CN115360926A - Power conversion module and cascade converter - Google Patents

Power conversion module and cascade converter Download PDF

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Publication number
CN115360926A
CN115360926A CN202211066018.2A CN202211066018A CN115360926A CN 115360926 A CN115360926 A CN 115360926A CN 202211066018 A CN202211066018 A CN 202211066018A CN 115360926 A CN115360926 A CN 115360926A
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China
Prior art keywords
power conversion
cascade
conversion module
cascaded
unit
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CN202211066018.2A
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Chinese (zh)
Inventor
庄加才
徐君
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Sungrow Power Supply Co Ltd
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Sungrow Power Supply Co Ltd
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Priority to CN202211066018.2A priority Critical patent/CN115360926A/en
Publication of CN115360926A publication Critical patent/CN115360926A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/493—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode the static converters being arranged for operation in parallel
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/0077—Plural converter units whose outputs are connected in series
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

The application provides a power conversion module and a cascade type converter, wherein the first side of each cascade unit in the power conversion module is respectively connected with a corresponding winding in a coupling inductor in series, and two branches connected in series in this way are connected between two interfaces in the cascade side of the power conversion module in series or in parallel; and then when a plurality of power conversion modules realize cascading through self-cascade side, each winding is all connected in series, is equivalent to this application with the centralized reactance of prior art decompose into a plurality of distributed inductance, each winding need not additionally to set up the interval that satisfies the requirement to ground insulation again, has reduced the outside extra insulated space demand of inductance, has improved power density. Moreover, by adjusting the connecting line inside the power conversion module, the series-parallel relation conversion between the two cascade units can be realized, so that the power conversion module can respectively meet the requirements of large current and high voltage, and the adaptability of the power conversion module is further improved.

Description

Power conversion module and cascade converter
Technical Field
The present disclosure relates to power converters, and particularly to a power conversion module and a cascade converter.
Background
In a conventional cascaded converter, a reactance is connected in series at the end of each phase, as shown in fig. 1, and the cascaded unit 1 To a cascade unit n After series, a reactance is connected in series at the port of the phase. Because of the reactance to earth voltage needed to reach the system powerIn a 35kVac system, the voltage to ground of the reactance will reach 35kVac, and therefore special considerations for the installation of the reactance will be required, which will take up a lot of space and affect the power density of the system.
Disclosure of Invention
In view of the above, the present application provides a power conversion module and a cascaded converter to reduce the space requirement for additional insulation of the inductor outside and increase the power density.
In order to achieve the above purpose, the present application provides the following technical solutions:
the present application provides in a first aspect a power conversion module, including: coupling inductors and two cascade units;
the first side of each cascade unit is respectively connected with the corresponding winding in the coupling inductor in series to form a corresponding series branch;
the two serial branches are connected in series or in parallel between two interfaces inside the cascade side of the power conversion module;
and the second side of each cascade unit is used for connecting the power supply side internal interface of the power conversion module.
Optionally, the first sides of the two cascade units are connected in series through the coupling inductor; and two ends of the branch obtained by series connection are respectively connected with two interfaces inside the cascade side of the power conversion module.
Optionally, one of the cascade units is connected to the different name end of the corresponding winding;
the other cascade unit is connected with the homonymous terminal of the other winding;
the other ends of the two windings are connected.
Optionally, one end of the first side of each of the two cascade units is connected in parallel to an interface inside the cascade side of the power conversion module;
the other end of the first side of each cascade unit is connected with one end of a corresponding winding in the coupling inductor, and the other end of each winding is connected in parallel with the other interface in the cascade side of the power conversion module.
Optionally, the two cascade units are respectively connected to the dotted terminals of the corresponding windings;
the different name ends of the two windings are connected.
Optionally, the cascade unit is an inversion unit;
the alternating current side of the inversion unit is used as the first side of the cascade unit;
and the direct current side of the inversion unit is used as the second side of the cascade unit.
Optionally, the dc side of the inverter unit and the power side of the power conversion module correspond to each other between the internal interfaces, and further provided with: a DC converter; or,
and the power supply side internal interface of the power conversion module is respectively connected with the direct current side of each inversion unit through a multi-port direct current converter.
Optionally, the inverter unit is a half-bridge inverter unit or a full-bridge inverter unit.
The second aspect of the present application further provides a cascaded converter, including at least one cascaded branch, where the cascaded branch includes: at least one power conversion module as described in any of the above first aspects;
when the number of the power conversion modules in the cascade branch is more than 1, the cascade side external interfaces of the power conversion modules are sequentially connected in series.
Optionally, the cascade branch further includes: a total inductance that suppresses output ripple;
the total inductor is connected with one end of the cascade branch in series.
Optionally, when there is no dc converter in the power conversion module, the cascade branch further includes: a plurality of DC converters disposed outside the power conversion module;
each direct current converter is correspondingly connected with the cascade unit of each power conversion module in the cascade branch one by one; or, each cascade unit in the same power conversion module is respectively connected with the same multi-port direct current converter.
Optionally, the cascade unit in the power conversion module is an inverter unit, the number of the cascade branches is 3, and the alternating current sides of the three-phase cascade branches are connected in a star or an angular shape.
According to the power conversion module, the first sides of all cascade units in the power conversion module are respectively connected with corresponding windings in the coupling inductors in series, and the branches after the series connection are used for being connected with the internal interfaces of the cascade sides of the power conversion module; when a plurality of power conversion modules realize cascade connection through the cascade connection side, all windings are connected in series, which is equivalent to the method for decomposing the centralized reactance in the prior art into a plurality of distributed inductors; because the potential of each winding is close to the cascade unit connected with the winding, and the distance between the cascade unit and the ground meets the insulation requirement, the windings do not need to be additionally provided with the distance meeting the requirement on the ground insulation, the space requirement of the inductor on external extra insulation is reduced, and the power density is improved. Moreover, by adjusting the connecting line inside the power conversion module, the series-parallel relation conversion between the two cascade units can be realized, so that the power conversion module can respectively meet the requirements of large current and high voltage, and the adaptability of the power conversion module is further improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a schematic diagram of a cascaded converter provided in the prior art;
fig. 2 to fig. 4 are schematic diagrams of three internal structures of a power conversion module according to an embodiment of the present disclosure;
fig. 5 and fig. 6 are schematic diagrams of a cascade of two other power conversion modules provided in this embodiment of the present application, respectively;
fig. 7 and fig. 8 are two topologies of a cascaded unit provided in an embodiment of the present application, respectively;
fig. 9 to fig. 12 are schematic diagrams of four structures of a cascade branch according to an embodiment of the present disclosure;
fig. 13 to fig. 16 are four topology diagrams of the power conversion module according to the embodiment of the present application;
fig. 17 and fig. 18 are two topologies of a cascaded branch according to an embodiment of the present application;
fig. 19 is a schematic structural diagram of a cascaded converter provided in an embodiment of the present application;
fig. 20 is another schematic structural diagram of a cascade branch according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a component of' 8230; \8230;" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.
The application provides a power conversion module to reduce the external extra insulated space requirement of inductance, improve power density.
As shown in fig. 2, the power conversion module 10 includes: a coupling inductor 102 and two cascade units 101; in fig. 2, an nth power conversion module 10 (module n for short) is shown as an example, and two cascade units 101 thereof are cascade units respectively n1 And a cascade unit n2 (ii) a Wherein:
the first side of each cascade unit 101 is connected in series with the corresponding winding of the coupling inductor 102, such as the cascade unit shown in fig. 2 n1 Cascade unit connected in series with winding L1 n2 The branch circuit is connected in series with the winding L2, and the branch circuit after the series connection is used for connecting the cascade side internal interface of the power conversion module 10; in practical applications, each of the cascade units 101 and the corresponding winding are connected in series to form a series branch, which may be connected in series (as shown in fig. 2) or in parallel (as shown in fig. 3 or fig. 4) between two interfaces inside the cascade side of the power conversion module 10, so as to further improve system compatibility. The cascade-side external interface of the power conversion module 10 is used for series connection with the cascade-side external interfaces of other power conversion modules 10.
The second side of each cascade unit 101 is used for connecting the power supply side internal interface of the power conversion module 10; the power source side external interface of the power conversion module 10 is used for connecting a corresponding power source, such as a photovoltaic module, a photovoltaic string, a battery module or a battery cluster.
As shown in fig. 2, when a plurality of power conversion modules 10 are cascaded by their own cascade side, each winding is connected in series, which is equivalent to the present application that the centralized reactance in the prior art is decomposed into a plurality of distributed inductances, and the distributed inductances are respectively arranged together with the corresponding cascade units 101.
Because the potential of each winding is close to that of the cascade unit 101 connected to the winding, and the distance between the cascade unit 101 itself and the ground meets the insulation requirement, the winding does not need to be additionally provided with a distance meeting the insulation requirement on the ground, so the power conversion module 10 provided by the embodiment can reduce the space requirement of the inductor for additionally insulating the inductor from the outside, and improve the power density.
Moreover, by adjusting the connecting line inside the power conversion module, the series-parallel relation conversion between the two cascade units can be realized, so that the power conversion module can respectively meet the requirements of large current and high voltage, and the adaptability of the power conversion module is further improved.
In practical applications, when two cascade units 101 need to be connected in series, the two cascade units 101 are connected in seriesA first side connected in series through a coupling inductor 102; two ends of the branch obtained by the series connection are respectively connected with two interfaces inside the cascade side of the power conversion module 10. At this time, one cascade unit 101 is connected to the synonym terminal of the corresponding winding; another cascade unit 101 connected to the end of the same name of another winding; the other ends of the two windings are connected. FIG. 2 shows an example of a module n, in which the upper cascade unit n1 The upper end output of the power conversion module 10 is used as the upper output of the power conversion module, the lower end of the power conversion module is connected with the synonym end of the winding L1 in the coupling inductor 102, and the synonym end of the winding L1 in the coupling inductor 102 is connected with the synonym end of the winding L2; while the following cascade cells n2 The output of the upper end of the power conversion module is connected to the dotted terminal of the winding L2 in the coupling inductor 102, and the output of the lower end of the power conversion module is used as the lower output of the power conversion module 10.
When the two cascade units 101 need to be used in parallel, one ends of the first sides of the two cascade units 101 are connected in parallel to an interface inside the cascade side of the power conversion module 10; the other ends of the first sides of the two cascade units 101 are connected to one end of the corresponding winding in the coupling inductor 102, and the other end of each winding is connected in parallel to the other interface inside the cascade side of the power conversion module 10. At this time, the two cascade units 101 are respectively connected to the homonymous terminals of the corresponding windings, and the heteronymous terminals of the two windings are connected. Fig. 3 also shows, by way of example, a module n, in which the upper cascade unit is arranged n1 The upper end of the inductor is connected with the same name end of the winding L1 in the coupling inductor 102, and the lower end of the inductor is connected with the lower cascade unit n2 And as the lower output of the module 10; the different name end of the winding L1 in the coupling inductor 102 is connected with the different name end of the winding L2 and is used as the upper output of the power conversion module 10, and the lower cascade unit n2 Is connected to the dotted terminal of winding L2 in coupled inductor 102. As shown in fig. 4, the coupling inductor 102 may also be connected to the lower output of the power conversion module 10, which is not described herein.
When the two cascade units 101 are connected in series through the coupling inductor 102, a plurality of such power conversion modules 10 can meet the high voltage requirement of the system after being cascaded; when the two cascade units 101 are connected in parallel through the coupling inductor 102, a plurality of power conversion modules 10 can meet the large current requirement of the system after being cascaded; in practical applications, the related components shown in fig. 2 to 4 are substantially the same, and the series-parallel relationship conversion between the two cascade units 101 can be realized only by adjusting the internal connection line of the power conversion module 10, so that the power conversion module 10 switches between meeting the requirements of large current and meeting the requirements of high voltage and low voltage, thereby increasing the application range of the power conversion module 10.
In addition, by designing the coupling coefficient of the coupling inductor 102, the cascade unit can be adjusted n1 、 n2 When the two units are operated in parallel, the equivalent differential mode impedance between the two units further inhibits the problems of current sharing, weak direct connection and the like caused by inconsistent characteristics of the two cascade units 101, and improves the reliability of the system.
In practical applications, the cascade unit 101 in the above embodiments may be a power conversion unit with any conversion function, such as an inverter unit, where an ac side of the inverter unit serves as a first side of the cascade unit 101, and a dc side of the inverter unit serves as a second side of the cascade unit 101. It should be noted that, if the dc side of the inverter unit is used to connect a photovoltaic module or a photovoltaic string, the inverter unit is only used to convert dc to ac; if the direct current side of the inverter unit is used for connecting a battery module or a battery cluster, the inverter unit needs to realize bidirectional conversion from direct current to alternating current; the circuit topology in both cases can be found in the prior art, and the details are not described here and are within the scope of the present application.
In addition, the front stage of the inversion unit can be provided with a corresponding direct current converter so as to realize a primary direct current voltage regulation function for the direct current input/output connected with the direct current converter or realize a photovoltaic maximum power point tracking function; in practical applications, the dc converter may be disposed inside the power conversion module 10, and certainly, may also be disposed outside the power conversion module 10, which are all within the protection scope of the present application.
When the dc converters are disposed inside the power conversion module 10, the dc converters may correspond to the cascade units 101 one by one (as shown in fig. 5), or may be connected to at least two cascade units 101 through a multi-port dc converter (as shown in fig. 6). Specifically, the method comprises the following steps:
referring to FIG. 5, each inversion unit (shown as a cascade unit in the figure) n1 And a cascade unit n2 ) Between the internal interfaces corresponding to the dc side and the power side of the power conversion module 10, there are respectively provided: a corresponding dc converter 103.
Referring to fig. 6, the power-side internal interface of the power conversion module 10 may also be connected to the dc side of each inverter unit through a multi-port dc converter 103; fig. 6 shows a 3-port dc converter 103 as an example, in which 2 ports are respectively connected to the dc sides of two inverter units in the power conversion module 10, and the other port is connected to an internal interface of the power supply side, so as to be connected to an external power supply as a dc input/output.
In practical application, the inverter unit may be a half-bridge inverter unit (as shown in fig. 7), or may also be a full-bridge inverter unit (as shown in fig. 8), or may also be other topology units capable of implementing an inverter function in the prior art, depending on the specific application environment, and all of them are within the protection scope of the present application.
Another embodiment of the present application further provides a cascaded converter, as shown in fig. 9 to 18, including at least one phase (one phase is shown as an example in the drawings) cascaded branch, where each cascaded branch includes: at least one power conversion module 10 as described in any of the above embodiments; in the cascade branch, the cascade-side external interfaces of the power conversion modules 10 are connected in series in sequence.
The structure and principle of the power conversion module 10 can be obtained by referring to the above embodiments, and are not described in detail herein. In the embodiment, the cascade converter adopts a plurality of power conversion modules 10 cascaded to form a phase cascaded branch, so that a common reactance in the prior art can be disassembled into each power conversion module 10, thereby reducing the insulation requirement. Moreover, when the power conversion module 10 is disassembled for application, two cascade units 101 and the coupling inductor 102 are adopted to form one power conversion module 10 (as shown in fig. 2 to fig. 4), and the series-parallel conversion of the cascade units 101 can be realized by changing the connection lines in the power conversion module 10, so that the switching is performed between the requirements of large current and high voltage, and the adaptability of the power conversion module 10 can be further improved. The following further describes the connection method of the multi-mode group cascade system when the coupling inductor is used to form the power conversion module.
As shown in fig. 9, two cascade units (cascade units shown in the figure) inside a plurality of power conversion modules (module 1 to module n shown in the figure) 10 11 And a cascade unit 12 Of cascaded units 21 And a cascade unit 22 And, a cascade unit n1 And a cascade unit n2 ) All are connected in series through corresponding coupling inductors to form a system, namely a one-phase cascade branch.
As shown in fig. 10, two cascade units (cascade units shown in the figure) inside a plurality of power conversion modules (module 1 to module n shown in the figure) 10 11 And a cascade unit 12 Of cascaded units 21 And a cascade unit 22 And, a cascade unit n1 And a cascade unit n2 ) The two inductors are connected in parallel through corresponding coupling inductors (the parallel connection at the lower end is taken as an example for demonstration), and then are connected in series to form a system. The parallel connection mode of the two cascade units at the same upper end is similar to the parallel connection mode and is not shown.
When there is a dc converter in the power conversion module (e.g., module 1 to module n shown in the figure) 10, each cascade unit (e.g., cascade unit shown in the figure) is shown in fig. 11 11 And a cascade unit 12 Of cascaded units 21 And a cascade unit 22 And, a cascade unit n1 And a cascade unit n2 ) The direct current sides of the cascade units are respectively connected with corresponding ports of a 3-port direct current converter, and the alternating current sides of the cascade units are connected in series after being connected in series to form a system. The dc converters are not shown one by one in the power conversion module 10, and the ac sides of the respective cascade units are connected in parallel, and the respective cascade units are equipped with a corresponding dc converter.
In practical applications, if there is no dc converter in the power conversion module 10, the cascade branch may further include: multiple sets of power conversion modulesA dc converter external to the bank 10. Each dc converter may be connected to the cascade units of each power conversion module 10 in the cascade branch in a one-to-one correspondence (not shown). Alternatively, each cascade unit in the same power conversion module 10 may also be connected to a dc converter with the same multi-port; as shown in fig. 12, two cascaded units (the cascaded units shown in the figure) 11 And a cascade unit 12 Of cascaded units 21 And a cascade unit 22 And, a cascade unit n1 And a cascade unit n2 ) The dc sides of the cascade units are connected to the external 3-port dc converters 20 of the modules (e.g., the modules 1 to n shown in the figure), and the ac sides of the cascade units are connected in parallel and then connected in series to form a system. The parallel connection mode of the common upper end of the two cascade units and the condition that the alternating current sides of the two cascade units are connected in series are not shown one by one.
As shown in fig. 13, the cascade unit may be an inverter unit with a half-bridge structure, and two half-bridge cascade units are connected to form a series structure to form a half-bridge series module.
As shown in fig. 14, the cascade unit may be an inverter unit with a half-bridge structure, and two half-bridge cascade units are connected in parallel (for example, a common-bottom-end parallel connection mode) to form a half-bridge parallel module.
As shown in fig. 15, the cascade unit may be an inverter unit with a full-bridge structure, and two full-bridge cascade units are connected to form a full-bridge series module.
As shown in fig. 16, the cascade unit may be an inverter unit with a full-bridge structure, and two full-bridge cascade units are connected in parallel to form a full-bridge parallel module.
As shown in fig. 17, a plurality of half-bridge series modules shown in fig. 13 are connected in series to constitute a system.
As shown in fig. 18, a plurality of half-bridge parallel modules shown in fig. 14 are connected in series to form a system.
As shown in fig. 19, three series systems of fig. 13 may be connected in three phases to form a three-phase structure. Moreover, the ac side of the three-phase cascade branch (each cascade branch is shown by taking the structure shown in fig. 12 as an example) may be in a star connection manner shown in fig. 19, or may also be in an angle connection manner (not shown), both connection manners are the same as those in the prior art, and are not described again; the specific connection mode is selected according to the specific application environment, and is within the protection scope of the present application.
In the embodiment, the centralized total reactance in the prior art is decomposed into each power conversion module, so that the space requirement of extra insulation outside the inductor is reduced, and the power density is improved. Moreover, when the coupling inductor and the two cascade unit groups are adopted to form the power conversion module, the series-parallel connection conversion of the internal cascade units can be realized by changing the wiring mode, various problems of direct parallel connection of the output of the power conversion module can be solved through the coupling coefficient design of the coupling inductor, and the universality of the power conversion module is improved.
It should be noted that, in the prior art, the centralized total reactance not only can implement a filtering function, but also can implement a function of suppressing sudden change of the port voltage, so that, for suppressing the total output fluctuation of the cascade system, such as zero voltage ride through required by the power grid, etc., under the condition that the required inductance is large, in order to keep the design of the power conversion module 10 consistent, only a part of the inductances for suppressing the switching ripple of the cascade units can be split into the cascade units, and the part of the inductances for suppressing the total output fluctuation of the system is still handled by one total inductance 30.
In this case, the system configuration may be as shown in fig. 20 (which is illustrated on the basis of fig. 2), and the cascade branch further includes: a total inductance 30 that suppresses output ripple; the total inductance 30 is connected in series at one end of the cascaded branch.
However, in practical application, not all application scenarios need to cope with the situation, so that on the occasion of no system voltage mutation, the equivalent switching frequency of the cascade system is very high, the requirement on the total reactance is low, and the distributed inductor L has a greater advantage because an additional insulation space of the centralized reactance is saved. In addition, the power conversion module 10 can also supplement the external total inductor 30 in the case of sudden change of the system voltage, thereby further increasing the adaptive range of the system.
The same and similar parts among the various embodiments in this specification can be referred to each other, and each embodiment focuses on differences from other embodiments. In particular, the system or system embodiments, which are substantially similar to the method embodiments, are described in a relatively simple manner, and reference may be made to some descriptions of the method embodiments for relevant points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement without inventive effort.
Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the components and steps of the various examples have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the above description of the disclosed embodiments, features described in various embodiments in this specification can be substituted for or combined with each other to enable those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (12)

1. A power conversion module, comprising: coupling inductors and two cascade units;
the first side of each cascade unit is respectively connected with the corresponding winding in the coupling inductor in series to form a corresponding series branch;
the two serial branches are connected in series or in parallel between two interfaces in the cascade side of the power conversion module;
and the second side of each cascade unit is respectively used for connecting the power supply side internal interface of the power conversion module.
2. The power conversion module of claim 1, wherein the first sides of the two cascaded units are connected in series via the coupling inductor; and two ends of the branch obtained by series connection are respectively connected with two interfaces inside the cascade side of the power conversion module.
3. The power conversion module of claim 2, wherein one of said cascade units is connected to a different-name terminal of a corresponding winding;
the other cascade unit is connected with the homonymous end of the other winding;
the other ends of the two windings are connected.
4. The power conversion module of claim 1, wherein the first side ends of the two cascaded units are connected in parallel to an interface inside the cascaded side of the power conversion module;
the other ends of the first sides of the two cascade units are connected with one end of a corresponding winding in the coupling inductor, and the other end of each winding is connected in parallel with the other interface inside the cascade side of the power conversion module.
5. The power conversion module of claim 4, wherein two of said cascaded units are connected to the same-name terminals of the corresponding windings, respectively;
the different name ends of the two windings are connected.
6. The power conversion module of any one of claims 1 to 5, wherein the cascade unit is an inverter unit;
the alternating current side of the inversion unit is used as the first side of the cascade unit;
and the direct current side of the inversion unit is used as the second side of the cascade unit.
7. The power conversion module according to claim 6, wherein between the dc side of the inverter unit and the corresponding internal interface of the power side of the power conversion module, there are further provided: a DC converter; or,
the power supply side internal interface of the power conversion module is respectively connected with the direct current side of each inversion unit through a multi-port direct current converter.
8. The power conversion module of claim 6, wherein the inverter unit is a half-bridge inverter unit or a full-bridge inverter unit.
9. A cascaded converter, comprising at least one cascaded branch, wherein the cascaded branch comprises: at least one power conversion module according to any one of claims 1 to 8;
when the number of the power conversion modules in the cascade branch is larger than 1, the cascade side external interfaces of the power conversion modules are sequentially connected in series.
10. The cascaded converter of claim 9, further comprising in the cascaded branch: a total inductance that suppresses output ripple;
the total inductor is connected with one end of the cascade branch in series.
11. The cascaded converter according to claim 9, wherein when there is no dc converter in the power conversion module, the cascaded branch further comprises: a plurality of DC converters disposed outside the power conversion module;
each direct current converter is connected with the cascade unit of each power conversion module in the cascade branch in a one-to-one correspondence manner; or each cascade unit in the same power conversion module is respectively connected with the direct current converter with the same multi-port.
12. The cascaded converter according to any one of claims 9 to 11, wherein the cascaded units in the power conversion module are inversion units, the number of the cascaded branches is 3, and the alternating-current sides of the three-phase cascaded branches are connected in a star shape or an angular shape.
CN202211066018.2A 2022-09-01 2022-09-01 Power conversion module and cascade converter Pending CN115360926A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117674063A (en) * 2024-02-01 2024-03-08 中科智寰(北京)科技有限公司 Direct-current electric energy router and photovoltaic access direct-current load power supply system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117674063A (en) * 2024-02-01 2024-03-08 中科智寰(北京)科技有限公司 Direct-current electric energy router and photovoltaic access direct-current load power supply system

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