270 may be connected to the second transformer unit 1231. The third inductor 1240 may be disposed between the second switching unit 1210 and the third capacitor unit 1250. The fourth inductor 1241 can be disposed between the third switching unit 1220 and the fourth capacitor unit 1251. The third capacitor unit 1250 can be disposed between the third inductor 1240 and the first transformer unit 1230. The fourth capacitor unit 1251 can be disposed between the fourth inductor 1241 and the second transformer unit 1231. The first transformer unit 1230 can be disposed between the third capacitor unit 1250 and the first rectifier circuit 1260. The second transformer unit 1231 can be disposed between the fourth capacitor unit 1251 and the second rectifier circuit 1270. The second switching unit 1210 and the third switching unit 1220 can each include four switches. The second switching unit 1210 and the third switching unit 1220 can be connected in parallel to the input unit 1500.

[0102] Figure 15dThis is a circuit diagram of a power conversion device according to the fourth embodiment.

[0103] Reference Figure 15dThe second power conversion unit 1200 may use two full-bridge LLC converters (transformers) connected in parallel to the input unit 1500. Each LLC converter can generate a link power output, and the first switching unit 1130 of the first power conversion unit 1100 may include four switches. The transformer unit may include two separate transformers. The first power conversion unit 1100 may include a first inductor 1110, a second inductor 1120, and a first switching unit 1130. The first switching unit 1130 may include first switches to fourth switches S1, S2, S3, and S4. The first inductor 1110 may be connected to the second electrode (-) of the first connection unit 1300, and the second inductor 1120 may be connected to the first electrode (+) of the second connection unit 1400. In this case, the first inductor 1110 and the second inductor 1120 may each include one inductor. The first inductor 1110 may be connected to point c between the third switch S3 and the fourth switch S4. The second inductor 1120 may be connected to point b between the first switch S1 and the second switch S2. The second power conversion unit 1200 may include a second switching unit 1210, a third switching unit 1220, a third inductor 1240, a fourth inductor 1241, a third capacitor unit 1250, a fourth capacitor unit 1251, a first transformer unit 1230, a second transformer unit 1231, a first rectifier circuit 1260, and a second rectifier circuit 1270. The first rectifier circuit 1260 may be connected to a first connection unit 1300. The second rectifier circuit 1260 may be connected to a second connection unit 1300. The first rectifier circuit 1260 and the second rectifier circuit 1270 may each include four switches. The first rectifier circuit 1260 may be connected to the first transformer unit 1230, and the second rectifier circuit 1270 may be connected to the second transformer unit 1231. The third inductor 1240 may be disposed between the second switching unit 1210 and the third capacitor unit 1250. The fourth inductor 1241 can be disposed between the third switching unit 1220 and the fourth capacitor unit 1251. The third capacitor unit 1250 can be disposed between the third inductor 1240 and the first transformer unit 1230. The fourth capacitor unit 1251 can be disposed between the fourth inductor 1241 and the second transformer unit 1231. The first transformer unit 1230 can be disposed between the third capacitor unit 1250 and the first rectifier circuit 1260. The second transformer unit 1231 can be disposed between the fourth capacitor unit 1251 and the second rectifier circuit 1270. The second switching unit 1210 and the third switching unit 1220 can each include four switches. The second switching unit 1210 and the third switching unit 1220 can be connected in series to the input unit 1500.

[0104] Figure 16 is a circuit diagram showing the power conversion device in the first mode, and Figure 17 is a circuit diagram showing the power conversion device in the second mode.

[0105] Referring to Figures 16 and 17, the first power conversion unit of the power conversion device according to the embodiment can be driven in a first mode or a second mode. The first mode can be a first bypass mode. The second mode can be a second bypass mode. The first power conversion unit uses a bypass mode that does not perform repeated switching to realize power transfer between the input and the output. The power conversion device can have the effect of realizing power transfer using both the first and second modes while minimizing switching losses.

[0106] Figure 16a The diagram illustrates a first mode state where the first switching unit 1130 of the first power conversion unit 1100 includes three switches. When the first power conversion unit 1100 is in the first mode, the output voltage of the output unit 1600 can be the sum of the voltages of the power inputs from the first connection unit 1300 and the second connection unit 1400 to the first power conversion unit. When the first power conversion unit 1100 is in the first mode, the first switch S1 and the third switch S3 can be in the off state, and the second switch S2 can be in the on state.

[0107] Figure 16b The diagram illustrates a first mode state where the first switching unit 1130 of the first power conversion unit 1100 includes four switches. When the first power conversion unit 1100 is in the first mode, the output voltage of the output unit 1600 can be the sum of the voltages of the power inputs from the first connection unit 1300 and the second connection unit 1400 to the first power conversion unit. When the first power conversion unit 1100 is in the first mode, the first switch S1 and the fourth switch S4 can be in the off state, and the second switch S2 and the third switch S3 can be in the on state.

[0108] Figure 17a The diagram illustrates a second mode state where the first switching unit 1130 of the first power conversion unit 1100 includes three switches. When the first power conversion unit 1100 is in the second mode, the output current of the output unit 1600 can be the sum of the currents from the first connection unit 1300 and the second connection unit 1400 to the power input to the first power conversion unit. When the first power conversion unit 1100 is in the second mode, the first switch S1 and the third switch S3 can be in a conducting state, and the second switch S2 can be in a disconnected state.

[0109] Figure 17bThe diagram illustrates a second mode state where the first switching unit 1130 of the first power conversion unit 1100 includes four switches. When the first power conversion unit 1100 is in the second mode, the output current of the output unit 1600 can be the sum of the currents from the first connection unit 1300 and the second connection unit 1400 to the power input to the first power conversion unit. When the first power conversion unit 1100 is in the second mode, the first switch S1 and the fourth switch S4 can be in a conducting state, and the second switch S2 and the third switch S3 can be in a disconnected state.

[0110] Figure 18 is an image showing the drive of each switch when the power conversion device is in the third mode.

[0111] Referring to FIG18, the first power conversion unit of the power conversion device according to the embodiment can be driven in a third mode. The third mode can be a switching mode. The third mode can be a mode of repeatedly switching the first switching unit of the first power conversion unit. The power conversion device uses the third mode to achieve a gain change for power capacity expansion. Each switch of the first switching unit of the first power conversion unit can be in an on state or an off state.

[0112] Figure 18a This is an image showing the operation according to a third switching mode when the first switching unit of the first power conversion unit includes three switches S1, S2, and S3. (Refer to...) Figure 18a When the second switch S2 is in the ON state, the first switch S1 and the third switch S3 can be in the OFF state. Conversely, when the second switch S2 is in the OFF state, the first switch S1 and the third switch S3 can be in the ON state. The entire cycle of one state transition for each of the second switch S2, the first switch S1, and the third switch S3 can be the switching period Ts. The ratio of the period of the second switch S2 to the switching period Ts can be the duty cycle D, and can have a value ranging from 0 to 100 (0% to 100%).

[0113] Figure 18b and Figure 18c This is an image showing the third switching mode being driven when the first switching unit of the first power conversion unit includes four switches S1, S2, S3 and S4. Figure 18a The third mode drive is shown in the case of a synchronization scheme without phase difference. Figure 18c The driving method according to the third mode is shown in the case of an interleaving scheme with phase difference.

[0114] Reference Figure 18bWhen the second switch S2 is in the ON state, the first switch S1 can be in the OFF state. Furthermore, when the second switch S2 is in the OFF state, the first switch S1 can be in the ON state. Furthermore, when the third switch S3 is in the ON state, the fourth switch S4 can be in the OFF state. Furthermore, when the third switch S3 is in the OFF state, the fourth switch S4 can be in the ON state. Furthermore, the drive states of the second switch S2 and the third switch S3 can be the same. Furthermore, the drive states of the first switch S1 and the fourth switch S4 can be the same. The entire cycle in which the states of the second switch S2 and the first switch S1, or the third switch S3 and the fourth switch S4, are switched once can be the switching period Ts. The ratio of the period of the second switch S2 or the third switch S3 to the switching period Ts can be the duty cycle D, and can have a value ranging from 0 to 1 (0% to 100%).

[0115] Reference Figure 18c When the second switch S2 is in the ON state, the first switch S1 can be in the OFF state. Furthermore, when the second switch S2 is in the OFF state, the first switch S1 can be in the ON state. Furthermore, when the third switch S3 is in the ON state, the fourth switch S4 can be in the OFF state. Furthermore, when the third switch S3 is in the OFF state, the fourth switch S4 can be in the ON state. The entire cycle in which the states of the second switch S2 and the first switch S1, or the third switch S3 and the fourth switch S4, are switched once can be the switching period Ts. The ratio of the period of the second switch S2 to the switching period Ts can be a first duty cycle D1, and can have a value ranging from 0 to 1 (0% to 100%). Furthermore, the ratio of the period of the third switch S3 to the switching period Ts can be a second duty cycle D2, and can have a value ranging from 0% to 100%. In this case, the first duty cycle D1 and the second duty cycle D2 can be the same. The switching periods Ts of the second switch S2 and the first switch S1, as well as the switching periods Ts of the third switch S3 and the fourth switch S4, can have a phase shift Φ. shift And phase shift Φ shift It can have values ​​ranging from 0° to 360°.

[0116] In the third mode, the input voltage of the input unit and the output voltage of the output unit can be as shown in Equation 1.

[0117] [Equation 1]

[0118] Here, V out The output voltage, V, from the first power conversion unit to the output unit. in1 and V in2 These are the input voltages from the first connection unit and the second connection unit, respectively, and D can be the duty cycle.

[0119] In the third mode, the input current of the input unit and the output current of the output unit can be as shown in Equation 2.

[0120] [Equation 2]

[0121] Here, I out The output power from the first power conversion unit to the output unit, I in1 and I in2 These are the input currents from the first connection unit and the second connection unit, respectively, and D can be the duty cycle.

[0122] Since D in Equations 1 and 2 has values ​​ranging from 0 to 1, therefore V out and I out Each can have a range from the sum of voltages (V) in1 +V in2 The value or range is 0.5 to 1.0 times the sum of the currents of the two input units (I). in1 +I in2 ) 0.5 to 1.0 times the value.

[0123] The first power conversion unit can use the first mode, the second mode, and the third mode in combination. In particular, when the third mode is used between the first mode and the second mode, it is possible to achieve continuous output voltage and output current.

[0124] Although embodiments have been primarily described above, these are merely examples and do not limit the invention. Those skilled in the art will understand that various modifications and applications not illustrated above are possible without departing from the essential characteristics of these embodiments. For example, each component specifically shown in the embodiments can be implemented by modification. Differences associated with such modifications and applications should be interpreted as including within the scope of the invention as defined in the appended claims.

Claims

1. A power conversion device, comprising: The first power conversion unit includes a first inductor, a second inductor, and a first switching unit; A first connection unit and a second connection unit are connected to the first power conversion unit; as well as A second power conversion unit is connected to both the first connection unit and the second connection unit. The first inductor is connected to the first connection unit, and the second inductor is connected to the second connection unit.

2. The power conversion device according to claim 1, wherein, The first connection unit includes a first electrode and a second electrode with opposite polarities, and The first inductor is connected to either the first electrode or the second electrode.

3. The power conversion device according to claim 2, wherein, The second connection unit includes a first electrode and a second electrode with opposite polarities, and The second inductor is connected to either the first electrode or the second electrode.

4. The power conversion device according to claim 3, wherein, The first inductor is connected between the first connection unit and the first switching unit, and The second inductor is connected between the second connection unit and the first switching unit.

5. The power conversion device according to claim 4, wherein, The first switching unit includes a first switch, a second switch, and a third switch, and The second switch is disposed between the first switch and the third switch.

6. The power conversion device according to claim 5, wherein, The first inductor is connected between the second switch and the third switch, and The second inductor is connected between the first switch and the second switch.

7. The power conversion device according to claim 5, wherein, The first switching unit further includes a fourth switch, and The fourth switch is connected to the third switch.

8. The power conversion device according to claim 7, wherein, The first inductor is connected between the third switch and the fourth switch, and The second inductor is connected between the first switch and the second switch.

9. The power conversion device according to claim 1, wherein, The second power conversion unit includes a second switching unit, and The second switching unit transmits power to the first connection unit and the second connection unit.

10. The power conversion device according to claim 9, wherein, The second power conversion unit further includes a third switching unit connected in series or in parallel with the second switching unit.

Images