CN205657607U - Supplementary electric capacity distributing type half -bridge / single clamp series -parallel connection MMC is from voltage -sharing topology based on inequality constraint - Google Patents

Abstract

The utility model provides a supplementary electric capacity distributing type half -bridge / single clamp series -parallel connection MMC is from voltage -sharing topology based on inequality constraint. Half -bridge / single clamp series -parallel connection MMC in the voltage -sharing topology, half -bridge / single clamp series -parallel connection MMC model with in the voltage -sharing auxiliary circuit passes through the auxiliary circuit 6 (i) (i) electric contact takes place to N for auxiliary switch, and auxiliary switch is closed, and both constitute supplementary electric capacity distributing type half -bridge / single clamp series -parallel connection MMC is from voltage -sharing topology based on inequality constraint, and auxiliary switch opens, and it is topological that the topoligical equivalence be half -bridge / single clamp series -parallel connection MMC. Do not stressing under the condition of two kinds of topological differences that (i) (i) a mechanical switch can leave out K 6 among the auxiliary switch. This half -bridge / single clamp series -parallel connection MMC is from voltage -sharing topology, can clamp direct current side trouble, do not rely on special voltage -sharing control simultaneously, can accomplish directly exchange the basis of energy conversion on, realize the equilibrium of submodule piece capacitance voltage spontaneously, can make with electric capacity appearance value, realization MMC's base frequency by corresponding reductions submodule piece triggering frequency in addition.

Description

The distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from all pressing topology

Technical field

This utility model relates to flexible transmission field, is specifically related to a kind of distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC from all pressing topology.

Background technology

Modularization multi-level converter MMC is the developing direction of following HVDC Transmission Technology, MMC uses submodule (Sub-module, SM) mode cascaded constructs converter valve, avoid the direct series connection of big metering device, reduce requirement conforming to device, simultaneously facilitate dilatation and redundant configuration.Along with the rising of level number, output waveform, close to sinusoidal, can effectively avoid the defect of low level VSC-HVDC.

Half-bridge/mono-clamp series-parallel connection MMC is combined by half-bridge submodule and single clamp submodule.Half-bridge submodule is made up of 2 IGBT module, 1 sub-module capacitance, 1 IGCT and 1 mechanical switch；Single clamp submodule is made up of 3 IGBT module, 1 sub-module capacitance, a diode and 1 mechanical switch.This series-parallel connection MMC, low cost, running wastage is little, can clamp DC side fault simultaneously.

Different from two level, three level VSC, the DC voltage of half-bridge/mono-clamp series-parallel connection MMC is not supported by a bulky capacitor, but is supported by a series of separate suspension submodule capacitances in series.In order to ensure that the waveform quality that AC voltage exports bears identical stress with each power semiconductor in guarantee module, also for preferably supporting DC voltage, reduce alternate circulation, it is necessary to assure submodule capacitor voltage is in the state of dynamic stability at the periodic current disorder of internal organs of brachium pontis power.

Sequence based on capacitance voltage sequence all presses algorithm to be the main flow thinking solving half-bridge/mono-clamp series-parallel connection MMC Neutron module capacitance voltage equalization problem at present.But, the realization of ranking function has to rely on the Millisecond sampling of capacitance voltage, needs substantial amounts of sensor and optical-fibre channel to be coordinated；Secondly, when group number of modules increases, the operand of capacitance voltage sequence increases rapidly, and the hardware designs for controller brings huge challenge；Additionally, submodule is cut-off frequency and has the highest requirement by sequence all realizations of pressure algorithm, cut-off frequency and be closely related with all pressure effects, in practice process, probably due to all press the restriction of effect, it has to improve the triggering frequency of submodule, and then bring the increase that inverter is lost.

Document " A DC-Link Voltage Self-Balance Method for a Diode-Clamped Modular Multilevel Converter With Minimum Number of Voltage Sensors ", it is proposed that a kind of rely on clamp diode and transformator to realize MMC submodule capacitor voltage equilibrium thinking.But the program the most to a certain degree destroys the modular nature of submodule, submodule capacitive energy interchange channel is also confined in mutually, could not make full use of the existing structure of MMC, introducing of three transformators also brings along bigger improvement cost while making control strategy complicate.

Utility model content

For the problems referred to above, the purpose of this utility model is to propose a kind of economy, modular, it is independent of all pressing algorithm, submodule can be reduced simultaneously accordingly and trigger frequency and capacitor's capacity and there is half-bridge/mono-clamp series-parallel connection MMC of DC Line Fault clamping ability from all pressing topology.

The concrete constituted mode of this utility model is as follows.

The distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from all pressing topology, including the half-bridge MMC model being made up of A, B, C three-phase, each brachium pontis of A, B, C three-phase respectively byKIndividual half-bridge submodule,N-KIndividual single clamp submodule and 1 brachium pontis reactor are in series；Including by 6NIndividual auxiliary switch (6KIndividual mechanical switch, 6N-6KIndividual IGBT module), 6N+ 11 clamp diodes, 8 auxiliary capacitors, 4 auxiliary IGBT module compositions from the most all pressing subsidiary loop.

The above-mentioned distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from all pressing topology, in series-parallel connection MMC model, and A phase upper and lower bridge arm, in single clamp submodule, diode connexon module capacitance positive pole, IGBT module connexon module capacitance negative pole.1st submodule of brachium pontis in A phase, its submodule electric capacity negative pole is connected with the 2nd of brachium pontis module I GBT module midpoint in A phase downwards, and its submodule IGBT module midpoint is upwards connected with dc bus positive pole；In A phase the of brachium pontisiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacity negative pole is downwards with in A phase the of brachium pontisi+ 1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisi-1 sub-module capacitance negative pole is connected；In A phase the of brachium pontisKIndividual half-bridge submodule, its submodule electric capacity negative pole is downwards with in A phase the of brachium pontisK+ 1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisK-1 sub-module capacitance negative pole is connected；In A phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, its submodule diode and IGBT module tie-point be brachium pontis the downwards and in A phasej+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards with brachium pontis in A phasej-1 submodule diode is connected with IGBT module tie-point；Brachium pontis in A phaseNIndividual submodule, its submodule diode and IGBT module tie-point are down through two brachium pontis reactorsL ₀1st sub-module I GBT module midpoint of brachium pontis lower with A phase is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisN-1 submodule diode is connected with IGBT module tie-point；The of the lower brachium pontis of A phaseiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacity negative pole downwards with A phase time brachium pontis thei+ 1 sub-module I GBT module midpoint is connected, its IGBT module midpoint upwards brachium pontis lower with A phase thei-1 sub-module capacitance negative pole is connected；The of the lower brachium pontis of A phaseKIndividual submodule, its submodule electric capacity negative pole downwards with A phase time brachium pontis theK+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards brachium pontis lower with A phase theK-1 sub-module capacitance negative pole is connected；The lower brachium pontis of A phase thejIndividual submodule, whereinjValue beK+ 2～N-1, its submodule diode and IGBT module tie-point downwards with A phase time brachium pontis thej+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards brachium pontis lower with A phase thej-1 submodule diode is connected with IGBT module tie-point；The lower brachium pontis of A phase theNIndividual submodule diode is connected with dc bus negative pole downwards with IGBT module tie-point, the of its submodule IGBT module midpoint upwards brachium pontis lower with A phaseN-1 submodule diode is connected with IGBT module tie-point.B phase upper and lower bridge arm, in single clamp submodule, IGBT module connexon module capacitance positive pole, diode connexon module capacitance negative pole, 1st submodule of upper brachium pontis, its submodule capacitance cathode is upwards connected with dc bus positive pole, and its submodule IGBT module midpoint is connected with the 2nd sub-module capacitance positive pole of brachium pontis in B phase downwards；In B phase the of brachium pontisiIndividual submodule, whereiniValue be 2～K-1, its submodule capacitance cathode is upwards with in B phase the of brachium pontisi-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is downwards with in B phase the of brachium pontisi+ 1 sub-module capacitance positive pole is connected；In B phase the of brachium pontisKIndividual submodule, its submodule capacitance cathode is upwards with in B phase the of brachium pontisK-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with brachium pontis in B phase theK+ 1 sub-module I GBT module is connected with diode connection point；In B phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, its submodule IGBT module and diode connection point upwards with brachium pontis in B phasej-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with brachium pontis in B phase thej+ 1 sub-module I GBT module is connected with diode connection point；Brachium pontis in B phaseNIndividual submodule, its submodule IGBT module and diode connection point upwards with brachium pontis in B phaseN-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is down through two brachium pontis reactorsL ₀1st sub-module capacitance positive pole of brachium pontis lower with B phase is connected；The of the lower brachium pontis of B phaseiIndividual submodule, whereiniValue be 2～K-1, the of its submodule capacitance cathode upwards brachium pontis lower with B phasei-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with the of B phase time brachium pontisi+ 1 sub-module capacitance positive pole is connected；The of the lower brachium pontis of B phaseKIndividual submodule, its submodule capacitance cathode upwards brachium pontis lower with B phase theK-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with B phase time brachium pontis theK+ 1 sub-module I GBT module is connected with diode connection point；The lower brachium pontis of B phase thejIndividual submodule, whereinjValue beK+ 2～N-1, its submodule IGBT module and diode connection point upwards brachium pontis lower with B phase thej-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with B phase time brachium pontis thej+ 1 sub-module I GBT module is connected with diode connection point；The lower brachium pontis of B phase theNIndividual submodule, its submodule IGBT module and diode connection point upwards brachium pontis lower with B phase theN-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is connected with dc bus negative pole downwards.The connected mode of C phase upper and lower bridge arm submodule is consistent with A phase or B.

The above-mentioned distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from all pressing topology, from all pressing in subsidiary loop, first auxiliary capacitor and second auxiliary capacitor are in parallel by clamp diode, and second auxiliary capacitor positive pole connects first auxiliary capacitor negative pole connection clamp diode of auxiliary IGBT module and be incorporated to dc bus positive pole；3rd auxiliary capacitor and the 4th auxiliary capacitor are in parallel by clamp diode, and the 3rd auxiliary capacitor negative pole connects the 4th auxiliary capacitor positive pole connection clamp diode of auxiliary IGBT module and be incorporated to dc bus negative pole；5th auxiliary capacitor and the 6th auxiliary capacitor are in parallel by clamp diode, and the 5th auxiliary capacitor positive pole connects the 6th auxiliary capacitor negative pole connection clamp diode of auxiliary IGBT module and be incorporated to dc bus positive pole；7th auxiliary capacitor and the 8th auxiliary capacitor are in parallel by clamp diode, and the 8th auxiliary capacitor negative pole connects the 7th auxiliary capacitor positive pole connection clamp diode of auxiliary IGBT module and be incorporated to dc bus negative pole.Clamp diode, by the 1st sub-module capacitance and first auxiliary capacitor positive pole in brachium pontis in auxiliary switch connection A phase；The is connected in A phase in brachium pontis by auxiliary switchiIndividual sub-module capacitance and thei+ 1 sub-module capacitance positive pole, whereiniValue be 1～N-1；The is connected in A phase in brachium pontis by auxiliary switchNIndividual sub-module capacitance brachium pontis 1st sub-module capacitance positive pole lower with A phase；The is connected in the lower brachium pontis of A phase by auxiliary switchiThe lower brachium pontis of individual sub-module capacitance and A phase thei+ 1 sub-module capacitance positive pole, whereiniValue be 1～N-1；The is connected in the lower brachium pontis of A phase by auxiliary switchNIndividual sub-module capacitance and the 3rd auxiliary capacitor positive pole.Clamp diode, by the 1st sub-module capacitance and the negative pole of second auxiliary capacitor in brachium pontis in auxiliary switch connection B phase；The is connected in B phase in brachium pontis by auxiliary switchiIndividual sub-module capacitance and theiThe negative pole of+1 sub-module capacitance, whereiniValue be 1～N-1；The is connected in B phase in brachium pontis by auxiliary switchNThe negative pole of individual sub-module capacitance brachium pontis 1st sub-module capacitance lower with B phase；The is connected in the lower brachium pontis of B phase by auxiliary switchiThe lower brachium pontis of individual sub-module capacitance and B phase theiThe negative pole of+1 sub-module capacitance, whereiniValue be 1～N-1；The is connected in the lower brachium pontis of B phase by auxiliary switchNIndividual sub-module capacitance and the negative pole of the 4th auxiliary capacitor.When the annexation of C phase submodule is consistent with A, between C phase upper and lower bridge arm Neutron module, the connected mode of clamp diode is consistent with A, 6th auxiliary capacitor positive pole connects the sub-module capacitance positive pole of brachium pontis first in C phase through auxiliary switch, clamp diode simultaneously, 5th auxiliary capacitor negative pole connects the upper sub-module capacitance negative pole of brachium pontis first of B phase through auxiliary switch, clamp diode, and the 8th auxiliary capacitor positive pole connects C phase time brachium pontis the through auxiliary switch, clamp diodeNIndividual sub-module capacitance positive pole, the 7th auxiliary capacitor negative pole connects the lower brachium pontis of B phase the through auxiliary switch, clamp diodeNIndividual sub-module capacitance negative pole；When the annexation of C phase submodule is consistent with B, between C phase upper and lower bridge arm Neutron module, the connected mode of clamp diode is consistent with B, 5th auxiliary capacitor negative pole connects the sub-module capacitance negative pole of brachium pontis first in C phase through auxiliary switch, clamp diode simultaneously, 6th auxiliary capacitor positive pole connects the upper sub-module capacitance positive pole of brachium pontis first of A phase through auxiliary switch, clamp diode, and the 7th auxiliary capacitor negative pole connects C phase time brachium pontis the through auxiliary switch, clamp diodeNIndividual sub-module capacitance negative pole, the 8th auxiliary capacitor positive pole connects the lower brachium pontis of A phase the through auxiliary switch, clamp diodeNIndividual sub-module capacitance positive pole.

Accompanying drawing explanation

Fig. 1 is the structural representation of half-bridge submodule；

Fig. 2 is single structural representation clamping submodule；

Fig. 3 is that the distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from all pressing topology.

Detailed description of the invention

For of the present utility model performance and operation principle are expanded on further, it is specifically described with operation principle to the constituted mode of utility model below in conjunction with accompanying drawing.But half-bridge based on this principle/mono-clamp series-parallel connection MMC is not limited to Fig. 3 from all pressure topologys.

With reference to Fig. 3, the distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC, oneself the most all presses topology, clamps series-parallel connection MMC model including the half-bridge being made up of A, B, C three-phase/mono-, each brachium pontis of A, B, C three-phase respectively byKIndividual half-bridge submodule,N-KIndividual single clamp submodule and 1 brachium pontis reactor are in series；Including by 6NIndividual auxiliary switch (6KIndividual mechanical switch, 6N-6KIndividual IGBT module), 6N+ 11 clamp diodes, 8 auxiliary capacitors, 4 auxiliary IGBT module compositions from the most all pressing subsidiary loop.

In half-bridge/mono-clamp series-parallel connection MMC model, A phase upper and lower bridge arm, in single clamp submodule, diode connexon module capacitance positive pole, IGBT module connexon module capacitance negative pole.1st submodule of brachium pontis, its submodule electric capacity in A phaseC­_{au­_1}Negative pole is connected with the 2nd of brachium pontis module I GBT module midpoint in A phase downwards, and its submodule IGBT module midpoint is upwards connected with dc bus positive pole；In A phase the of brachium pontisiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC­_{au­_i} Negative pole is downwards with in A phase the of brachium pontisi+ 1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisi-1 sub-module capacitanceC _{­au­_i-1}Negative pole is connected；In A phase the of brachium pontisKIndividual half-bridge submodule, its submodule electric capacityC _{­ au­_K} Negative pole is downwards with in A phase the of brachium pontisK+ 1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisK-1 sub-module capacitanceC­_{au­_K-1}Negative pole is connected；In A phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, its submodule diode and IGBT module tie-point be brachium pontis the downwards and in A phasej+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards with brachium pontis in A phasej-1 submodule diode is connected with IGBT module tie-point；Brachium pontis in A phaseNIndividual submodule, its submodule diode and IGBT module tie-point are down through two brachium pontis reactorsL ₀1st sub-module I GBT module midpoint of brachium pontis lower with A phase is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisN-1 submodule diode is connected with IGBT module tie-point；The of the lower brachium pontis of A phaseiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC­_{al­_i} Negative pole downwards with A phase time brachium pontis thei+ 1 sub-module I GBT module midpoint is connected, its IGBT module midpoint upwards brachium pontis lower with A phase thei-1 sub-module capacitanceC­ _{al­_i-1}Negative pole is connected；The of the lower brachium pontis of A phaseKIndividual submodule, its submodule electric capacityC _{­ al_K} Negative pole downwards with A phase time brachium pontis theK+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards brachium pontis lower with A phase theK-1 sub-module capacitanceC­_{al­_K-1}Negative pole is connected；The lower brachium pontis of A phase thejIndividual submodule, whereinjValue beK+ 2～N-1, its submodule diode and IGBT module tie-point downwards with A phase time brachium pontis thej+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards brachium pontis lower with A phase thej-1 submodule diode is connected with IGBT module tie-point；The lower brachium pontis of A phase theNIndividual submodule diode is connected with dc bus negative pole downwards with IGBT module tie-point, the of its submodule IGBT module midpoint upwards brachium pontis lower with A phaseN-1 submodule diode is connected with IGBT module tie-point.B phase upper and lower bridge arm, in single clamp submodule, IGBT module connexon module capacitance positive pole, diode connexon module capacitance negative pole, the 1st submodule of upper brachium pontis, its submodule electric capacityC _{­ bu­_1}Positive pole is upwards connected with dc bus positive pole, its submodule IGBT module midpoint downwards with the 2nd sub-module capacitance of brachium pontis in B phaseC _{­bu­_2}Positive pole is connected；In B phase the of brachium pontisiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC­_{bu­_i} Positive pole is upwards with in B phase the of brachium pontisi-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is downwards with in B phase the of brachium pontisi+ 1 sub-module capacitanceC­_{bu­_i+1}Positive pole is connected；In B phase the of brachium pontisKIndividual submodule, its submodule electric capacityC­_{bu­_K} Positive pole is upwards with in B phase the of brachium pontisK-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with brachium pontis in B phase theK+ 1 sub-module I GBT module is connected with diode connection point；In B phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, its submodule IGBT module and diode connection point upwards with brachium pontis in B phasej-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with brachium pontis in B phase thej+ 1 sub-module I GBT module is connected with diode connection point；Brachium pontis in B phaseNIndividual submodule, its submodule IGBT module and diode connection point upwards with brachium pontis in B phaseN-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is down through two brachium pontis reactorsL ₀1st sub-module capacitance of brachium pontis lower with B phaseC _{­bl­_1}Positive pole is connected；The of the lower brachium pontis of B phaseiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC _{­bl_i} The of positive pole upwards brachium pontis lower with B phasei-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with the of B phase time brachium pontisi+ 1 sub-module capacitanceC­ _{bl­_i+1}Positive pole is connected；The of the lower brachium pontis of B phaseKIndividual submodule, its submodule electric capacityC _{­bl_K} Positive pole upwards brachium pontis lower with B phase theK-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with B phase time brachium pontis theK+ 1 sub-module I GBT module is connected with diode connection point；The lower brachium pontis of B phase thejIndividual submodule, whereinjValue beK+ 2～N-1, its submodule IGBT module and diode connection point upwards brachium pontis lower with B phase thej-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with B phase time brachium pontis thej+ 1 sub-module I GBT module is connected with diode connection point；The lower brachium pontis of B phase theNIndividual submodule, its submodule IGBT module and diode connection point upwards brachium pontis lower with B phase theN-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is connected with dc bus negative pole downwards.The connected mode of C phase upper and lower bridge arm submodule is consistent with A.

From all pressing in subsidiary loop, auxiliary capacitorC ₁With auxiliary capacitorC ₂In parallel by clamp diode, auxiliary capacitorC ₂Positive pole connects auxiliary IGBT moduleT ₁, auxiliary capacitorC ₁Negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₃With auxiliary capacitorC ₄In parallel by clamp diode, auxiliary capacitorC ₃Negative pole connects auxiliary IGBT moduleT ₂, auxiliary capacitorC ₄Positive pole connects clamp diode and is incorporated to dc bus negative pole；Auxiliary capacitorC ₅With auxiliary capacitorC ₆In parallel by clamp diode, auxiliary capacitorC ₅Positive pole connects auxiliary IGBT moduleT ₃, auxiliary capacitorC ₆Negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₇With auxiliary capacitorC ₈In parallel by clamp diode, auxiliary capacitorC ₈Negative pole connects auxiliary IGBT moduleT ₄, auxiliary capacitorC ₇Positive pole connects clamp diode and is incorporated to dc bus negative pole.Clamp diode, passes through auxiliary switchK _{au_12}1st sub-module capacitance in brachium pontis in connection A phaseC _{­au­_1}With auxiliary capacitorC ₁Positive pole；Pass through auxiliary switchK _{au_i2}、K _{au_ ( i +1 ) 2}Connect in A phase in brachium pontis theiIndividual sub-module capacitanceC _{­au­_i} Withi+ 1 sub-module capacitanceC _{­au­_i+1}Positive pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{au_K2}、T _{au_K+1}Connect in A phase in brachium pontis theKIndividual sub-module capacitanceC _{­au­_K} WithK+ 1 sub-module capacitanceC­ _{au_K+1}Positive pole；Pass through auxiliary switchT _{au_j} 、T _{au_j+1}Connect in A phase in brachium pontis thejIndividual sub-module capacitanceC _{­au­_j} Withj+ 1 sub-module capacitanceC _{­au­_j+1}Positive pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{au_N} 、K _{al_12}Connect in A phase in brachium pontis theNIndividual sub-module capacitanceC­_{au_N} Brachium pontis 1st sub-module capacitance lower with A phaseC _{­al­_1}Positive pole；Pass through auxiliary switchK _{al_i2}、K _{al_ ( i +1 ) 2}Connect in the lower brachium pontis of A phase theiIndividual sub-module capacitanceC _{­al­_i} Withi+ 1 sub-module capacitanceC _{­al­_i+1}Positive pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{al_K2}、T _{al_K+1}Connect in the lower brachium pontis of A phase theKIndividual sub-module capacitanceC­_{al­_K} WithK+ 1 sub-module capacitanceC­_{al­_K+1}Positive pole；Pass through auxiliary switchT _{al_j} 、T _{al_j+1}Connect in the lower brachium pontis of A phase thejIndividual sub-module capacitanceC _{­al_j} Withj+ 1 sub-module capacitanceC _{­al­_j+1}Positive pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{al_N} Connect in the lower brachium pontis of A phase theNIndividual sub-module capacitanceC _{­al_N} With auxiliary capacitorC ₃Positive pole.Clamp diode, passes through auxiliary switchK _{bu_12}1st sub-module capacitance in brachium pontis in connection B phaseC _{­bu­_1}With auxiliary capacitorC ₂, auxiliary capacitorC ₅Negative pole；Pass through auxiliary switchK _{bu_i2}、K _{bu_ ( i +1 ) 2}Connect in B phase in brachium pontis theiIndividual sub-module capacitanceC­_{bu­_i} Withi+ 1 sub-module capacitanceC­_{bu­_i+1}Negative pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{bu_K2}、T _{bu_K+1}Connect in B phase in brachium pontis theKIndividual sub-module capacitanceC­_{bu­_K} WithK+ 1 sub-module capacitanceC­_{bu­_K+1}Negative pole；Pass through auxiliary switchT _{bu_j} 、T _{bu_j+1}Connect in B phase in brachium pontis thejIndividual sub-module capacitanceC­_{bu­_j} Withj+ 1 sub-module capacitanceC­_{bu­_j+1}Negative pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{bu_N} 、K _{bl_12}Connect in B phase in brachium pontis theNIndividual sub-module capacitanceC­_{bu­_N} 1st sub-module capacitance in brachium pontis lower with B phaseC­_{bl_1}Negative pole；Pass through auxiliary switchK _{bl_i2}、K _{bl_ ( i +1 ) 2}Connect in the lower brachium pontis of B phase theiIndividual sub-module capacitanceC­_{bl­_i} Withi+ 1 sub-module capacitanceC­_{bl­_i+1}Negative pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{bl_K2}、T _{bl_K+1}Connect in the lower brachium pontis of B phase theKIndividual sub-module capacitanceC­_{bl_K} WithK+ 1 sub-module capacitanceC­_{bl­_K+1}Negative pole；Pass through auxiliary switchT _{bl_j} 、T _{bl_j+1}Connect in the lower brachium pontis of B phase thejIndividual sub-module capacitanceC­_{bl­_j} Withj+ 1 sub-module capacitanceC­_{bl_j+1}Negative pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{bl_N} Connect in the lower brachium pontis of B phase theNIndividual sub-module capacitanceC _{­bl­_N} With auxiliary capacitorC ₄, auxiliary capacitorC ₇Negative pole.Auxiliary capacitorC ₆Positive pole is through auxiliary switchK _{cu_12}, clamp diode connect first sub-module capacitance of brachium pontis in C phaseC _{cu_1}Positive pole；Auxiliary capacitorC ₈Positive pole is through auxiliary switchT _{cl_N} , clamp diode connect the lower brachium pontis of C phase theNIndividual sub-module capacitanceC _{cl_N} Positive pole.

Under normal circumstances, from the most all pressure subsidiary loop in 6NIndividual auxiliary switchK _{au_i2}、K _{al_i2}、K _{bu_i2}、K _{bl_i2}、K _{cu_i2}、K _{cl_i2}、T _{au_j} 、T _{al_j} 、T _{bu_j} 、T _{bl_j} 、T _{cu_j} 、T _{cl_j} Normally closed, whereiniValue be 1～K,jValue beK+ 1～N, first sub-module capacitance of brachium pontis in A phaseC­_{au­_1}During bypass, now assist IGBT moduleT ₁Disconnect, submodule electric capacityC _{­au­_1}With auxiliary capacitorC ₁In parallel by clamp diode；Brachium pontis in A phaseiIndividual sub-module capacitanceC­_{au­_i} During bypass, whereiniValue be 2～N, submodule electric capacityC­_{au­_i} With submodule electric capacityC­_{au­_i-1}In parallel by clamp diode；Lower first the sub-module capacitance of brachium pontis of A phaseC­_{al_1}During bypass, submodule electric capacityC­_{al­_1}By clamp diode, two brachium pontis reactorsL ₀With submodule electric capacityC­ _{au­_N} In parallel；The lower brachium pontis of A phase theiIndividual sub-module capacitanceC­_{al_i} During bypass, whereiniValue be 2～N, submodule electric capacityC­ _{al­_i} With submodule electric capacityC­_{al_i-1}In parallel by clamp diode；Auxiliary IGBT moduleT ₂During Guan Bi, auxiliary capacitorC ₃By clamp diode and submodule electric capacityC­_{al_N} In parallel.

Under normal circumstances, from the most all pressure subsidiary loop in 6NIndividual auxiliary switchK _{au_i2}、K _{al_i2}、K _{bu_i2}、K _{bl_i2}、K _{cu_i2}、K _{cl_i2}、T _{au_j} 、T _{al_j} 、T _{bu_j} 、T _{bl_j} 、T _{cu_j} 、T _{cl_j} Normally closed, whereiniValue be 1～K,jValue beK+ 1～N, assist IGBT moduleT ₁During Guan Bi, auxiliary capacitorC ₂With submodule electric capacityC­_{bu­_1}In parallel by clamp diode；Brachium pontis in B phaseiIndividual sub-module capacitanceC­_{bu­_i} During bypass, whereiniValue be 1～N-1, submodule electric capacityC­_{bu­_i} With submodule electric capacityC­ _{bu­_i+1}In parallel by clamp diode；Brachium pontis in B phaseNIndividual sub-module capacitanceC­_{bu_N} During bypass, submodule electric capacityC _{­bu­_N} By clamp diode, two brachium pontis reactorsL ₀With submodule electric capacityC­ _{bl­_1}In parallel；The lower brachium pontis of B phase theiIndividual sub-module capacitanceC­_{bl_i} During bypass, whereiniValue be 1～N-1, submodule electric capacityC _{­bl­_i} With submodule electric capacityC­ _{bl_i+1}In parallel by clamp diode；The lower brachium pontis of B phase theNIndividual sub-module capacitanceC­_{bl_N} During bypass, submodule electric capacityC­_{bl­_N} With auxiliary capacitorC­ ₄In parallel by clamp diode.Above-mentioned auxiliary IGBT moduleT ₁Trigger signal consistent with the triggering signal of first submodule of brachium pontis in A phase；Auxiliary IGBT moduleT ₂The lower brachium pontis of triggering signal and B phase theNThe triggering signal of individual submodule is consistent.

During orthogonal stream energy is changed, each submodule alternately puts into, bypass, assists IGBT moduleT ₁、T ₂Being alternately closed, turn off, between A, B phase upper and lower bridge arm, capacitance voltage is under the effect of clamp diode, column constraint under meeting:

Auxiliary capacitorC ₁、C ₂Between voltage, auxiliary capacitorC ₃、C ₄Inequality constraints condition is there is between voltage:

It follows that at half-bridge/mono-clamp series-parallel connection MMC in the dynamic process completing the conversion of orthogonal stream energy, meet following constraints:

In like manner, B, C phase upper and lower bridge arm submodule capacitor voltage meets following constraints:

Being illustrated from above-mentioned, this half-bridge/mono-clamp series-parallel connection MMC topology possesses submodule capacitor voltage from the ability of equalization.

Finally should be noted that: described embodiment is only some embodiments of the present application rather than whole embodiments.Based on the embodiment in the application, the every other embodiment that those of ordinary skill in the art are obtained under not making creative work premise, broadly fall into the scope of the application protection.

Claims (5)

1. the distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from the most all pressing topology, it is characterised in that: include that the half-bridge being made up of A, B, C three-phase/mono-clamps series-parallel connection MMC model, each brachium pontis of A, B, C three-phase respectively byKIndividual half-bridge submodule,N-KIndividual single clamp submodule and 1 brachium pontis reactor are in series；Including by 6NIndividual auxiliary switch (6KIndividual mechanical switch, 6N-6KIndividual IGBT module), 6N+ 11 clamp diodes, 8 auxiliary capacitorsC ₁、C ₂、C ₃、C ₄、C ₅、C ₆、C ₇、C ₈, 4 auxiliary IGBT moduleT ₁、T ₂、T ₃、T ₄Constitute the most all presses subsidiary loop.

2. according to the distributed half-bridge of auxiliary capacitor based on inequality constraints described in right 1/mono-clamp series-parallel connection MMC from all pressing topology, it is characterized in that: A phase upper and lower bridge arm, in single clamp submodule, diode connexon module capacitance positive pole, IGBT module connexon module capacitance negative pole；1st submodule of brachium pontis, its submodule electric capacity in A phaseC­_{au­_1}Negative pole is connected with the 2nd of brachium pontis module I GBT module midpoint in A phase downwards, and its submodule IGBT module midpoint is upwards connected with dc bus positive pole；In A phase the of brachium pontisiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC­_{au­_i} Negative pole is downwards with in A phase the of brachium pontisi+ 1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisi-1 sub-module capacitanceC _{­au­_i-1}Negative pole is connected；In A phase the of brachium pontisKIndividual half-bridge submodule, its submodule electric capacityC _{­ au­_K} Negative pole is downwards with in A phase the of brachium pontisK+ 1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisK-1 sub-module capacitanceC­_{au­_K-1}Negative pole is connected；In A phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, its submodule diode and IGBT module tie-point be brachium pontis the downwards and in A phasej+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards with brachium pontis in A phasej-1 submodule diode is connected with IGBT module tie-point；Brachium pontis in A phaseNIndividual submodule, its submodule diode and IGBT module tie-point are down through two brachium pontis reactorsL ₀1st sub-module I GBT module midpoint of brachium pontis lower with A phase is connected, and its submodule IGBT module midpoint is upwards with in A phase the of brachium pontisN-1 submodule diode is connected with IGBT module tie-point；The of the lower brachium pontis of A phaseiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC­_{al­_i} Negative pole downwards with A phase time brachium pontis thei+ 1 sub-module I GBT module midpoint is connected, its IGBT module midpoint upwards brachium pontis lower with A phase thei-1 sub-module capacitanceC­ _{al­_i-1}Negative pole is connected；The of the lower brachium pontis of A phaseKIndividual submodule, its submodule electric capacityC _{­ al_K} Negative pole downwards with A phase time brachium pontis theK+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards brachium pontis lower with A phase theK-1 sub-module capacitanceC­_{al­_K-1}Negative pole is connected；The lower brachium pontis of A phase thejIndividual submodule, whereinjValue beK+ 2～N-1, its submodule diode and IGBT module tie-point downwards with A phase time brachium pontis thej+ 1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards brachium pontis lower with A phase thej-1 submodule diode is connected with IGBT module tie-point；The lower brachium pontis of A phase theNIndividual submodule diode is connected with dc bus negative pole downwards with IGBT module tie-point, the of its submodule IGBT module midpoint upwards brachium pontis lower with A phaseN-1 submodule diode is connected with IGBT module tie-point；B phase upper and lower bridge arm, in single clamp submodule, IGBT module connexon module capacitance positive pole, diode connexon module capacitance negative pole, the 1st submodule of upper brachium pontis, its submodule electric capacityC _{­ bu­_1}Positive pole is upwards connected with dc bus positive pole, its submodule IGBT module midpoint downwards with the 2nd sub-module capacitance of brachium pontis in B phaseC _{­bu­_2}Positive pole is connected；In B phase the of brachium pontisiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC­_{bu­_i} Positive pole is upwards with in B phase the of brachium pontisi-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is downwards with in B phase the of brachium pontisi+ 1 sub-module capacitanceC­_{bu­_i+1}Positive pole is connected；In B phase the of brachium pontisKIndividual submodule, its submodule electric capacityC­_{bu­_K} Positive pole is upwards with in B phase the of brachium pontisK-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with brachium pontis in B phase theK+ 1 sub-module I GBT module is connected with diode connection point；In B phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, its submodule IGBT module and diode connection point upwards with brachium pontis in B phasej-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with brachium pontis in B phase thej+ 1 sub-module I GBT module is connected with diode connection point；Brachium pontis in B phaseNIndividual submodule, its submodule IGBT module and diode connection point upwards with brachium pontis in B phaseN-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is down through two brachium pontis reactorsL ₀1st sub-module capacitance of brachium pontis lower with B phaseC _{­bl­_1}Positive pole is connected；The of the lower brachium pontis of B phaseiIndividual submodule, whereiniValue be 2～K-1, its submodule electric capacityC _{­bl_i} The of positive pole upwards brachium pontis lower with B phasei-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with the of B phase time brachium pontisi+ 1 sub-module capacitanceC­ _{bl­_i+1}Positive pole is connected；The of the lower brachium pontis of B phaseKIndividual submodule, its submodule electric capacityC _{­bl_K} Positive pole upwards brachium pontis lower with B phase theK-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with B phase time brachium pontis theK+ 1 sub-module I GBT module is connected with diode connection point；The lower brachium pontis of B phase thejIndividual submodule, whereinjValue beK+ 2～N-1, its submodule IGBT module and diode connection point upwards brachium pontis lower with B phase thej-1 sub-module I GBT module midpoint is connected, its submodule IGBT module midpoint downwards with B phase time brachium pontis thej+ 1 sub-module I GBT module is connected with diode connection point；The lower brachium pontis of B phase theNIndividual submodule, its submodule IGBT module and diode connection point upwards brachium pontis lower with B phase theN-1 sub-module I GBT module midpoint is connected, and its submodule IGBT module midpoint is connected with dc bus negative pole downwards；The connected mode of C phase upper and lower bridge arm submodule can be consistent with A, it is also possible to consistent with B；Due to single existence clamping submodule, unnecessary configuration IGCT between the upper and lower output lead of half-bridge submodule；Therefore it is parallel with mechanical switch between the output lead up and down of A, B, C phase upper and lower bridge arm submoduleK _{au_i1}、K _{al_i1}、K _{bu_i1}、K _{bl_i1}、K _{cu_i1}、K _{cl_i1}、K _{au_j} 、K _{al_j} 、K _{bu_j} 、K _{bl_j} 、K _{cu_j} 、K _{cl_j} , whereiniValue be 1～K,jValue beK+ 1～N；A, B, C three-phase status that above-mentioned annexation is constituted is consistent, and other topologys after three-phase symmetrized in turn are in interest field.

3. according to the distributed half-bridge of auxiliary capacitor based on inequality constraints described in right 1/mono-clamp series-parallel connection MMC from all pressing topology, it is characterised in that: in all pressure subsidiary loops, auxiliary capacitorC ₁With auxiliary capacitorC ₂In parallel by clamp diode, auxiliary capacitorC ₂Positive pole connects auxiliary IGBT moduleT ₁, auxiliary capacitorC ₁Negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₃With auxiliary capacitorC ₄In parallel by clamp diode, auxiliary capacitorC ₃Negative pole connects auxiliary IGBT moduleT ₂, auxiliary capacitorC ₄Positive pole connects clamp diode and is incorporated to dc bus negative pole；Auxiliary capacitorC ₅With auxiliary capacitorC ₆In parallel by clamp diode, auxiliary capacitorC ₅Positive pole connects auxiliary IGBT moduleT ₃, auxiliary capacitorC ₆Negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₇With auxiliary capacitorC ₈In parallel by clamp diode, auxiliary capacitorC ₈Negative pole connects auxiliary IGBT moduleT ₄, auxiliary capacitorC ₇Positive pole connects clamp diode and is incorporated to dc bus negative pole；Clamp diode, passes through auxiliary switchK _{au_12}1st sub-module capacitance in brachium pontis in connection A phaseC _{­au­_1}With auxiliary capacitorC ₁Positive pole；Pass through auxiliary switchK _{au_i2}、K _{Au_(i+ 1) 2}Connect in A phase in brachium pontis theiIndividual sub-module capacitanceC _{­au­_i} Withi+ 1 sub-module capacitanceC _{­au­_i+1}Positive pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{au_K2}、T _{au_K+1}Connect in A phase in brachium pontis theKIndividual sub-module capacitanceC _{­au­_K} WithK+ 1 sub-module capacitanceC­ _{au_K+1}Positive pole；Pass through auxiliary switchT _{au_j} 、T _{au_j+1}Connect in A phase in brachium pontis thejIndividual sub-module capacitanceC _{­au­_j} Withj+ 1 sub-module capacitanceC _{­au­_j+1}Positive pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{au_N} 、K _{al_12}Connect in A phase in brachium pontis theNIndividual sub-module capacitanceC­_{au_N} Brachium pontis 1st sub-module capacitance lower with A phaseC _{­al­_1}Positive pole；Pass through auxiliary switchK _{al_i2}、K _{Al_(i+ 1) 2}Connect in the lower brachium pontis of A phase theiIndividual sub-module capacitanceC _{­al­_i} Withi+ 1 sub-module capacitanceC _{­al­_i+1}Positive pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{al_K2}、T _{al_K+1}Connect in the lower brachium pontis of A phase theKIndividual sub-module capacitanceC­_{al­_K} WithK+ 1 sub-module capacitanceC­_{al­_K+1}Positive pole；Pass through auxiliary switchT _{al_j} 、T _{al_j+1}Connect in the lower brachium pontis of A phase thejIndividual sub-module capacitanceC _{­al_j} Withj+ 1 sub-module capacitanceC _{­al­_j+1}Positive pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{al_N} Connect in the lower brachium pontis of A phase theNIndividual sub-module capacitanceC _{­al_N} With auxiliary capacitorC ₃Positive pole；Clamp diode, passes through auxiliary switchK _{bu_12}1st sub-module capacitance in brachium pontis in connection B phaseC _{­bu­_1}With auxiliary capacitorC ₂Negative pole；Pass through auxiliary switchK _{bu_i2}、K _{Bu_(i+ 1) 2}Connect in B phase in brachium pontis theiIndividual sub-module capacitanceC­_{bu­_i} Withi+ 1 sub-module capacitanceC­_{bu­_i+1}Negative pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{bu_K2}、T _{bu_K+1}Connect in B phase in brachium pontis theKIndividual sub-module capacitanceC­_{bu­_K} WithK+ 1 sub-module capacitanceC­_{bu­_K+1}Negative pole；Pass through auxiliary switchT _{bu_j} 、T _{bu_j+1}Connect in B phase in brachium pontis thejIndividual sub-module capacitanceC­_{bu­_j} Withj+ 1 sub-module capacitanceC­_{bu­_j+1}Negative pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{bu_N} 、K _{bl_12}Connect in B phase in brachium pontis theNIndividual sub-module capacitanceC­_{bu­_N} 1st sub-module capacitance in brachium pontis lower with B phaseC­_{bl_1}Negative pole；Pass through auxiliary switchK _{bl_i2}、K _{Bl_(i+ 1) 2}Connect in the lower brachium pontis of B phase theiIndividual sub-module capacitanceC­_{bl­_i} Withi+ 1 sub-module capacitanceC­_{bl­_i+1}Negative pole, whereiniValue be 1～K-1；Pass through auxiliary switchK _{bl_K2}、T _{bl_K+1}Connect in the lower brachium pontis of B phase theKIndividual sub-module capacitanceC­_{bl_K} WithK+ 1 sub-module capacitanceC­_{bl­_K+1}Negative pole；Pass through auxiliary switchT _{bl_j} 、T _{bl_j+1}Connect in the lower brachium pontis of B phase thejIndividual sub-module capacitanceC­_{bl­_j} Withj+ 1 sub-module capacitanceC­_{bl_j+1}Negative pole, whereinjValue beK+ 1～N-1；Pass through auxiliary switchT _{bl_N} Connect in the lower brachium pontis of B phase theNIndividual sub-module capacitanceC _{­bl­_N} With auxiliary capacitorC ₄Negative pole；When the annexation of C phase submodule is consistent with A, between C phase upper and lower bridge arm Neutron module, the connected mode of clamp diode is consistent with A, auxiliary capacitor simultaneouslyC ₆Positive pole is through auxiliary switchK _{cu_12}, clamp diode connect first sub-module capacitance of brachium pontis in C phaseC _{cu_1}Positive pole, auxiliary capacitorC ₅Negative pole is through auxiliary switchK _{bu_12}, clamp diode connect first sub-module capacitance of brachium pontis in B phaseC _{bu_1}Negative pole, auxiliary capacitorC ₈Positive pole is through auxiliary switchT _{cl_N} , clamp diode connect the lower brachium pontis of C phase theNIndividual sub-module capacitanceC _{cl_N} Positive pole, auxiliary capacitorC ₇Negative pole is through auxiliary switchT _{bl_N} , clamp diode connect the lower brachium pontis of B phase theNIndividual sub-module capacitanceC _{bl_N} Negative pole；When the annexation of C phase submodule is consistent with B, between C phase upper and lower bridge arm Neutron module, the connected mode of clamp diode is consistent with B, auxiliary capacitor simultaneouslyC ₅Negative pole is through auxiliary switchK _{cu_12}, clamp diode connect first sub-module capacitance of brachium pontis in C phaseC _{cu_1}Negative pole, auxiliary capacitorC ₆Positive pole is through auxiliary switchK _{au_12}, clamp diode connect first sub-module capacitance of brachium pontis in A phaseC _{au_1}Positive pole, auxiliary capacitorC ₇Negative pole is through auxiliary switchT _{cl_N} , clamp diode connect the lower brachium pontis of C phase theNIndividual sub-module capacitanceC _{cl_N} Negative pole, auxiliary capacitorC ₈Positive pole is through auxiliary switchT _{al_N} , clamp diode connect the lower brachium pontis of A phase theNIndividual sub-module capacitanceC _{al_N} Positive pole；In above-mentioned A, B, C three-phase 6NIndividual auxiliary switchK _{au_i2}、K _{al_i2}、K _{bu_i2}、K _{bl_i2}、K _{cu_i2}、K _{cl_i2}、T _{au_j} 、T _{al_j} 、T _{bu_j} 、T _{bl_j} 、T _{cu_j} 、T _{cl_j} , whereiniValue be 1～K,jValue beK+ 1～N, 6N+ 11 clamp diodes, 8 auxiliary capacitorsC ₁、C ₂、C ₃、C ₄、C ₅、C ₆、C ₇、C ₈And 4 auxiliary IGBT moduleT ₁、T ₂、T ₃、T ₄, collectively form from all pressing subsidiary loop.

4. according to the distributed half-bridge of auxiliary capacitor based on inequality constraints described in right 1/mono-clamp series-parallel connection MMC from the most all pressing topology, it is characterised in that: during normal condition, in the most all pressure subsidiary loops 6NIndividual auxiliary switchK _{au_i2}、K _{al_i2}、K _{bu_i2}、K _{bl_i2}、K _{cu_i2}、K _{cl_i2}、T _{au_j} 、T _{al_j} 、T _{bu_j} 、T _{bl_j} 、T _{cu_j} 、T _{cl_j} Normally closed, whereiniValue be 1～K,jValue beK+ 1～N；During failure condition, 6N-6KIndividual auxiliary switchT _{au_j} 、T _{al_j} 、T _{bu_j} 、T _{bl_j} 、T _{cu_j} 、T _{cl_j} Disconnect, whereinjValue beK+ 1～N；Under normal circumstances, first sub-module capacitance of brachium pontis in A phaseC­_{au­_1}During bypass, now assist IGBT moduleT ₁Disconnect, submodule electric capacityC _{­au­_1}With auxiliary capacitorC ₁In parallel by clamp diode；Brachium pontis in A phaseiIndividual sub-module capacitanceC­_{au­_i} During bypass, whereiniValue be 2～N, submodule electric capacityC­_{au­_i} With submodule electric capacityC­_{au­_i-1}In parallel by clamp diode；Lower first the sub-module capacitance of brachium pontis of A phaseC­_{al_1}During bypass, submodule electric capacityC­_{al­_1}By clamp diode, two brachium pontis reactorsL ₀With submodule electric capacityC­ _{au­_N} In parallel；The lower brachium pontis of A phase theiIndividual sub-module capacitanceC­_{al_i} During bypass, whereiniValue be 2～N, submodule electric capacityC­ _{al­_i} With submodule electric capacityC­_{al_i-1}In parallel by clamp diode；Auxiliary IGBT moduleT ₂During Guan Bi, auxiliary capacitorC ₃By clamp diode and submodule electric capacityC­_{al_N} In parallel；Auxiliary IGBT moduleT ₁During Guan Bi, auxiliary capacitorC ₂With submodule electric capacityC­_{bu­_1}In parallel by clamp diode；Brachium pontis in B phaseiIndividual sub-module capacitanceC­_{bu­_i} During bypass, whereiniValue be 1～N-1, submodule electric capacityC­_{bu­_i} With submodule electric capacityC­ _{bu­_i+1}In parallel by clamp diode；Brachium pontis in B phaseNIndividual sub-module capacitanceC­_{bu_N} During bypass, submodule electric capacityC _{­bu­_N} By clamp diode, two brachium pontis reactorsL ₀With submodule electric capacityC­ _{bl­_1}In parallel；The lower brachium pontis of B phase theiIndividual sub-module capacitanceC­_{bl_i} During bypass, whereiniValue be 1～N-1, submodule electric capacityC _{­bl­_i} With submodule electric capacityC­ _{bl_i+1}In parallel by clamp diode；The lower brachium pontis of B phase theNIndividual sub-module capacitanceC­_{bl_N} During bypass, submodule electric capacityC­_{bl­_N} With auxiliary capacitorC­ ₄In parallel by clamp diode；Wherein assist IGBT moduleT ₁Trigger signal consistent with the triggering signal of first submodule of brachium pontis in A phase；Auxiliary IGBT moduleT ₂The lower brachium pontis of triggering signal and B phase theNThe triggering signal of individual submodule is consistent；During orthogonal stream energy is changed, each submodule alternately puts into, bypass, assists IGBT moduleT ₁、T ₂Being alternately closed, turn off, A phase upper and lower bridge arm submodule capacitor voltage, under the effect of clamp diode, meets lower column constraint,U _{C 1}≥U _{C ­au_1}≥U _{C ­au_2}…≥U _{C ­au_N} ≥U _{C ­al_1}≥U _{C ­al_2}…≥U _{C ­al_N} ≥U _{C 3}；B phase upper and lower bridge arm submodule capacitor voltage, under the effect of clamp diode, meets lower column constraint,U _{C 2}≤U _{C ­bu_1}≤U _{C ­bu_2}…≤U _{C ­bu_N} ≤U _{C ­bl_1}≤U _{C ­bl_2}…≤U _{C ­bl_N} ≤U _{C 4}；Against auxiliary capacitorC ₁、C ₂Between voltage, auxiliary capacitorC ₃、C ₄Two inequality constraints between voltage,U _{C 1}≤U _{C 2},U _{C 3}≥U _{C 4}, in A, B phase upper and lower bridge arm 4NIndividual sub-module capacitance,C _{au_i} 、C_{al_i} 、C _{bu_i} 、C _{bl_i} , whereiniValue be 1～N, and auxiliary capacitorC ₁、C ₂、C ₃、C ₄, voltage be in self-balancing state, A, B are alternate possesses submodule capacitor voltage from the ability of equalization for topology；If the form of the composition of C phase is consistent with A in topology, then pass through auxiliary capacitorC ₅、C ₆、C ₇、C ₈Effect, the constraints of C, B capacitive coupling voltage is similar with capacitance voltage constraints between A, B；If the form of the composition of C phase is consistent with B in topology, then pass through auxiliary capacitorC ₅、C ₆、C ₇、C ₈Effect, the constraints of A, C capacitive coupling voltage is similar with capacitance voltage constraints between A, B, and topology possesses submodule capacitor voltage from the ability of equalization；In utilizing clamp diode to realize mutually between adjacent submodule on the basis of capacitive energy single-phase flow; rely on the inequality constraints between auxiliary capacitor; the alternate flowing realizing capacitive energy constitutes the peripheral passage of capacitive energy; and then keep alternate submodule capacitor voltage stable, it is the protection content of this right.

5. according to the distributed half-bridge of auxiliary capacitor based on inequality constraints described in right 1/mono-clamp series-parallel connection MMC from all pressing topology, it is characterized in that: the distributed half-bridge of auxiliary capacitor based on inequality constraints/mono-clamp series-parallel connection MMC is from all pressing topology, not only serve as multi-level voltage source current converter and directly apply to flexible direct-current transmission field, also can be by constituting STATCOM (STATCOM), Research on Unified Power Quality Conditioner (UPQC), the device such as THE UPFC (UPFC) is applied to flexible AC transmission field；Other application scenarios of this utility model topology of indirect utilization and thought are in interest field.