WO2020007516A1 - Convertisseur modulaire à plusieurs niveaux amélioré - Google Patents

Convertisseur modulaire à plusieurs niveaux amélioré Download PDF

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Publication number
WO2020007516A1
WO2020007516A1 PCT/EP2019/060495 EP2019060495W WO2020007516A1 WO 2020007516 A1 WO2020007516 A1 WO 2020007516A1 EP 2019060495 W EP2019060495 W EP 2019060495W WO 2020007516 A1 WO2020007516 A1 WO 2020007516A1
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WO
WIPO (PCT)
Prior art keywords
waveshaper
connection point
branch
string
point
Prior art date
Application number
PCT/EP2019/060495
Other languages
English (en)
Inventor
Yuhei OKAZAKI
Kalle ILVES
Panagiotis Bakas
Anshuman Shukla
Original Assignee
Abb Schweiz Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Abb Schweiz Ag filed Critical Abb Schweiz Ag
Priority to GB2100235.7A priority Critical patent/GB2590211B/en
Publication of WO2020007516A1 publication Critical patent/WO2020007516A1/fr

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Classifications

    • 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
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H02M7/49—Combination of the output voltage waveforms of a plurality of converters
    • 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
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • 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
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H02M7/4835—Converters with outputs that each can have more than two voltages levels comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage
    • 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
    • H02M7/497—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 sinusoidal output voltages being obtained by combination of several voltages being out of phase
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
    • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
    • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
    • H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
    • H02P27/14—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation with three or more levels of voltage

Definitions

  • the present invention relates to a voltage source converter.
  • the thyristor-based load commutated converter has been employed for high-power High Voltage Direct Current (HVDC) systems.
  • HVDC High Voltage Direct Current
  • One of the drawbacks of such a converter is its lack of black start capability and independent active and reactive power controllability.
  • a modular multilevel converter is one type of voltage source converter that has been accepted to be an alternative of the LCC in lower power range, e.g., active power up to 3 GW in bipole system. This is because of the fact that the MMC can overcome the mentioned drawbacks in the LCC. In order to replace the LCC with the MMC, the MMC needs to handle as much current as the LCC is capable of, so that the MMC can cover the entire power range of the LCC.
  • An active power device is typically a power device that is controllable to both being turned on an off, and may be a transistor.
  • This hybrid topology employs a string of director switches connected between two Direct Current (DC) poles and a waveshaper branch comprising multilevel submodules connected to this string of director switches.
  • the director switches are used for directivity and the multilevel submodules for waveshaping.
  • EP 2999105 discloses one such hybrid modular multilevel converter (MMC) having three parallel phase legs, where each phase leg comprises a string of director switches realized as anti-parallel thyristors connected in series with submodules.
  • MMC modular multilevel converter
  • US 2014/0092661 discloses another hybrid converter with parallel phase legs, where a phase leg has a first string comprising a plurality of controllable semiconductor switches, a first connecting node and a second connecting node. Furthermore, the leg includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, where the second string includes submodules.
  • SMMC series MMC
  • a number of converter modules are connected in series between two DC terminals and each converter module comprises a string of director switches connected in parallel with a string of submodules.
  • SMMC series MMC
  • the hybrid topology cannot maximize the thyristor-current capability in terms of its peak/average/rms current because the transmission power is limited by a peak/rms current rating of the submodule switches that are realized as active power devices.
  • the thyristor current in both peak and rms can be close to twice as high as those of the active power devices such as
  • Reduce cost/MVA Mega Volt Ampere
  • the MMC can be used for an alternative of LCC in terms of the power transmission capability if two MMCs or two arms are connected in parallel. However, it doubles the required number of power devices, leading to the same cost/MVA to the single MMC.
  • Reduce DC voltage stress on transformer The series converter
  • the present invention is directed towards obtaining an improved modular multilevel converter where at least some of the above-mentioned issues are overcome.
  • a voltage source converter having a first and a second direct current, DC, terminal for connection to a DC voltage and comprising: a number of converter modules, one for each phase of an alternating current, AC, waveshape to be generated, the converter modules being connected between the DC terminals and each comprising
  • a first and a second DC connection point for connection between the first and second DC terminals
  • a first string of director switches comprising at least two director switches, the midpoint of which string provides a third connection point
  • a first and a second waveshaper branch connected in parallel with each other as well as connected to the first string of director switches, each waveshaper branch comprising a number of submodules and being connected to an AC connection point provided for the branch
  • the first and second waveshaper branches are controllable to produce two similar waveshapes for the AC link and the director switches are controllable to change the way the waveshapes are applied to some of the connection points.
  • the converter modules may be connected in series between the DC terminals using the first and second DC connection points. As an alternative, the converter modules may be connected in parallel between the DC terminals using the first and second DC connection points.
  • the director switches may be thyristor switches, for instance realized using pairs of anti-parallel thyristors.
  • the director switches may also be controllable to change the polarity of the waveshape provided by the waveshaper branches.
  • first and second waveshaper branches there may be least one first inductor connected between the associated AC connection point of the waveshaper branch and a first point of the first string leading to the first DC connection point and at least one second inductor connected between the associated AC connection point and a second point of the first string leading to the second DC connection point.
  • Each waveshaper branch may furthermore have a first and a second end.
  • at least one end of each waveshaper branch is connected to the corresponding point of the first string via the corresponding at least one inductor.
  • the ends being connected in this way may be the same ends of the waveshaper branches.
  • the first ends of both waveshaper branches may be connected to the first point of the first string via the at least one first inductor.
  • the second ends are connected to the second point of the first string via the at least one second inductor.
  • first end of the first waveshaper branch may additionally be connected to the first point of the first string via a separate inductor
  • the first end of the second waveshaper branch may be connected to the first point of the first string via a separate inductor
  • the second end of the first waveshaper branch may be connected to the second point of the first string via a separate inductor
  • the second end of the second waveshaper branch is connected to the second point of the first string via a separate inductor.
  • the at least one first inductor may be a first common inductor connected between the waveshaper branches and having a midpoint with a connection leading to the first point of the first string and the at least one second inductor may be a second common inductor connected between the waveshaper branches and having a midpoint with a connection leading to the second point of the first string.
  • the first ends of the first and second waveshaper branches are connected to the first point of the first string via a midpoint of a first common inductor.
  • the second ends of the first and second waveshaper branches are connected to the second point of the first string via a midpoint of the second common inductor.
  • Each waveshaper branch may additionally comprise a first and a second chain link with submodules.
  • a first end of the first chain link of the first waveshaper branch is directly connected to the first point of the string and a second end of the first chain link of the first waveshaper branch is connected to the AC connection point of the first waveshaper branch via a first separate inductor
  • a first end of the first chain link of the second waveshaper branch is directly connected to the first point of the string
  • a second end of the first chain link of the second waveshaper branch is connected to the AC connection point of the second waveshaper branch via another first separate inductor
  • a first end of the second chain link of the first waveshaper branch is directly connected to the second point of the string
  • a second end of the second chain link of the first waveshaper branch is connected to the AC
  • connection point of the first waveshaper branch via a second separate inductor a first end of the second chain link of the second waveshaper branch is directly connected to the second point of the string and a second end of the second chain link of the second waveshaper branch is connected to the AC connection point of the second waveshaper branch via another second separate inductor.
  • the first and second waveshaper branches may furthermore be connected in parallel with the first and second switches.
  • Each waveshaper branch may furthermore comprise an upper waveshaper arm comprising submodules, a lower waveshaper arm comprising submodules and an intermediate arm between the lower and upper waveshaper arms, where the intermediate arm is connected in parallel with a second string of switches, wherein the AC connection point associated with a waveshaper branch is provided at a midpoint of the second string of switches.
  • the second string of switches may thereby be connected between a first and a second junction of a waveshaper branch, where the first junction is a junction between the upper and intermediate arm and the second junction is a junction between the intermediate and lower arm.
  • the intermediate arms may comprise submodules. As an alternative they may each comprise a capacitor in series with a bypass switch.
  • the AC connection point associated with a waveshaper branch is a first AC connection point that is common to or shared by the first and second waveshaper branches.
  • a first AC connection point may alternatively be provided for the first waveshaper branch and a second AC connection point may be provided for the second waveshaper branch.
  • the first AC connection point may for instance be provided at a midpoint of the first waveshaper branch while the second AC connection point may be provided at a midpoint of the second waveshaper branch.
  • the first and second AC connection points may also be connected to the same conductor for the phase of the AC link for forming an AC voltage of the converter module, while the third connection point may be an AC connection point connected to another conductor for the phase of the AC link.
  • the first and second AC connection points of the first and second waveshaper branches may be interconnected.
  • the first AC connection point of the first waveshaper branch may be connected to a secondary winding of a first transformer and the second AC connection point of the second waveshaper branch may be connected to a secondary winding of a second transformer, where the primary windings of these two transformers are connected in parallel to the corresponding phase of the
  • the first point of the first string may be placed at a junction between the first switch and the first DC connection point and the second point of the first string may be placed at a junction between the second switch and the second DC connection point.
  • the present invention has a number of advantages. It allows an increase of the current through the first string of switches to twice the size compared with the current through a waveshaper branch, which improves the efficiency of a string if thyristors are used. The current capability of the whole system is thereby also raised through only doubling the number of components in the submodules, but retaining the number of director switch components. Another advantage is that the number of redundant submodules may be reduced compared with the use of redundant parallel submodules for a single waveshaper branch.
  • the replacement of an LCC HVDC system with the MMC using the above-described converter module offers several further advantages such as black start capability,
  • fig. 2 schematically shows a second type of voltage source converter with first, second and third converter modules connected in parallel with each other,
  • fig. 3 schematically shows a first type of converter module that may be used in both the first and second types of converters
  • fig. 4A and 4B schematically show two types of submodules that may be used in the converter module
  • fig. 5 schematically shows a second type of converter module that may be used in both the first and second types of converters
  • fig. 6 schematically shows a third type of converter module that may be used in both the first and second types of converters
  • fig. 7 schematically shows a variation of the third type of converter module
  • fig. 8 schematically shows the second type of converter module connected to a first and a second transformer
  • fig. 9 schematically shows a fourth type of converter module
  • fig. n shows one realization of the second type of converter where the fifth type of converter module is used with first and second transformers.
  • Fig. l shows a first type of modular multilevel converter (MMC) in the form of a series modular multilevel converter (SMMC) 10A.
  • the converter IOA converts between Direct Current (DC) and Alternating Current (AC) and may with advantage be provided as an interface between a High Voltage Direct Current (HVDC) network, such as an Ultra High Voltage Direct Current (UHVDC) network, and an AC network, where the connection to the AC network is made via an AC link.
  • HVDC High Voltage Direct Current
  • UHVDC Ultra High Voltage Direct Current
  • the converter ioA comprises a number of stacked converter modules, one for each phase of an AC waveshape to be generated for a corresponding phase of the AC link.
  • the converter modules are also connected in series between a first and a second DC terminal DCi and DC2 of the converter 10a for connection to a DC voltage Ud.
  • the converter modules are thus connected in series between a first and a second DC terminal DCi and DC2 and this connection is done using first and second DC connection points DCCPi and DCCP2.
  • the DC terminals DCi and DC2 are each connected to a corresponding (DC) pole Pi and P2, where a first pole Pi has a first voltage +UDC/2 and a second pole P2 has a second voltage -UDC/2. It should be realized that as an alternative one of the DC terminals may be connected to ground instead.
  • Each module has the first and the second DC connection point DCCPi and DCCP2 for connection between the two DC terminals DCi and DC2 and at least one
  • AC connection point- In the example shown in fig. 1 there are two AC connection points ACCPi and ACCP2.
  • the first module 12 thus has a first DC connection point DCCPi connected to the first DC terminal DCi and a second DC connection point DCCP2 connected to the first DC connection point DCCPi of the second module 14, which second module 14 in turn has a second DC connection point DCCP2 connected to a first DC connection point DCCPi of the third module 16, which third module i6has a second DC connection point DCCP2 connected to the second DC terminal DC2.
  • the first converter module 12 transmits power PA to or from the first phase of the AC link
  • the second converter module 14 transmits power PB to or from the second phase of the AC link
  • the third converter module 16 transmits power PC to or from the third phase of the AC link.
  • the first module 12 has a first and a second AC connection point ACCPi and ACCP2 and the third connection point CP3 that may also act as an AC connection point for connection to the corresponding phase of the AC link.
  • at least one of the AC connection points and the third connection point is a connection point for connection to the corresponding phase of the AC link, which in this case is the first phase A of the AC link.
  • the third connection point is an AC connection point perhaps all three, of the AC connection points may be connected to the phase of the AC link. If two AC connection points are connected to the AC link, it is furthermore possible that they are connected to two different conductors.
  • the third connection point CP3 is an AC connection point connected to the first conductor ACLAi and the first AC connection point ACCPi is connected to the second conductor ACLA2 of the AC link provided for the first phase.
  • three AC connection points two may be connected to the same conductor.
  • the first and second AC connection points ACCPi and ACCP2 are connected to the second conductor ACLA2 when the third connection point CP3 is an AC connection point connected to the first conductor ACLAi.
  • the first and second AC connection points ACCPi and ACCP2 are connected to the same conductor of the AC link provided for the phase
  • the third connection point CP3 may be an AC connection point connected to another conductor of the AC link provided for the phase.
  • the second module 14 has a first and a second AC connection point ACCPi, and ACCP2 and a third connection point CP3 that may also act as an AC connection point, where at least one of the AC connection points and the third connection point is a connection point for connection to a corresponding phase of the AC link, which in this case is the second phase B of the AC link. Also here at least two and perhaps all three of the AC connection points may be connected to the phase of the AC link, where if two AC connection points are connected to the AC link, it is possible that they are connected to two different conductors and if three AC connection points are used, two are connected to the same conductor.
  • the third module 16 has a first and a second AC connection point ACCPi, ACCP2 and a third connection point CP3 that may also act as an AC connection point, where at least one of the AC connection points and the third connection points is a connection point for connection to a corresponding phase of the AC link, which in this case is the third phase C of the AC link. Also here at least two and perhaps all three of the AC connection points may be connected to the phase of the AC link, where if two AC connection points are connected to the AC link, it is possible that they are connected to two different conductors and if three AC connection points are used, two are connected to the same conductor. These connections may be made in the same way as was described above in relation to the first converter module 12.
  • control unit 18 set to control the different converter modules 12, 14 and 16, which control involves the forming of an AC voltage, which AC voltage is provided by the converter module using at least two of the first and second AC connection points and the third connection point.
  • Fig. 2 schematically shows a second type of converter 10B where instead the three modules 12, 14 and 16 are connected in parallel between the two DC terminals DCi and DC2 using the first and second DC connection points DCCPi and DCCP2.
  • the third connection point CP3 may in this case be either a DC connection point or an AC connection point.
  • connection points of each of the modules such as the first AC connection point ACCPi or the third connection point CP3, may be provided for connection to the corresponding phase of the AC link.
  • This connection point may more particularly be connected to a conductor of the
  • connection points may be connected to the phase.
  • the first and second AC connection points ACCPi and ACCP2 or the first AC connection point ACCPi and the third connection point CP3 of a converter module may be connected to the phase.
  • the first and the second AC connection points ACCPi and ACCP2 may be connected to the same conductor of the phase and the first AC connection point ACCPi and the third connection point
  • CP3 may be connected to separate conductors of the phase. If the third connection point is an AC connection point and all three AC connection points are used, the first and the second AC connection points ACCPi and ACCP2 may be connected to the same conductor of the phase while the third connection point CP3 may be connected to another conductor of the phase.
  • the structure of a first variation of the first converter module 12A which is also the structure of a first type of converter module, is shown in fig. 3.
  • this converter module 12A a first string of director switches connected between the first and second DC connection points DCCPi and DCCP2, where the first string comprises at least two director switches; a first director switch Si and a second director switch S2.
  • first switch Si is connected between the first DC connection point DCCPi and the third connection point CP3, while the second switch S2 is connected between the third connection point CP3 and the second DC connection point DCCP2.
  • first and a second waveshaper branch WSBi and WSB2 connected in parallel with each other and with the first and second director switches of the first string of director switches.
  • These waveshaper branches WSBi and WSB2 are more particularly connected between a first and a second connection point SPi and SP2 of the first string, where in this first type of converter module the first string connection point SPi is provided or placed at a junction between the first switch Si and the first DC connection point DCCPi and the second string connection point SP2 is provided or placed at a junction between the second switch S2 and the second DC connection point DCCP2.
  • Each waveshaper branch is also connected to an AC connection point provided for the branch, which may be a common or a separate connection point. In the example in fig. 3 there are two separate AC connection points; a first and a second AC connection point ACCPi and ACCP2.
  • the first and second waveshaper branches WSBi and WSB2 also both have a first and a second end, where the first end of the first waveshaper branch WSBi is connected to the first string connection point SPi via a separate inductor LiA and the second end of the first waveshaper branch WSBi is connected to the second string connection point SP2 via a separate inductor L2A.
  • the first end of the second waveshaper branch WSB2 is connected to the first string connection point SPi via a separate inductor LiB and the second end of the second waveshaper branch WSB2 is connected to the second string connection point SP2 via a separate inductor L2B.
  • the first waveshaper branch WSBi comprises a first and a second chain link CLiA and CL2A connected between the first and second ends, where each chainlink comprises a number of submodules. As an example each chainlink is shown as comprising two submodules.
  • CLiA thus comprises a first and second submodule SMAi and SMA2, while the second chainlink CL2A comprises a third and a fourth submodule SMA3 and SMA4.
  • the first AC connection point ACCPi is connected to the junction between the two chainlinks CLiA and CL2A, which in this example is the junction between the second and third submodules SMA2 and SMA3, which is also a midpoint of the waveshaper branch WSBi.
  • the second waveshaper branch WSB2 comprises a first and a second chain link CLiB and CL2B connected between the first and second ends, where each chainlink comprises a number of
  • each chainlink is shown as comprising two submodules.
  • the first chainlink CLiB thus comprises a first and second submodule SMBi and SMB2, while the second chainlink CL2B comprises a third and a fourth submodule SMB3 and SMB4.
  • the second AC connection point ACCP2 is connected to the junction between the two chainlinks CLiB and CL2B, which in this example is the junction between the second and third submodules SMB2 and SMB3. It can thereby be seen that the AC connection point is provided at the midpoint of the second waveshaper branch WSB2.
  • each of the first and second waveshaper branches WSBi and WSB2 there is at least one first inductor connected between the associated AC connection point and the first string connection point SPi that leads to the first DC connection point DCCPi and at least one second inductor connected between the associated AC connection point and the second string connection point SP2 that leads to the second DC connection point DCCP2. It is furthermore possible that at least one end of each waveshaper branch is connected to the corresponding connection point of the first string via the corresponding at least one inductor. It is in this case possible that the first ends of both waveshaper branches WSBi and WSB2 are connected to the first string connection point SPi via the at least one first inductor.
  • the second ends of both waveshaper branches WSBi and WSB2 are connected to the second string connection point SP2 via the at least one second inductor.
  • the at least one first inductor comprises the separate inductors LiA and LiB and the at least one second inductor comprises the separate inductors L2A and L2B.
  • the at least one first inductor comprises the separate inductors LiA and LiB and the at least one second inductor comprises the separate inductors L2A and L2B.
  • the first ends of the first and second waveshaper branches are connected to the first string connection point via at least one first inductor, in this example the separate inductors LiA and L2A and the second ends of the first and second waveshaper branches are connected to the second string connection point via at least one second inductor, in the form of separate inductors L2A and L2B.
  • the AC connection point associated with the first waveshaper branch WSBi is the first AC connection point ACCPi and the AC connection point associated with the second waveshaper branch is the second AC connection point ACCP2.
  • the first and second AC connection points ACCPi and ACCP2 may be interconnected and thereby they may be connected to a conductor of the corresponding phase of the AC link, such as the second conductor of the phase. However, they may also, as will be seen later on, be connected to this conductor via separate transformers.
  • An alternative inductor realization is the following:
  • a first end of the first chain link CLiA of the first waveshaper branch WSBi is directly connected to the first string connection point SPi, a second end of the first chain link CLiA of the first waveshaper branch WSBi is connected to the first AC connection point ACCPi via a first separate inductor, a first end of the first chain link CLiB of the second waveshaper branch WSB2 is directly connected to the first string connection point SPi, a second end of the first chain link CLiB of the second waveshaper branch WSB2 is connected to the second AC connection point ACCP2 via another first separate inductor, a first end of the second chain link CL2A of the first waveshaper branch WSBi is directly connected to the second string connection point SP2, a second end of the second chain link CL2A of the first waveshaper branch WSBi is connected to the first AC connection point ACCPi via a second separate inductor, a first end of the second chain link CL2B of the second waveshaper branch WSB2
  • each chain link is used for forming a number of discrete voltage levels of an AC waveshape. Therefore each chain link may comprise more submodules than two.
  • the submodules may, as can be seen in fig. 4a, be realized as a first type of submodule SMTi having unipolar voltage contribution capability, here exemplified by a half-bridge submodules, where two switches are connected in parallel with an energy storage element, for instance realized as a capacitor. One submodule terminal is then provided at the junction between the two switches and the other submodule terminal is provided at a junction between one of the switches and the energy storage element.
  • the half-bridge submodule is configured to either provide a zero voltage or a unipolar voltage corresponding to the voltage across the submodule capacitor.
  • the submodules may as an alternative be realized as a second type of submodule SMT2 having a bipolar voltage contribution capability.
  • a full-bridge submodule where there are two strings of series connected switches connected in parallel with the energy storage element, Here one submodule terminal is provided at the midpoint of one of the strings, while the other submodule terminal is provided at the midpoint of the other string.
  • the full-bridge submodule has a zero and bipolar voltage contribution capability corresponding to the voltage across the capacitor.
  • the director switches are bidirectional switches and may be realized as either anti-parallel self-commutated components or active power devices, such as two transistors, like Insulated Gate Bipolar Transistors (IGBTs), Bimode Insulated Gate Transistors (BIGTs) or Metal-Oxide- Semiconductor Field-Effect Transistor (MOSFETs), or Integrated Gate- Commutated Thyristors (IGCTS), using a self-commutated circuit with anti-parallel circuit-commutated components, such as an IGBT or IGCT together with a diode or thyristor, or as anti-parallel circuit commutated components, such as two anti-parallel thyristors or a thyristor with anti- parallel diode.
  • IGBT Insulated Gate Bipolar Transistors
  • BIGTs Bimode Insulated Gate Transistors
  • MOSFETs Metal-Oxide- Semiconductor Field-Effect Transistor
  • ICTS Integrated Gate
  • a self-commutated component is here a component that may be directly turned off through receiving a control signal in order to stop conducting current, while a circuit-commutated component is a component needing an applied negative voltage to stop conducting current, for instance through the use of a dedicated circuit.
  • a thyristor is an example of one type of circuit commutated component, it can be seen that this type of circuit commutated component also has the ability of being directly turned on through receiving a control signal in addition to requiring an applied external negative voltage for being turned off.
  • a string may be realized through a number of series-connected component combinations of the types described above.
  • a switch formed through a self-commutated component with anti-parallel self-commutated component such as a pair of anti-parallel IGBTs, or as a self-commutated component with anti-parallel circuit-commutated component, such as an IGBT with anti-parallel diode, will be termed a self- commutated switch
  • a switch with two anti-parallel circuit- commutated components such as a pair of anti-parallel thyristors will be termed a circuit-commutated switch.
  • the director switches of the first string are circuit commuted switches.
  • the submodule switches may also be realized through the use of self- commutated or circuit-commutated switches or as combinations of such switches. It may here also be mentioned that in case the director switches are realized in the form of circuit-commutated switches, then a full-bridge submodule in any chain link of a waveshaper branch may be used for turning off a switch.
  • One way of operating the first converter module 12 will now be described.
  • the third connection point CP3 is a third AC connection point and forms a first AC terminal of the converter module 12A and the first and second AC connection points ACCP2 and ACCP3 are
  • control unit 18 controls a converter module 12A for forming a first part of a waveshape in a half cycle or first half-period and for forming a second part of the waveshape in a second half cycle or half- period, which waveshape is formed between the two AC terminals.
  • the first switch Si is turned on and the second switch S2 turned off.
  • the first chain link CLiA of the first waveshaper branch WSBi comprising the submodules SMAi and SMA2 is connected between the first AC connection point ACCPi and the third connection point CP3 via the inductor LiA and thereby these submodules SMAi and SMA2 are also connected between the two AC terminals.
  • the first chain link CLiB of the second waveshaper branch WSB2 comprising the submodules SMBi and
  • SMB2 are connected between the second AC connection point ACCP2 and the third connection point CP3 via the inductor LiB and thereby these submodules SMBi and SMB2 are also connected between the two AC terminals.
  • the submodules SMAi, SMA2, SMBi and SMB2 of the two first chain links CLiA and CLiB are also controlled to form a half period or half cycle of two separate but similar waveshapes being combined into a half period or half cycle of an output waveshape via the inductors.
  • the submodules SMAi, SMA2, SMBi, SMB2 of the first chain links CLiA and CLiB can be controlled by the control unit 18 to produce the first half period of the output waveshape.
  • the first switch Si is turned off and the second switch S2 is turned on.
  • the second chain link CL2A of the first waveshaper branch WSBi comprising the third and the fourth submodules SMA3 and SMA4 is connected between the first AC connection point ACCPi and the third connection point CP3 via the inductor L2A.
  • the second chain link CL2B of the second waveshaper branch WSB2 comprising the submodules SMB3 and SMB4 is connected between the second AC connection point ACCP2 and the third connection point CP3 via the inductor L2B.
  • the two chain links CL2A and CL2B are also controlled to form a half period or half cycle of two separate but similar waveshapes being combined into a half period or half cycle of an output waveshape via the inductors.
  • the submodules SMA3, SMA4, SMB3, SMB4 of the second chain links CL2A and CL2B of the first and second waveshaper branches WSBi and WSB2 can be controlled by the control unit 18 to produce the second half period of the output waveshape.
  • control unit 18 controls the first and second switches Si and S2 of the first string to alternatingly connect the first and second chainlinks CLiA, CLiB, CL2A and CL2B of the first and second waveshaper branches WSBi and WSB2 between the two AC terminals.
  • the control unit 18 more particularly controls the two waveshaper branches to form the same waveshape.
  • first and second waveshaper branches WSBi and WSB2 are controlled to produce two similar waveshapes for the same phase of the AC link and the director switches Si and S2 are controlled to change the way the waveshapes are applied to some of the connection points, which in the first type of converter is to change the way the waveshapes are applied to the first and second AC connection points ACCPi and ACCP2 and the third connection point CP3.
  • the operation more particularly involves changing the polarity of the waveshapes provided by the waveshaper branches WSBi and WSB2.
  • the second and third converter modules perform the same type of operation for the other two phases.
  • a converter employing this converter module realization has a number of advantages. It allows a current of twice the size of the current through the first string of director switches compared with the current through a waveshaper branch, which improves the utilization of a string if thyristors are used.
  • the current capability of the converter is thereby also raised through only doubling the number of components in the submodules, such as doubling the number of transistors like IGBT/BIGT, but retaining the number of director switch components, that may be thyristors, leading to reduced cost/MVA (Mega Volt Ampere).
  • the inductors LiA, LiB, L2A and L2B balance the current flowing through each wavehaper branch.
  • One submodule failure in the parallel waveshaper branch configuration does not affect to the parallel waveshaper branch, which reduces the number of required redundant submodules.
  • the parallel waveshaper branch configuration can reduce the number of redundant submodules compared to the parallel submodule configuration.
  • the first type of converter employing the above described converter module can enhance transmission of power from parallel arm MMC without increasing switching component costs.
  • This circuit configuration is thus a cost-effective alternative to a load commutated converter used for LCC HVDC system.
  • SMMC using the above-described converter module also offers several further advantages such as black start capability, independent
  • Fig 5 shows the first converter module 12B according to a second type.
  • This converter module 12B has essentially the same realization as the first type. However, in this case there are no separate inductors between a waveshaper end and a string connection point.
  • center tapped inductors are used.
  • a first common inductor Li interconnecting the first end of the first waveshaper branch WSBi with the first end of the second waveshaper branch WSB2, where a midpoint of this first inductor Li is connected to the first string connection point SPi between the first switch Si and the first DC connection point DCCPi. It can thereby be seen that the first common inductor Li is connected between the waveshaper branches and has a midpoint leading to the first string connection point SPi.
  • WSBi and WSB2 are connected to the first string connection point via a midpoint in the first common inductor Li and the second ends of the first and second waveshaper branches WSBi and WSB2 are connected to the second string connection point via a midpoint in the second common inductor L2.
  • the center tapped inductor can be used only to regulate circulating current which is sufficient to achieve current sharing between the two waveshaper branches.
  • the first waveshaper branch WSBi in this case comprises a first or upper waveshaper arm uaa or upper chainlink with submodules SMAi and SMA2 and second or lower waveshaper arm laa or lower chainlink with submodules SMA3 and SMA4.
  • the first end of the first waveshaper branch at the first submodule SMAi is also a first end of the upper waveshaper arm uaa, while a second end of the upper waveshaper arm is formed after the last submodule of the arm, which is after the second submodule SMA2.
  • the second end of the first waveshaper branch WSBi i.e. after the last submodule SMA4 of the waveshaper branch, is also the second end of the lower waveshaper arm laa, while a first end of the lower waveshaper arm laa is provided before the first submodule of lower waveshaper arm, which in this case is before the third submodule SMA3.
  • a first end of the intermediate arm iaa is formed before the first submodule of the arm, which in this case is before the first intermediate submodule SMAIi, while a second end of the intermediate arm iaa is formed after the last submodule of the arm, which in this case is after the second intermediate submodule SMAI2 .
  • the second waveshaper branch WSB2 comprises the first or upper waveshaper arm uab or upper chainlink with submodules SMBi and SMB2 and second or lower waveshaper arm lab or lower chainlink with submodules SMB3 and SMB4 as well as an intermediate arm iab or intermediate chain link with submodules SMBIi and SMBI2.
  • the first end of the second waveshaper branch WSB2 at the first submodule SMBi is also a first end of the upper waveshaper arm uab, while a second end of the upper waveshaper arm uab is formed after the last submodule of the arm, which is after the second submodule SMB2.
  • the second end of the second waveshaper branch WSB2, i.e. after the last submodule SMB4, is also the second end of the lower waveshaper arm lab, while a first end of the lower waveshaper arm lab is provided before the first submodule of the arm, which in this case is before the third submodule SMB3.
  • a first end of the intermediate arm iab is formed before the first submodule of the arm, which in this case is before the first intermediate submodule SMBIi, while a second end of the intermediate arm iab is formed after the last submodule of the arm, which in this case is after the second intermediate submodule SMBI2.
  • each waveshaper branch comprises an upper waveshaper arm, a lower waveshaper arm and an intermediate arm between the upper and lower waveshaper arms.
  • a second string of switches for instance bidirectional switches, which second string is at a first end connected to the second ends of the upper arms uaa and uab of both the first and the second waveshaper branches WSBi and WSB2, while a second end of the second string of switches is connected to the second ends of the intermediate arms iaa and iab of both the waveshaper branches WSBi and WSB2.
  • the second string comprises a third and a fourth switch S3 and S4 and the midpoint between the switches of the second string also forms the first AC connection point ACCPi, where it can also be seen that the third and fourth switches S3 and S4 are provided on opposite sides of this midpoint.
  • the first AC connection point ACCPi is associated with both the waveshaper branches WSBi and WSB2.
  • the AC connection point associated with a waveshaper branch is thereby provided at the midpoint of the second string of switches connected between a first and a second junction of the waveshaper branch, where the first junction is a junction between the upper and intermediate arm and the second junction is a junction between the intermediate and lower arm.
  • the second inductor L.2 is connected between the first ends of the lower arms laa and lab of the first and second waveshaper branches WSBi and WSB2, where the center point of the second inductor L2 is connected to the second ends of the intermediate branches iaa and iab of both the first and second waveshaper branches WSBi and WSB2. It can finally be seen that in this case the second ends of both the waveshaper branches are directly connected to the second string connection point, i.e. directly to the second connection point of the first string of switches, which is here provided at the junction between the second switch S2 and the second DC connection point DCCP2.
  • the converter module 12C also forms an AC waveshape between the first AC connection point ACCPi and the third connection point CP3, which connection points thus forms two AC terminals.
  • the director switches Si and S2 again provides the direction or polarity of the wave and the wavehshaper branches WSBi and WSB2 the shapes through suitable control of the submodules in the arms. It is thereby possible to for example form a sine wave on a pair of AC terminals.
  • the fourth switch S4 When the first switch Si is on and used to form a connection between the first AC connection point ACCPi and the third connection point CP3, also the fourth switch S4 is on. Thereby the upper and intermediate arms uaa, uab, iaa, and iab of both waveshaper arms WSBi and WSB2 are connected in parallel between the AC terminals formed by the first AC connection point ACCPi and the third connection point CP3 and controlled to form the first half period of the waveshape.
  • the second switch S2 When the second switch S2 is on and used to form a connection between the first AC connection point ACCPi and the third connection point CP3, also the third switch S3 is on.
  • both waveshaper arms WSBi and WSB2 are connected in parallel between the AC connection terminals ACCPi and ACCP3 and controlled to form the second half period of the waveshape.
  • the submodules in the intermediate branch are used for forming waveshapes in both half- periods, which increases the efficiency of the submodule usage as well as allows the number of submodules to be reduced.
  • this concept can be made of this concept of separating the waveshaper branches into upper, lower and intermediate arms.
  • the first AC connection point ACCPi is shared by the first and second waveshaper branches WSBi and WSB2. It should be realized that it is possible to provide separate AC connections for the branches also in this type of waveshaper branch realization.
  • the second string of switches comprising the third and fourth switch S3 and S4 would only be connected between the submodules of the first waveshaper branch WSBi.
  • the second string would thus have its first end connected to a junction between the second end of the upper arm uaa and first end of the intermediate arm iaa and its second end connected to the junction between the second end of the intermediate arm iaa and the first end of the lower arm laa.
  • the second AC connection point would in this case be provided at a midpoint of a third string of switches comprising at least two switches, which third string is only connected between the submodules of the second waveshaper branch WSB2.
  • the third string would thus have a first end connected to a junction between the second end of the upper arm uab and a first end of the intermediate arm iab and a second end connected to the junction between the second end of the intermediate arm iab and the first end of the lower arm lab.
  • each intermediate arm comprises a common capacitor CCA and CCB in series with a bypass switch BPSWA and BPSWB.
  • control unit 18 controls the switches S3, S4 to make the common capacitor CC contribute to the voltage level of an AC waveshape being formed.
  • the fourth switch S4 is on, which makes the common capacitors CCA and CCB contribute to the forming of the waveshape in this half period
  • the third switch S3 is on, which makes the common capacitors CCA and CCB contribute to the forming of the waveshape in this half period.
  • bypass switch BPSWA or BPSWB is used to selectively bypass the common capacitor CCA or CCB, which is accomplished through turning off the bypass switches BPSWA or BPSWB while turning on both S3 and S4.
  • the common capacitor CCA and CCB of a waveshaper branch is thus shared between the upper arm VAp and the lower arm Van. This leads to a reduction of the number of submodules being used.
  • the converter module 12D in fig. 7 It is naturally also possible to change the converter module 12D in fig. 7 to obtain the second AC connection point.
  • Another possibility that may be used in different converter module realizations is to have the two waveshaper branches connected to two different transformers.
  • the first and the second AC connections points ACCPi and ACCP2 may thus be connected to two different transformers and may more particularly be connected to secondary windings of a first and a second transformer, respectively.
  • FIG. 8 shows the second type of converter module 12B, where the secondary winding of a first transformer
  • TRi is connected between the first AC connection point ACCPi and the third connection point CP3, while a secondary winding of a second transformer TR2 is connected between the second AC connection point ACCP2 and the third connection point CP3.
  • the primary windings of these transformers TRi and TR2 are connected in parallel to the corresponding phase of the AC link.
  • FIG. 9 shows a fourth type of converter module 12E.
  • the converter module comprises a first and second parallel waveshaper branch WSBi and WSB2, the first ends of which are interconnected by a first inductor Li and the second ends of which are interconnected by a second inductor L2.
  • the center point of the first inductor Li is connected to the first DC connection point DCCPi
  • the center point of the second inductor L2 is connected to a first end of a first string of switches comprising a first and a second switch Si and S2, where the second end of the string is connected to a midpoint of a third inductor L3 interconnecting the first ends of a third and a fourth waveshaper branch WSB3 and WSB4, the second ends of which are interconnected by a fourth inductor L4, the center point of which fourth inductor L4 is finally connected to the second DC connection point DCCP2.
  • the first and second AC connection points ACCPi and ACCP2 of the first and second waveshaper branches WSBi and WSB2 are not used, which is indicated through dashed lines.
  • Corresponding AC connection points of the third and fourth wavehaper branches WSB3 and WSB4 are also unused.
  • connection point that is used as an AC connection point is the third connection point CP3 which is provided at the midpoint of the first string of switches. As before the switches are used for directivity and the waveshaper branches for forming waveshapes.
  • Fig. 10 shows the first converter module 12F according to a fifth type having basically the same realization as the second type in fig. 5. The difference here is that there are two further switches in the first string of switches. There is an upper switch Su connected between the first DC connection point DCCPi and the first switch Si and a lower switch Sl connected between the second switch S2 and the second DC connection point DCCP2. Moreover, the first string connection point SPi is provided at the junction between the first and upper switches Si and Su, while the second string connection point SP2 is provided at the junction between the second and the lower switches S2 and Sl.
  • the third connection point CP3 is a DC connection point. This type of converter module is with advantage used in a converter of the type shown in fig. 2.
  • This type of module may have a different type of operation.
  • the upper and the second switch Su and S2 may be closed, with the first and the lower switches Si and Sl being open for providing a DC current path from the first DC connection point DCCPi to the third connection point CP3.
  • the first and lower switches Si and Sl may be closed with the upper and second switches Su and S2 being open for providing a DC current path from the third connection point CP3 to the second DC connection point DCCP2.
  • the first and second switches Si and S2 are closed for providing a free-wheeling current flow path through the first and second switches of the first string and the two waveshaper branches, while the upper and lower switches Su and Sl are open.
  • FIG. 11 Another converter realization that may be used is shown in fig. 11.
  • This converter is of the second type, i.e. with three parallel converter blocks 12F, 14F and 16F.
  • converter module type used is the fifth type shown in fig. 10 employing upper and lower switches in the first string of switches.
  • this type of converter module is also combined with transformers, where the secondary winding of a first transformer is connected to the first AC connection point of a first waveshaper branch and the secondary winding of a second transformer is connected to the second AC connection point of a second waveshaper branch.
  • the third connection point is not used as an AC terminal.
  • the transformers may be single-phase transformers, where the first ends of three secondary windings TRAi, TRBi and TRCi of three first transformers are connected to the first AC connection points of the three modules 12F, 14F and 16F, with the second ends of the secondary windings being interconnected, for instance in a Y connection
  • the first ends of three secondary windings TRA2, TRB2 and TRC2 of three second transformers are connected to the second AC connection points of the three modules 12F, 14F and 16F, with the second ends of the secondary windings being interconnected, for instance in a Y connection.
  • this converter also the three third connection points of the converter modules
  • the thyristor current can be maximized, leading to increased power with less number of series connected converter modules per pole.
  • each waveshaper branch is equipped with separate inductors instead of sharing a center-tapped inductor with the other waveshaper branch.
  • the control unit may be realized in the form of discrete components, such as Field-Programmable Gate Arrays (FPGAs) and Application-Specific Integrated Circuits (ASICs). However, it may also be implemented in the form of a processor with accompanying program memory comprising computer program code that performs the desired control functionality when being run on the processor.
  • a computer program product carrying this code can be provided as a data carrier such as one or more CD ROM discs or one or more memory sticks carrying the computer program code, which performs the above-described control functionality when being loaded into a processor performing the role of control unit of the voltage source converter.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)
  • Ac-Ac Conversion (AREA)
  • Rectifiers (AREA)

Abstract

L'invention concerne un convertisseur de source de tension comprenant un certain nombre de modules convertisseurs, un module pour chaque phase d'une forme d'onde de CA à générer, connectés entre deux bornes de CC et comprenant chacun un premier et un deuxième point de connexion de CC (DCCP1, DCCP2), une chaîne de commutateurs directeurs (S1, S2) dont le point médian fournit un troisième point de connexion (CP3), et des branches de mise en forme d'ondes (WSB1, WSB2) connectées en parallèle l'une à l'autre ainsi qu'à la chaîne, chaque branche de mise en forme d'ondes (WSB1, WSB2) comprenant des sous-modules (SMA1, SMA2, SMA3, SMA4, SMB1, SMB2, SMB3, SMB4) et étant connectée à un point de connexion de CA (ACCP1, ACCP2) prévu pour la branche, le point de connexion de CA et/ou le troisième point de connexion étant prévus pour une connexion à une phase correspondante d'une liaison de CA, les première et seconde branches de mise en forme d'ondes produisant deux formes d'ondes similaires pour la liaison de CA et les commutateurs changeant la manière dont les formes d'ondes sont appliquées à des points de connexion.
PCT/EP2019/060495 2018-07-06 2019-04-24 Convertisseur modulaire à plusieurs niveaux amélioré WO2020007516A1 (fr)

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130258726A1 (en) * 2010-10-15 2013-10-03 Abb Technology Ag Arrangement for transmitting power between a dc power line and an ac power line
US20140092661A1 (en) 2012-09-28 2014-04-03 General Electric Company Multilevel converter system
WO2014082661A1 (fr) * 2012-11-27 2014-06-05 Abb Technology Ltd Convertisseur de phase comprenant des cellules couplées à un transformateur, convertisseur ca/cc ht et procédé associé
US20140355321A1 (en) * 2011-11-25 2014-12-04 Tokyo Institute Of Technology Single-phase power converter, three-phase two-phase power converter, and three-phase power converter
EP2999105A1 (fr) 2014-09-17 2016-03-23 Alstom Technology Ltd Convertisseur hybride modulaire multi-cellule avec thyristeurs bidirectionels
CN105515422A (zh) * 2016-01-12 2016-04-20 上海交通大学 适用于超低调制比应用的多重分叉的模块化多电平变换器
WO2016177398A1 (fr) 2015-05-05 2016-11-10 Abb Technology Ltd Convertisseur de source de tension à fonctionnement amélioré
US20170005590A1 (en) * 2014-02-03 2017-01-05 Kabushiki Kaisha Toshiba Power converter
WO2017021169A1 (fr) * 2015-07-31 2017-02-09 Abb Schweiz Ag Convertisseur multiniveau modulaire hybride

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130258726A1 (en) * 2010-10-15 2013-10-03 Abb Technology Ag Arrangement for transmitting power between a dc power line and an ac power line
US20140355321A1 (en) * 2011-11-25 2014-12-04 Tokyo Institute Of Technology Single-phase power converter, three-phase two-phase power converter, and three-phase power converter
US20140092661A1 (en) 2012-09-28 2014-04-03 General Electric Company Multilevel converter system
WO2014082661A1 (fr) * 2012-11-27 2014-06-05 Abb Technology Ltd Convertisseur de phase comprenant des cellules couplées à un transformateur, convertisseur ca/cc ht et procédé associé
US20170005590A1 (en) * 2014-02-03 2017-01-05 Kabushiki Kaisha Toshiba Power converter
EP2999105A1 (fr) 2014-09-17 2016-03-23 Alstom Technology Ltd Convertisseur hybride modulaire multi-cellule avec thyristeurs bidirectionels
WO2016177398A1 (fr) 2015-05-05 2016-11-10 Abb Technology Ltd Convertisseur de source de tension à fonctionnement amélioré
WO2017021169A1 (fr) * 2015-07-31 2017-02-09 Abb Schweiz Ag Convertisseur multiniveau modulaire hybride
CN105515422A (zh) * 2016-01-12 2016-04-20 上海交通大学 适用于超低调制比应用的多重分叉的模块化多电平变换器

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GB2590211A (en) 2021-06-23

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