CN108494261A - A kind of active current-limiting method suitable for MMC type commutator transformer DC Line Fault - Google Patents
A kind of active current-limiting method suitable for MMC type commutator transformer DC Line Fault Download PDFInfo
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- CN108494261A CN108494261A CN201810329464.5A CN201810329464A CN108494261A CN 108494261 A CN108494261 A CN 108494261A CN 201810329464 A CN201810329464 A CN 201810329464A CN 108494261 A CN108494261 A CN 108494261A
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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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
- H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
- H02H9/025—Current limitation using field effect transistors
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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
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
Abstract
The invention discloses a kind of active current-limiting method suitable for MMC type commutator transformer DC Line Fault, the inductive drop Δ exported using virtual impedance moduleU dc2Generate the additional bias Δ of DC component contained by bridge arm voltageuAnd the gain of AC compounentK u.When systematic steady state is run, constant output current, ΔU dc2=0, Δu=0,K u=1；When DC Line Fault occurs, output current increases rapidly, at this time ΔU dc2>0, work as ΔU dc2More than dead zone the upper bound when, ΔuIt is increased rapidly from 0, is then limited in Δu max=U dc2It keeps stablizing at/2, eliminates the direct current biasing in bridge arm voltage, while ΔuVariation makeK uFrom 1 saltus step to 2/n, so that AC compounent amplitude is declined so that the reference value of bridge arm voltage adjusts, modulated module effect make failure side MMC per the submodule number mutually put into fromn sum=nIt is reduced ton ’ sum∈ { 0,1 }, so that the submodule quantity that synchronization participates in electric discharge is reduced, the capacitance velocity of discharge reduces, and has reached current limliting purpose.
Description
Technical field
The present invention relates to a kind of active current-limiting methods suitable for MMC type commutator transformer DC Line Fault, belong to modularization
More level and high power DC converter technique field.
Background technology
Modular multilevel converter (Modular Multilevel Converter, MMC) technology is in recent years in high pressure
Direct current transportation field obtains successfully commercialization and promotes, and the high-power commutator transformer based on MMC is following soft
It has a good application prospect in property high-voltage direct current power grid.
Since flexible high pressure DC grid is " low inertia " system, responsive time constant is small, therefore MMC type direct current
The DC fault research of transformer is one of the technical issues of researcher faces, due to the bipolar short circuit event of MMC DC sides
Barrier is fault type the most serious in MMC systems, caused submodule over-current level highest, therefore is become to MMC type direct current
The bipolar short trouble current limliting research of depressor DC side is of great significance.Document " modular multilevel converter type high voltage direct current
The DC Line Fault characteristic research of transformer " analyzes dc-side short-circuit fault mechanism and the event of system of MMC type commutator transformer
Hinder output characteristics, show that MMC type commutator transformer has bipolar short trouble the conclusion of trouble isolation serviceability.
Make MMC type commutator transformer that bipolar short trouble be isolated, failure side MMC transverters are latched, and are sent out
It before going out block action needs that DC Line Fault is identified, block action generally lags behind failure, therefore block action
The fault current for occurring to rise before makes switching device current stress increase, and may cannot be satisfied flexible direct current power grid about fast
The requirement of speed limit stream.Existing scholar begins one's study and is controlled certainly in fault identification, by MMC itself in advance when failure occurs at present
The active current limliting method of dynamic current limliting, such as document " Active Control of DC Fault Currents in DC Solid-
State Transformers During Ride-Through Operation of Multi-Terminal HVDC
Systems " passes through Set scale --- integral --- derivative controller dynamic implement and carries out direct current event to the adjustment of bridge arm voltage
Barrier passes through, and controlling unit is cumbersome；Document " the MMC AC and DCs side fault overcurrent suppressing method based on virtual impedance " proposes
Current limliting strategy based on virtual impedance, the equivalent reactance increased in discharge loop, it is suppressed that overcurrent caused by DC Line Fault, but
The current limitation effect of the method is limited.
Therefore, it is necessary to which design procedure is simple, is easy to the active current-limiting method of parameter regulation, function admirable.
Invention content
The technical problem to be solved by the present invention is to：A kind of master suitable for MMC type commutator transformer DC Line Fault is provided
Dynamic current-limiting method shifts to an earlier date in fault identification when failure occurs, controls the automatic limiting realized to fault current by MMC itself
System.
The present invention uses following technical scheme to solve above-mentioned technical problem：
A kind of active current-limiting method suitable for MMC type commutator transformer DC Line Fault, the MMC type commutator transformer
Structure is connection, including primary side transverter and secondary side transverter face-to-face；Secondary side transverter includes a, b two-phase, per phase
It is divided into upper and lower two bridge arms, each bridge arm includes n submodule, and all submodules are half-bridge structure；The active current limliting side
Method includes the following steps：
Step 1, when DC bipolar short trouble occurs, output current Idc2Voltage is induced in virtual impedance module
It is reduced to Δ Udc2, voltage drop Δ Udc2It is superimposed upon the actual measured value U of DC output voltagedc2On obtain the reality of DC output voltage
Border value of feedback U 'dc2；
Step 2, the initial phase δ of primary side transverter modulating wavepIt is 0；The reference value U of DC output voltagedc2_refWith it is straight
Flow the actual feedback U ' of output voltagedc2After the outer voltage formed through pi controller, secondary side transverter tune is exported
The initial phase δ of wave processeds, initial phase δsIt is single-phase that internal control module again through secondary side transverter obtains secondary side transverter
The reference value u of output voltageout_ref；
Step 3, voltage drop Δ Udc2The value obtained through dead zone and clipping module is that DC component contained by bridge arm voltage is additional inclined
Set Δ u twice；
Step 4, voltage drop Δ Udc2The gain K of AC compounent contained by bridge arm voltage is obtained through comparison moduleu；
Step 5, the actual measured value U of DC output voltagedc2, secondary side transverter single-phase output voltage reference value
uout_ref, AC compounent contained by DC component additional bias Δ u, bridge arm voltage contained by bridge arm voltage gain KuThrough following formula
Obtain bridge arm voltage reference value u ' in a, b phasepx_ref：
A, b phase lower bridge arm voltage reference value u ' are obtained through following formulanx_ref：
u′px_ref、u′nx_refEach switching device of secondary side transverter is exported by the modulation module of secondary side transverter
Pwm pulse signal.
As a preferred embodiment of the present invention, the transmission function of virtual impedance module described in step 1 is：
Wherein, H (s) is transmission function, RvirdcFor virtual resistance, LvirdcFor virtual inductor, s is Laplace operator.
As a preferred embodiment of the present invention, when the MMC type commutator transformer steady-state operation, output current Idc2For
Constant Direct Current, voltage drop Δ Udc2It is 0, DC component additional bias Δ u contained by bridge arm voltage is 0, the contained exchange point of bridge arm voltage
The gain K of amountuIt is 1, at this point, bridge arm voltage reference value is in a, b phaseA, b phases lower bridge arm voltage reference value isWherein, Udc2For the actual measured value of DC output voltage, uout_refFor secondary side transverter single-phase output electricity
The reference value of pressure.
It is defeated when DC bipolar short trouble occurs for the MMC type commutator transformer as a preferred embodiment of the present invention
Go out electric current Idc2The voltage drop Δ U induced in virtual impedance moduledc2>0, as Δ Udc2More than dead zone the upper bound when, bridge arm electricity
The contained DC component additional bias Δ u of pressure increases to U from 0dc2/ 2, the gain K of AC compounent contained by bridge arm voltageuFrom 1 saltus step to
2/n, Udc2For the actual measured value of DC output voltage, n is the upper bridge arm of each phase of secondary side transverter or the son that lower bridge arm includes
Number of modules.
As a preferred embodiment of the present invention, when DC bipolar short trouble occurs for the MMC type commutator transformer, therefore
The submodule number that respectively mutually puts into of barrier side transverter, that is, secondary side transverter is from nsum=n is reduced to n 'sum∈ { 0,1 }, n are secondary side
The submodule number that the upper bridge arm or lower bridge arm of each phase of transverter include.
The present invention has the following technical effects using above technical scheme is compared with the prior art：
1, the velocity of discharge is slowed down after active current-limiting method of the present invention makes permanent bipolar short trouble occur.
2, active current-limiting method of the present invention is using in a particular embodiment so that peak value of short reduces 31.7%；
So that the time of short circuit current to peaking increases 10.4ms；So that about 10ms bridge arm current instantaneous values are small after failure occurs
In the basic phase shifting control lower bridge arm current instantaneous value of no current limliting；Under identical switching device peak point current index, side of the present invention
Method is that protection act has won the 4.2ms times；When being latched in 2~3ms after failure generation, the method for the present invention lower switch device
Part current stress is smaller, and the safety margin of switching device increases, and system reliability is also improved.
Description of the drawings
Fig. 1 is the structure chart of MMC type commutator transformer of the present invention.
Fig. 2 is the MMC type commutator transformer system control block figure based on the basic phase shift of no current limliting.
Fig. 3 is the MMC type commutator transformer system control block figure based on active current-limiting method of the present invention.
Fig. 4 is DC side additional virtual impedance of the present invention.
Fig. 5 is bridge arm voltage reference value and submodule input quantity relation schematic diagram.
Fig. 6 is the submodule quantity that a phases of MMC2 under the basic phase shifting control of no current limliting are put into.
Fig. 7 is the submodule quantity that a phases of the lower MMC2 of active current-limiting method control of the present invention are put into.
Fig. 8 is a phase submodule capacitor voltage oscillograms under different current limiting measures.
Fig. 9 is the fault point short circuit current waveform figure under different current limiting measures.
Figure 10 is bridge arm current oscillogram in a phases under different current limiting measures.
Specific implementation mode
Embodiments of the present invention are described below in detail, the example of the embodiment is shown in the accompanying drawings.Below by
The embodiment being described with reference to the drawings is exemplary, and is only used for explaining the present invention, and is not construed as limiting the claims.
As shown in Figure 1, being MMC type DC Transformer structure, which is that face-to-face (Front-to-Front, F2F) connects
It connects, uses no-load voltage ratio for KTIntermediate-frequency transformer T carry out isolation and voltage matches.MMC1 is primary side change of current end, including A, B two
Phase, per upper and lower two bridge arms are mutually divided into, each bridge arm includes m submodule；MMC2 is secondary side change of current end, including a, b two
Phase, per upper and lower two bridge arms are mutually divided into, each bridge arm includes n submodule；LpAnd LsRespectively represent the bridge arm electricity of first and second side
Sense；Udc1And Udc2Respectively input voltage and output voltage；Idc2For output current；iLpa、iLnaThe respectively upper and lower bridge arm electricity of a phases
Stream；iLpb、iLnbThe respectively upper and lower bridge arm current of b phases.All submodules are half-bridge structure shown in Fig. 1.
The common phase shifting control of MMC type commutator transformer is as shown in Fig. 2, the tune for passing through the phase shifting angle between MMC1 and MMC2
Section can realize the adjusting to power.Phase shifting control has the advantages that system dynamic response is fast and no-load voltage ratio is unrestricted, obtain compared with
It uses more.U in figuredc2For the actual measured value of output voltage, Udc2_refFor the reference value of DC output voltage, δp=0 is MMC1
The initial phase of modulating wave, δsFor the initial phase of MMC2 modulating waves.
As shown in figure 3, being the MMC type commutator transformer system control block figure based on active current-limiting method of the present invention.It transmits
Function isLink be equivalent to DC side additional virtual impedance module shown in Fig. 4, therefore export electricity
Flow Idc2Voltage drop Δ U is induced in the linkdc2, it is superimposed upon the actual measured value U of output voltagedc2On obtain direct current output
The actual feedback amount U ' of voltagedc2；The reference value U of DC output voltagedc2_refWith the actual feedback amount U ' of DC output voltagedc2
After the outer voltage formed through proportional integration (PI) controller, the initial phase δ of MMC2 modulating waves is exporteds, then through internal control
Link obtains the reference value u of MMC2 single-phase output voltagesout_ref；Voltage drop Δ Udc2Bridge arm electricity is obtained through dead zone and amplitude limit link
Twice of 2 Δ u of the contained DC component additional bias of pressure；Voltage drop Δ Udc2Exchange point contained by bridge arm voltage is obtained through comparing element
The gain K of amountu；The actual measured value U of output voltagedc2, MMC2 single-phase output voltages reference value uout_ref, it is straight contained by bridge arm voltage
The gain K of AC compounent contained by twice of 2 Δ u of flow component additional bias, bridge arm voltageuThrough
Obtain bridge arm voltage reference value u ' in x (x=a, b) phasepx_ref, warpObtain x (x=a, b)
Phase lower bridge arm voltage reference value u 'nx_ref。u′px_ref、u′nx_refBy the fields MMC, commonly nearest level approaches modulation
(Nearest Level Modulation, NLM) link exports the pwm pulse signal of each switching devices of MMC2.
As shown in figure 5, for bridge arm voltage reference value and submodule input quantity relation schematic diagram, when systematic steady state is run
When, output current Idc2For Constant Direct Current, Δ Udc2=0, Δ u=0, Ku=1, upper bridge arm voltage and the lower bridge arm electricity generated at this time
Press reference valueFor MMC normal operations when reference value, current-limiting method
Systematic steady state operation is not had an impact, the submodule number n that bridge arm is put into the every phases of failure side MMC at this timex_up∈ { 0, n }, under
The submodule number n of bridge arm inputx_down∈ { 0, n }, the sum of submodule number of upper and lower bridge arm input nsum=n.When DC bipolar is short
When road failure occurs, output current Idc2It increases rapidly, the voltage drop Δ U induced at this time by virtual impedance moduledc2>0, and
ΔUdc2Also it increases rapidly.As Δ Udc2More than dead zone the upper bound when, Δ u is increased rapidly from 0, is then limited in Δ umax=
Udc2It keeps stablizing at/2, eliminates the direct current biasing in bridge arm voltage, while the variation of Δ u makes KuFrom 1 saltus step to 2/n, make
AC compounent amplitude declines in bridge arm voltage so that the reference value u of bridge arm voltagepx_ref、unx_refIt is adjusted to：Make the submodule number of bridge arm input in the every phases of failure side MMC through the effect of NLM links
n′x_up∈ { 0,1 }, the submodule number n ' of lower bridge arm inputx_down∈ { 0,1 }, the sum of submodule number of upper and lower bridge arm input n 'sum
∈{0,1}。
Simulation comparison is carried out with a specific embodiment below, simulation parameter is as shown in table 1, in fault time tfault=
Permanent bipolar short trouble occurs for 0.25s moment MMC2 DC sides.
Table 1
| Parameter | Numerical value |
| Input voltage Udc1 | 4kV |
| Output voltage reference value Udc2_ref | 2kV |
| Transimission power P | 0.5MW |
| A-c cycle fac | 500Hz |
| MMC1 submodule numbers m | 4 |
| MMC1 submodule capacitances CSMp | 4.7mF |
| MMC1 bridge arm inductance Lp | 0.8mH |
| MMC1 bridge arm equivalent resistance Rp | 0.04Ω |
| MMC2 submodule numbers n | 4 |
| MMC2 submodule capacitances CSM | 4.7mF |
| MMC2 bridge arm inductance Ls | 0.8mH |
| MMC2 bridge arm equivalent resistance Rs | 0.04Ω |
| Intermediate-frequency transformer leakage inductance LT | 0.2mH |
| Intermediate-frequency transformer no-load voltage ratio KT | 2:1 |
| Short dot equivalent resistance Rsc | 0.01Ω |
As shown in fig. 6, for the submodule quantity that puts into of a phases of MMC2 under the basic phase shifting control of no current limliting.A phases are shown in figure
The submodule number n of upper bridge arm inputa_up∈ { 0,4 }, the submodule number n of lower bridge arm inputa_down∈ { 0,4 }, upper and lower bridge arm input
The sum of submodule number nsum=4.
As shown in fig. 7, the submodule quantity that a phases for controlling lower MMC2 for active current limliting method of the present invention are put into.It is shown in figure
When systematic steady state is run, the submodule number of input is consistent with the basic phase shifting control of no current limliting；After failure occurs, bridge in a phases
The submodule number n ' of arm inputa_up∈ { 0,1 }, the submodule number n ' of lower bridge arm inputa_down∈ { 0,1 }, upper and lower bridge arm input
The sum of submodule number n 'sum∈{0,1}。
As shown in figure 8, for a phase submodule capacitor voltage waveforms under different current limiting measures.No current limliting base is shown in figure
Under this phase shifting control, submodule capacitor voltage is reduced to rapidly 0 after failure occurs, and illustrates that the velocity of discharge is very fast at this time；And it is of the invention
Under the control of active current limliting method, the velocity of discharge is slowed down after failure occurs.
As shown in figure 9, for the fault point short circuit current waveform under different current limiting measures.No current limliting is shown in figure to move substantially
Under phase control, peak value of short Ipeak1=4.63A, tpeak1=0.2533s the moment is to peaking；In active current limliting of the present invention
Under method control, peak value of short Ipeak2=3.16kA, tpeak2=0.2637s the moment to peaking, illustrates that the method for the present invention makes
Obtaining peak value of short reduces 31.7% so that the time of short circuit current to peaking increases 10.4ms.
As shown in Figure 10, it is bridge arm current waveform in a phases under different current limiting measures.It is shown in figure after failure occurs about
In 10ms, the method for the present invention lower bridge arm current instantaneous value is respectively less than without the basic phase shifting control lower bridge arm current instantaneous value of current limliting, and
The failure locking time of commutator transformer is usually no more than 2~3ms after failure occurs, the method for the present invention lower bridge arm in time period
Current instantaneous value fall bigger.Such as assume that MMC internal switch device peak electric currents are 1500A, figure bridge arm electric current reaches
The time of 1500A is respectively t1=0.2506s, t2=0.2548s, i.e. the method for the present invention are by the time of bridge arm current to peaking
4.2ms is extended, is illustrated under identical switching device peak point current index, when the method for the present invention is that protection act has been won
Between；As assumed the 2ms moment (t after failure generationblock=0.252s) block action, at this time bridge arm current instantaneous value occur for system
Respectively Iblock1=1.85kA, Iblock2=0.65kA illustrates in identical locking moment, the method for the present invention lower switch device electricity
Stream stress is smaller, and the safety margin of switching device increases, and system reliability is also improved.
Above example is merely illustrative of the invention's technical idea, and protection scope of the present invention cannot be limited with this, every
According to technological thought proposed by the present invention, any change done on the basis of technical solution each falls within the scope of the present invention
Within.
Claims (5)
1. a kind of active current-limiting method suitable for MMC type commutator transformer DC Line Fault, the knot of the MMC type commutator transformer
Structure is connection, including primary side transverter and secondary side transverter face-to-face；Secondary side transverter includes a, b two-phase, is divided per phase
For upper and lower two bridge arms, each bridge arm includes n submodule, and all submodules are half-bridge structure；It is characterized in that, described
Active current-limiting method includes the following steps：
Step 1, when DC bipolar short trouble occurs, output current Idc2Voltage is induced in virtual impedance module to be reduced to
ΔUdc2, voltage drop Δ Udc2It is superimposed upon the actual measured value U of DC output voltagedc2On obtain the practical anti-of DC output voltage
Feedback value Ud′c2；
Step 2, the initial phase δ of primary side transverter modulating wavepIt is 0；The reference value U of DC output voltagedc2_refIt is defeated with direct current
Go out the actual feedback U of voltaged′c2After the outer voltage formed through pi controller, secondary side transverter modulating wave is exported
Initial phase δs, initial phase δsInternal control module again through secondary side transverter obtains secondary side transverter single-phase output
The reference value u of voltageout_ref；
Step 3, voltage drop Δ Udc2The value obtained through dead zone and clipping module is DC component additional bias Δ contained by bridge arm voltage
Twice of u；
Step 4, voltage drop Δ Udc2The gain K of AC compounent contained by bridge arm voltage is obtained through comparison moduleu；
Step 5, the actual measured value U of DC output voltagedc2, secondary side transverter single-phase output voltage reference value uout_ref、
The gain K of AC compounent contained by DC component additional bias Δ u, bridge arm voltage contained by bridge arm voltageuA, b are obtained through following formula
Bridge arm voltage reference value u in phasep′x_ref：
A, b phase lower bridge arm voltage reference value u ' are obtained through following formulanx_ref：
up′x_ref、u′nx_refThe PWM arteries and veins of each switching device of secondary side transverter is exported by the modulation module of secondary side transverter
Rush signal.
2. being suitable for the active current-limiting method of MMC type commutator transformer DC Line Fault according to claim 1, feature exists
In the transmission function of virtual impedance module described in step 1 is：
Wherein, H (s) is transmission function, RvirdcFor virtual resistance, LvirdcFor virtual inductor, s is Laplace operator.
3. being suitable for the active current-limiting method of MMC type commutator transformer DC Line Fault according to claim 1, feature exists
When, the MMC type commutator transformer steady-state operation, output current Idc2For Constant Direct Current, voltage drop Δ Udc2It is 0, bridge arm electricity
The contained DC component additional bias Δ u of pressure is 0, the gain K of AC compounent contained by bridge arm voltageuIt is 1, at this point, bridge arm in a, b phase
Voltage reference value isA, b phases lower bridge arm voltage reference value isWherein, Udc2It is defeated for direct current
Go out the actual measured value of voltage, uout_refFor the reference value of secondary side transverter single-phase output voltage.
4. being suitable for the active current-limiting method of MMC type commutator transformer DC Line Fault according to claim 1, feature exists
In, when DC bipolar short trouble occurs for the MMC type commutator transformer, output current Idc2Incude in virtual impedance module
The voltage drop Δ U gone outdc2>0, as Δ Udc2More than dead zone the upper bound when, DC component additional bias Δ u contained by bridge arm voltage is from 0
Increase to Udc2/ 2, the gain K of AC compounent contained by bridge arm voltageuFrom 1 saltus step to 2/n, Udc2For the reality of DC output voltage
Measured value, n are the upper bridge arm of each phase of secondary side transverter or the submodule number that lower bridge arm includes.
5. being suitable for the active current-limiting method of MMC type commutator transformer DC Line Fault according to claim 1, feature exists
In when DC bipolar short trouble occurs for the MMC type commutator transformer, failure side transverter, that is, secondary side transverter is each congenial
The submodule number entered is from nsum=n is reduced to ns′um∈ { 0,1 }, n are the upper bridge arm of each phase of secondary side transverter or lower bridge arm includes
Submodule number.
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| CN109474169A (en) * | 2018-12-24 | 2019-03-15 | 北京四方继保自动化股份有限公司 | A kind of MMC DC side fault current control method based on DC voltage fuzzy control |
| CN110311542A (en) * | 2019-07-09 | 2019-10-08 | 南方电网科学研究院有限责任公司 | The virtual reactance control method of modularization multi-level converter and control device |
| CN111371302A (en) * | 2020-03-11 | 2020-07-03 | 合肥科威尔电源系统股份有限公司 | Multi-stage soft charging control method and system for multi-level direct current solid-state transformer |
| CN111654051A (en) * | 2020-05-21 | 2020-09-11 | 东南大学 | Direct current fault ride-through control method suitable for mixed MMC |
| CN112865163A (en) * | 2021-01-15 | 2021-05-28 | 中国南方电网有限责任公司超高压输电公司 | Additional control method for current converter |
| CN113036739A (en) * | 2021-05-11 | 2021-06-25 | 东北电力大学 | Direct-current fault current suppression method based on submodule two-stage active control |
| CN114024294A (en) * | 2021-10-22 | 2022-02-08 | 武汉大学 | Virtual-entity integrated current limiting system and method suitable for half-bridge type MMC |
| CN115118164A (en) * | 2022-06-22 | 2022-09-27 | 国网浙江省电力有限公司电力科学研究院 | Method and system for inhibiting magnetic bias of modular multilevel direct current transformer |
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| CN109474169B (en) * | 2018-12-24 | 2020-05-05 | 北京四方继保自动化股份有限公司 | MMC direct-current side fault current control method based on direct-current voltage fuzzy control |
| CN110311542A (en) * | 2019-07-09 | 2019-10-08 | 南方电网科学研究院有限责任公司 | The virtual reactance control method of modularization multi-level converter and control device |
| CN111371302A (en) * | 2020-03-11 | 2020-07-03 | 合肥科威尔电源系统股份有限公司 | Multi-stage soft charging control method and system for multi-level direct current solid-state transformer |
| CN111654051A (en) * | 2020-05-21 | 2020-09-11 | 东南大学 | Direct current fault ride-through control method suitable for mixed MMC |
| CN112865163A (en) * | 2021-01-15 | 2021-05-28 | 中国南方电网有限责任公司超高压输电公司 | Additional control method for current converter |
| CN112865163B (en) * | 2021-01-15 | 2022-09-23 | 中国南方电网有限责任公司超高压输电公司 | Additional control method for current converter |
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| CN113036739B (en) * | 2021-05-11 | 2022-09-20 | 东北电力大学 | Direct-current fault current suppression method based on submodule two-stage active control |
| CN114024294A (en) * | 2021-10-22 | 2022-02-08 | 武汉大学 | Virtual-entity integrated current limiting system and method suitable for half-bridge type MMC |
| CN114024294B (en) * | 2021-10-22 | 2023-08-15 | 武汉大学 | Virtual-physical integrated current limiting system and method suitable for half-bridge MMC |
| CN115118164A (en) * | 2022-06-22 | 2022-09-27 | 国网浙江省电力有限公司电力科学研究院 | Method and system for inhibiting magnetic bias of modular multilevel direct current transformer |
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