Power conversion device having multiphase interleaving structure
A hybrid power converter design combining IGBTs and SiC MOSFETs optimizes power conversion efficiency and reduces costs by controlling switch elements' frequencies based on load conditions, addressing the high-cost issue of SiC MOSFETs in conventional designs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KOREA ELECTRONICS TECH INST
- Filing Date
- 2025-11-20
- Publication Date
- 2026-05-28
AI Technical Summary
Conventional power converters with multiphase interleaving structures using Si-based IGBTs or MOSFETs face high costs due to the need for numerous SiC MOSFETs, which are expensive despite their ability to increase power density, especially in non-isolated DC/DC converters for battery charging and discharging applications.
A power converter design that combines IGBTs and SiC MOSFETs, employing a hybrid half-bridge configuration where IGBTs operate at lower frequencies and SiC MOSFETs at higher frequencies based on load conditions, allowing for efficient power conversion and cost-effective operation.
This hybrid approach enhances power converter efficiency and reduces overall system costs by leveraging the fast switching capabilities of SiC MOSFETs while utilizing IGBTs for lower frequency operation, achieving both performance improvement and price competitiveness.
Smart Images
Figure KR2025019345_28052026_PF_FP_ABST
Abstract
Description
Power converter with a multiphase interleaving structure
[0001] The present invention relates to a power converter, and more specifically, to a power converter having a multiphase interleaving structure.
[0002] Conventional power converters with a multiphase interleaving structure are composed of Si-based IGBTs or MOSFETs.
[0003] With the recent development of WBG devices, technology is being applied to replace existing Si-based power converters with SiC MOSFETs.
[0004] SiC MOSFETs have the advantage of enabling fast switching, which can increase the power density of power converters, but they have the problem of not being widely applied in actual products due to their high price compared to conventional devices.
[0005] In particular, in the case of non-isolated DC / DC converters applied to battery charging and discharging applications, there is a problem in that a large number of power semiconductors are required due to the current capacity, which can significantly increase the overall system cost.
[0006] [Prior Art Literature]
[0007] [Patent Literature]
[0008] Korean Patent Publication No. 2018-0004937 (Published January 15, 2018)
[0009] The objective of the present invention is to provide a power converter with a multiphase interleaving structure that applies a mixture of IGBTs and SiC MOSFETs.
[0010] A power conversion device according to one embodiment of the present invention includes at least one hybrid half-bridge having a first type of switch element and a second type of switch element, and at least one single-type half-bridge having a second type of switch element.
[0011] The above hybrid half-bridge includes at least one of a high hybrid half-bridge in which a first type of switch element is positioned at the top and a second type of switch element is positioned at the bottom, and a low hybrid half-bridge in which a first type of switch element is positioned at the bottom and a second type of switch element is positioned at the top.
[0012] When the above power converter operates as a boost converter, the first type of switch element of the low hybrid half-bridge operates at a relatively lower frequency (fsw,low) than the second type of switch element of the high hybrid half-bridge and the second type of switch element of the single half-bridge, and the second type of switch element of the high hybrid half-bridge and the second type of switch element of the single half-bridge operate at a relatively higher frequency (fsw,high) than the first type of switch element of the low hybrid half-bridge.
[0013] At this time, the first type of switch element of the high hybrid half-bridge is characterized by not operating.
[0014] When the above power converter operates as a step-down converter, the first type of switch element of the high hybrid half-bridge operates at a relatively lower frequency (fsw,low) than the second type of switch element of the low hybrid half-bridge and the second type of switch element of the single half-bridge, and the second type of switch element of the low hybrid half-bridge and the second type of switch element of the single half-bridge operate at a relatively higher frequency (fsw,high) than the first type of switch element of the high hybrid half-bridge.
[0015] At this time, the first type of switch element of the low hybrid half-bridge is characterized by not operating.
[0016] The current rate of each of the switch elements, including the first type of switch element and the second type of switch element, is characterized by being controlled according to the size of the load.
[0017] The number of the hybrid half-bridges and the number of the single-type half-bridges are characterized by being configured optionally.
[0018] The currents of the high hybrid half-bridge, the low hybrid half-bridge, and the single-type half-bridge are each controlled differently.
[0019] The first type of switch element is an IGBT, and the second type of switch element is a SiC MOSFET.
[0020] A power conversion device according to one embodiment of the present invention includes at least one hybrid half-bridge having an IGBT and a SiC MOSFET, and at least one single half-bridge having a SiC MOSFET.
[0021] The above hybrid half-bridge includes at least one of a high hybrid half-bridge in which an IGBT is placed at the top and a SiC MOSFET is placed at the bottom, and a low hybrid half-bridge in which an IGBT is placed at the bottom and a SiC MOSFET is placed at the top.
[0022] When the above power converter operates as a boost converter, the IGBT of the low hybrid half-bridge operates at a relatively lower frequency (fsw,low) than the SiC MOSFET of the high hybrid half-bridge and the SiC MOSFET of the single half-bridge, and the SiC MOSFET of the high hybrid half-bridge and the SiC MOSFET of the single half-bridge operate at a relatively higher frequency (fsw,high) than the IGBT of the low hybrid half-bridge.
[0023] At this time, the IGBT of the high hybrid half-bridge is characterized by not operating.
[0024] When the above power converter operates as a step-down converter, the IGBT of the high hybrid half-bridge operates at a relatively lower frequency (fsw,low) than the SiC MOSFET of the low hybrid half-bridge and the SiC MOSFET of the single-type half-bridge, and the SiC MOSFET of the low hybrid half-bridge and the SiC MOSFET of the single-type half-bridge operate at a relatively higher frequency (fsw,high) than the IGBT of the high hybrid half-bridge.
[0025] At this time, the IGBT of the low hybrid half-bridge is characterized by not operating.
[0026] The current flow rate of each of the switch elements, including the above IGBT and the above SiC MOSFET, is characterized by being controlled according to the size of the load.
[0027] The currents of the high hybrid half-bridge, the low hybrid half-bridge, and the single-type half-bridge are each controlled differently.
[0028] A power converter according to one embodiment of the present invention includes a high hybrid half-bridge in which an IGBT is positioned at the top and a SiC MOSFET is positioned at the bottom, a low hybrid half-bridge in which an IGBT is positioned at the bottom and a SiC MOSFET is positioned at the top, and at least one single-type half-bridge having two SiC MOSFETs.
[0029] When the above power converter operates as a boost converter, the IGBT of the low hybrid half-bridge operates at a relatively lower frequency (fsw,low) than the SiC MOSFET of the high hybrid half-bridge and the SiC MOSFET of the single half-bridge, and the SiC MOSFET of the high hybrid half-bridge and the SiC MOSFET of the single half-bridge operate at a relatively higher frequency (fsw,high) than the IGBT of the low hybrid half-bridge.
[0030] At this time, the IGBT of the high hybrid half-bridge is characterized by not operating.
[0031] When the above power converter operates as a step-down converter, the IGBT of the high hybrid half-bridge operates at a relatively lower frequency (fsw,low) than the SiC MOSFET of the low hybrid half-bridge and the SiC MOSFET of the single-type half-bridge, and the SiC MOSFET of the low hybrid half-bridge and the SiC MOSFET of the single-type half-bridge operate at a relatively higher frequency (fsw,high) than the IGBT of the high hybrid half-bridge.
[0032] At this time, the IGBT of the low hybrid half-bridge is characterized by not operating.
[0033] The current flow rate of each of the switch elements, including the above IGBT and the above SiC MOSFET, is characterized by being controlled according to the size of the load.
[0034] The currents of the high hybrid half-bridge, the low hybrid half-bridge, and the single-type half-bridge are each controlled differently.
[0035] According to the present invention, a system is configured by mixing low-cost IGBTs and SiC-based power semiconductors according to the switching conditions required in a power converter. Accordingly, the operating state of the power semiconductor can be determined according to load conditions and charge / discharge states.
[0036] In the case of conventional technology, since only one type of Si-based power semiconductor or SiC-based power semiconductor is applied to the system, the design must be made by selecting either price or performance. However, since the present invention applies a mixture of two types of power semiconductors, it is possible to design by compromising on price and performance.
[0037] In addition, the output of a conventional interleaving power converter is controlled by a phase difference for each half-bridge, with all switches operating at the same frequency. However, the present invention can improve efficiency by controlling the switching frequency of the hybrid half-bridge and the switching frequency of the general leg differently.
[0038] Specifically, by applying the method proposed in this invention, it is possible to increase the switching frequency of a general half-bridge using SiC to enable high-density power conversion devices, and by utilizing a hybrid half-bridge composed of existing IGBTs and SiC, it is possible to improve the efficiency of power conversion devices and secure price competitiveness.
[0039] In summary, the present invention can secure both performance improvement and price competitiveness of a power converter by applying a combination of an IGBT, which has a low operating frequency but improved efficiency and low unit cost, and a SiC MOSFET, which can increase the switching frequency.
[0040] FIG. 1 is a diagram illustrating a power conversion device to which a SiC MOSFET according to the prior art is applied.
[0041] FIG. 2 is a drawing for explaining a power conversion device to which an IGBT according to the prior art is applied.
[0042] FIG. 3 is a diagram illustrating the structure of a power conversion device with a multiphase interleaving structure according to an embodiment of the present invention.
[0043] FIG. 4 is a diagram illustrating the switching operation during boosting of a power converter with a multiphase interleaving structure according to an embodiment of the present invention.
[0044] FIG. 5 is a diagram illustrating the switching operation during step-down of a power converter with a multiphase interleaving structure according to an embodiment of the present invention.
[0045] This invention is being filed with the support of the following national research and development project.
[0046] [National R&D projects that supported this invention]
[0047] [Project ID] 2410004215
[0048] [Assignment No.] 20024898
[0049] [Ministry Name] Ministry of Trade, Industry and Energy
[0050] [Project Management (Specialized) Agency Name] Korea Institute of Industrial Technology Planning and Evaluation
[0051] [Research Project Name] Development of Materials and Components Technology
[0052] [Project Title] Development of Battery Emulator Technology for 600kW Motor Dynamo
[0053] [Project Performing Organization Name] Phoenixon Controls Co., Ltd.
[0054] [Research Period] July 1, 2023 ~ December 31, 2026
[0055]
[0056] Prior to the detailed description of the present invention, the terms and words used in the specification and claims described below should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, they should be interpreted in a sense and concept consistent with the technical spirit of the present invention, based on the principle that the inventor may appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all aspects of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.
[0057] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that identical components in the accompanying drawings are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that could obscure the essence of the invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted, and the size of each component does not entirely reflect its actual size.
[0058] First, the configuration of a multiphase interleaving power converter according to the prior art will be described. FIG. 1 is a diagram illustrating a power converter using a SiC MOSFET according to the prior art. FIG. 2 is a diagram illustrating a power converter using an IGBT according to the prior art.
[0059] A multiphase interleaving power converter according to the prior art is basically composed of a half-bridge power circuit including two power switching elements (SiC MOSFET, IGBT). And an inductor (L) or a capacitor (C) is installed at the input or output terminal.
[0060] Here, the switch element may be a SiC MOSFET (silicon carbide metal-oxide-semiconductor field-effect transistor), as in the switch element of Fig. 1. Alternatively, the switch element may be an IGBT (Insulated Gate Bipolar Transistor), as in the switch element of Fig. 2.
[0061] As shown in FIGS. 1 and 2, the half-bridge of a power converter according to the prior art uses the same type of switch element.
[0062] Next, a power converter with a multiphase interleaving structure according to an embodiment of the present invention will be described. FIG. 3 is a diagram illustrating the structure of a power converter with a multiphase interleaving structure according to an embodiment of the present invention. FIG. 4 is a diagram illustrating the switching operation during voltage boosting of a power converter with a multiphase interleaving structure according to an embodiment of the present invention. FIG. 5 is a diagram illustrating the switching operation during voltage reduction of a power converter with a multiphase interleaving structure according to an embodiment of the present invention.
[0063] First, referring to FIG. 3, a power converter with a multiphase interleaving structure according to an embodiment of the present invention includes at least one hybrid half-bridge (100: 110, 120) and at least one single-type half-bridge (200). An inductor (L) or a capacitor (C) is installed at an input or output terminal. Additionally, although not shown, a resistor (R) may be additionally connected to an input or output terminal.
[0064] The hybrid half-bridge (100: 110, 120) includes a first type of switch element (SW1) and a second type of switch element (SW2). That is, the hybrid half-bridge (100: 110, 120) is a mixed form of the first type of switch element (SW1) and the second type of switch element (SW2).
[0065] The hybrid half-bridge (100) can be a high hybrid half-bridge (110) or a low hybrid half-bridge (120).
[0066] In the high hybrid half-bridge (110), a first type of switch element (SW1) is positioned at the top and a second type of switch element (SW2) is positioned at the bottom. That is, in the high hybrid half-bridge (110), the first type of switch element (SW1) is positioned at the top and the second type of switch element (SW2) is positioned at the bottom based on the branching point for the load, i.e., the inductor (L).
[0067] In the low hybrid half-bridge (120), a first type of switch element (SW1) is located at the bottom and a second type of switch element (SW2) is located at the top. That is, in the low hybrid half-bridge (120), the first type of switch element (SW1) is located at the bottom and the second type of switch element (SW2) is located at the top based on the branch point for the load, i.e., the inductor (L).
[0068] The single-type half-bridge (200) includes two second-type switch elements (SW2). That is, the single-type half-bridge (200) is composed only of a single-type switch element, i.e., a second-type switch element (SW2).
[0069] Here, the first type of switch element (SW1) may be an IGBT (Insulated Gate Bipolar Transistor).
[0070] In addition, the second type of switch element (SW2) may be a SiC MOSFET (silicon carbide metal-oxide-semiconductor field-effect transistor).
[0071] The number of hybrid half-bridges (100: 110, 120) and the number of single-type half-bridges (200) can be optionally configured. That is, the number of hybrid half-bridges (100: 110, 120) and the number of single-type half-bridges (200) are adjusted considering the target efficiency of the power converter (10) and the system price.
[0072] The power converter (10) of the embodiment of FIG. 3 is equipped with two hybrid half-bridges (100: 110, 120) and two single half-bridges (200).
[0073] Here, among the two hybrid half-bridges (100: 110, 120), the high hybrid half-bridge (110) has an IGBT placed at the top and a SiC MOSFET placed at the bottom. That is, in the high hybrid half-bridge (110), the IGBT is placed at the top and the SiC MOSFET is placed at the bottom based on the branch point for the load, i.e., the inductor (L).
[0074] Of the two hybrid half-bridges (100: 110, 120), the low hybrid half-bridge (120) has an IGBT placed at the bottom and a SiC MOSFET placed at the top, that is, the low hybrid half-bridge (120) has an IGBT placed at the bottom and a SiC MOSFET placed at the top based on the branch point for the load, i.e., the inductor (L).
[0075] According to one embodiment as illustrated in FIG. 4, when the power converter (10) operates as a boost converter (power conversion from left to right in FIG. 3), the first type of switch element (SW1, i.e., IGBT) of the low hybrid half-bridge (120) operates at a relatively lower frequency (fsw, low) than the second type of switch element (SW2, i.e., SiC MOSFET) of the high hybrid half-bridge (110) and the second type of switch element (SW2, i.e., SiC MOSFET) of the single half-bridge (200), thereby minimizing switching losses.
[0076] On the other hand, the second type of switch element (SW2, i.e., SiC MOSFET) of the high hybrid half-bridge (110) and the second type of switch element (SW2, i.e., SiC MOSFET) of the single half-bridge (200) operate at a relatively higher frequency (fsw, high) than the first type of switch element (SW1, i.e., IGBT) of the low hybrid half-bridge (120).
[0077] At this time, the first type of switch element (SW1, i.e., IGBT) of the high hybrid half-bridge (110) does not operate to improve efficiency.
[0078] According to one embodiment as illustrated in FIG. 5, conversely, when the power converter (10) operates as a step-down converter (power conversion from right to left in FIG. 3), the first type of switch element (SW1, i.e., IGBT) of the high hybrid half-bridge (110) operates at a relatively lower frequency (fsw, low) than the second type of switch element (SW2, i.e., SiC MOSFET) of the low hybrid half-bridge (120) and the second type of switch element (SW2, i.e., SiC MOSFET) of the single half-bridge (200), thereby minimizing switching losses.
[0079] On the other hand, the second type of switch element (SW2, i.e., SiC MOSFET) of the low hybrid half-bridge (120) and the second type of switch element (SW2, i.e., SiC MOSFET) of the single half-bridge (200) operate at a relatively higher frequency (fsw, high) than the first type of switch element (SW1, i.e., IGBT) of the high hybrid half-bridge (110).
[0080] At this time, the first type of switch element (SW1, i.e., IGBT) of the low hybrid half-bridge (120) does not operate to improve efficiency.
[0081] The duty ratio of each of the switch elements (SW1, SW2), including the first type of switch element (SW1, i.e., IGBT) and the second type of switch element (SW2, i.e., SiC MOSFET), can be controlled according to the size of the load.
[0082] In particular, in the case of conventional technology, the current of each switch bridge is controlled to conduct equally, but according to an embodiment of the present invention, the current of each of the high hybrid half-bridge (110), low hybrid half-bridge (120), and single half-bridge (200) can be controlled differently for the purpose of improving efficiency.
[0083] The present invention described above can determine the operating state of a power semiconductor according to load conditions and charge / discharge conditions by configuring a system by mixing a low-cost IGBT and a SiC-based power semiconductor according to the switching conditions required in a power converter (10).
[0084] In the case of existing methods, only one type of power semiconductor, either Si-based or SiC-based, is applied to the system, so there are limitations in selecting price or performance. However, since the present invention applies a mixture of two types of power semiconductors, it is possible to design a compromise between price and performance.
[0085] In addition, the output of a conventional interleaving power converter is controlled by a phase difference for each half-bridge, with all switches operating at the same frequency. However, the present invention can improve efficiency by controlling the switching frequency of the hybrid half-bridge (100: 110, 120) and the switching frequency of the general leg differently.
[0086] As explained above, although this specification contains details of a number of specific embodiments, they should not be understood as limiting the scope of any invention or claimables, but rather as descriptions of features that may be characteristic of a specific embodiment of a specific invention. In the context of individual embodiments, specific features described in this specification may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. Furthermore, while features may operate in a specific combination and be described as initially claimed, one or more features from the claimed combination may be excluded from the combination in some cases, and the claimed combination may be changed to a sub-combination or a variation of the sub-combination.
[0087] Likewise, although operations are depicted in the drawings in a specific order, this should not be understood as requiring that such operations be performed in that specific or sequential order depicted to obtain a desirable result, or that all depicted operations must be performed. In certain cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of the various system components of the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together into a single software product or packaged into multiple software products.
[0088] Specific embodiments of the subject matter described herein have been explained. Other embodiments fall within the scope of the following claims. For example, the operations cited in the claims may be performed in different orders and still achieve desirable results. As an example, the process illustrated in the accompanying drawings does not necessarily require the specific illustrated order or sequential order to obtain desirable results. In specific embodiments, multitasking and parallel processing may be advantageous.
[0089] The description provided herein presents the best mode of the invention and offers examples to explain the invention and to enable those skilled in the art to manufacture and use the invention. The specification thus written is not intended to limit the invention to the specific terms presented. Accordingly, although the invention has been described in detail with reference to the examples above, those skilled in the art may make modifications, changes, and variations to these examples without departing from the scope of the invention.
[0090] Therefore, the scope of the present invention should not be determined by the described embodiments but by the claims.
[0091] [Explanation of the symbol]
[0092] 100: Hybrid Half-bridge
[0093] 110: High Hybrid Half-Bridge
[0094] 120: Low Hybrid Half-Bridge
[0095] 200: Single half-bridge
Claims
1. In a power converter, At least one hybrid half-bridge having a first type of switch element and a second type of switch element; and At least one single half-bridge having a second type of switch element; including Power converter.
2. In Paragraph 1, The above hybrid half-bridge is A high hybrid half-bridge having a first type of switch element positioned at the top and a second type of switch element positioned at the bottom; and A low hybrid half-bridge having a first type of switch element positioned at the bottom and a second type of switch element positioned at the top; Characterized by including at least one of Power converter.
3. In Paragraph 2, When the above power converter operates as a boost converter, The first type of switch element of the above low hybrid half-bridge is It operates at a relatively lower frequency than the second type of switch element of the above high hybrid half-bridge and the second type of switch element of the single half-bridge, and The second type of switch element of the above high hybrid half-bridge and the second type of switch element of the single half-bridge are Characterized by operating at a relatively higher frequency than the first type of switch element of the above low hybrid half-bridge. Power converter.
4. In Paragraph 3, The first type of switch element of the above high hybrid half-bridge is characterized by not operating. Power converter.
5. In Paragraph 2, When the above power converter operates as a step-down converter, The first type of switch element of the above high hybrid half-bridge operates at a relatively lower frequency than the second type of switch element of the above low hybrid half-bridge and the second type of switch element of the single half-bridge, and The second type of switch element of the low hybrid half-bridge and the second type of switch element of the single half-bridge are characterized by operating at a relatively higher frequency than the first type of switch element of the high hybrid half-bridge. Power converter.
6. In Paragraph 5, The first type of switch element of the above low hybrid half-bridge is characterized by not operating. Power converter.
7. In Paragraph 1, The current rate of each of the switch elements, including the first type of switch element and the second type of switch element, is controlled according to the size of the load. Power converter.
8. In Paragraph 1, The number of the above hybrid half-bridges and the number of the above single-type half-bridges are Characterized by being optionally configured Power converter.
9. In Paragraph 2, The currents of the high hybrid half-bridge, the low hybrid half-bridge, and the single-type half-bridge, respectively, are each controlled differently. Power converter.
10. In Paragraph 1, The first type of switch element mentioned above is an IGBT, and The above second type of switch element is characterized as being a SiC MOSFET. Power converter.