CN107196539A - A kind of MMC zero DC voltage fault traversing control methods under bridge arm parameter unbalance state - Google Patents

A kind of MMC zero DC voltage fault traversing control methods under bridge arm parameter unbalance state Download PDF

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CN107196539A
CN107196539A CN201710488320.XA CN201710488320A CN107196539A CN 107196539 A CN107196539 A CN 107196539A CN 201710488320 A CN201710488320 A CN 201710488320A CN 107196539 A CN107196539 A CN 107196539A
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bridge arm
voltage
phase
submodule
phases
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CN107196539B (en
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王跃
段国朝
尹太元
尹诗媛
周晖
王璋
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Xian Jiaotong University
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Xian Jiaotong University
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H02M7/4835—Converters with outputs that each can have more than two voltages levels comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/322—Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

The invention discloses the DC voltage fault traversing control methods of MMC zero under a kind of bridge arm parameter unbalance state, MMC Neutron modules are all using full-bridge submodule, and addition subsidiary loop builds new topology between the bridge arm of same dc bus side；During zero DC voltage fault traversing, the balancing energy of the balancing energy of three upper bridge arms of auxiliary circuit work holding and three lower bridge arms between bridge arm；Make all module voltages overall balanced by the regulation of upper and lower bridge arm voltage deviation again, ensure to remove fault current during the DC voltage fault traversings of MMC zero, continue to provide reactive power support to AC system, maintain submodule balancing energy, particularly in MMC bridge arm parameter unbalances, the topology and its control method can still realize voltage deviation caused by 6 bridge arm shared bridge arm parameter unbalances, maintain energy overall balanced, short circuit current flow is restricted to very low level, zero DC voltage fault traversing is realized.

Description

A kind of DC voltage fault traversings of MMC zero control under bridge arm parameter unbalance state Method
Technical field
The invention belongs to Technology of HVDC based Voltage Source Converter field, and in particular to the MMC under a kind of bridge arm parameter unbalance state Zero DC voltage fault traversing control method.
Background technology
Technology of HVDC based Voltage Source Converter (voltage sourced converter based high voltage direct Current, VSC-HVDC) it is to build one of key technology of energy internet and DC distribution net, the modular multilevel change of current Device (modular multilevel converter, MMC) relies on without static state voltage equipoise, high efficiency, the advantage such as low EMI into For the prevailing topology of flexible direct current transmission converter station, in VSC-HVDC technology evolutions, direct-current short circuit fault traversing is One of major issue faced at present.Although traditional MMC topologys use advantage of the half-bridge submodule with low-cost high-efficiency, But do not possess DC Line Fault ride-through capability, occur to need AC circuit breaker protection after DC Line Fault.In order that MMC possesses failure Ride-through capability, researcher successively proposes full-bridge submodule clamp Shuangzi module, series connection Shuangzi module, strengthened from resistance type submodule Block etc. can realize the submodule topology that fault current is blocked, and the MMC constituted using such submodule will when occurring DC Line Fault Submodule locking, submodule electric capacity provides counter electromotive force and blocks alternating current path, realizes MMC DC Line Fault self-cleanings.
Due to full-bridge submodule output generating positive and negative voltage under can normal work, be widely used, with full-bridge submodule constitute MMC (hereinafter referred to as bridge-type MMC) there are more advantages, not locking converter valve during such as DC Line Fault continues as exchange System provides reactive power support, realizes zero DC voltage fault traversing；Negative voltage goes to dissociate after Failure elimination, acceleration disturbance point insulating Recover etc..It is due to DC side electricity although bridge-type MMC has as above many advantages during zero DC voltage fault traversing Pressure is zero, and upper and lower bridge arm submodule electric voltage equalization is difficult.Electric capacity electricity during the zero DC voltage fault traversing proposed at present Press balance control method to include circulation injection method and upper and lower bridge arm independent control method, when bridge arm parameter is symmetrical, son can be ensured Module capacitance electric voltage equalization, removes direct fault current；But, when bridge arm parameter unbalance, during fault traversing above and below Bridge arm module balancing energy is difficult, causes DC side output voltage to be not zero, i.e., larger short circuit current flow can be produced in short dot, It can not realize that bridge arm parameter is full symmetric in Practical Project.
The content of the invention
During for bridge-type MMC bridge arm parameter unbalances, the upper and lower bridge arm submodule during zero DC voltage fault traversing Block presses difficulty, and the problem of DC side output voltage is not zero, the present invention is proposed under a kind of bridge arm parameter unbalance state The DC voltage fault traversing control methods of MMC zero, it is ensured that MMC removes fault current during zero DC voltage fault traversing, Continue to provide reactive power support to AC system, maintain submodule balancing energy.
The present invention is adopted the following technical scheme that：
A kind of DC voltage fault traversing control methods of MMC zero under bridge arm parameter unbalance state, the MMC is by full-bridge Aid in pushing back road composition between the MMC models and bridge arm of module composition, the control method comprises the following steps：
1) under bridge arm parameter unbalance state the DC voltage fault traversings of MMC zero control using dq coordinate systems voltage and Current double closed-loop control strategy, the actual three-phase output current and line voltage of transverter are obtained through over-sampling, is sat Mark conversion obtains the dq components i of output currentdAnd iq, the dq components of line voltage are usdAnd usq, and lock electric using phaselocked loop Net voltage-phase ω t；
2) outer loop voltag control, the voltage for gathering all modules is averaged Uave_all, and with submodule capacitor voltage volume Determine UcValue is made comparisons, and compares difference and watt current control instruction is obtained after proportional integration link
3) open sea wharf, idle reference instruction QrefDivided by the d axis components u of line voltagesdObtain reactive current reference Instruction
4) inner ring current feed-forward uneoupled control, the watt current reference instruction that outer shroud is obtainedWith reactive current reference instructionU is generated after current feed-forward uneoupled control linkd,uq, and try to achieve ud,uqThe amplitude U of resultant voltagemAnd phase angle
5) bridge arm voltage bias adjustment is controlled, and chooses electric to its electric capacity per three bridge arms mutually not in same dc bus side Pressure is adjusted, bridge arm average voltage Uave_armRespectively with submodule capacitor voltage rated value UcMake comparisons, difference is through proportional integration After device, the phase angle adjustment amount of bridge arm reference instruction under generation three-phaseJ=a, b, c；
6) step 5) obtained phase angle adjustment amountThe rapid voltage-phase ω t 1) obtained, step 4 are added respectively) obtain Phase angleAdd the phase difference of three-phase respectively againThe phase angle of bridge arm modulation waveform under transverter three-phase is obtained afterwards
7) step 6) bridge arm modulating wave phase angle under obtained three-phaseTake sine value and be multiplied by step 4) obtained modulation letter Number amplitude UmThe modulated signal u of bridge arm under circulator three-phase is obtained afterwardsad_ref,ubd_ref,ucd_ref, it is changed after negating respectively Flow the modulated signal u of bridge arm on device three-phaseau_ref,ubu_ref,ucu_ref, the nearest level of process approaches modulation and equal to modulated signal again The trigger signal of transverter submodule is obtained after pressure sequence algorithm, and then for triggering corresponding submodule.
The present invention, which is further improved, to be, the bridge arm structure of three-phase six that MMC topologys are made up of bridge-type submodule.
Of the invention further improve be, aiding in pushing back road between bridge arm, to be arranged in bridge arm first on three-phase complete Between bridge submodule and under three-phase between bridge arm n-th full-bridge submodule, the auxiliary between two neighboring module pushes back route Three diodes, an auxiliary capacitor and an IGBT composition；The sub- module capacitance C of bridge arm first in A phasesAu_1Positive pole through two Pole pipe connection auxiliary capacitor C1Positive pole, electric capacity C1Negative pole be connected to through diode in direct current positive bus, in addition, auxiliary capacitor C1 Positive pole through aid in IGBT T1It is connected to the 1st module capacitance C of bridge arm in B phasesBu_1Positive pole, electric capacity CBu_1Negative pole through two poles Pipe is connected to bridge arm auxiliary capacitor C in A phases1Negative pole, constitute alternate loop, by that analogy, bridge arm auxiliary capacitor C in B phases2's Positive pole is through aiding in IGBT T2It is connected to the 1st module capacitance C of bridge arm in C phasesCu_1Positive pole, CCu_1Negative pole be connected in B phases Bridge arm auxiliary capacitor C2Negative pole, likewise, bridge arm auxiliary capacitor C in C phases3It is connected to first sub- module capacitance of bridge arm in A phases CAu_1On, first module composition triangle loop of bridge arm on three-phase；Similar with upper bridge arm, the alternate auxiliary for lower bridge arm is returned Bridge arm n-th module capacitance C under road, A phasesAd_nPositive pole be connected to lower bridge arm auxiliary capacitor C through booster diode4Positive pole, auxiliary Electric capacity C4Negative pole be directly connected in direct current negative busbar, C4Positive pole through aid in IGBT T4Be connected under B phases bridge arm last Individual sub- module capacitance CBd_nPositive pole, auxiliary capacitor C4With last submodule electric capacity of B phases CBd_nNegative pole pass through the negative mother of direct current Line is connected, likewise, last submodule electric capacity of bridge arm C under B phasesBd_nPositive pole connect auxiliary capacitor C through diode5Just Pole, auxiliary capacitor C5Negative pole connect direct current negative busbar, auxiliary capacitor C5Positive pole through aid in IGBT T5It is connected to bridge arm under C phases last One sub- module capacitance CCd_nPositive pole, CCd_nNegative pole constitute loop through direct current negative busbar, last submodule of bridge arm under C phases Block electric capacity CCd_nPositive pole connect auxiliary capacitor C through diode6Positive pole, auxiliary capacitor C6Negative pole connect direct current negative busbar, auxiliary electricity Hold C6Positive pole through aid in IGBT T6It is connected to last submodule electric capacity of bridge arm C under A phasesAd_nPositive pole, CAd_nNegative pole warp Direct current negative busbar constitutes loop；So, last submodule of bridge arm is triangle by alternate auxiliary circuit under three-phase The mutual equilibrium between mutual balanced and lower bridge arm in loop, realization between bridge arm.
Further improve of the invention is that A, B, the upper bridge arm of C three-phases number respectively 1,3,5, and lower bridge arm numbering is 4,6,2, three bridge arms not in same dc bus side are chosen in bridge arm voltage bias adjustment link its capacitance voltage is carried out Adjustment, totally 1,2,3,2,3,4,3,4,5,4,5,6,5,6,1,6,1,2 six kind of combination, choose any one combination, will correspondence bridge Arm energy adjusting is to specified.
Further improve of the invention is that submodule capacitor switching follows low pressure molding when bridge arm module charges inside bridge arm Block preferentially charges, when submodule discharges, the principle switching of high-pressure modular preferential discharge.
Compared with prior art, the present invention has the advantage that：
The DC voltage fault traversing control methods of MMC zero under a kind of bridge arm parameter unbalance state that the present invention is provided In, not locking converter valve during bridge-type MMC DC Line Faults is remained running under STATCOM patterns, is the friendship of current conversion station connection Streaming system provides reactive power support, when occurring dc-side short-circuit fault using the negative pressure output characteristics of full-bridge modules, by DC side Voltage control is zero, and short circuit current flow is reduced to zero, realizes zero DC voltage fault traversing.
Further, aiding in pushing back road between converter bridge arm reaches the energy between same three bridge arms in dc bus side The triangle structure in road is pushed back by alternate auxiliary between first submodule of bridge arm on equilibrium, three-phase, after stable operation Energy energy automatic equalization, similarly, aids in pushing back the triangle structure in road between bridge arm under three-phase also by alternate, therefore under Energy energy also can automatic equalization between bridge arm.
Further, only the energy of single bridge arm is adjusted by deviation in the method being uniformly controlled using upper and lower bridge arm, every phase Rated value is arrived in section regulation, it is ensured that upper and lower bridge arm modulation waveform moment etc. is big anti-phase, it is ensured that upper and lower bridge arm output voltage and all the time It is zero.
Further, module capacitance voltage is reached unanimously by sequence pressure strategy in bridge arm；It is auxiliary between bridge arm bridge arm on three-phase Helping the auxiliary for pushing back road and making to reach between bridge arm between equilibrium, lower bridge arm to push back road maintains the voltage between lower bridge arm equal Weighing apparatus, using not setting up contact by the way of same three bridge arm bias adjustments in dc bus side between upper and lower bridge arm, therefore works as bridge During arm parameter unbalance, the energy deviation of generation has all module shareds, and all module voltages reach overall equilibrium, Short circuit current flow can be restricted to very low level during zero DC voltage fault traversing.
Further, hardware-assist circuit only works in the poor crossing process of failure, will not introduce excessive operating cost, and Hardware-assist circuit merely add 6 IGBT, 6 electric capacity and 18 diodes, be changed for high-voltage large-capacity flexible DC power transmission In stream station for hundreds and thousands of modules, the cost of investment that auxiliary circuit is introduced is also very limited.
Brief description of the drawings
Fig. 1 is the schematic diagram of bridge-type submodule；
Fig. 2 is the topological schematic diagrames of MMC for possessing zero DC voltage fault ride-through capacity；
Fig. 3 be same three bridge arms in dc bus side between aid in pushing back road operating diagram；
System equivalent model during Fig. 4 is zero DC voltage fault traversing；
Fig. 5 is the overall control block diagram of system；
When Fig. 6 is bridge arm parameter unbalance under the bipolar short trouble of DC side, the submodule electricity that conventional method control is obtained Corrugating；
When Fig. 7 is bridge arm parameter unbalance under the bipolar short trouble of DC side, the submodule electricity that inventive method control is obtained Corrugating；
When Fig. 8 is bridge arm parameter unbalance under the bipolar short trouble of DC side, the short dot electricity that conventional method control is obtained Current voltage waveform；
When Fig. 9 is bridge arm parameter unbalance under the bipolar short trouble of DC side, the short dot electricity that inventive method control is obtained Current voltage waveform.
Embodiment
The topology and operation principle of the present invention are described in further detail with reference to specific embodiment, it is described to be Explanation of the invention rather than restriction.
It is the DC voltage fault traversing controlling parties of MMC zero under a kind of bridge arm parameter unbalance state of the invention with reference to Fig. 1 Full-bridge submodule used in the topology of method control.
With reference to Fig. 2, the DC voltage fault traversing control methods of MMC zero under a kind of bridge arm parameter unbalance state of the invention The topology of control is every to be made up of upper and lower two bridge arms by the phase composition of A, B, C tri-, a total of N number of full-bridge submodule on each bridge arm Full-bridge submodule block number is followed successively by 1~N from top to bottom on block, each bridge arm.
It is arranged in reference to aiding in pushing back road between Fig. 2 bridge arms on three-phase between first full-bridge submodule of bridge arm and three Under phase between n-th of full-bridge submodule of bridge arm, the auxiliary between two neighboring module pushes back three diodes of route, and one auxiliary Help electric capacity and an IGBT composition；The sub- module capacitance C of bridge arm first in A phasesAu1Positive pole connect auxiliary capacitor C through diode1 Positive pole, electric capacity C1Negative pole be connected to through diode in direct current positive bus, in addition, auxiliary capacitor C1Positive pole through aid in IGBT T1 It is connected to the 1st module capacitance C of bridge arm in B phasesBu1Positive pole, electric capacity CBu1Negative pole through diode to be connected to bridge arm in A phases auxiliary Help electric capacity C1Negative pole, constitute alternate loop, by that analogy, bridge arm auxiliary capacitor C in B phases2Positive pole through aid in IGBT T2Even It is connected to the 1st module capacitance C of bridge arm in C phasesCu1Positive pole, CCu1Negative pole be connected to bridge arm auxiliary capacitor C in B phases2Negative pole, Likewise, bridge arm auxiliary capacitor C in C phases3It is connected to the sub- module capacitance C of bridge arm first in A phasesAu1On, bridge arm first on three-phase Individual module composition triangle loop；It is similar with upper bridge arm, for the alternate subsidiary loop of lower bridge arm, bridge arm n-th module under A phases Electric capacity CAdnPositive pole be connected to lower bridge arm auxiliary capacitor C through booster diode4Positive pole, auxiliary capacitor C4Negative pole be directly connected to In direct current negative busbar, C4Positive pole through aid in IGBT T4It is connected to last submodule electric capacity of bridge arm C under B phasesBdnPositive pole, Auxiliary capacitor C4With last submodule electric capacity of B phases CBdnNegative pole be connected by direct current negative busbar, likewise, bridge under B phases Last submodule electric capacity of arm CBdnPositive pole connect auxiliary capacitor C through diode5Positive pole, auxiliary capacitor C5Negative pole connect direct current Negative busbar, auxiliary capacitor C5Positive pole through aid in IGBT T5It is connected to last submodule electric capacity of bridge arm C under C phasesCdnPositive pole, CCdnNegative pole constitute loop through direct current negative busbar, last submodule electric capacity of bridge arm C under C phasesCdnPositive pole connect through diode Meet auxiliary capacitor C6Positive pole, auxiliary capacitor C6Negative pole connect direct current negative busbar, auxiliary capacitor C6Positive pole through aid in IGBT T6Connect Last submodule electric capacity of bridge arm C under to A phasesAdnPositive pole, CAdnNegative pole through direct current negative busbar constitute loop；So, three Last submodule of bridge arm also passes through mutual between bridge arm in the alternate triangle loop of auxiliary circuit, realization under phase Mutual equilibrium between balanced and lower bridge arm.
With reference to Fig. 3 with A, exemplified by the subsidiary loop in B phases between first submodule of bridge arm, C1,C2Respectively A, B phase Auxiliary capacitor, T1Switched for alternate subsidiary loop, D1Clamp diode in road is pushed back for alternate auxiliary, when bridge arm the in A phases The IGBT T of one submodule0During conducting, if now first module capacitance C of bridge arm in A phasesAu1Voltage higher than auxiliary electricity Hold C1Voltage when, module capacitance CAu1Auxiliary capacitor C can be given1Charging, because of diode clamp effect, meets U during stable operationc1 ≥UcAu1；When first module is in excision state, allows and aid in IGBT T1Conducting, if now auxiliary capacitor C1On voltage it is high In first module capacitance C of bridge arm in B phasesBu1Voltage, auxiliary capacitor will be to module capacitance CBu1Electric discharge.
Occurs structure class after short trouble with reference to a kind of MMC DC sides for possessing zero DC voltage fault ride-through capacity of Fig. 4 It is similar to two star-like STATCOM of chain type to be in parallel, full-bridge submodule constitutes the star-like Hes of STATCOM 1 in bridge arm on three-phase in such as figure The star-like STATCOM 2 that full-bridge submodule is constituted in bridge arm under three-phase is connected in parallel on exchange system simultaneously by respective bridge arm reactor On system, but compared with two general star-like STATCOM parallel-connection structures, equivalent after short trouble two occur for MMC direct currents STATCOM neutral point is connected by MMC dc-side short-circuits point.
With reference to the DC voltage fault traversing control methods of MMC zero under a kind of bridge arm parameter unbalance states of Fig. 5 include with Lower step：
1) under bridge arm parameter unbalance state the DC voltage fault traversings of MMC zero control using dq coordinate systems voltage and Current double closed-loop control strategy, the actual three-phase output current and line voltage of transverter are obtained through over-sampling, is sat Mark conversion obtains the dq components i of output currentdAnd iq, the dq components of line voltage are usdAnd usq, and lock electric using phaselocked loop Net voltage-phase ω t；
2) outer loop voltag control, the voltage for gathering all modules is averaged Uave_all, and with submodule capacitor voltage volume Determine UcValue is made comparisons, and compares difference and watt current control instruction is obtained after proportional integration link
3) open sea wharf, idle reference instruction QrefDivided by the d axis components u of line voltagesdObtain reactive current reference Instruction
4) inner ring current feed-forward uneoupled control, the watt current reference instruction that outer shroud is obtainedWith reactive current reference instructionU is generated after current feed-forward uneoupled control linkd,uq, and try to achieve ud,uqThe amplitude U of resultant voltagemAnd phase angle
5) bridge arm voltage bias adjustment is controlled, and chooses electric to its electric capacity per three bridge arms mutually not in same dc bus side Pressure is adjusted, bridge arm average voltage Uave_armRespectively with submodule capacitor voltage rated value UcMake comparisons, difference is through proportional integration After device, the phase angle adjustment amount of bridge arm reference instruction under generation three-phaseJ=a, b, c；
6) step 5) obtained phase angle adjustment amountThe rapid voltage-phase ω t 1) obtained, step 4 are added respectively) obtain Phase angleAdd the phase difference of three-phase respectively againThe phase angle of bridge arm modulation waveform under transverter three-phase is obtained afterwards
7) step 6) bridge arm modulating wave phase angle under obtained three-phaseTake sine value and be multiplied by step 4) obtained modulation letter Number amplitude UmThe modulated signal u of bridge arm under circulator three-phase is obtained afterwardsad_ref,ubd_ref,ucd_ref, it is changed after negating respectively Flow the modulated signal u of bridge arm on device three-phaseau_ref,ubu_ref,ucu_ref, the nearest level of process approaches modulation and equal to modulated signal again The trigger signal of transverter submodule is obtained after pressure sequence algorithm, and then for triggering corresponding submodule.
Embodiment
According to description of the invention, in examples of simulation using the capacitance voltage of three-phase symmetrical from balanced topology as shown in figure 1, It exchanges side joint 380V AC network rated voltages, and DC side rated voltage is 700V；Using 11 level blocks, i.e., often above and below phase Bridge arm respectively has 10 sub- full-bridge modules to constitute, and submodule electric capacity is 3300 μ F, and submodule electric capacity rated voltage is 70V；Bridge arm electricity Anti- device is 20mH；When bridge arm parameter is full symmetric, traditional control method and institute's extracting method of the present invention can realize balancing energy.If Bridge arm loss increase 10W, i.e. A phases upper and lower bridge arm parameter unbalance under A phases is put, matlab/Simulink simulation results are as follows, are Unite after stable operation, with reference to Fig. 6, during using traditional control method, bridge arm loss increase 10W under A phases, bias adjustment is acted on to it The more active maintenance balancing energies of injection, now bridge arm note is due to the injection of A phases active power in A phases, and module voltage rises, partially From rated value 70V, 74V is reached, is fluctuated more than 5%, B, C phase are consistent due to loss, and upper and lower bridge arm module capacitance voltage is consistent；Adopt After the control method in the present invention, with reference to Fig. 7, energy caused by bridge arm parameter unbalance is unbalanced by all bridge arms under A phases Shared, although deviation is all occurred in that per phase upper and lower bridge arm, but deviation voltage is no more than 2%, i.e., 2.8%, all modules Reach overall equilibrium；With reference to Fig. 8, because A phase fluctuating plates are more excessive than deviation under traditional control method, dc-side short-circuit point electric current compared with Greatly, amplitude reaches 2.5A, and after the control control method using the present invention, current in the short amplitude drops to 0.4A, is original 1/6, thus for high-power bridge-type MMC current conversion stations during zero DC voltage fault traversing, the present invention propose Control method can significantly reduce dc-side short-circuit electric current.

Claims (5)

1. the DC voltage fault traversing control methods of MMC zero under a kind of bridge arm parameter unbalance state, it is characterised in that should Aid in pushing back road between MMC models and bridge arm that MMC is made up of full-bridge submodule and constitute, the control method includes following step Suddenly：
1) the DC voltage fault traversings of MMC zero control under bridge arm parameter unbalance state uses the voltage and current of dq coordinate systems Double-loop control strategy, the actual three-phase output current and line voltage of transverter are obtained through over-sampling, coordinate change is carried out Get the dq components i of output current in returndAnd iq, the dq components of line voltage are usdAnd usq, and lock to obtain power network electricity using phaselocked loop Press phase ω t；
2) outer loop voltag control, the voltage for gathering all modules is averaged Uave_all, and with the specified U of submodule capacitor voltagecValue Make comparisons, compare difference and watt current control instruction is obtained after proportional integration link
3) open sea wharf, idle reference instruction QrefDivided by the d axis components u of line voltagesdObtain reactive current reference instruction
4) inner ring current feed-forward uneoupled control, the watt current reference instruction that outer shroud is obtainedWith reactive current reference instructionThrough electricity U is generated after stream feed forward decoupling control linkd,uq, and try to achieve ud,uqThe amplitude U of resultant voltagemAnd phase angle
5) bridge arm voltage bias adjustment is controlled, and chooses and its capacitance voltage is entered per three bridge arms mutually not in same dc bus side Row adjustment, bridge arm average voltage Uave_armRespectively with submodule capacitor voltage rated value UcMake comparisons, difference is through proportional integrator Afterwards, the phase angle adjustment amount of bridge arm reference instruction under three-phase is generatedJ=a, b, c；
6) step 5) obtained phase angle adjustment amountThe rapid voltage-phase ω t 1) obtained, step 4 are added respectively) obtained phase angleAdd the phase difference of three-phase respectively againThe phase angle of bridge arm modulation waveform under transverter three-phase is obtained afterwards
7) step 6) bridge arm modulating wave phase angle under obtained three-phaseTake sine value and be multiplied by step 4) obtained modulated signal amplitude UmThe modulated signal u of bridge arm under circulator three-phase is obtained afterwardsad_ref,ubd_ref,ucd_ref, it obtains transverter three after negating respectively The modulated signal u of bridge arm in phaseau_ref,ubu_ref,ucu_ref, modulated signal is approached by nearest level again modulates and equal pressure sequence The trigger signal of transverter submodule is obtained after algorithm, and then for triggering corresponding submodule.
2. the DC voltage fault traversings of MMC zero control under a kind of bridge arm parameter unbalance state according to claim 1 Method, it is characterised in that the bridge arm structure of three-phase six that MMC topologys are made up of bridge-type submodule.
3. DC voltage fault traversing controlling parties of MMC zero under a kind of bridge arm parameter unbalance state according to claim 1 Method, it is characterised in that aid in pushing back road between bridge arm and be arranged on three-phase between first full-bridge submodule of bridge arm and three Under phase between bridge arm n-th full-bridge submodule, the auxiliary between two neighboring module pushes back three diodes of route, and one auxiliary Help electric capacity and an IGBT composition；The sub- module capacitance C of bridge arm first in A phasesAu_1Positive pole connect auxiliary capacitor C through diode1 Positive pole, electric capacity C1Negative pole be connected to through diode in direct current positive bus, in addition, auxiliary capacitor C1Positive pole through aid in IGBT T1 It is connected to the 1st module capacitance C of bridge arm in B phasesBu_1Positive pole, electric capacity CBu_1Negative pole through diode to be connected to bridge arm in A phases auxiliary Help electric capacity C1Negative pole, constitute alternate loop, by that analogy, bridge arm auxiliary capacitor C in B phases2Positive pole through aid in IGBT T2Even It is connected to the 1st module capacitance C of bridge arm in C phasesCu_1Positive pole, CCu_1Negative pole be connected to bridge arm auxiliary capacitor C in B phases2It is negative Pole, likewise, bridge arm auxiliary capacitor C in C phases3It is connected to the sub- module capacitance C of bridge arm first in A phasesAu_1On, bridge arm on three-phase First module composition triangle loop；It is similar with upper bridge arm, for the alternate subsidiary loop of lower bridge arm, bridge arm n-th under A phases Module capacitance CAd_nPositive pole be connected to lower bridge arm auxiliary capacitor C through booster diode4Positive pole, auxiliary capacitor C4Negative pole it is direct It is connected in direct current negative busbar, C4Positive pole through aid in IGBT T4It is connected to last submodule electric capacity of bridge arm C under B phasesBd_n Positive pole, auxiliary capacitor C4With last submodule electric capacity of B phases CBd_nNegative pole be connected by direct current negative busbar, likewise, Last submodule electric capacity of bridge arm C under B phasesBd_nPositive pole connect auxiliary capacitor C through diode5Positive pole, auxiliary capacitor C5It is negative Pole connects direct current negative busbar, auxiliary capacitor C5Positive pole through aid in IGBT T5It is connected to last submodule electric capacity of bridge arm under C phases CCd_nPositive pole, CCd_nNegative pole constitute loop through direct current negative busbar, last submodule electric capacity of bridge arm C under C phasesCd_nJust Pole connects auxiliary capacitor C through diode6Positive pole, auxiliary capacitor C6Negative pole connect direct current negative busbar, auxiliary capacitor C6Positive pole through auxiliary Help IGBT T6It is connected to last submodule electric capacity of bridge arm C under A phasesAd_nPositive pole, CAd_nNegative pole through direct current negative busbar constitute Loop；So, last submodule of bridge arm passes through bridge arm in the triangle loop of alternate auxiliary circuit, realization under three-phase Between mutual balanced and lower bridge arm between mutual equilibrium.
4. DC voltage fault traversing controlling parties of MMC zero under a kind of bridge arm parameter unbalance state according to claim 3 Method, it is characterised in that the upper bridge arm numbering of A, B, C three-phase is respectively 1,3,5, lower bridge arm numbering is 4,6,2, bridge arm voltage deviation Three bridge arms not in same dc bus side are chosen in governing loop to be adjusted its capacitance voltage, totally 1,2,3,2,3,4, 3,4,5,4,5,6,5,6,1,6, any one combination is chosen in 1,2 six kind of combination, will correspondence bridge arm energy adjusting to specified.
5. DC voltage fault traversing controlling parties of MMC zero under a kind of bridge arm parameter unbalance state according to claim 1 Method, it is characterised in that low-voltage module preferentially charges when submodule capacitor switching follows bridge arm module charging inside bridge arm, submodule During electric discharge, the principle switching of high-pressure modular preferential discharge.
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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CN109830977A (en) * 2019-04-08 2019-05-31 武汉大学 The control method of direct current transportation circuit, DC transmission system and direct current transportation circuit
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Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102931863A (en) * 2012-11-12 2013-02-13 华北电力大学 Method for setting up modularized multi-level converter composite structure model
CN103532419A (en) * 2013-09-09 2014-01-22 西安交通大学 Module capacitor voltage sharing control method for modular multilevel converter
CN104037733A (en) * 2014-06-03 2014-09-10 中国科学院电工研究所 Direct current fault isolation type flexible direct current transmission converter station subelement topology
CN104167912A (en) * 2014-08-14 2014-11-26 华中科技大学 MMC with zero direct voltage fault ride-through capability and design method thereof
CN204068699U (en) * 2014-09-11 2014-12-31 华南理工大学 A kind of MMC submodule with direct-current short circuit fault self-cleaning ability
CN204497991U (en) * 2015-02-04 2015-07-22 国家电网公司 A kind of autocoupling type modular multilevel high voltage direct current-direct current transformer
JP2015162999A (en) * 2014-02-28 2015-09-07 株式会社日立製作所 Power conversion apparatus and control method of power conversion apparatus
CN105471307A (en) * 2016-01-25 2016-04-06 华北电力大学 Auxiliary capacitor distributed type half-bridge/single-clamping series-parallel MMC automatic voltage-equalizing topology based on inequality constraint
CN105576691A (en) * 2016-03-01 2016-05-11 西安许继电力电子技术有限公司 Method and system for evaluating DC fault crossing capability of modularized multi-level transverter
CN106099873A (en) * 2016-06-30 2016-11-09 全球能源互联网研究院 A kind of subregion interconnect device monopolar grounding fault guard method without connection transformator
CN106099968A (en) * 2016-08-05 2016-11-09 西安许继电力电子技术有限公司 Marine wind electric field DC transmission system DC short trouble traversing method and system
CN106452147A (en) * 2016-11-21 2017-02-22 西安交通大学 Three-phase symmetric topology for self-balance of capacitor voltage of MMC (Modular Multilevel Converter) module

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102931863A (en) * 2012-11-12 2013-02-13 华北电力大学 Method for setting up modularized multi-level converter composite structure model
CN103532419A (en) * 2013-09-09 2014-01-22 西安交通大学 Module capacitor voltage sharing control method for modular multilevel converter
JP2015162999A (en) * 2014-02-28 2015-09-07 株式会社日立製作所 Power conversion apparatus and control method of power conversion apparatus
CN104037733A (en) * 2014-06-03 2014-09-10 中国科学院电工研究所 Direct current fault isolation type flexible direct current transmission converter station subelement topology
CN104167912A (en) * 2014-08-14 2014-11-26 华中科技大学 MMC with zero direct voltage fault ride-through capability and design method thereof
CN204068699U (en) * 2014-09-11 2014-12-31 华南理工大学 A kind of MMC submodule with direct-current short circuit fault self-cleaning ability
CN204497991U (en) * 2015-02-04 2015-07-22 国家电网公司 A kind of autocoupling type modular multilevel high voltage direct current-direct current transformer
CN105471307A (en) * 2016-01-25 2016-04-06 华北电力大学 Auxiliary capacitor distributed type half-bridge/single-clamping series-parallel MMC automatic voltage-equalizing topology based on inequality constraint
CN105576691A (en) * 2016-03-01 2016-05-11 西安许继电力电子技术有限公司 Method and system for evaluating DC fault crossing capability of modularized multi-level transverter
CN106099873A (en) * 2016-06-30 2016-11-09 全球能源互联网研究院 A kind of subregion interconnect device monopolar grounding fault guard method without connection transformator
CN106099968A (en) * 2016-08-05 2016-11-09 西安许继电力电子技术有限公司 Marine wind electric field DC transmission system DC short trouble traversing method and system
CN106452147A (en) * 2016-11-21 2017-02-22 西安交通大学 Three-phase symmetric topology for self-balance of capacitor voltage of MMC (Modular Multilevel Converter) module

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CN109830977A (en) * 2019-04-08 2019-05-31 武汉大学 The control method of direct current transportation circuit, DC transmission system and direct current transportation circuit
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