CN205754046U - The distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge series-parallel connection MMC is from all pressing topology - Google Patents

Abstract

This utility model provides the distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge series-parallel connection MMC from all pressing topology.Half-bridge/full-bridge series-parallel connection MMC is in all pressure topologys, half-bridge/full-bridge series-parallel connection MMC model and the auxiliary switch generation electrical link in all pressure subsidiary loop is by subsidiary loop, auxiliary switch closes, both constitute the distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge series-parallel connection MMC from all pressing topology, auxiliary switch is opened, and topoligical equivalence is half-bridge/full-bridge series-parallel connection MMC topology.In the case of not emphasizing two kinds of topological variations, 6 in auxiliary switchKIndividual mechanical switch can omit.This half-bridge/full-bridge series-parallel connection MMC is from all pressing topology, there is DC Line Fault clamping ability, do not rely on special Pressure and Control, can be on the basis of completing the conversion of orthogonal stream energy, spontaneously realize the equilibrium of submodule capacitor voltage, submodule can be reduced simultaneously accordingly and trigger frequency and capacitor's capacity, it is achieved the fundamental frequency modulation of MMC.

Description

The distributed half-bridge of auxiliary capacitor based on equality constraint / Full-bridge series-parallel connection MMC 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 equality constraint/full-bridge 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/full-bridge series-parallel connection MMC is combined by half-bridge and full-bridge submodule, and half-bridge sub modular structure is simple, and low cost, running wastage is little, and full-bridge submodule has DC Line Fault clamping ability.

Different from two level, three level VSC, the DC voltage of 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 MMC Neutron module capacitance voltage equalization problem at present, but is also constantly expose its some inherent shortcomings.First, 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 the half-bridge/full-bridge 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 equality constraint/full-bridge 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 full-bridge submodule and 1 brachium pontis reactor are in series；Including by 6NIndividual auxiliary switch (6KIndividual mechanical switch, 6N-6KIndividual IGBT module), 6N+ 7 clamp diodes, 4 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 equality constraint/full-bridge series-parallel connection MMC is from all pressing topology, 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 pontisKOne IGBT module midpoint of+1 submodule 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, one IGBT module midpoint of its submodule downwards with brachium pontis in A phase thejOne IGBT module midpoint of+1 submodule is connected, another IGBT module midpoint upwards with brachium pontis in A phasejOne IGBT module midpoint of-1 submodule is connected；Brachium pontis in A phaseNIndividual submodule, one IGBT module midpoint of its submodule is down through two brachium pontis reactorsL ₀1st sub-module I GBT module midpoint of brachium pontis lower with A phase is connected, and another IGBT module midpoint is upwards with in A phase the of brachium pontisNOne IGBT module midpoint of-1 submodule is connected；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 theKOne IGBT module midpoint of+1 submodule 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, one IGBT module midpoint of its submodule downwards with A phase time brachium pontis thejOne IGBT module midpoint of+1 submodule is connected, another IGBT module midpoint upwards brachium pontis lower with A phase thejOne IGBT module midpoint of-1 submodule is connected；The lower brachium pontis of A phase theNOne IGBT module midpoint of individual submodule is connected with dc bus negative pole downwards, the of another IGBT module midpoint upwards brachium pontis lower with A phaseNOne IGBT module midpoint of-1 submodule is connected.1st submodule of brachium pontis in B phase, 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 theKOne IGBT module midpoint of+1 submodule is connected；In B phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, one IGBT module midpoint of its submodule upwards with brachium pontis in B phasejOne IGBT module midpoint of-1 submodule is connected, another IGBT module midpoint downwards with brachium pontis in B phase thejOne IGBT module midpoint of+1 submodule is connected；Brachium pontis in B phaseNIndividual submodule, one IGBT module midpoint of its submodule upwards with brachium pontis in B phaseNOne IGBT module midpoint of-1 submodule is connected, and another 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 theKOne IGBT module midpoint of+1 submodule is connected；The lower brachium pontis of B phase thejIndividual submodule, whereinjValue beK+ 2～N-1, one IGBT module midpoint of its submodule upwards brachium pontis lower with B phase thejOne IGBT module midpoint of-1 submodule is connected, another IGBT module midpoint downwards with B phase time brachium pontis thejOne IGBT module midpoint of+1 submodule is connected；The lower brachium pontis of B phase theNIndividual submodule, one IGBT module midpoint of its submodule upwards brachium pontis lower with B phase theNOne IGBT module midpoint of-1 submodule is connected, and another 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.

From all pressing in subsidiary loop, first auxiliary capacitor positive pole connects auxiliary IGBT module negative pole connection clamp diode and is incorporated to dc bus positive pole；Second auxiliary capacitor negative pole connects auxiliary IGBT module positive pole connection clamp diode and is incorporated to dc bus negative pole；3rd auxiliary capacitor positive pole connects auxiliary IGBT module negative pole connection clamp diode and is incorporated to dc bus positive pole, and the 4th auxiliary capacitor negative pole connection auxiliary IGBT module positive pole connects clamp diode 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 second auxiliary capacitor positive pole.Clamp diode, by the 1st sub-module capacitance and the negative pole of first 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 second 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, 3rd auxiliary capacitor positive pole connects the sub-module capacitance positive pole of brachium pontis first in C phase through mechanical switch, clamp diode simultaneously, 3rd auxiliary capacitor negative pole connects the upper sub-module capacitance negative pole of brachium pontis first of B phase through mechanical switch, clamp diode, and the 4th auxiliary capacitor positive pole connects C phase time brachium pontis the through mechanical switch, clamp diodeNIndividual sub-module capacitance positive pole, the 4th auxiliary capacitor negative pole connects the lower brachium pontis of B phase the through mechanical 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, 3rd auxiliary capacitor negative pole connects the sub-module capacitance negative pole of brachium pontis first in C phase through mechanical switch, clamp diode simultaneously, 3rd auxiliary capacitor positive pole connects the upper sub-module capacitance positive pole of brachium pontis first of A phase through mechanical switch, clamp diode, and the 4th auxiliary capacitor negative pole connects C phase time brachium pontis the through mechanical switch, clamp diodeNIndividual sub-module capacitance negative pole, the 4th auxiliary capacitor positive pole connects the lower brachium pontis of A phase the through mechanical switch, clamp diodeNIndividual sub-module capacitance positive pole.

Accompanying drawing explanation

Below in conjunction with the accompanying drawings this utility model is further illustrated.

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

Fig. 2 is the structural representation of full-bridge submodule；

Fig. 3 is that the distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge 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, below in conjunction with accompanying drawing, the constituted mode of utility model is specifically described with operation principle.But half-bridge based on this principle/full-bridge 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 equality constraint/full-bridge series-parallel connection MMC from all pressing topology, including the half-bridge being made up of A, B, C three-phase/full-bridge series-parallel connection MMC model, each brachium pontis of A, B, C three-phase respectively byKIndividual half-bridge submodule,N-KIndividual full-bridge submodule and 1 brachium pontis reactor are in series；Including 6NIndividual auxiliary switch (6KIndividual mechanical switch, 6N-6KIndividual IGBT module) and 6N+7 clamp diode, 4 auxiliary capacitors, 2 auxiliary IGBT module constitute from the most all pressing subsidiary loop.

In half-bridge/full-bridge series-parallel connection MMC model, the 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 pontisKOne IGBT module midpoint of+1 submodule 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, one IGBT module midpoint of its submodule downwards with brachium pontis in A phase thejOne IGBT module midpoint of+1 submodule is connected, another IGBT module midpoint upwards with brachium pontis in A phasejOne IGBT module midpoint of-1 submodule is connected；Brachium pontis in A phaseNIndividual submodule, one IGBT module midpoint of its submodule is down through two brachium pontis reactorsL ₀1st sub-module I GBT module midpoint of brachium pontis lower with A phase is connected, and another IGBT module midpoint is upwards with in A phase the of brachium pontisNOne IGBT module midpoint of-1 submodule is connected；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 theKOne IGBT module midpoint of+1 submodule 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, one IGBT module midpoint of its submodule downwards with A phase time brachium pontis thejOne IGBT module midpoint of+1 submodule is connected, another IGBT module midpoint upwards brachium pontis lower with A phase thejOne IGBT module midpoint of-1 submodule is connected；The lower brachium pontis of A phase theNOne IGBT module midpoint of individual submodule is connected with dc bus negative pole downwards, the of another IGBT module midpoint upwards brachium pontis lower with A phaseNOne IGBT module midpoint of-1 submodule is connected.1st submodule of brachium pontis, its submodule electric capacity in B phaseC _{­ 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 theKOne IGBT module midpoint of+1 submodule is connected；In B phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, one IGBT module midpoint of its submodule upwards with brachium pontis in B phasejOne IGBT module midpoint of-1 submodule is connected, another IGBT module midpoint downwards with brachium pontis in B phase thejOne IGBT module midpoint of+1 submodule is connected；Brachium pontis in B phaseNIndividual submodule, one IGBT module midpoint upwards with brachium pontis in B phaseNOne IGBT module midpoint of-1 submodule is connected, and another 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 theKOne IGBT module midpoint of+1 submodule is connected；The lower brachium pontis of B phase thejIndividual submodule, whereinjValue beK+ 2～N-1, one IGBT module midpoint upwards brachium pontis lower with B phase thejOne IGBT module midpoint of-1 submodule is connected, another IGBT module midpoint downwards with B phase time brachium pontis thejMono-IGBT module midpoint of+1 sub-module I GBT is connected；The lower brachium pontis of B phase theNIndividual submodule, one IGBT module midpoint of its submodule upwards brachium pontis lower with B phase theNOne IGBT module midpoint of-1 submodule is connected, and another 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 ₁Positive pole connects auxiliary IGBT moduleT ₁, negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₂Negative pole connects auxiliary IGBT moduleT ₂, positive pole connects clamp diode and is incorporated to dc bus negative pole；Auxiliary capacitorC ₃Positive pole connects auxiliary IGBT moduleT ₃, negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₄Negative pole connects auxiliary IGBT moduleT ₄, positive 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 ₂Positive 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 ₁, auxiliary capacitorC ₃Negative 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 ₂, auxiliary capacitorC ₄Negative pole.Between C phase upper and lower bridge arm submodule, the annexation of clamp diode is consistent with A；First sub-module capacitance of brachium pontis in C phaseC _{cu­­­_1}Positive pole is through auxiliary switchK _{cu_12}And clamp diode is connected to auxiliary capacitorC ₃Positive pole；The lower brachium pontis of C phase theNIndividual sub-module capacitanceC _{c­­l_N} Positive pole is through auxiliary switchT _{cl_N} And clamp diode is connected to auxiliary capacitorC ₄Positive 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 ₂By 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 ₁With 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 ₂In 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:

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

In like manner between C, B phase upper and lower bridge arm, the constraints of capacitance voltage is:

Being illustrated from above-mentioned, this half-bridge/full-bridge 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 (6)

1. the distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge series-parallel connection MMC is from the most all pressing topology, it is characterised in that: include the half-bridge/full-bridge series-parallel connection 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 full-bridge submodule and 1 brachium pontis reactor are in series；Including 6NIndividual auxiliary switch (6KIndividual mechanical switch, 6N-6KIndividual IGBT module), 6N+7 clamp diode, 4 auxiliary capacitorsC ₁、C ₂、C ₃、C ₄And 4 auxiliary IGBT moduleT ₁、T ₂、T ₃、T ₄Constitute from all pressing subsidiary loop.

2. according to the distributed half-bridge of auxiliary capacitor based on the equality constraint/full-bridge series-parallel connection MMC described in right 1 from all pressing topology, it is characterised in that: the 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 pontisKOne IGBT module midpoint of+1 submodule 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, one IGBT module midpoint of its submodule downwards with brachium pontis in A phase thejOne IGBT module midpoint of+1 submodule is connected, another IGBT module midpoint upwards with brachium pontis in A phasejOne IGBT module midpoint of-1 submodule is connected；Brachium pontis in A phaseNIndividual submodule, one IGBT module midpoint of its submodule is down through two brachium pontis reactorsL ₀1st sub-module I GBT module midpoint of brachium pontis lower with A phase is connected, and another IGBT module midpoint is upwards with in A phase the of brachium pontisNOne IGBT module midpoint of-1 submodule is connected；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 theKOne IGBT module midpoint of+1 submodule 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, one IGBT module midpoint of its submodule downwards with A phase time brachium pontis thejOne IGBT module midpoint of+1 submodule is connected, another IGBT module midpoint upwards brachium pontis lower with A phase thejOne IGBT module midpoint of-1 submodule is connected；The lower brachium pontis of A phase theNOne IGBT module midpoint of individual submodule is connected with dc bus negative pole downwards, the of another IGBT module midpoint upwards brachium pontis lower with A phaseNOne IGBT module midpoint of-1 submodule is connected；1st submodule of brachium pontis, its submodule electric capacity in B phaseC _{­ 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 theKOne IGBT module midpoint of+1 submodule is connected；In B phase the of brachium pontisjIndividual submodule, whereinjValue beK+ 2～N-1, one IGBT module midpoint of its submodule upwards with brachium pontis in B phasejOne IGBT module midpoint of-1 submodule is connected, another IGBT module midpoint downwards with brachium pontis in B phase thejOne IGBT module midpoint of+1 submodule is connected；Brachium pontis in B phaseNIndividual submodule, one IGBT module midpoint upwards with brachium pontis in B phaseNOne IGBT module midpoint of-1 submodule is connected, and another 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 theKOne IGBT module midpoint of+1 submodule is connected；The lower brachium pontis of B phase thejIndividual submodule, whereinjValue beK+ 2～N-1, one IGBT module midpoint upwards brachium pontis lower with B phase thejOne IGBT module midpoint of-1 submodule is connected, another IGBT module midpoint downwards with B phase time brachium pontis thejMono-IGBT module midpoint of+1 sub-module I GBT is connected；The lower brachium pontis of B phase theNIndividual submodule, one IGBT module midpoint of its submodule upwards brachium pontis lower with B phase theNOne IGBT module midpoint of-1 submodule is connected, and another 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 the existence of full-bridge 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 the equality constraint/full-bridge series-parallel connection MMC described in right 1 from all pressing topology, it is characterised in that: in all pressure subsidiary loops, auxiliary capacitorC ₁Positive pole connects auxiliary IGBT moduleT ₁, negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₂Negative pole connects auxiliary IGBT moduleT ₂, positive pole connects clamp diode and is incorporated to dc bus negative pole；Auxiliary capacitorC ₃Positive pole connects auxiliary IGBT moduleT ₃, negative pole connects clamp diode and is incorporated to dc bus positive pole；Auxiliary capacitorC ₄Negative pole connects auxiliary IGBT moduleT ₄, positive 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 ₂Positive 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 ₁Negative 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 ₂Negative 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 ₃Positive 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 ₃Negative 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 ₄Positive pole 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 ₄Negative 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 ₃Negative 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 ₃Positive 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 ₄Negative 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 ₄Positive 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+ 7 clamp diodes, 4 auxiliary capacitorsC ₁、C _2、 C ₃、C ₄, and 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 the equality constraint/full-bridge series-parallel connection MMC described in right 1 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 ₂By clamp diode and submodule electric capacityC­_{al_N} In parallel；Auxiliary IGBT moduleT ₁During Guan Bi, auxiliary capacitorC ₁With 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 ₂In 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 2}；B phase upper and lower bridge arm submodule capacitor voltage, under the effect of clamp diode, meets lower column constraint,U _{C 1}≤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 2}；The distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge series-parallel connection MMC is from all pressing topology, in dynamic process, and auxiliary capacitorC ₁Both can be as the highest electric capacity of A phase voltage, again can be as the minimum electric capacity of B phase voltage；Auxiliary capacitorC ₂Both can be as the minimum electric capacity of A phase voltage, again can be as the highest electric capacity of B phase voltage；Against two equality constraints, max(U _{C a­})=min(U _{C b}), min(U _{C a})=max(U _{C b}), 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, 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 ₃、C ₄Effect, 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 ₃、C₄Effect, 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 equality constraint max(between auxiliary capacitor voltageU _{C a­})=min(U _{C b}), min(U _{C a})=max(U _{C b}), or max(U _{C a­})=min(U _{C c}), min(U _{C a})=max(U _{C c}), or max(U _{C c})=min(U _{C b}), min(U _{C c})=max(U _{C b}), it is achieved the alternate flowing of capacitive energy constitutes the peripheral passage of capacitive energy, and then keeps alternate submodule capacitor voltage stable, is the protection content of this right.

5. according to the distributed half-bridge of auxiliary capacitor based on the equality constraint/full-bridge series-parallel connection MMC described in right 1 from all pressing topology, it is characterised in that: auxiliary capacitorC ₁、C ₂As the passage of A, B capacitive coupling energy exchange, auxiliary capacitorC ₃、C ₄Passage as B, C capacitive coupling energy exchange；The function of auxiliary capacitor is distributed utilization to strengthen system reliability, functional independence in topology.

6. according to the distributed half-bridge of auxiliary capacitor based on the equality constraint/full-bridge series-parallel connection MMC described in right 1 from all pressing topology, it is characterized in that: the distributed half-bridge of auxiliary capacitor based on equality constraint/full-bridge 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.