Partial power dc-dc converter with controllable topology
By designing a controllable topology partial power DC-DC converter and utilizing a combination of current-isolated DC-DC converters and switches, the problem of uncontrollable Type I and Type II topologies in existing technologies has been solved, enabling efficient applications in photovoltaic power generation and electric vehicles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TECH UNIV OF FEDERICO SANTA MARIA
- Filing Date
- 2021-12-28
- Publication Date
- 2026-06-05
AI Technical Summary
There is a lack of controllable partial power DC-DC converter topologies between Type I and Type II in the current technology, which is in particular needed for photovoltaic power generation and electric vehicle applications.
A partial power DC-DC converter with a controllable topology is designed. By combining a current-isolated DC-DC converter and a switch, it can switch between type I and type II topologies, including unidirectional and bidirectional switch configurations, supporting positive input, negative input, positive output, and negative output, and achieving bidirectional current through a transformer and H-bridge structure.
It enables flexible switching of topology under different application scenarios, improves the adaptability and efficiency of the system, and reduces power loss and system cost.
Smart Images
Figure CN116830444B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power generation, conversion or distribution; more specifically, to the field of converting DC input to DC output, and particularly to a partial power DC-DC converter having a controllable topology. Background Technology
[0002] In the field of power conversion, partial power converters have become increasingly important in recent years. Typically, partial power converters offer inherent advantages such as reduced power loss, system size, and cost. The basic principle is the distribution of power between the direct power link between the input and output and the portion handled by the DC-DC converter. This is achieved by connecting one of the inputs of the DC-DC converter to one of its outputs.
[0003] Some power DC-DC converters exist in two types: Type I (see...) Figure 1 ) and Type II (see Figure 2 In Type I, power distribution is performed on the input side of the partial power DC-DC converter, while in Type II, power distribution is performed on the output side of the partial power converter (often referred to as the DC link). Furthermore, in each configuration (Type I or Type II), there are boost configurations (where the output voltage is higher than the input voltage) and buck configurations (where the output voltage is lower than the input voltage). Additionally, for each configuration (Type I or Type II), there is also a boost-buck configuration where the output voltage can be higher or lower than the input voltage.
[0004] One of the characteristics of partial power DC-DC converters is that the relationship between input voltage and output voltage and converter power depends only on the connection topology, rather than on the type of DC-DC converter used.
[0005] In the prior art, the application of partial power DC-DC converters in photovoltaic power generation and electric vehicles is known. For example, document US 9,960,687 describes a Type I partial power DC-DC converter using a current-isolated bidirectional DC-DC converter.
[0006] However, the inventors of this invention have discovered that in some applications, a partial power DC-DC converter with a topology controllable between Type I and Type II is preferred. However, partial power DC-DC converters with both of these characteristics are not described in the prior art. Therefore, there is a need for a partial power DC-DC converter with a topology controllable between Type I and Type II. Summary of the Invention
[0007] This invention provides a partial power DC-DC converter with a controllable topology, characterized in that it comprises: a current-isolated DC-DC converter having a positive input, a negative input, a positive output, and a negative output; a first DC voltage input electrically connected to the negative output of the DC-DC converter; an input reference; a first DC voltage output electrically connected to the positive output of the DC-DC converter; and an output reference electrically connected to the input reference and the negative input of the DC-DC converter; wherein the partial power DC-DC converter further comprises: a first switch arranged to selectively connect the first DC voltage input to the positive input of the DC-DC converter; and a second switch arranged to selectively connect the positive output of the DC-DC converter to the positive input of the DC-DC converter, and wherein the DC-DC converter is bidirectional in power and bipolar in voltage.
[0008] In a preferred embodiment, the partial power converter is characterized in that the first switch and the second switch are unidirectional switches. In a more preferred embodiment, the partial power converter is characterized in that each of the unidirectional switches is formed by a field-effect transistor connected in antiparallel to a rectifier diode.
[0009] In another preferred embodiment, the partial power converter is characterized in that the first switch and the second switch are bidirectional switches.
[0010] In another preferred embodiment, the partial power converter is characterized in that the DC-DC converters connected in a partial configuration are selected from the group consisting of forward converters, push-pull converters, H-bridge converters, flyback converters, half-bridge converters, and KUK converters.
[0011] In another preferred embodiment, the partial power converter is characterized in that the DC-DC converter includes a transformer having a primary and a secondary, a first H-bridge connected to the primary of the transformer, and a second H-bridge connected to the secondary of the transformer. Attached Figure Description
[0012] Figure 1 The prior art type I partial power converter is shown.
[0013] Figure 2 The prior art type II partial power converter is shown.
[0014] Figure 3 An embodiment of a partial power converter with a controllable topology, which is the subject of this invention, is illustrated schematically.
[0015] Figure 4An exemplary embodiment of a partial power converter with a controllable topology, which is the subject of this invention, is shown.
[0016] Figure 5 Interconnection of multiple partial power DC-DC converters according to the present invention in a series-input series-output configuration is shown.
[0017] Figure 6 Interconnection of multiple partial power DC-DC converters according to the present invention in a series-input, parallel-output configuration is shown.
[0018] Figure 7 Interconnection of multiple partial power DC-DC converters according to the present invention in a parallel-input, series-output configuration is shown.
[0019] Figure 8 Interconnection of multiple partial power DC-DC converters according to the present invention in a parallel-input parallel-output configuration is shown. Detailed Implementation
[0020] The present invention will now be described in detail with reference to the accompanying drawings.
[0021] In the first subject matter of this invention, such as Figure 3 Schematic illustration shows a partial power DC-DC converter (1) with a controllable topology, mainly comprising: a current-isolated DC-DC converter (2) having a positive input (3), a negative input (4), a positive output (5), and a negative output (6); a first DC voltage input (7) electrically connected to the negative output (6) of the DC-DC converter (2); an input reference (8); a first DC voltage output (9) electrically connected to the positive output (5) of the DC-DC converter (2); and an output reference (10) electrically connected to the input reference (8) and the negative input (4) of the DC-DC converter (2); wherein the partial power DC-DC converter (1) further comprises: a first switch (11) arranged to selectively connect the first DC voltage input (7) to the positive input (3) of the DC-DC converter (2); and a second switch (12) arranged to selectively connect the positive output (5) of the DC-DC converter (2) to the positive input (3) of the DC-DC converter (2).
[0022] In the following text, for the sake of simplicity and without limiting the scope of the invention, reference will be made to a partial power DC-DC converter (1) with a controllable topology, which is the subject of the invention, as a partial power DC-DC converter (1).
[0023] In the context of this invention, a DC-DC converter will be understood as a set of electrical and electronic components arranged such that they generate a DC output signal in response to a continuous (DC) input signal. Typically, the relationship between the input voltage and the output voltage of a DC-DC converter is controlled by the ratio between the opening and closing times of one or more switches forming part of the DC-DC converter.
[0024] The DC-DC converter (2), which forms part of the partial power DC-DC converter (1) that is the subject of this invention, has two inputs, which will be referred to as positive input (3) and negative input (4) in the context of this invention and without limiting the scope of this invention. In addition, the DC-DC converter (2) has two outputs, which will be referred to as positive output (5) and negative output (6) in the context of this invention and without limiting the scope of this invention.
[0025] Without limiting the scope of the invention, the DC-DC converter (2) can be any type of DC-DC converter (2) with current isolation. In a more preferred embodiment, without limiting the scope of the invention, the DC-DC converter (2) can be a current-isolated converter, for example, and without limiting the scope of the invention, the current-isolated converter can be selected from the group consisting of forward converters, push-pull converters, H-bridge converters, flyback converters, half-bridge converters, and KUK converters. In addition, the DC-DC converter (2) is a power bidirectional and voltage bipolar converter.
[0026] For example, and without limiting the scope of the invention, the partial power DC-DC converter (1), which is the subject of the invention, can be used to connect a solar photovoltaic module to a DC bus. In another example, without limiting the scope of the invention, the partial power DC-DC converter (1), which is the subject of the invention, can be used to connect a battery to an inverter in an electric vehicle. In both cases, the DC-DC converter (2) is a bidirectional power converter.
[0027] In the context of this invention, without limiting the scope of the invention, the DC-DC converter will be understood as power bidirectional, or implicitly as a bidirectional component having input and output, wherein power can flow from the input to the output or from the output to the input. Furthermore, without limiting the scope of the invention, it should be understood that the component is voltage bipolar or ambiguous bipolar when the voltage measured between the first and second outputs of the component can be both positive and negative.
[0028] In a preferred embodiment, without limiting the scope of the invention, the DC-DC converter (2) may include a transformer (21) having a primary and a secondary, a first H-bridge (22) connected to the primary of the transformer (21), and a second H-bridge (23) connected to the secondary of the transformer (21). Furthermore, the second H-bridge (23) is bidirectional and bipolar. The relationship between the number of turns in the primary and secondary windings of the transformer (21) does not limit the scope of the invention.
[0029] Furthermore, the partial power DC-DC converter (1), the subject of this invention, also includes a first DC voltage input (7) electrically connected to the negative output (6) of the DC-DC converter (2) and a first DC voltage output (9) electrically connected to the positive output (5) of the DC-DC converter (2). Additionally, the partial power DC-DC converter (1), the subject of this invention, includes an input reference (8) and an output reference (10) electrically connected to both the input reference (8) and the negative input (4) of the DC-DC converter (2). In this way, for example and without limiting the scope of the invention, the partial power DC-DC converter (1), the subject of this invention, allows connection between two DC devices connected to the first DC voltage input (7) and the input reference (8), respectively; and connection to the first DC voltage output (9) and the output reference (10).
[0030] As previously described, the partial power DC-DC converter (1), the subject of this invention, further includes a set of switches (11, 12) that allow control of the topology of the partial power DC-DC converter (1) between a Type I topology and a Type II topology. A first switch (11) is arranged to selectively connect a first DC voltage input (7) to the positive input (3) of the DC-DC converter (2). A second switch (12) is arranged to selectively connect the positive output (5) of the DC-DC converter (2) to the positive input (3) of the DC-DC converter.
[0031] In the context of this invention, the term "selective connection" should be understood as a connection controlled by the switching state of a switch. In this sense, for example and without limiting the scope of the invention, when the first switch (11) is in the closed position, an electrical connection is provided between the first DC voltage input (7) and the positive input (3) of the DC-DC converter (2). Conversely, when the first switch (11) is in the open position, the electrical connection between the first DC voltage input (7) and the positive input (3) of the DC-DC converter (2) is interrupted. Similarly, without limiting the scope of the invention, the electrical connection between the positive output (5) of the DC-DC converter (2) and the positive input (3) of the DC-DC converter will be controlled by the switching state of the second switch (12).
[0032] Furthermore, the properties of the first switch (11) and the second switch (12) do not limit the scope of the invention. Without limiting the scope of the invention, the first switch (11) and the second switch (12) may or may not be implemented in the same manner.
[0033] In a preferred embodiment, without limiting the scope of the invention, the first switch (11) and the second switch (12) may be unidirectional switches. For example, and without limiting the scope of the invention, the configuration may be obtained by arranging transistors in parallel with the rectifier diode. Without limiting the scope of the invention, the transistors may be bipolar transistors or field-effect transistors. In a preferred embodiment, without limiting the scope of the invention, the transistors are field-effect transistors, and the rectifier diodes are connected in anti-parallel to the source and drain of the field-effect transistor.
[0034] However, in other preferred embodiments, the first switch (11) and the second switch (12) may be bidirectional switches. For example, and without limiting the scope of the invention, the configuration can be obtained by arranging two unidirectional switches in parallel with each other, wherein the unidirectional switches allow current to flow in opposite directions. Furthermore, in this preferred embodiment, the two unidirectional switches connected in parallel must be controlled such that their switching states are always the same.
[0035] As previously stated, the switching states of the first switch (11) and the second switch (12) allow control of the topology of the partial power DC-DC converter, the subject of this invention, between Type I and Type II topologies. However, advantageously and without limiting the scope of the invention, the partial power DC-DC converter (1), the subject of this invention, has a third operating mode, which will be referred to as bypass without limiting the scope of the invention. In this bypass configuration, independent of the operation of the DC-DC converter (2), the DC device connected to the first voltage input (7) and the first reference (8) is directly connected to the DC device connected to the first voltage output (9) and the second reference (10).
[0036] In order for the partial power DC-DC converter (1), which is the subject of this invention, to adopt a Type I topology, the first switch (11) must remain closed and the second switch (12) must remain open. In this way, Figure 3 The schematically shown partial power DC-DC converter (1) will obtain Figure 1 The topology shown.
[0037] In order for the partial power DC-DC converter (1), which is the subject of this invention, to adopt a Type II topology, the first switch (11) must remain open and the second switch (12) must remain closed. In this way, Figure 3 The schematically shown partial power DC-DC converter (1) will obtain Figure 2 The topology shown.
[0038] Finally, in order for the partial power DC-DC converter (1), which is the subject of this invention, to adopt a bypass topology, the first switch (11) and the second switch (12) must remain closed.
[0039] Based on the preceding description, a partial power DC-DC converter (1) with a topology controllable between Type I, Type II and bypass topologies and allowing connection of two DC devices can be obtained.
[0040] Furthermore, in other preferred embodiments, and without limiting the scope of the invention, other configurations can be provided for the interconnection between DC devices. For this purpose, multiple partial-power DC-DC converters (1a, 1b, 1c), each according to the invention, can be arranged and connected according to desired configurations.
[0041] In the first exemplary embodiment, as Figure 5As shown and without limiting the scope of the invention, the plurality of partial power DC-DC converters (1a, 1b, 1c) can be connected in an input-in-series-output-in-series (ISOS) configuration. In this configuration, the positive DC terminal of the first DC device is connected to the first DC voltage input (7a) of the first partial power DC-DC converter (1a) of the plurality of partial power DC-DC converters. For its own sake, the negative DC terminal of the first DC device is connected to the input reference (8c) of the last partial power DC-DC converter (1c). Similarly, the positive DC terminal of the second DC device is connected to the first DC voltage output (9a) of the first partial power DC-DC converter (1a), and the negative DC terminal of the second DC device is connected to the output reference (10c) of the last partial power DC-DC converter (1c). Furthermore, the input reference (8a) of the first partial power DC-DC converter (1a) is connected to the first voltage input (7b) of the second partial power DC-DC converter (1b); the input reference (8b) of the second partial power DC-DC converter (1b) is connected to the first voltage input (7c) of the third partial power DC-DC converter (1c), and so on, until all inputs of the multiple partial power DC-DC converters (1a, 1b, 1c) are connected. Similarly, the output reference (10a) of the first partial power DC-DC converter (1a) is connected to the first voltage output (9b) of the second partial power DC-DC converter (1b); the output reference (10b) of the second partial power DC-DC converter (1b) is connected to the first voltage output (9c) of the third partial power DC-DC converter (1c), and so on, until all outputs of the multiple partial power DC-DC converters (1a, 1b, 1c) are connected.
[0042] In the second exemplary embodiment, as Figure 6As shown and without limiting the scope of the invention, the plurality of partial power DC-DC converters (1a, 1b, 1c) can be connected in an input series-output parallel (ISOP) configuration. In this configuration, the positive DC terminal of the first DC device is connected to the first DC voltage input (7a) of the first partial power DC-DC converter (1a) of the plurality of partial power DC-DC converters. For its own sake, the negative DC terminal of the first DC device is connected to the input reference (8c) of the last partial power DC-DC converter (1c). On the other hand, the positive DC terminal of the second DC device is connected to each of the first DC voltage outputs (9a, 9b, 9c) of the partial power DC-DC converters (1a, 1b, 1c) that form part of the plurality of partial power DC-DC converters, and the negative DC terminals of the plurality of DC devices are connected to each of the output references (10a, 10b, 10c) of the partial power DC-DC converters (1a, 1b, 1c) that form part of the plurality of partial power DC-DC converters. Furthermore, the input reference (8a) of the first partial power DC-DC converter (1a) is connected to the first voltage input (7b) of the second partial power DC-DC converter (1b); the input reference (8b) of the second partial power DC-DC converter (1b) is connected to the first voltage input (7c) of the third partial power DC-DC converter (1c), and so on, until all inputs of the multiple partial power DC-DC converters (1a, 1b, 1c) are connected.
[0043] In the third exemplary embodiment, such as Figure 7As shown and without limiting the scope of the invention, the plurality of partial power DC-DC converters (1a, 1b, 1c) can be connected in an input parallel output series (IPOS) configuration. In this configuration, the positive DC terminal of the first DC device is connected to each of the first DC voltage inputs (7a, 7b, 7c) of the plurality of partial power DC-DC converters (1a, 1b, 1c). Specifically, the negative DC terminal of the first DC device is connected to each of the input references (8a, 8b, 8c) of the plurality of partial power DC-DC converters (1a, 1b, 1c). On the other hand, the positive DC terminal of the second DC device is connected to the first DC voltage output (9a) of the first partial power DC-DC converter (1a), and the negative DC terminal of the second DC device is connected to the output reference (10c) of the last partial power DC-DC converter (1c). Furthermore, the output reference (10a) of the first partial power DC-DC converter (1a) is connected to the first voltage output (9b) of the second partial power DC-DC converter (1b); the output reference (10b) of the second partial power DC-DC converter (1b) is connected to the first voltage output (9c) of the third partial power DC-DC converter (1c), and so on, until all outputs of the multiple partial power DC-DC converters (1a, 1b, 1c) are connected.
[0044] In the fourth exemplary embodiment, such as Figure 8 As shown and without limiting the scope of the invention, the plurality of partial power DC-DC converters (1a, 1b, 1c) can be connected in an input-parallel-output-parallel (IPOP) configuration. In this configuration, the positive DC terminal of the first DC device is connected to each of the first DC voltage inputs (7a, 7b, 7c) of the plurality of partial power DC-DC converters (1a, 1b, 1c). For its own sake, the negative DC terminal of the first DC device is connected to each of the input references (8a, 8b, 8c) of the partial power DC-DC converters (1a, 1b, 1c). Similarly, the positive DC terminal of the second DC device is connected to each of the first DC voltage outputs (9a, 9b, 9c) of the plurality of partial power DC-DC converters (1a, 1b, 1c), and the negative DC terminals of the plurality of DC devices are connected to each of the output references (10a, 10b, 10c) of the plurality of partial power DC-DC converters (1a, 1b, 1c).
[0045] Based on the preceding detailed description, a topology can be obtained for a partial power DC-DC converter (1) that can be controlled by means of the switching states of the first switch (11) and the second switch (12).
[0046] It should be understood that various options described for the technical features of the partial power DC-DC converter (1), which is the subject of this invention, can be combined with each other or with other options known to those skilled in the art in any conceivable manner and without limiting the scope of the invention.
[0047] Examples of embodiments of the present invention will now be described. It should be understood that these examples are intended to provide a better understanding of the invention and do not limit its scope. Furthermore, without limiting the scope of the invention, the technical features described in the different examples can be combined with each other in any manner contemplated by those skilled in the art, or combined with other previously described technical features.
[0048] Example 1: Use of a partial power DC-DC converter in a battery array
[0049] like Figure 4 Schematably, a partial-power DC-DC converter, the subject of this invention, can be used to connect a group of batteries or a battery array (13) to a DC voltage line or bus (14). For this purpose, the positive terminal (131) and negative terminal (132) of the battery group or battery array are connected to the first voltage input (7) and input reference (8) of the partial-power DC-DC converter (1), respectively. Furthermore, the positive terminal (141) and negative terminal (142) of the DC voltage bus (14) are connected to the first voltage output (9) and output reference (10) of the partial-power DC-DC converter (1), respectively. In addition, an input capacitor (15) is provided to connect the first voltage input (7) to the input reference (8) and an output capacitor (16) is provided to connect the first voltage output (9) to the output reference (10). In addition, an output inductor (17) is provided to connect the positive output (5) of the DC-DC converter (2) to the first voltage output (9). Furthermore, in this exemplary embodiment, the DC-DC converter (2) is bidirectional in power, which allows for the charging and discharging of the battery (13).
[0050] Example 2: Implementation of a partial power DC-DC converter combined with a battery array
[0051] Figure 4 A schematic diagram of a partial power DC-DC converter combined with a battery array (13) is also shown. The connections are made as described in Example 1.
[0052] In this example, the DC-DC converter (2) is a current-isolated converter and includes a transformer (21) having a primary and a secondary. A first H-bridge (22) formed by four unidirectional switches is connected to the primary of the transformer (21), and a second H-bridge (23) formed by four bidirectional switches is connected to the secondary of the transformer (21). In addition, an output inductor (17) is provided to connect the positive output (5) of the DC-DC converter (2) to a first voltage output (9).
Claims
1. A partial power DC-DC converter (1) with a controllable topology, characterized in that, include: - A current-isolated DC-DC converter (2) with a positive input (3), a negative input (4), a positive output (5) and a negative output (6). - A first DC voltage input (7) is electrically connected to the negative output (6) of the DC-DC converter (2); - Input baseline (8); - A first DC voltage output (9) is electrically connected to the positive output (5) of the DC-DC converter (2); and - Output reference (10), electrically connected to the input reference (8) and the negative input (4) of the DC-DC converter (2); The partial power DC-DC converter (1) further includes: - A first switch (11) is arranged to selectively connect the first DC voltage input (7) to the positive input (3) of the DC-DC converter (2); and - A second switch (12) is arranged to selectively connect the positive output (5) of the DC-DC converter (2) to the positive input (3) of the DC-DC converter (2); and The DC-DC converter (2) is bidirectional in power and bipolar in voltage.
2. The partial power DC-DC converter (1) with a controllable topology according to claim 1, characterized in that, The first switch (11) and the second switch (12) are one-way switches.
3. The partial power DC-DC converter (1) with a controllable topology according to claim 2, characterized in that, Each of the unidirectional switches is formed by a field-effect transistor connected in parallel with a rectifier diode.
4. The partial power DC-DC converter (1) with a controllable topology according to claim 1, characterized in that, The first switch (11) and the second switch (12) are bidirectional switches.
5. The partial power DC-DC converter (1) with a controllable topology according to claim 1, characterized in that, The DC-DC converter (2) is selected from the group consisting of forward converters, push-pull converters, H-bridge converters, flyback converters, half-bridge converters and Ćuk converters.
6. The partial power DC-DC converter (1) with a controllable topology according to claim 1, characterized in that, The DC-DC converter (2) includes a transformer (21) having a primary and a secondary, a first H-bridge (22) connected to the primary of the transformer, and a second H-bridge (23) connected to the secondary of the transformer (21).