CN111092544A - Direct current transformer subunit and direct current transformer comprising same - Google Patents

Direct current transformer subunit and direct current transformer comprising same Download PDF

Info

Publication number
CN111092544A
CN111092544A CN201911316468.0A CN201911316468A CN111092544A CN 111092544 A CN111092544 A CN 111092544A CN 201911316468 A CN201911316468 A CN 201911316468A CN 111092544 A CN111092544 A CN 111092544A
Authority
CN
China
Prior art keywords
voltage
direct current
igbt
module
branch
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
CN201911316468.0A
Other languages
Chinese (zh)
Inventor
查鲲鹏
燕翚
朱宁辉
顾然
张加林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NARI Group Corp
China EPRI Electric Power Engineering Co Ltd
Original Assignee
NARI Group Corp
China EPRI Electric Power Engineering Co Ltd
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 NARI Group Corp, China EPRI Electric Power Engineering Co Ltd filed Critical NARI Group Corp
Priority to CN201911316468.0A priority Critical patent/CN111092544A/en
Publication of CN111092544A publication Critical patent/CN111092544A/en
Pending legal-status Critical Current

Links

Images

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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/285—Single converters with a plurality of output stages connected 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • H02M3/33584—Bidirectional converters

Abstract

The invention provides a direct current transformation subunit and a direct current transformer comprising the same, wherein the direct current transformation subunit comprises a fault isolation voltage balancing module and a DC/DC converter; the high-voltage side of the fault isolation voltage balancing module is connected with the high-voltage direct-current bus, the low-voltage side of the DC/DC converter is connected with the low-voltage direct-current bus, the quality and the occupied area are small, and the cost is low; the direct current transformer of the direct current transformation subunit comprises a plurality of direct current transformation subunits; the high-voltage sides of the plurality of direct current transformer subunits are connected in series to meet the requirement of voltage-resistant grade, the low-voltage sides of the plurality of direct current transformer subunits are connected in parallel to meet the requirement of high power, the number of layers of the direct current transformer subunits is greatly reduced, the occupied area is reduced, the cost is saved, different application scenes of unidirectional power flow and bidirectional power flow can be met, and automatic isolation and crossing of faults of the high-voltage sides can be realized.

Description

Direct current transformer subunit and direct current transformer comprising same
Technical Field
The invention relates to the technical field of direct current power transmission and distribution, in particular to a direct current transformation subunit and a direct current transformer comprising the same.
Background
In an alternating current power grid, voltage conversion and energy transfer can be realized only by a power frequency transformer. However, the dc power grid must rely on power electronics to achieve voltage matching and energy interaction between different grids.
The topological structure of the direct current transformer mainly comprises an MMC type topology, an ultrahigh voltage device type topology and an ISOP type topology. Among them, the ISOP type topology is most widely used, and the ISOP type topology realizes electrical isolation and voltage matching among different power grids through a plurality of high-frequency transformers. The medium-voltage side series structure solves the contradiction between low voltage resistance of the power semiconductor device and high voltage of a power grid, and the output side is connected on the low-voltage direct-current bus in parallel to realize large-current output.
In the direct current transformer, each layer of the DC/DC sub-unit may adopt a Dual Active bridge converter (DAB) type structure, a CLLC type structure, an LLC type structure, and the like. The DC/DC subunit of the ISOP topological structure can not realize high-voltage side fault isolation, and an SC module is usually added on the high-voltage side of a DC/DC module to realize high-voltage side fault isolation, but the DC transformer has more cascaded layers, larger quality and occupied area and high cost.
Disclosure of Invention
In order to overcome the defects of large mass and occupied area and high cost of the direct current transformer in the prior art, the invention provides a direct current transformation subunit and a direct current transformer comprising the same, wherein the direct current transformation subunit comprises a fault isolation voltage balancing module and a DC/DC converter which are connected in series; the high-voltage side of the fault isolation voltage balancing module is connected with a high-voltage direct-current bus, and the low-voltage side of the DC/DC converter is connected with a low-voltage direct-current bus; the fault isolation voltage balancing module is used for isolating faults from the high-voltage direct-current bus/low-voltage direct-current bus and achieving voltage balancing, and is small in mass and occupied area and low in cost.
In order to achieve the purpose of the invention, the invention adopts the following technical scheme:
the invention provides a direct current transformer unit, which comprises a fault isolation voltage balancing module and a DC/DC converter which are connected in series;
the high-voltage side of the fault isolation voltage balancing module is connected with a high-voltage direct-current bus, and the low-voltage side of the DC/DC converter is connected with a low-voltage direct-current bus;
the fault isolation voltage balancing module is used for isolating faults from the high-voltage direct-current bus/low-voltage direct-current bus and realizing voltage balancing.
The fault isolation voltage balancing module comprises a bypass switch K, a first IGBT module, a second IGBT module, a voltage balancing branch and a direct-current support capacitor branch;
the bypass switch K, the voltage balancing branch and the direct current support capacitor branch are connected between the positive high-voltage direct current bus and the negative high-voltage direct current bus, the first IGBT module is connected in series on the positive high-voltage direct current bus and located between the bypass switch K and the voltage balancing branch, and the second IGBT module is connected in series on the negative high-voltage direct current bus and located between the bypass switch K and the voltage balancing branch.
The voltage balancing branch comprises an IGBT branch and an LC branch;
the IGBT branch comprises a plurality of IGBT modules which are connected end to end, and each IGBT module comprises an upper IGBT and a lower IGBT which are connected end to end;
the LC branch circuit comprises one less LC resonance module than the IGBT module, the LC resonance modules are connected in series, and each LC resonance module comprises a resonance inductor and a resonance capacitor connected in series with the resonance inductor;
and two ends of each LC resonance module are respectively connected with the middle leading-out points of two adjacent IGBT modules.
The direct current support capacitor branch comprises direct current support capacitors with the same number as the IGBT modules;
the positive electrode and the negative electrode of all the direct current support capacitors are connected end to end, each direct current support capacitor is connected with the corresponding IGBT module in parallel, the positive electrode of each direct current support capacitor is connected with the collector electrode of the upper IGBT, and the negative electrode of each direct current support capacitor is connected with the emitter electrode of the lower IGBT.
The first IGBT module comprises a first IGBT and a diode D1 connected with the first IGBT in an anti-parallel mode;
the second IGBT module includes a second IGBT and a diode D2 connected in anti-parallel with the second IGBT.
The DC/DC converter adopts an LLC type converter, a DAB type converter or a CLLC type converter and comprises a high-voltage side converter, a high-frequency transformer and a low-voltage side converter which are connected in series.
The high-voltage side converter and the low-voltage side converter are H-bridge converters, and each bridge arm comprises an IGBT and a diode connected with the IGBT in an anti-parallel mode.
In another aspect, the present invention further provides a dc transformer, located between the high voltage dc bus and the low voltage dc bus, including a plurality of dc transformer sub-units;
the high-voltage sides of the plurality of direct current voltage converting subunits are connected in series and connected with a high-voltage direct current bus;
the low-voltage sides of the plurality of direct current voltage converting subunits are connected in parallel and connected with a low-voltage direct current bus.
Compared with the closest prior art, the technical scheme provided by the invention has the following beneficial effects:
the direct current transformer sub-unit provided by the invention comprises a fault isolation voltage balancing module and a DC/DC converter which are connected in series; the high-voltage side of the fault isolation voltage balancing module is connected with a high-voltage direct-current bus, and the low-voltage side of the DC/DC converter is connected with a low-voltage direct-current bus; the fault isolation voltage balancing module is used for isolating faults from the high-voltage direct-current bus/low-voltage direct-current bus and realizing voltage balancing, and has the advantages of small quality, small occupied area and low cost;
the direct current transformer comprising the direct current voltage transformation subunit comprises a plurality of direct current voltage transformation subunits; the high-voltage sides of the plurality of direct current transformer subunits are connected in series to meet the requirement of voltage-resistant grade, the low-voltage sides of the plurality of direct current transformer subunits are connected in parallel to meet the requirement of high power, the number of layers of the direct current transformer subunits is greatly reduced, the occupied area is reduced, and the cost is reduced;
the direct current transformer subunit provided by the invention can meet different application scenes of unidirectional power flow and bidirectional power flow;
the direct-current transformer provided by the invention can realize automatic isolation and ride-through of high-voltage side faults, and can also avoid the discharge short-circuit impact of the closed bypass switch on the capacitor;
under the condition that the high-voltage side of the direct-current transformer has a fault, the diode which is connected in the IGBT module in an anti-parallel mode automatically blocks the internal capacitor of the direct-current transformation subunit from discharging to a high-voltage fault point, the direct-current transformation subunit can be maintained to work normally, and high-voltage fault ride-through of the direct-current transformer is realized;
when the bypass switch K is closed, the first IGBT module and the second IGBT module work in an anti-parallel diode mode, so that overcurrent can be avoided in the closing process of the bypass switch K;
the number of layers of the direct current transformer sub-units in the direct current transformer provided by the invention can be adjusted according to the change of the rated power of the direct current transformer, and is not a fixed number of layers, so that the volume and the cost of equipment are further reduced.
Drawings
FIG. 1 is a diagram of a DC-DC converter sub-unit according to an embodiment of the present invention;
fig. 2 is a structural diagram of a dc transformer in the embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Example 1
Embodiment 1 of the present invention provides a direct current transformer unit, as shown in fig. 1, including a fault isolation voltage balancing module and a DC/DC converter connected in series;
the high-voltage side of the fault isolation voltage balancing module is connected with a high-voltage direct-current bus, and the low-voltage side of the DC/DC converter is connected with a low-voltage direct-current bus;
the fault isolation voltage balancing module is used for isolating faults from the high-voltage direct-current bus/low-voltage direct-current bus and realizing voltage balancing.
The fault isolation voltage balancing module comprises a bypass switch K, a first IGBT module, a second IGBT module, a voltage balancing branch and a direct-current support capacitor branch;
the bypass switch K, the voltage balancing branch and the direct current support capacitor branch are connected between the positive high-voltage direct current bus and the negative high-voltage direct current bus, the first IGBT module is connected in series on the positive high-voltage direct current bus and located between the bypass switch K and the voltage balancing branch, and the second IGBT module is connected in series on the negative high-voltage direct current bus and located between the bypass switch K and the voltage balancing branch.
The voltage balancing branch comprises an IGBT branch and an LC branch;
the IGBT branch comprises a plurality of IGBT modules which are connected end to end, and each IGBT module comprises two IGBTs 1 and an IGBT2 which are connected end to end;
the LC branch circuit comprises one less LC resonance module than the IGBT module, the LC resonance modules are connected in series, and each LC resonance module comprises a resonance inductor and a resonance capacitor connected in series with the resonance inductor;
and two ends of each LC resonance module are respectively connected with the middle leading-out points of two adjacent IGBT modules.
The direct current support capacitor branch comprises direct current support capacitors with the same number as the IGBT modules;
the positive electrode and the negative electrode of all the direct current support capacitors are connected end to end, each direct current support capacitor is connected with the corresponding IGBT module in parallel, the positive electrode of each direct current support capacitor is connected with the collector electrode of the IGBT1, and the negative electrode of each direct current support capacitor is connected with the emitter electrode of the IGBT 2.
As shown in fig. 1, in embodiment 1 of the present invention, the left side of the fault isolation voltage balancing module is used as an input terminal, the right side of the DC/DC converter is used as an output terminal, and high-voltage to low-voltage conversion is realized, Vin is the input voltage of the fault isolation voltage balancing module, Vm is the input voltage of the high-voltage side converter, VL is the output voltage of the low-voltage side converter, K is a bypass switch, C4 is a first IGBT module, C5 is a second IGBT module, C is a first IGBT module, and C is a second IGBT modulei1、Ci2、……、CinFor n DC support capacitors, C, in a DC support capacitor branchr1Is the resonant capacitance of the first LC resonant module in the LC branch, Lr1The number of the resonance inductors in the LC branch circuit is the same as that of the resonance inductors of the first LC resonance module, and the number of the resonance inductors in the LC branch circuit is m; c1a、C1bIs the first IGBT module in an IGBT branch, C1aUpper IGBT, C called first IGBT module1bCalled the lower IGBT of the first IGBT module, and so on, Cna、CnbThe number of the LC resonance modules is 1 less than that of the IGBT modules, namely m is n-1.
The first IGBT module comprises a first IGBT and a diode D1 connected with the first IGBT in anti-parallel;
the second IGBT module includes a second IGBT and a diode D2 connected in anti-parallel with the second IGBT.
The DC/DC converter adopts an LLC type converter, a DAB type converter or a CLLC type converter and comprises a high-voltage side converter, a high-frequency transformer and a low-voltage side converter which are connected in series.
The high-voltage side converter and the low-voltage side converter are H-bridge converters, and each bridge arm comprises an IGBT and a diode connected with the IGBT in an anti-parallel mode.
In embodiment 1 of the present invention, the high-voltage side converter and the low-voltage side converter both use LLC converters, where A1a, A2a, A1b, and A2b in fig. 1 are IGBTs and C in the high-voltage side converterii、CrThe capacitors in the high-voltage side converter are B1a, B2a, B1B and B2B which are all IGBTs and C in the low-voltage side converteroIs a capacitor in the low-voltage side converter, LrAnd LmFor high frequency transformationInductance in the device.
The direct current transformer subunit provided by the invention can meet different application scenes of unidirectional power flow and bidirectional power flow, and specifically comprises the following steps:
1) the power flow direction is from high pressure side to low pressure side:
a) c4 and C5 are locked, so that diodes connected in anti-parallel in C4 and C5 are enabled to flow through, when a high-voltage side fault occurs, the anti-parallel diodes in C4 and C5 automatically block internal capacitors of the direct-current transformer sub-unit from discharging to a high-voltage fault point, and the high-voltage fault ride-through function of the direct-current transformer is achieved;
b) the resonant capacitor (Cr 1-Crm) and the resonant inductor (Lr 1-Lrm) are formed into an LC branch circuit matched with the switching frequency of the IGBT string, and the IGBT branch circuit (C) is controlled according to a certain proportion of duty ratio1a/b～Cna/b) is switched on and off to realize voltage sharing of the direct current support capacitors (Ci 1-Cin);
c) when any device in the direct current transformation subunit breaks down, the bypass switch K can be controlled to bypass the layer so as to ensure that the residual direct current transformation subunit can still work normally. When the bypass switch K is closed, the operation of the C4 and the C5 and the anti-parallel diode mode can ensure that the overcurrent cannot occur in the closing process of the bypass switch;
2) the power flow direction is from low pressure side to high pressure side:
a) the C4 and the C5 are triggered all the time, and the anti-parallel diodes in the C4 and the C5 are naturally turned off, so that the IGBTs in the C4 and the C5 are reversely flowed. When a high-voltage side fault occurs, the IGBTs in C4 and C5 are blocked, and the diodes in anti-parallel connection with the IGBTs in C4 and C5 automatically block the internal capacitor of the direct-current transformer sub-unit from discharging to a high-voltage fault point, so that the high-voltage fault ride-through function of the direct-current transformer is realized;
b) and the resonance capacitors (Cr 1-Crm) and the resonance inductors (Lr 1-Lrm) are constructed into an LC branch circuit matched with the switching frequency of the IGBT string. Controlling IGBT branch circuit (C) according to a certain proportion of duty ratio1a/b～Cna/b) is switched on and off to realize voltage sharing of the direct current support capacitors (Ci 1-Cin);
c) when any device in the direct current transformer subunit breaks down, the trigger pulse of the IGBT is blocked firstly, and meanwhile, the bypass switch K is controlled to bypass the layer, so that the remaining subunits can still work normally. When the bypass switch K is closed, the anti-parallel diodes inside the C4 and the C5 can ensure that overcurrent does not occur in the closing process of the bypass switch because the trigger pulse of the IGBTs in the C4 and the C5 is blocked.
And a certain proportional relation is satisfied between the input voltage Vin of the fault isolation voltage balancing module and the input voltage Vm of the high-voltage side converter. When the capacitance values of all the series capacitors are equal, the proportional relation is the same as the number of the direct current supporting capacitors.
The maximum transmission power of the dc-to-dc converter unit is limited by the manufacturing process and the heat dissipation level of the high frequency transformer. Assuming that the maximum transmission power of the high-frequency transformer is P0 and the total power of the dc transformer is P, the number of layers X connected in series and parallel is P/P0. When the calculated value is not an integer, the integer is fetched upward.
When the high-voltage side voltage of the dc transformer is VH, the input voltage Vin of each sub dc transformer unit is VH/X when the redundant layer is not considered.
According to the input voltage Vin of each layer of direct current sub-unit and the voltage grade (1700V, 3300V, 4500V and the like) of the selected IGBT device, the number of direct current support capacitors in the fault isolation voltage balancing module can be calculated: and n is Vin/(the allowed direct current allowed voltage of the IGBT).
And designing the number of resonance capacitors and resonance inductors required by voltage balance according to the number of the direct current support capacitors in the fault isolation voltage balancing module.
The number of layers of the direct current transformer sub-units in the direct current transformer provided by the invention can be adjusted according to the change of the rated power of the direct current transformer, and is not a fixed number of layers, so that the volume and the cost of equipment are further reduced.
Example 2
Embodiment 2 of the present invention provides a dc transformer, as shown in fig. 2, where in fig. 2, VHIs the voltage of the high voltage DC bus, VLFor the voltage of the low voltage DC bus, a DC transformer is arranged between the high voltage DC bus and the low voltage DC bus, and comprises a plurality of DC transformer sub-units, embodiment 2 of the invention includesComprises k direct current transformation subunits;
the high-voltage sides of the k direct current transformer sub-units are connected in series and connected with a high-voltage direct current bus, so that the requirement of voltage-resistant grade is met;
the low-voltage sides of the k direct current transformer sub-units are connected in parallel and connected with a low-voltage direct current bus, so that the requirement of high power is met.
Finally, it should be noted that: the above embodiments are only intended to illustrate the technical solution of the present invention and not to limit the same, and a person of ordinary skill in the art can make modifications or equivalents to the specific embodiments of the present invention with reference to the above embodiments, and such modifications or equivalents without departing from the spirit and scope of the present invention are within the scope of the claims of the present invention as set forth in the claims.

Claims (8)

1. A direct current transformation subunit is characterized by comprising a fault isolation voltage balancing module and a DC/DC converter which are connected in series;
the high-voltage side of the fault isolation voltage balancing module is connected with a high-voltage direct-current bus, and the low-voltage side of the DC/DC converter is connected with a low-voltage direct-current bus;
the fault isolation voltage balancing module is used for isolating faults from the high-voltage direct-current bus/low-voltage direct-current bus and realizing voltage balancing.
2. The direct current transformer subunit of claim 1 wherein the fault isolation voltage balancing module comprises a bypass switch K, a first IGBT module, a second IGBT module, a voltage balancing branch, and a direct current support capacitance branch;
the bypass switch K, the voltage balancing branch and the direct current support capacitor branch are connected between the positive high-voltage direct current bus and the negative high-voltage direct current bus, the first IGBT module is connected in series on the positive high-voltage direct current bus and located between the bypass switch K and the voltage balancing branch, and the second IGBT module is connected in series on the negative high-voltage direct current bus and located between the bypass switch K and the voltage balancing branch.
3. The dc transformer sub-unit of claim 2, wherein the voltage equalization branch comprises an IGBT branch and an LC branch;
the IGBT branch comprises a plurality of IGBT modules which are connected end to end, and each IGBT module comprises an upper IGBT and a lower IGBT which are connected end to end;
the LC branch circuit comprises one less LC resonance module than the IGBT module, the LC resonance modules are connected in series, and each LC resonance module comprises a resonance inductor and a resonance capacitor connected in series with the resonance inductor;
and two ends of each LC resonance module are respectively connected with the middle leading-out points of two adjacent IGBT modules.
4. The direct current transformer subunit of claim 3, wherein the direct current support capacitor branches comprise the same number of direct current support capacitors as the number of IGBT modules;
the positive electrode and the negative electrode of all the direct current support capacitors are connected end to end, each direct current support capacitor is connected with the corresponding IGBT module in parallel, the positive electrode of each direct current support capacitor is connected with the collector electrode of the upper IGBT, and the negative electrode of each direct current support capacitor is connected with the emitter electrode of the lower IGBT.
5. The direct current transformer sub-unit of claim 2, wherein the first IGBT module comprises a first IGBT and a diode D1 connected in anti-parallel with the first IGBT;
the second IGBT module includes a second IGBT and a diode D2 connected in anti-parallel with the second IGBT.
6. The DC transformer sub-unit according to claim 1, wherein the DC/DC converter is an LLC type converter, a DAB type converter or a CLLC type converter, and comprises a high-voltage side converter, a high-frequency transformer and a low-voltage side converter connected in series.
7. The DC transformer sub-unit of claim 6, wherein the high and low side converters are H-bridge converters, each bridge arm comprising an IGBT and a diode in anti-parallel with the IGBT.
8. A dc transformer between a high voltage dc bus and a low voltage dc bus, comprising a plurality of dc transformer sub-units according to any of claims 1-7;
the high-voltage sides of the plurality of direct current voltage converting subunits are connected in series and connected with a high-voltage direct current bus;
the low-voltage sides of the plurality of direct current voltage converting subunits are connected in parallel and connected with a low-voltage direct current bus.
CN201911316468.0A 2019-12-19 2019-12-19 Direct current transformer subunit and direct current transformer comprising same Pending CN111092544A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911316468.0A CN111092544A (en) 2019-12-19 2019-12-19 Direct current transformer subunit and direct current transformer comprising same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911316468.0A CN111092544A (en) 2019-12-19 2019-12-19 Direct current transformer subunit and direct current transformer comprising same

Publications (1)

Publication Number Publication Date
CN111092544A true CN111092544A (en) 2020-05-01

Family

ID=70395863

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911316468.0A Pending CN111092544A (en) 2019-12-19 2019-12-19 Direct current transformer subunit and direct current transformer comprising same

Country Status (1)

Country Link
CN (1) CN111092544A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112152464A (en) * 2020-09-04 2020-12-29 东南大学 Device series type direct current transformer with fault blocking capability and control method thereof
CN113726173A (en) * 2021-07-28 2021-11-30 国网江苏省电力有限公司电力科学研究院 Multiport direct current power electronic transformer
CN114050566A (en) * 2021-08-19 2022-02-15 天津大学 Short-circuit fault ride-through circuit of direct-current power distribution network containing DAB type direct-current transformer
CN117175920A (en) * 2023-09-01 2023-12-05 国网经济技术研究院有限公司 High-efficiency multiport direct current converter applied to wind power mismatch

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112152464A (en) * 2020-09-04 2020-12-29 东南大学 Device series type direct current transformer with fault blocking capability and control method thereof
CN113726173A (en) * 2021-07-28 2021-11-30 国网江苏省电力有限公司电力科学研究院 Multiport direct current power electronic transformer
CN113726173B (en) * 2021-07-28 2024-03-15 国网江苏省电力有限公司电力科学研究院 Multiport direct current power electronic transformer
CN114050566A (en) * 2021-08-19 2022-02-15 天津大学 Short-circuit fault ride-through circuit of direct-current power distribution network containing DAB type direct-current transformer
CN114050566B (en) * 2021-08-19 2023-06-13 天津大学 Short-circuit fault ride-through circuit of direct-current distribution network containing DAB (DAB) type direct-current transformer
CN117175920A (en) * 2023-09-01 2023-12-05 国网经济技术研究院有限公司 High-efficiency multiport direct current converter applied to wind power mismatch
CN117175920B (en) * 2023-09-01 2024-03-01 国网经济技术研究院有限公司 High-efficiency multiport direct current converter applied to wind power mismatch

Similar Documents

Publication Publication Date Title
CN111092544A (en) Direct current transformer subunit and direct current transformer comprising same
US10523131B2 (en) Reconfigurable MMC sub-module unit and control unit thereof
CN105870877B (en) passive hybrid direct current breaker based on thyristor and application method thereof
EP3041127A1 (en) Submodule topology for modular multi-level converter and application thereof
WO2017063413A1 (en) High-voltage direct-current breaker and control method therefor
US8779730B2 (en) Capacitor discharge in a cell based voltage source converter
CN103444068B (en) There is the modularity multiple convertor of the power semiconductor switch of energy reverse-conducting
RU2652690C2 (en) Modular multi-point valve inverter for high voltages
CN107769239B (en) Novel alternating current power electronic transformer topological structure
JP2014533485A (en) Power electronics module
CN104821736A (en) Modularized multi-level converter with function of DC side short circuit protection
CN108134384B (en) Staggered connection soft switch hybrid multi-level direct current interconnected converter
CN110417290B (en) Novel modular multilevel converter submodule topological circuit and control method thereof
CN107592017B (en) DC-DC converter and control method
US10873254B2 (en) Electrical circuit for zero-voltage soft-switching in DC-DC converter under all load conditions
CN209448659U (en) A kind of more DC port inverters
CN104980137A (en) Forced current conversion type all-solid-state high-speed DC circuit breaker and current conversion switch
CN103441489A (en) Direct-current breaker used for multi-terminal direct current system and control method of direct-current breaker
CN115241850B (en) Combined high-voltage direct-current breaker and control strategy thereof
CN113726173B (en) Multiport direct current power electronic transformer
CN109327016B (en) Direct-current interelectrode breaking device and control method
CN105071675A (en) Hybrid power switch and application thereof in flexible direct current power transmission converter
Diao et al. A novel fault ride-through topology with high efficiency and fast fault clearing capability for MVdc PV system
CN205123611U (en) Modular converter topology and transverter system
CN111049389A (en) Direct current transformer

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination