CN104821736A - Modularized multi-level converter with function of DC side short circuit protection - Google Patents

Modularized multi-level converter with function of DC side short circuit protection Download PDF

Info

Publication number
CN104821736A
CN104821736A CN201510250406.XA CN201510250406A CN104821736A CN 104821736 A CN104821736 A CN 104821736A CN 201510250406 A CN201510250406 A CN 201510250406A CN 104821736 A CN104821736 A CN 104821736A
Authority
CN
China
Prior art keywords
switching device
submodule
submodules
level
electric capacity
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
CN201510250406.XA
Other languages
Chinese (zh)
Inventor
鲁思兆
赵争鸣
袁立强
魏树生
曹阳
鲁挺
贺凡波
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.)
Tsinghua University
State Grid Corp of China SGCC
State Grid Beijing Electric Power Co Ltd
Original Assignee
Tsinghua University
State Grid Corp of China SGCC
State Grid Beijing Electric Power 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 Tsinghua University, State Grid Corp of China SGCC, State Grid Beijing Electric Power Co Ltd filed Critical Tsinghua University
Priority to CN201510250406.XA priority Critical patent/CN104821736A/en
Publication of CN104821736A publication Critical patent/CN104821736A/en
Pending legal-status Critical Current

Links

Abstract

The invention discloses a modularized multi-level converter with function of DC side short circuit protection, and belongs to the technical field of power and electronic converters. Each phase of the converter is divided into an upper bridge arm and a lower bridge arm. Each bridge arm is formed by the series connection of An unipolar submodules and Bm bipolar submodules, wherein Bm is not less than An. Two buffering inductors are connected between each upper bridge arm and the corresponding lower bridge arm in a series connection manner. A leading-out output end between two buffering inductors of each phase is connected with a filter inductor. The bipolar submodules employ five-level cross connection submodules. According to the external characteristics of different types of submodules, the converter achieves the function of DC side short circuit protection through the combination of different types of optimized submodules, and employs the multi-level submodules to reduce the total number of submodules and the number of elements related to the submodules. During normal operation, the control of the two types of submodules is similar, thereby enabling the control algorithm of the whole system to be simple. The submodules are low in loss, and are high in system efficiency.

Description

There is the Modular multilevel converter of dc-side short-circuit defencive function
Technical field
The invention belongs to converters technical field, particularly relate to a kind of Modular multilevel converter main circuit topology for high voltage direct current transmission.
Background technology
Modular multilevel converter (MMC) has modular construction, common DC bus, and the advantage such as efficient and low output harmonic wave, obtain increasing application in high-voltage large-capacity field, its basic structure as shown in Figure 1.Each phase of MMC is all divided into brachium pontis and lower brachium pontis two parts, and each brachium pontis is connected by N number of submodule and obtained, and is usually connected in series two buffer inductance L between upper brachium pontis and lower brachium pontis a, prevent brachium pontis from switching process, bridge arm direct pass occurring, cause large bridge arm current.If the voltage between positive bus-bar P+ and negative busbar N-is V dc, then the voltage born needed for each submodule is V dc/ N.Output (i.e. two buffer inductance L of each phase of MMC abetween draw) meet filter inductance L o, make the electric current of output meet load R lto the requirement of THD (TotalHarmonic Distortion).The submodule of MMC can be divided into unipolarity submodule and bipolarity submodule, unipolarity submodule can only export positive level and zero level, and bipolarity submodule can export positive level, zero level and negative level, two basic level unipolarity submodules and bipolarity sub modular structure figure are respectively as shown in Figures 2 and 3.Two level unipolarity submodules in Fig. 2 comprise two switching device (S 1and S 2) and an electric capacity (C 1); Wherein two switching device S 1, S 2series connection, electric capacity C 1with switching device S 1, S 2in parallel; S 1and S 2complementary conducting; Work as S 2during conducting, this submodule is bypassed.In submodule, the switching tube of two complimentary action produces two effective on off states, electric capacity C 1access in whole brachium pontis or bypassed, producing many level staircase waveform in this way.Two level unipolarity sub modular structures are simple, and required switching device is few, and efficiency is high, but can not export negative level.Two level bipolarity submodules in Fig. 3 comprise four switching device (S 3, S 4, S 5and S 6) and an electric capacity (C 2); Wherein switching device S 3, S 4series connection, S 5, S 6series connection; Electric capacity C 2with switching device S 3, S 4, S 5, S 6in parallel; S during normal work 3and S 4complementary conducting, S 5keep normally closed, S 6keep normal open; Work as S 2and S 6during conducting, this submodule is bypassed; Work as S 5conducting, S 6during closedown, this submodule exports negative level; Two level bipolarity submodules can export positive level voltage, no-voltage and negative level voltage, but derailing switch number of packages needed for each submodule is many, makes efficiency low compared to two level unipolarity submodules.In application scenarios such as high voltage direct current transmissions (HVDC); the short-circuit protection of DC side is a very important functional requirement, based on the MMC of unipolarity submodule, because submodule cannot export negative voltage; therefore when DC side is short-circuited fault, cannot fault current limiting.Based on the MMC of bipolarity submodule, because submodule can go out negative voltage, therefore when DC side is short-circuited fault, can limit DC side fault current and realize fault traversing, but bipolarity submodule device count used is many, loss be large, and efficiency is low.Have scholar to propose to adopt unipolarity submodule and bipolarity submodule to form the brachium pontis of MMC simultaneously, its structure chart as shown in Figure 4, in figure, A 1~ A n: unipolarity submodule, B 1~ B m: bipolarity submodule; These unipolarity submodules and bipolarity submodule mix according to a certain percentage, realize the requirement of output voltage grade and dc-side short-circuit protection.
Existing unipolarity submodule and the hybrid MMC topology of bipolarity submodule, its submodule is all the submodule based on two level, respectively as shown in Figures 2 and 3.The submodule of two level, the voltage that can bear due to single submodule is lower, thus adds total submodule number and other component counts relevant to submodule.Adopt many level submodule, significantly can reduce submodule number and other component counts relevant to submodule.
Summary of the invention
The object of the invention is for the hybrid MMC Neutron module number based on two level submodules described in prior art and the more problem of other relevant component counts, propose a kind of Modular multilevel converter with dc-side short-circuit defencive function, adopt many level submodule to decrease total submodule number and the component counts relevant to submodule; Submodule loss is low, and efficiency is high, thus makes the efficiency of whole system get a promotion.
A kind of Modular multilevel converter with dc-side short-circuit defencive function that the present invention proposes, each phase of this Modular multilevel converter is all divided into brachium pontis and lower brachium pontis two parts, and each brachium pontis is by A nindividual unipolarity submodule and B mindividual bipolarity submodule series connection obtains, and B m>=A n; Be connected in series two buffer inductances between upper brachium pontis and lower brachium pontis, draw between two buffer inductances of each phase and export termination one filter inductance; It is characterized in that, described unipolarity submodule adopts two half-bridge submodules of three level; Described bipolarity submodule adopts five level cross connexon modules.
Technical characterstic of the present invention is:
In five level cross connexon modules of multi-level converter of the present invention, any time electric current only need flow through three switching devices, conduction loss is low, and efficiency is high;
The voltage that submodule in the brachium pontis of multi-level converter of the present invention can bear is the twice of original two level submodules, and under identical DC bus-bar voltage, the total number of modules of each brachium pontis is only the half of employing two level submodule topology;
Cross connect switch device (S in five level cross connexon modules of multi-level converter of the present invention 25and S 26) withstand voltage be other switching device (S 21, S 22, S 23and S 24) twice;
When converter normally works, the cross connect switch device (S in bipolarity submodule 26) keeping conducting, unipolarity submodule is identical with the control of bipolarity submodule;
When DC side is short-circuited fault, the switching device locking of all submodules in brachium pontis, realizes the restriction to DC side fault current;
When needs to AC carry out reactive power compensation realize fault traversing time, all unipolarity submodules in brachium pontis are bypassed, and all bipolarity submodules are access in, and the switching device in bipolarity submodule carries out action according to control overflow;
Effect of the present invention is:
The present invention, according to the external characteristic of dissimilar submodule, by the combination of dissimilar submodule, achieves the defencive function of dc-side short-circuit, adopts many level submodule to decrease total submodule number and the component counts relevant to submodule; During normal operation, the control of two class submodules is similar, makes the control algolithm of whole system simple; Submodule loss is low, and system effectiveness is high.
The present invention can realize the defencive function of dc-side short-circuit, when DC side is short-circuited fault by controlling the switching device in submodule, and can disengagement failure electric current rapidly; Reactive power compensation can be carried out to AC and realize fault traversing, improve the stability of network system;
The present invention adopts many level submodule to decrease total submodule number and the component counts relevant to submodule; When converter normally runs, the control of two class submodules is similar, makes the control algolithm of whole system simple; Submodule loss is low, and efficiency is high, thus makes the efficiency of whole system get a promotion.
Accompanying drawing explanation
Fig. 1 is the basic block diagram of existing MMC;
Fig. 2 is two level unipolarity sub modular structure figure in existing MMC;
Fig. 3 is two level bipolarity sub modular structure figure in existing MMC;
Fig. 4 is unipolarity submodule of the present invention and bipolarity submodule hybrid MMC main circuit topological structure figure;
Fig. 5 is the unipolarity sub modular structure figure adopted in topology of the present invention;
Fig. 6 is the bipolarity sub modular structure figure adopted in topology of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in detail.
A kind of Modular multilevel converter MMC with dc-side short-circuit defencive function that the present invention proposes, as shown in Figure 4, each phase of this Modular multilevel converter is all divided into brachium pontis and lower brachium pontis two parts, and each brachium pontis is by A nindividual unipolarity submodule and B mindividual bipolarity submodule series connection obtains, Cell A in figure 1-Cell A nfor unipolarity submodule, Cell B 1-CellB mfor bipolarity submodule.Number of modules (A total in brachium pontis n+ B m) determined by DC bus-bar voltage and the withstand voltage of switching device that adopts, can disengagement failure electric current rapidly time simultaneously for ensureing that DC side breaks down, the number of bipolarity submodule is greater than the number equaling unipolarity submodule, i.e. B m>=A n.Two buffer inductance L are connected in series between upper brachium pontis and lower brachium pontis aprevent brachium pontis from switching process, bridge arm direct pass occurring, cause large bridge arm current.If the voltage between positive bus-bar P+ and negative busbar N-is V dc, then the voltage born needed for each submodule is V dc/ (A n+ B m).Two buffer inductance L of each phase of MMC abetween draw and export termination one filter inductance L o, make the electric current of output meet load R lto the requirement of THD (Total HarmonicDistortion).
Described unipolarity submodule adopts two half-bridge submodule example structure of three level, as shown in Figure 5.In Fig. 5, unipolarity submodule is by 4 switching device S 11, S 12, S 13, S 14with two electric capacity C 11, C 12form; Wherein, 4 switching device S 11, S 12, S 13, S 14connect successively, the first electric capacity C 11with first, second switching device S 11, S 12parallel connection, the second electric capacity C 12with the 3rd, the 4th switching device S 13, S 14in parallel; First, second switching device S 11and S 12complementary conducting; Three, the 4th switching device S 13and S 14complementary conducting; When second and the 3rd switching device S 12and S 13during conducting, this submodule is bypassed.
Described bipolarity submodule adopts five level cross connexon modules, as shown in Figure 6.In Fig. 6, bipolarity submodule is by 6 switching device S 21, S 22, S 23, S 24, S 25, S 26with two electric capacity C 21, C 22form.Wherein first and second switching device S 21with S 22series connection, the 3rd and the 4th switching device S 23with S 24series connection; First electric capacity C 21with first, second switching device S 21, S 22parallel connection, the second electric capacity C 22with the 3rd, the 4th switching device S 23, S 24in parallel; First and second electric capacity C 21with C 22between by the 5th and the 6th switching device S 25and S 26interconnection; First and second switching device S 21and S 22complementary conducting, the third and fourth switching device S 23and S 24complementary conducting; 5th switching device S during normal work 25keep normally closed, the 6th switching device S 26keep normal open; As the second, the 6th, the 3rd switching device S 22, S 26, S 23during conducting, this submodule is bypassed; As the 5th switching device S 25conducting, the 6th switching device S 26during closedown, this submodule exports negative level.First, second, third and fourth switching device S in five described level cross connexon modules 21, S 22, S 23and S 24there is identical electric pressure; 5th and the 6th switching device S 25and S 26electric pressure be first, second, third or the 4th twice of switching device.
Effect of the present invention: the voltage that described converter brachium pontis Neutron module can bear is V dc/ (A n+ B m), be the twice of original two level submodules, if the voltage between positive bus-bar P+ and negative busbar N-is V dctime identical, the number of modules (A that each brachium pontis is total n+ B m) be only the half of employing two level submodule topology, i.e. (A n+ B m)=N/2; In five described level cross connexon modules, any time electric current only need flow through three switching devices, conduction loss is low, and efficiency is high; When converter normally works, the cross connect switch device (S in five described level cross connexon modules 26) keeping conducting, unipolarity submodule is identical with the control of bipolarity submodule; When DC side is short-circuited fault, the switching device locking of all submodules in brachium pontis, realizes the restriction to DC side fault current; When needs to AC carry out reactive power compensation realize fault traversing time, all unipolarity submodules in brachium pontis are bypassed, and all bipolarity submodules are access in, and the switching device in bipolarity submodule carries out action according to control overflow.
The above, be only the present invention preferably embodiment be not intended to limit, be anyly familiar with those skilled in the art in the technical scope that the present invention discloses, the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims (4)

1. have a Modular multilevel converter for dc-side short-circuit defencive function, each phase of this Modular multilevel converter is all divided into brachium pontis and lower brachium pontis two parts, and each brachium pontis is by A nindividual unipolarity submodule and B mindividual bipolarity submodule series connection obtains, and B m>=A n; Be connected in series two buffer inductances between upper brachium pontis and lower brachium pontis, draw between two buffer inductances of each phase and export termination one filter inductance; It is characterized in that, described unipolarity submodule adopts two half-bridge submodules of three level; Described bipolarity submodule adopts five level cross connexon modules.
2. multi-level converter as claimed in claim 1, it is characterized in that, described unipolarity submodule is by 4 switching device (S 11, S 12, S 13, S 14) and two electric capacity (C 11, C 12) form; Wherein, 4 switching device (S 11, S 12, S 13, S 14) connect successively, the first electric capacity (C 11) and first, second switching device (S 11, S 12) in parallel, the second electric capacity (C 12) and the 3rd, the 4th switching device (S 13, S 14) in parallel; First and second switching device (S 11and S 12) complementary conducting; Third and fourth switching device (S 13and S 14) complementary conducting; When second and the 3rd switching device (S 12and S 13) conducting time, this unipolarity submodule is bypassed.
3. multi-level converter as claimed in claim 1, it is characterized in that, described bipolarity submodule is by 6 switching device (S 21, S 22, S 23, S 24, S 25, S 26) and two electric capacity (C 21, C 22) form; Wherein first and second switching device (S 21with S 22) series connection, the 3rd and the 4th switching device (S 23with S 24) series connection; First electric capacity (C 21) and first, second switching device (S 21, S 22) in parallel, the second electric capacity (C 22) and the 3rd, the 4th switching device (S 23, S 24) in parallel; First and second electric capacity (C 21with C 22) between by the 5th and the 6th switching device (S 25and S 26) interconnection; First and second switching device (S 21and S 22) complementary conducting, the third and fourth switching device (S 23and S 24) complementary conducting; During normal work, the 5th switching device (S 25) keep normally closed, the 6th switching device (S 26) keep normal open; As the second, the 6th, the 3rd switching device (S 22, S 26, S 23) conducting time, this bipolarity submodule is bypassed; As the 5th switching device (S 25) conducting, the 6th switching device (S 26) close time, this submodule export negative level.
4. multi-level converter as claimed in claim 3, is characterized in that, first, second, third and fourth switching device (S in described bipolarity connexon module 21, S 22, S 23and S 24) there is identical electric pressure; 5th and the 6th switching device (S 25and S 26) electric pressure be first, second, third or the 4th twice of switching device.
CN201510250406.XA 2015-05-15 2015-05-15 Modularized multi-level converter with function of DC side short circuit protection Pending CN104821736A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510250406.XA CN104821736A (en) 2015-05-15 2015-05-15 Modularized multi-level converter with function of DC side short circuit protection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510250406.XA CN104821736A (en) 2015-05-15 2015-05-15 Modularized multi-level converter with function of DC side short circuit protection

Publications (1)

Publication Number Publication Date
CN104821736A true CN104821736A (en) 2015-08-05

Family

ID=53731934

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510250406.XA Pending CN104821736A (en) 2015-05-15 2015-05-15 Modularized multi-level converter with function of DC side short circuit protection

Country Status (1)

Country Link
CN (1) CN104821736A (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105356747A (en) * 2015-10-27 2016-02-24 中国电力科学研究院 Power sub module for novel flexible direct current transmission current converter
CN105897026A (en) * 2016-06-16 2016-08-24 叶亚萱 Modular multilevel converter
CN105978375A (en) * 2016-06-21 2016-09-28 浙江大学 Cross-connected sub-module suitable for long-distance and large-capacity overhead line power transmission and MMC control method of cross-connected sub-module
CN106411166A (en) * 2016-11-15 2017-02-15 北京四方继保自动化股份有限公司 Modular multi-level converter hybrid bridge arm topology structure
CN106452104A (en) * 2016-09-13 2017-02-22 清华大学 Unipolar current cross-connected three-level sub-module
CN106455278A (en) * 2016-11-15 2017-02-22 上海联影医疗科技有限公司 X-ray high-voltage generator and circuit and method for controlling series resonant converter
CN106877698A (en) * 2015-12-10 2017-06-20 特变电工新疆新能源股份有限公司 A kind of flexible direct current power transmission system topological structure
WO2017128499A1 (en) * 2016-01-27 2017-08-03 东南大学 Four-port power electronic transformer based on hybrid modular multilevel converter
CN108418454A (en) * 2018-03-05 2018-08-17 武汉大学 Modular multilevel converter and its multiple cross submodule
CN109067218A (en) * 2018-09-12 2018-12-21 上海交通大学 A kind of solid-state transformer topological structure method based on more level submodules
CN109149986A (en) * 2018-10-11 2019-01-04 昆明理工大学 The hybrid Modular multilevel converter of one type, three level and its control method
CN112953274A (en) * 2019-11-26 2021-06-11 新疆金风科技股份有限公司 Power module and control method thereof
WO2022110267A1 (en) * 2020-11-27 2022-06-02 株洲中车时代电气股份有限公司 Bidirectional dc/dc converter, urban rail vehicle and traction system thereof
CN116488491A (en) * 2023-06-12 2023-07-25 湖南大学 Multi-index comprehensive optimized hybrid multi-level converter and regulation and control method thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101971475A (en) * 2008-03-19 2011-02-09 西门子公司 Method for controlling a multi-phase power converter having distributed energy accumulator at low output frequencies
CN104601017A (en) * 2014-12-25 2015-05-06 清华大学 Modularized multi-level converter being able to traverse direct current short circuit fault

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101971475A (en) * 2008-03-19 2011-02-09 西门子公司 Method for controlling a multi-phase power converter having distributed energy accumulator at low output frequencies
CN104601017A (en) * 2014-12-25 2015-05-06 清华大学 Modularized multi-level converter being able to traverse direct current short circuit fault

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ALIREZA NAMI* 等: "Five level cross connected cell for cascaded converters", 《POWER ELECTRONICS ANS APPLICATIONS》 *
向往 等: "一种能够阻断直流故障电流的新型子模块拓扑及混合型模块化多电平环流器", 《中国电机工程学报》 *

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105356747B (en) * 2015-10-27 2019-07-12 中国电力科学研究院 A kind of power modules of flexible direct-current transmission converter
CN105356747A (en) * 2015-10-27 2016-02-24 中国电力科学研究院 Power sub module for novel flexible direct current transmission current converter
CN106877698A (en) * 2015-12-10 2017-06-20 特变电工新疆新能源股份有限公司 A kind of flexible direct current power transmission system topological structure
US9960666B2 (en) 2016-01-27 2018-05-01 Southeast University Four-port power electronic transformer based on hybrid modular multilevel converter
WO2017128499A1 (en) * 2016-01-27 2017-08-03 东南大学 Four-port power electronic transformer based on hybrid modular multilevel converter
CN105897026A (en) * 2016-06-16 2016-08-24 叶亚萱 Modular multilevel converter
CN105978375B (en) * 2016-06-21 2018-07-24 浙江大学 Chiasma type submodule and its MMC control methods suitable for the transmission of electricity of remote large capacity overhead line
CN105978375A (en) * 2016-06-21 2016-09-28 浙江大学 Cross-connected sub-module suitable for long-distance and large-capacity overhead line power transmission and MMC control method of cross-connected sub-module
CN106452104B (en) * 2016-09-13 2019-03-29 清华大学 Monopolar current is cross-linked three level submodules
CN106452104A (en) * 2016-09-13 2017-02-22 清华大学 Unipolar current cross-connected three-level sub-module
CN106455278B (en) * 2016-11-15 2017-09-29 上海联影医疗科技有限公司 X-ray high-voltage generator, the control circuit of series resonant converter and method
CN106411166A (en) * 2016-11-15 2017-02-15 北京四方继保自动化股份有限公司 Modular multi-level converter hybrid bridge arm topology structure
CN106455278A (en) * 2016-11-15 2017-02-22 上海联影医疗科技有限公司 X-ray high-voltage generator and circuit and method for controlling series resonant converter
CN108418454B (en) * 2018-03-05 2019-12-24 武汉大学 Modular multilevel converter and multiple cross sub-module thereof
CN108418454A (en) * 2018-03-05 2018-08-17 武汉大学 Modular multilevel converter and its multiple cross submodule
CN109067218A (en) * 2018-09-12 2018-12-21 上海交通大学 A kind of solid-state transformer topological structure method based on more level submodules
CN109149986A (en) * 2018-10-11 2019-01-04 昆明理工大学 The hybrid Modular multilevel converter of one type, three level and its control method
CN109149986B (en) * 2018-10-11 2024-03-08 昆明理工大学 Three-level-like hybrid modular multilevel converter and control method thereof
CN112953274A (en) * 2019-11-26 2021-06-11 新疆金风科技股份有限公司 Power module and control method thereof
WO2022110267A1 (en) * 2020-11-27 2022-06-02 株洲中车时代电气股份有限公司 Bidirectional dc/dc converter, urban rail vehicle and traction system thereof
CN116488491A (en) * 2023-06-12 2023-07-25 湖南大学 Multi-index comprehensive optimized hybrid multi-level converter and regulation and control method thereof
CN116488491B (en) * 2023-06-12 2023-09-12 湖南大学 Hybrid multi-level converter and regulation and control method thereof

Similar Documents

Publication Publication Date Title
CN104821736A (en) Modularized multi-level converter with function of DC side short circuit protection
CN104320011B (en) Hybrid sub-module MMC converter with direct-current fault ride-through capability
EP2786479B1 (en) Power converter
CN102124625B (en) Power conversion device
CN104410260B (en) Fault-tolerance-capability-equipped MMC sub-module structure capable of realizing DC fault self-protection, and MMC modulation method thereof
CN103595064B (en) Expansion double-electrode direct current transmission system
CN104167912A (en) MMC with zero direct voltage fault ride-through capability and design method thereof
CN103715930B (en) A kind of method promoting flexible direct current power transmission system capacity
CN102097967B (en) Cascaded multi-level converter
CN107039980B (en) High-voltage direct current power flow controller
CN106411166A (en) Modular multi-level converter hybrid bridge arm topology structure
CN103236710A (en) Unified power flow controller in modular structure
CN104022666A (en) Modularization multi-level converter valve for flexible DC power transmission system
CN106655841A (en) Novel three-phase current converter topology based on modular multilevel converter
CN103490656A (en) Four-level inverter topological structure based on H-bridge and carrier modulation method thereof
CN104993716A (en) Modular multilevel converter and hybrid double-unit sub-module
CN104601017A (en) Modularized multi-level converter being able to traverse direct current short circuit fault
CN104796025A (en) Sub-module topological structure of modular multilevel converter
CN106787877B (en) Antithesis unipolar voltage module chain and its mixed multi-level current transformer
EP3157120B1 (en) Modular multi-level flexible direct-current topology circuit suitable for fault ride-through
CN106655850A (en) Modular multilevel converter for eliminating low-frequency voltage fluctuation
CN103326608A (en) Sub module, phase unit, voltage source type multi-level current converter and control methods
CN105186550A (en) Improved modularized multi-level converter submodule topology
CN104883084B (en) A kind of neutral point clamp type cascaded H-bridges mixed multi-level current transformer
CN103236693A (en) Unified electric energy quality controller

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
EXSB Decision made by sipo to initiate substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20150805

WD01 Invention patent application deemed withdrawn after publication