CN206099810U - There is not supplementary capacitanc list clamp MMC from voltage -sharing topology based on inequality constraint - Google Patents

Abstract

The utility model provides a there is not supplementary capacitanc list clamp MMC from voltage -sharing topology based on inequality constraint. Single clamp MMC is from the voltage -sharing topology, by single clamp MMC model with jointly found from the voltage -sharing auxiliary circuit. Single clamp MMC model with in the voltage -sharing auxiliary circuit passes through the auxiliary circuit 6 (i) N (i) electric contact takes place for a IGBT module, and the IGBT module triggers, and both constitute there is not supplementary capacitanc list clamp MMC from voltage -sharing topology based on inequality constraint, the shutting of IGBT module, it is topological that the topoligical equivalence be single clamp MMC. This list clamp 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, simultaneously can corresponding reductions submodule piece triggering frequency worth with the electric capacity appearance, realize that single clamp MMC's base frequency is maked.

Description

Based on inequality constraints without auxiliary capacitor formula list clamp MMC from pressure topology

Technical field

The utility model is related to flexible transmission field, and in particular to it is a kind of based on inequality constraints without auxiliary capacitor formula list Clamp MMC is from pressure topology.

Background technology

Modularization multi-level converter MMC is the developing direction of following HVDC Transmission Technology, and MMC is using sub-module cascade Mode constructs converter valve, it is to avoid the direct series connection of big metering device, reduces requirement conforming to device, while being easy to dilatation And redundant configuration.With the rising of level number, output waveform is close to sine, can effectively avoid the defect of low level VSC-HVDC.

Single clamp MMC is combined by singly clamp submodule, and each singly clamps submodule by 3 IGBT modules, 1 submodule Block electric capacity, 1 diode and 1 mechanical switch are constituted, and low cost, running wastage is little.

Different from two level, three level VSC, the DC voltage of MMC is not supported by a bulky capacitor, but is by one The separate suspension submodule capacitances in series of row is supported.In order to ensure the waveform quality of AC voltage output and ensure module In each power semiconductor bear identical stress, also for DC voltage is preferably supported, reduce alternate circulation, it is necessary to protect Card submodule capacitor voltage is in the state of dynamic stability in the periodicity flowing of bridge arm power.

It is to solve MMC Neutron module capacitance voltage equalization problems at present that algorithm is pressed in the sequence sorted based on capacitance voltage Main flow thinking.First, the realization of ranking function has to rely on the Millisecond sampling of capacitance voltage, need substantial amounts of sensor and Optical-fibre channel is coordinated；Secondly, when group number of modules increases, the operand of capacitance voltage sequence increases rapidly, is control The hardware design of device brings huge challenge；Additionally, sequence press the realization of algorithm to submodule cut-off frequency have it is very high will Ask, cut-off frequency and be closely related with voltage equalizing, in practice process, probably due to the restriction of voltage equalizing, it has to improve The triggering frequency of submodule, and then bring the increase of transverter loss.

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 one Plant and MMC submodule capacitor voltages thinking in a balanced way is realized by clamp diode and transformer.But the program in design Determine the modular nature that degree destroys submodule, submodule capacitive energy interchange channel is also confined in phase, could not be fully sharp With the existing structure of MMC, the introducing of three transformers also brings along larger being transformed into while control strategy is complicated This.

The content of the invention

For the problems referred to above, the purpose of this utility model is to propose a kind of economy, is independent of pressing algorithm, while energy Corresponding reduction submodule triggering frequency and capacitor's capacity and the single clamp MMC with DC Line Fault clamping ability are from pressure topology.

The specific constituted mode of the utility model is as follows.

Based on inequality constraints without auxiliary capacitor formula list clamp MMC from topology is pressed, including what is be made up of A, B, C three-phase Single clamp MMC models, A, B, C three-phase is respectively by 2NIndividual single clamp submodule, 2 bridge arm reactors are in series；Including by 6N Individual IGBT module, 6N+ 1 clamp diode constitute from pressing subsidiary loop.

It is above-mentioned that topology, A phase upper and lower bridge arms, single pincers are pressed based on inequality constraints certainly without auxiliary capacitor formula list clamp MMC In bit submodule, diode connexon module capacitance positive pole, IGBT module connexon module capacitance negative pole.The 1st of bridge arm in A phases Individual submodule, its submodule diode and IGBT module tie-point downwards with the 2nd sub- module I GBT module of bridge arm in A phases in Point is connected, and its submodule IGBT module midpoint is connected upwards with dc bus positive pole；The of bridge arm in A phasesiIndividual submodule, whereiniValue be 2～N- 1, its submodule diode and IGBT module tie-point are downwards with of bridge arm in A phasesi+ 1 submodule IGBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with the of bridge arm in A phasesi- 1 submodule diode with IGBT module tie-point is connected；The of bridge arm in A phasesNIndividual submodule, its submodule diode is downward with IGBT module tie-point Two bridge arm reactors of JingL ₀It is connected with the 1st sub- module I GBT module midpoint of bridge arm under A phases, in its submodule IGBT module Point is upwards with the of bridge arm in A phasesN- 1 submodule diode is connected with IGBT module tie-point；The of bridge arm under A phasesiHeight Module, whereiniValue be 2～N- 1, its submodule diode and IGBT module tie-point are downwards with of bridge arm under A phasesi+1 Individual sub- module I GBT module midpoint is connected, and its IGBT module midpoint is upwards with the of bridge arm under A phasesi- 1 submodule diode with IGBT module tie-point is connected；The of bridge arm under A phasesNIndividual submodule, its submodule diode is downward with IGBT module tie-point It is connected with dc bus negative pole, its submodule IGBT module midpoint is upwards with of bridge arm under A phasesN- 1 submodule diode with IGBT module tie-point is connected.B phase upper and lower bridge arms, in single clamp submodule, IGBT module connexon module capacitance positive pole, two poles Pipe connexon module capacitance negative pole.1st submodule of bridge arm in B phases, its submodule diode and IGBT module tie-point to It is upper to be connected with dc bus positive pole, its submodule IGBT module midpoint downwards with the 2nd submodule diode of bridge arm in B phases and IGBT module tie-point is connected；The of bridge arm in B phasesiIndividual submodule, whereiniValue be 2～N- 1, its submodule diode With IGBT module tie-point upwards with of bridge arm in B phasesi- 1 sub- module I GBT module midpoint is connected, its submodule IGBT moulds Block midpoint is downwards with of bridge arm in B phasesi+ 1 submodule diode is connected with IGBT module tie-point；The of bridge arm in B phasesN Individual submodule, its submodule diode and IGBT module tie-point are upwards with of bridge arm in B phasesN- 1 sub- module I GBT module Midpoint is connected, and its submodule IGBT module midpoint is down through two bridge arm reactorsL ₀With the 1st submodule two of bridge arm under B phases Pole pipe is connected with IGBT module tie-point；The of bridge arm under B phasesiIndividual submodule, whereiniValue be 2～N- 1, its submodule Diode and IGBT module tie-point are upwards with of bridge arm under B phasesi- 1 sub- module I GBT module midpoint is connected, its submodule IGBT module midpoint is downwards with of bridge arm under B phasesi+ 1 submodule diode is connected with IGBT module tie-point；Bridge under B phases The of armNIndividual submodule, its submodule diode and IGBT module tie-point upwards with bridge arm under B phasesN- 1 submodule IGBT module midpoint is connected, and its submodule IGBT module midpoint is connected downwards with dc bus negative pole.C phase upper and lower bridge arm submodules Connected mode can be consistent with A, it is also possible to it is consistent with B.In A, B, C phase upper and lower bridge armiIndividual submodule is exported up and down It is parallel with mechanical switch between line respectivelyK _{au_i} 、K _{al_i} 、K _{bu_i} 、K _{bl_i} 、K _{cu_i} 、K _{cl_i} , whereiniValue be 1～N。

Above-mentioned topological from pressure without auxiliary capacitor formula list clamp MMC based on inequality constraints, it presses subsidiary loop certainly In, clamp diode connects in A phases in bridge arm the by IGBT moduleiIndividual sub- module capacitance and thei+ 1 sub- module capacitance is just Pole, whereiniValue be 1～N-1；Connect in A phases in bridge arm the by IGBT moduleNIndividual sub- module capacitance and bridge arm under A phases 1st sub- module capacitance positive pole；Connect under A phases in bridge arm the by IGBT moduleiIndividual sub- module capacitance and bridge arm under A phasesi+ 1 sub- module capacitance positive pole, whereiniValue be 1～N-1.Clamp diode, by bridge arm in IGBT module connection B phases TheiIndividual sub- module capacitance and thei+ 1 sub- module capacitance negative pole, whereiniValue be 1～N-1；B is connected by IGBT module In phase in bridge armNThe 1st sub- module capacitance negative pole of individual sub- module capacitance and bridge arm under B phases；Connected under B phases by IGBT module In bridge armiIndividual sub- module capacitance and bridge arm under B phasesi+ 1 sub- module capacitance negative pole, whereiniValue be 1～N-1.Together When clamp diode, by IGBT module connect A phases on first submodule of first sub- module capacitance of bridge arm and bridge arm in B phases Electric capacity negative pole；Bridge arm the under A phases is connected by IGBT moduleNIndividual sub- module capacitance and bridge arm under B phasesNIndividual sub- module capacitance is just Pole.The annexation of clamp diode is similar to A phases or B phases in C phases.

During normal condition, from 6 in pressure subsidiary loopNIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i} 、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Often Close, during failure condition, 6NIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i} 、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Disconnect, whereiniValue be 1～N； Under normal circumstances, bridge arm in A phasesiWhen individual sub- module capacitance is bypassed, whereiniValue be 2～N, its with bridge arm in A phases ini- 1 sub- module capacitance is in parallel by clamp diode；When the sub- module capacitance of bridge arm first is bypassed under A phases, it passes through clamper Diode, two bridge arm reactorsL ₀With bridge arm in A phasesNIndividual sub- module capacitance is in parallel；Bridge arm under A phasesiIndividual submodule electricity When holding bypass, whereiniValue be 2～N, its with bridge arm under A phases ini- 1 sub- module capacitance passes through clamp diode simultaneously Connection；Bridge arm in B phasesiWhen individual sub- module capacitance is bypassed, whereiniValue be 1～N- 1, itself and bridge arm in B phasesi+ 1 son Module capacitance is in parallel by clamp diode；Bridge arm in B phasesNWhen individual sub- module capacitance is bypassed, its pass through clamp diode, two Individual bridge arm reactorL ₀It is in parallel with the 1st sub- module capacitance of bridge arm under B phases；Bridge arm under B phasesiWhen individual sub- module capacitance is bypassed, WhereiniValue be 1～N- 1, itself and bridge arm under B phasesi+ 1 sub- module capacitance is in parallel by clamp diode；While A phases When the sub- module capacitance of upper bridge arm the 1st puts into, the 1st sub- module capacitance of itself and bridge arm in B phases is in parallel by clamp diode；B Bridge arm under phaseNWhen individual sub- module capacitance puts into, it is the with bridge arm under A phasesNIndividual sub- module capacitance is in parallel by clamp diode； During orthogonal stream energy is changed, each submodule alternately input, bypass, A phase upper and lower bridge arm submodule capacitor voltages exist In the presence of clamp diode, the 4 of A, B phase upper and lower bridge armNIndividual sub- module capacitance, whereiniValue be 1～N, voltage is in certainly flat Weighing apparatus state, A, B of topology are alternate to possess submodule capacitor voltage from the ability of equalization；If the form of the composition of C phases and A phases one in topology Cause, then the constraints of C, B capacitive coupling voltage is consistent with A, B capacitive coupling voltage constraints；If the composition of C phases in topology Form is consistent with B, then the constraints of A, C capacitive coupling voltage is consistent with A, B capacitive coupling voltage constraints, topology tool Standby submodule capacitor voltage is from the ability of equalization.

During normal condition, from 6 in pressure subsidiary loopNIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i} 、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Often Close, during failure condition, 6NIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i} 、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Disconnect, whereiniValue be 1～N； Under normal circumstances, bridge arm in A phasesiWhen individual sub- module capacitance is bypassed, whereiniValue be 2～N, its with bridge arm in A phases ini- 1 sub- module capacitance is in parallel by clamp diode；When the sub- module capacitance of bridge arm first is bypassed under A phases, it passes through clamper Diode, two bridge arm reactorsL ₀With bridge arm in A phasesNIndividual sub- module capacitance is in parallel；Bridge arm under A phasesiIndividual submodule electricity When holding bypass, whereiniValue be 2～N, its with bridge arm under A phases ini- 1 sub- module capacitance passes through clamp diode simultaneously Connection；Bridge arm in B phasesiWhen individual sub- module capacitance is bypassed, whereiniValue be 1～N- 1, itself and bridge arm in B phasesi+ 1 son Module capacitance is in parallel by clamp diode；Bridge arm in B phasesNWhen individual sub- module capacitance is bypassed, its pass through clamp diode, two Individual bridge arm reactorL ₀It is in parallel with the 1st sub- module capacitance of bridge arm under B phases；Bridge arm under B phasesiWhen individual sub- module capacitance is bypassed, WhereiniValue be 1～N- 1, itself and bridge arm under B phasesi+ 1 sub- module capacitance is in parallel by clamp diode；While A phases When the sub- module capacitance of upper bridge arm the 1st puts into, the 1st sub- module capacitance of itself and bridge arm in B phases is in parallel by clamp diode；B Bridge arm under phaseNWhen individual sub- module capacitance puts into, it is the with bridge arm under A phasesNIndividual sub- module capacitance is in parallel by clamp diode； During orthogonal stream energy is changed, each submodule alternately input, bypass, A phase upper and lower bridge arm submodule capacitor voltages exist In the presence of clamp diode, the 4 of A, B phase upper and lower bridge armNIndividual sub- module capacitance, whereiniValue be 1～N, voltage is in certainly flat Weighing apparatus state, A, B of topology are alternate to possess submodule capacitor voltage from the ability of equalization；If the form of the composition of C phases and A phases one in topology Cause, then the constraints of C, B capacitive coupling voltage is consistent with A, B capacitive coupling voltage constraints；If the composition of C phases in topology Form is consistent with B, then the constraints of A, C capacitive coupling voltage is consistent with A, B capacitive coupling voltage constraints, topology tool Standby submodule capacitor voltage is from the ability of equalization.

Description of the drawings

The utility model is further illustrated below in conjunction with the accompanying drawings.

Fig. 1 is the structural representation of single clamp；

Fig. 2 is from pressure topology based on inequality constraints without auxiliary capacitor formula list clamp MMC.

Specific embodiment

For performance of the present utility model and operation principle is expanded on further, below in conjunction with accompanying drawing to the composition to utility model Mode is specifically described with operation principle.But Fig. 2 is not limited to from pressure topology based on single clamp MMC of the principle.

With reference to Fig. 2, based on inequality constraints without auxiliary capacitor formula list clamp MMC from topology is pressed, including by A, B, C tri- The single clamp MMC models for mutually constituting, A, B, C three-phase is respectively by 2NIndividual single clamp submodule, 2 bridge arm reactors are in series； Including by 6NIndividual IGBT module, 6N+ 1 clamp diode constitute from pressing subsidiary loop.

In single clamp MMC models, A phase upper and lower bridge arms, in single clamp submodule, diode connexon module capacitance positive pole, IGBT module connexon module capacitance negative pole.1st submodule of bridge arm in A phases, its submodule diode joins with IGBT module Node is connected downwards with the 2nd sub- module I GBT module midpoint of bridge arm in A phases, its submodule IGBT module midpoint upwards with directly Stream bus positive pole is connected；The of bridge arm in A phasesiIndividual submodule, whereiniValue be 2～N- 1, its submodule diode with IGBT module tie-point is downwards with of bridge arm in A phasesi+ 1 sub- module I GBT module midpoint is connected, its submodule IGBT module Midpoint is upwards with of bridge arm in A phasesi- 1 submodule diode is connected with IGBT module tie-point；The of bridge arm in A phasesNIt is individual Submodule, its submodule diode is with IGBT module tie-point down through two bridge arm reactorsL ₀With the 1st of bridge arm under A phases Submodule IGBT module midpoint is connected, and its submodule IGBT module midpoint is upwards with the of bridge arm in A phasesN- 1 pole of submodule two Pipe is connected with IGBT module tie-point；The of bridge arm under A phasesiIndividual submodule, whereiniValue be 2～N- 1, its submodule two Pole pipe and IGBT module tie-point are downwards with of bridge arm under A phasesi+ 1 sub- module I GBT module midpoint is connected, its IGBT module Midpoint is upwards with of bridge arm under A phasesi- 1 submodule diode is connected with IGBT module tie-point；The of bridge arm under A phasesNIt is individual Submodule, its submodule diode is connected downwards with IGBT module tie-point with dc bus negative pole, its submodule IGBT module Midpoint is upwards with of bridge arm under A phasesN- 1 submodule diode is connected with IGBT module tie-point.B phase upper and lower bridge arms, single pincers In bit submodule, IGBT module connexon module capacitance positive pole, diode connexon module capacitance negative pole.The 1st of bridge arm in B phases Individual submodule, its submodule diode is connected upwards with IGBT module tie-point with dc bus positive pole, its submodule IGBT moulds Block midpoint is connected downwards with the 2nd submodule diode of bridge arm in B phases with IGBT module tie-point；The of bridge arm in B phasesiIt is individual Submodule, whereiniValue be 2～N- 1, its submodule diode and IGBT module tie-point are upwards with of bridge arm in B phasesi- 1 sub- module I GBT module midpoint is connected, and its submodule IGBT module midpoint is downwards with the of bridge arm in B phasesi+ 1 submodule Block diode is connected with IGBT module tie-point；The of bridge arm in B phasesNIndividual submodule, its submodule diode and IGBT module Tie-point is upwards with of bridge arm in B phasesN- 1 sub- module I GBT module midpoint is connected, and its submodule IGBT module midpoint is downward Two bridge arm reactors of JingL ₀It is connected with IGBT module tie-point with the 1st submodule diode of bridge arm under B phases；Bridge under B phases The of armiIndividual submodule, whereiniValue be 2～N- 1, its submodule diode and IGBT module tie-point upwards with B phases under The of bridge armi- 1 sub- module I GBT module midpoint is connected, and its submodule IGBT module midpoint is downwards with the of bridge arm under B phasesi+ 1 submodule diode is connected with IGBT module tie-point；The of bridge arm under B phasesNIndividual submodule, its submodule diode with IGBT module tie-point upwards with bridge arm under B phasesN- 1 sub- module I GBT module midpoint is connected, in its submodule IGBT module Point is connected downwards with dc bus negative pole.The connected mode of C phase upper and lower bridge arm submodules is consistent with A.

From in pressure subsidiary loop, clamp diode, by IGBT moduleT _{au_i} 、T _{au_i+1}In connection A phases the in bridge armi Individual sub- module capacitance C_{au_i} Withi+ 1 sub- module capacitanceC _{au_i+1}Positive pole, whereiniValue be 1～N-1；By IGBT moduleT _{au_N} 、T _{al_1}In connection A phases the in bridge armNIndividual sub- module capacitanceC _{au_N} With the 1st sub- module capacitance of bridge arm under A phasesC _{al_1}Positive pole； By IGBT moduleT _{al_i} 、T _{al_i+1}Under connection A phases the in bridge armiIndividual sub- module capacitanceC _{al_i} With bridge arm under A phasesi+ 1 submodule Block electric capacityC _{al_i+1}Positive pole, whereiniValue be 1～N-1.Clamp diode, by IGBT moduleT _{bu_i} 、T _{bl_i+1}Connection B phases In upper bridge armiIndividual sub- module capacitance C_{bu_i} Withi+ 1 sub- module capacitanceC _{bu_i+1}Negative pole, whereiniValue be 1～N-1； By IGBT moduleT _{bu_N} 、T _{bl_1}In connection B phases the in bridge armNIndividual sub- module capacitanceC _{bu_N} With the 1st submodule of bridge arm under B phases Electric capacityC _{bl_1}Negative pole；By IGBT moduleT _{bu_i} 、T _{bl_i+1}Under connection B phases the in bridge armiIndividual sub- module capacitanceC _{bl_i} With bridge under B phases Armi+ 1 sub- module capacitance C_{bl_i+1}Negative pole, whereiniValue be 1～N-1.While clamp diode, by IGBT moduleT _{bu_1}First sub- module capacitance of bridge arm in connection A phasesC _{au_1}With first sub- module capacitance of bridge arm in B phasesC _{bu_1}Negative pole；Pass through IGBT moduleT _{al_N} Bridge arm the under connection A phasesNIndividual sub- module capacitanceC _{al_N} With bridge arm under B phasesNIndividual sub- module capacitance C_{bl_N} Just Pole.The annexation of C phase clamp diodes is consistent with A.

Under normal circumstances, from 6 in pressure subsidiary loopNIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i}、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Often Close, whereiniValue be 1～N, bridge arm in A phasesiIndividual sub- module capacitanceC _{au_i}During bypass, whereiniValue be 2～N, son Module capacitanceC _{au_i} With submodule electric capacityC _{au_i-1}It is in parallel by clamp diode；First sub- module capacitance of bridge arm under A phasesC _{al_1} During bypass, submodule electric capacityC _{al_1}By clamp diode, two bridge arm reactorsL ₀With submodule electric capacityC _{au_N} It is in parallel；Under A phases Bridge armiIndividual sub- module capacitanceC _{al_i} During bypass, whereiniValue be 2～N, submodule electric capacityC _{al_i} With submodule electric capacityC _{al_i-1}It is in parallel by clamp diode.

Under normal circumstances, from 6 in pressure subsidiary loopNIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i}、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Often Close, whereiniValue be 1～N, bridge arm in B phasesiIndividual sub- module capacitance C_{bu_i} During bypass, whereiniValue be 1～N- 1, Submodule electric capacityC _{bu_i} With submodule electric capacityC _{bu_i+1}It is in parallel by clamp diode；Bridge arm in B phasesNIndividual sub- module capacitanceC _{bu_N} During bypass, submodule electric capacityC _{bu_N} By clamp diode, two bridge arm reactorsL ₀With submodule electric capacityC _{bl_1}It is in parallel；Under B phases Bridge armiIndividual sub- module capacitanceC _{bl_i} During bypass, whereiniValue be 1～N- 1, submodule electric capacityC _{bl_i} With submodule electric capacityC _{bl_i+1}It is in parallel by clamp diode.

During orthogonal stream energy is changed, alternately input, the bypass of each submodule, A, B phase upper and lower bridge arm submodule Capacitance voltage meets lower column constraint in the presence of clamp diode：

U _{Cau_1}≥U _{Cau_2}…≥U _{Cau_N} ≥U _{Cal_1}≥U _{Cal_2}…≥U _{Cal_N}

U _{Cbu_1}≤U _{Cbu_2}…≤U _{Cbu_N} ≤U _{Cbl_1}≤U _{Cbl_2}…≤U _{Cbl_N}

At the same time, the 1st sub- module capacitance of bridge arm in A phasesC _{au_1}During input, submodule electric capacityC _{au_1}With submodule electric capacityC _{bu_1}It is in parallel by clamp diode；Bridge arm under B phasesNIndividual sub- module capacitanceC _{bl_N} During input, submodule electric capacityC _{al_N} With submodule Block electric capacityC _{bl_N} It is in parallel by clamp diode, thus there is following inequality constraints：

U _{Cau_1}≤U _{Cbu_1},U _{Cal_N} ≥U _{Cbl_N}

So can obtain：

U _{Cau_1}…=U _{Cau_N} =U _{Cal_1}…=U _{Cal_N} =U _{Cbu_1}…=U _{Cbu_N} =U _{Cbl_1}…=U _{Cbl_N}

C, B alternate constraints constraints alternate with A, B is consistent.

Illustrated from above-mentioned, the list clamp MMC topologys possess submodule capacitor voltage from the ability of equalization.

Finally it should be noted that：Described embodiment is only some embodiments of the present application, rather than the reality of whole Apply example.Based on the embodiment in the application, those of ordinary skill in the art are obtained under the premise of creative work is not made Every other embodiment, belong to the application protection scope.

Claims (4)

1. topological from pressure without auxiliary capacitor formula list clamp MMC based on inequality constraints, it is characterised in that：Including by A, B, C Single clamp MMC models that three-phase is constituted, A, B, C three-phase is respectively by 2NIndividual single clamp submodule, 2 bridge arm reactors series connection and Into；Including by 6NIndividual IGBT module, 6N+ 1 clamp diode constitute from pressing subsidiary loop.

2. according to claim 1 topological from pressure without auxiliary capacitor formula list clamp MMC based on inequality constraints, it is special Levy and be：A phase upper and lower bridge arms, in single clamp submodule, diode connexon module capacitance positive pole, IGBT module connection submodule Electric capacity negative pole；1st submodule of bridge arm in A phases, its submodule diode and IGBT module tie-point downwards with bridge arm in A phases The 2nd sub- module I GBT module midpoint be connected, its submodule IGBT module midpoint is connected upwards with dc bus positive pole；A phases The of upper bridge armiIndividual submodule, whereiniValue be 2～N- 1, its submodule diode and IGBT module tie-point are downwards and A The of bridge arm in phasei+ 1 sub- module I GBT module midpoint is connected, its submodule IGBT module midpoint upwards with bridge arm in A phases Thei- 1 submodule diode is connected with IGBT module tie-point；The of bridge arm in A phasesNIndividual submodule, its submodule diode With IGBT module tie-point down through two bridge arm reactorsL ₀With the 1st of bridge arm under A phases sub- module I GBT module midpoint phase Even, its submodule IGBT module midpoint is upwards with the of bridge arm in A phasesN- 1 submodule diode and IGBT module tie-point phase Even；The of bridge arm under A phasesiIndividual submodule, whereiniValue be 2～N- 1, its submodule diode and IGBT module tie-point Downwards with of bridge arm under A phasesi+ 1 sub- module I GBT module midpoint is connected, its IGBT module midpoint upwards with bridge arm under A phases i- 1 submodule diode is connected with IGBT module tie-point；The of bridge arm under A phasesNIndividual submodule, its pole of submodule two Pipe be connected with dc bus negative pole downwards with IGBT module tie-point, its submodule IGBT module midpoint upwards with bridge arm under A phases N- 1 submodule diode is connected with IGBT module tie-point；B phase upper and lower bridge arms, in single clamp submodule, IGBT module Connexon module capacitance positive pole, diode connexon module capacitance negative pole；1st submodule of bridge arm, its submodule two in B phases Pole pipe is connected upwards with IGBT module tie-point with dc bus positive pole, its submodule IGBT module midpoint downwards with bridge in B phases 2nd submodule diode of arm is connected with IGBT module tie-point；The of bridge arm in B phasesiIndividual submodule, whereiniValue For 2～N- 1, its submodule diode and IGBT module tie-point are upwards with of bridge arm in B phasesi- 1 sub- module I GBT module Midpoint is connected, and its submodule IGBT module midpoint is downwards with the of bridge arm in B phasesi+ 1 submodule diode joins with IGBT module Node is connected；The of bridge arm in B phasesNIndividual submodule, its submodule diode and IGBT module tie-point upwards with bridge arm in B phases N- 1 sub- module I GBT module midpoint is connected, and its submodule IGBT module midpoint is down through two bridge arm reactorsL ₀With B The 1st submodule diode of bridge arm is connected with IGBT module tie-point under phase；The of bridge arm under B phasesiIndividual submodule, whereini Value be 2～N- 1, its submodule diode and IGBT module tie-point are upwards with of bridge arm under B phasesi- 1 submodule IGBT module midpoint is connected, and its submodule IGBT module midpoint is downwards with the of bridge arm under B phasesi+ 1 submodule diode with IGBT module tie-point is connected；The of bridge arm under B phasesNIndividual submodule, its submodule diode is with IGBT module tie-point upwards With bridge arm under B phasesN- 1 sub- module I GBT module midpoint is connected, and its submodule IGBT module midpoint is negative with dc bus downwards Extremely it is connected；The connected mode of C phase upper and lower bridge arm submodules can be consistent with A, it is also possible to consistent with B；In A, B, C phase up and down Bridge armiMechanical switch is parallel with respectively between the upper and lower output line of individual submoduleK _{au_i} 、K _{al_i} 、K _{bu_i} 、K _{bl_i} 、K _{cu_i} 、K _{cl_i} , its IniValue be 1～N。

3. according to claim 1 topological from pressure without auxiliary capacitor formula list clamp MMC based on inequality constraints, it is special Levy and be：From in pressure subsidiary loop, clamp diode, by IGBT moduleT _{au_i} 、T _{au_i+1}In connection A phases the in bridge armiIt is individual Submodule electric capacityC _{au_i} Withi+ 1 sub- module capacitanceC _{au_i+1}Positive pole, whereiniValue be 1～N-1；By IGBT moduleT _{au_N} 、T _{al_1}In connection A phases the in bridge armNIndividual sub- module capacitanceC _{au_N} With the 1st sub- module capacitance of bridge arm under A phasesC _{al_1}Positive pole； By IGBT moduleT _{al_i} 、T _{al_i+1}Under connection A phases the in bridge armiIndividual sub- module capacitanceC _{al_i} With bridge arm under A phasesi+ 1 submodule Block electric capacityC _{al_i+1}Positive pole, whereiniValue be 1～N-1；Clamp diode, by IGBT moduleT _{bu_i} 、T _{bl_i+1}Connection B phases In upper bridge armiIndividual sub- module capacitance C_{bu_i} Withi+ 1 sub- module capacitanceC _{bu_i+1}Negative pole, whereiniValue be 1～N-1； By IGBT moduleT _{bu_N} 、T _{bl_1}In connection B phases the in bridge armNIndividual sub- module capacitanceC _{bu_N} With the 1st submodule of bridge arm under B phases Electric capacityC _{bl_1}Negative pole；By IGBT moduleT _{bu_i} 、T _{bl_i+1}Under connection B phases the in bridge armiIndividual sub- module capacitanceC _{bl_i} With bridge under B phases Armi+ 1 sub- module capacitance C_{bl_i+1}Negative pole, whereiniValue be 1～N-1；While clamp diode, by IGBT moduleT _{bu_1}First sub- module capacitance of bridge arm in connection A phasesC _{au_1}With first sub- module capacitance of bridge arm in B phasesC _{bu_1}Negative pole；Pass through IGBT moduleT _{al_N} Bridge arm the under connection A phasesNIndividual sub- module capacitanceC _{al_N} With bridge arm under B phasesNIndividual sub- module capacitance C_{bl_N} Just Pole；The annexation of clamp diode is consistent with A phases or B in C phases.

4. according to claim 1 topological from pressure without auxiliary capacitor formula list clamp MMC based on inequality constraints, it is special Levy and be：During normal condition, from 6 in pressure subsidiary loopNIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i} 、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Often Close, during failure condition, 6NIndividual IGBT moduleT _{au_i} 、T _{al_i} 、T _{bu_i} 、T _{bl_i} 、T _{cu_i} 、T _{cl_i} Disconnect, whereiniValue be 1～N； Under normal circumstances, bridge arm in A phasesiIndividual sub- module capacitanceC _{au_i} During bypass, whereiniValue be 2～N, submodule electric capacityC _{au_i} With submodule electric capacityC _{au_i-1}It is in parallel by clamp diode；First sub- module capacitance of bridge arm under A phasesC _{al_1}During bypass, submodule Block electric capacityC _{al_1}By clamp diode, two bridge arm reactorsL ₀With submodule electric capacityC _{au_N} It is in parallel；Bridge arm under A phasesiHeight Module capacitanceC _{al_i} During bypass, whereiniValue be 2～N, submodule electric capacityC _{al_i} With submodule electric capacityC _{al_i-1}By clamper two Pole pipe is in parallel；Bridge arm in B phasesiIndividual sub- module capacitance C_{bu_i} During bypass, whereiniValue be 1～N- 1, submodule electric capacityC _{bu_i} With submodule electric capacityC _{bu_i+1}It is in parallel by clamp diode；Bridge arm in B phasesNIndividual sub- module capacitanceC _{bu_N} During bypass, submodule Electric capacityC _{bu_N} By clamp diode, two bridge arm reactorsL ₀With submodule electric capacityC _{bl_1}It is in parallel；Bridge arm under B phasesiIndividual submodule Block electric capacityC _{bl_i} During bypass, whereiniValue be 1～N- 1, submodule electric capacityC _{bl_i} With submodule electric capacityC _{bl_i+1}By clamper two Pole pipe is in parallel；While the 1st sub- module capacitance of bridge arm in A phasesC _{au_1}During input, submodule electric capacityC _{au_1}With submodule electric capacityC _{bu_1} It is in parallel by clamp diode；Bridge arm under B phasesNIndividual sub- module capacitanceC _{bl_N} During input, submodule electric capacityC _{al_N} With submodule electricity HoldC _{bl_N} It is in parallel by clamp diode；During orthogonal stream energy is changed, alternately input, the bypass of each submodule, A phases Upper and lower bridge arm submodule capacitor voltage meets lower column constraint in the presence of clamp diode,U _{Cau_1}≥U _{Cau_2}…≥U _{Cau_N} ≥U _{Cal_1}≥U _{Cal_2}…≥U _{Cal_N} ；B phase upper and lower bridge arm submodule capacitor voltages in the presence of clamp diode, meet it is following about Beam,U _{Cbu_1}≤U _{Cbu_2}…≤U _{Cbu_N} ≤U _{Cbl_1}≤U _{Cbl_2}…≤U _{Cbl_N} ；By across two A, B alternate clamp diodes, Pressed certainly in topology without auxiliary capacitor formula list clamp MMC based on inequality constraints, submodule electric capacityC _{au_1}With submodule electric capacityC _{bu_1}Voltage between, submodule electric capacityC _{al_N} With submodule electric capacityC _{bl_N} Voltage between there is following inequality constraints,U _{Cau_1} ≤U _{Cbu_1},U _{Cal_N} ≥U _{Cbl_N} ；Based on the inequality constraints, the 4 of A, B phase upper and lower bridge armNIndividual sub- module capacitance,C _{au_i} 、C _{al_i} 、C _{bu_i} 、C _{bl_i} , whereiniValue be 1～N, in self-balancing state, A, B of topology are alternate to possess submodule capacitor voltage to voltage From the ability of equalization；If the form of the composition of C phases is consistent with A in topology, constraints and A, B phase of C, B capacitive coupling voltage Between capacitance voltage constraints it is consistent；If the form of the composition of C phases is consistent with B in topology, the constraint of A, C capacitive coupling voltage Condition is consistent with A, B capacitive coupling voltage constraints, and topology possesses submodule capacitor voltage from the ability of equalization.