CN107623456A - Multiport electric power electric transformer topology and its control method based on MMC - Google Patents
Multiport electric power electric transformer topology and its control method based on MMC Download PDFInfo
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Abstract
The invention discloses the topology of the multiport electric power electric transformer based on MMC and its control method, transformer is high-voltage alternating level including input stage, for the transformation of electrical energy exchanged by high pressure industrial frequency AC to HVDC with low-voltage high-frequency；Two output stages are respectively HVDC level and low-voltage direct level, are converted into high-voltage dc voltage and low-voltage dc voltage for the HVDC after high-voltage alternating level is converted and low-voltage high-frequency AC energy and export；Control method includes：To high-voltage alternating level using low-voltage direct level output voltage or submodule capacitor averaging voltage as outer voltage feedback quantity, double-closed-loop control is carried out by inner loop feedback amount of high-voltage alternating level electric current, the overlapped high-frequency square wave signal component in the output modulating wave of high-voltage alternating level, to obtain high-voltage alternating level output high-voltage dc voltage and low-voltage high-frequency DC voltage；The present invention only has two-layer configuration from high-voltage alternating to low-voltage direct, saves big metering device, is favorably improved transformer whole efficiency and reliability, reduces cost.
Description
Technical field
The present invention relates to a kind of multiport electric power electric transformer topology and its control method based on MMC, belong to electric power
The technical field of system.
Background technology
As the developing rapidly of renewable energy power generation, direct current type load increase, traditional Industrial Frequency Transformer is due to lacking
Few intelligent control link and DC converting port, the requirement and challenge of modern power systems it have been not enough to tackle.And work
Frequency power transformer is bulky, and weight is larger, it is desirable to larger floor space.And developing rapidly with semiconductor devices, carry
Go out a kind of Novel intelligent transformer based on High Power Electronic Converter Technology, can not only reduce the weighing body of transformer
Product, and a variety of alternating current-direct current ports can be provided, there is flexible and changeable controllability, facilitate various distributed energies, energy storage
With the flexible access of load, many problems faced efficiently to solve current power network provide possibility.
Existing many scholars propose a variety of electric power electric transformer topological structures at present, but are typically all to utilize modularization
Multilevel Inverters or the topological structure for cascading full-bridge, by High Level AC Voltage rectifying conversion into high voltage direct current, are reused more
The individual series-parallel structure of DC-DC converter is low-voltage DC to high voltage direct current decompression.These electric power electric transformers topology
Electric energy conversion series is more, has used more power device, causes to be lost larger, and multiple DC converter connection in series-parallel are deposited
Need to suppress in circulation problem, the control of direct current switching stage is complicated.Cost is higher, and control is complicated, and reliability is not high, power density
It is not high, it is difficult to realize large-scale use.
The content of the invention
The technical problems to be solved by the invention are overcome the deficiencies in the prior art, there is provided a kind of multiterminal based on MMC
Mouth electric power electric transformer topology and its control method, solution electric power electric transformer topology electric energy conversion series is more, uses
More power device, causes to be lost larger, and multiple DC converter connection in series-parallel have circulation problem needs what is suppressed
Problem.
It is of the invention specifically to solve above-mentioned technical problem using following technical scheme：
Multiport electric power electric transformer based on MMC is topological, including is made up of input stage and two output stages, wherein institute
It is high-voltage alternating level to state input stage, for the transformation of electrical energy exchanged by high pressure industrial frequency AC to HVDC with low-voltage high-frequency；Institute
It is respectively HVDC level and low-voltage direct level to state two output stages, for the HVDC after high-voltage alternating level is converted respectively
High-voltage dc voltage and low-voltage dc voltage are converted into low-voltage high-frequency AC energy and are exported；Wherein, the high-voltage alternating level
It is described to be made up of per phase bridge arm upper and lower two and half bridge arm by being formed using the modular multi-level converter of three-phase bridge arm, and often
Individual half bridge arm is in series by N number of half-bridge submodule or full-bridge submodule and a bridge arm inductance；Above and below every phase bridge arm
The intermediate point of bridge arm distinguishes filtered inductance connection to mesohigh AC network, and two ports after three-phase bridge arm in parallel is made
For high-voltage alternating level output port.
Further, as a preferred technical solution of the present invention：The HVDC level includes trapper and high pressure
DC energy storage electric capacity, a port of the trapper are connected with one of output port of high-voltage alternating level, and in high pressure
HVDC level output port is used as between the another port of another output port of exchange level and trapper, and in HVDC level
Parallel high voltage DC energy storage electric capacity between output port.
Further, as a preferred technical solution of the present invention：The trapper is by filter inductance and filter capacitor
Compose in parallel.
Further, as a preferred technical solution of the present invention：The low-voltage direct level includes capacitance, high frequency
Isolating transformer, H-bridge circuit and low-voltage direct storage capacitor, wherein described two high-voltage alternating level output ports series connection blocking electricity
A side ports of high-frequency isolation transformer, and the secondary port connection H-bridge circuit of high-frequency isolation transformer are connected to after appearance
First and second bridge arm intermediate point；Exported after the H-bridge circuit output port parallel connection low-voltage direct storage capacitor for low-voltage direct level
Port.
Further, as a preferred technical solution of the present invention：Described two output stages also include low-voltage alternating-current level,
The low-voltage alternating-current level includes bandwidth-limited circuit and low-voltage alternating-current level circuit；The secondary port string of the high-frequency isolation transformer
Associated bandpass filter circuit, and the parallel connection low-voltage alternating-current level circuit at first and second bridge arm intermediate point of H-bridge circuit；The low pressure
It is in series by low-voltage alternating-current filter inductance and low-voltage alternating-current filter capacitor to exchange level circuit, and by low-voltage alternating-current filter capacitor
Both ends are as low-voltage alternating-current output port.
Further, as a preferred technical solution of the present invention：The H-bridge circuit by two pairs series connection switching tubes simultaneously
Connection composition.
A kind of control method of the multiport electric power electric transformer topology based on MMC, comprises the following steps：
It is anti-as outer voltage using low-voltage direct level output voltage or submodule capacitor averaging voltage to the high-voltage alternating level
Feedback amount, double-closed-loop control is carried out as inner loop feedback amount using high-voltage alternating level electric current and obtains the basic modulated signal of three-phase bridge arm, and
Overlapped high-frequency square wave signal component in the output modulating wave of high-voltage alternating level, to obtain high-voltage alternating level output high-voltage dc voltage
With low-voltage high-frequency DC voltage；The HVDC that high-voltage alternating level is exported respectively is converted into high pressure with low-voltage high-frequency AC energy
DC voltage and low-voltage dc voltage simultaneously export；
Also, when power transmits between high-voltage alternating level and low-voltage direct level, the low-voltage direct level is controlled to produce
Voltage waveform with institute's overlapped high-frequency square wave signal component with frequency same-phase.
Further, as a preferred technical solution of the present invention, double-closed-loop control is carried out in methods described, specifically
For：
PLL locks are carried out with three-phase alternating current according to the three-phase alternating voltage of the high-voltage alternating level of sampling and mutually obtain phase
Angle, and respectively three-phase alternating voltage and three-phase alternating current are converted to obtain each comfortable d axles and q axis components；
It is outer voltage feedback quantity by low-voltage direct level output voltage or submodule capacitor averaging voltage, with given voltage ratio
Compared with a reference value after Voltage loop PI regulations as d shaft current rings；The a reference value and three-phase alternating current of d shaft current rings will be obtained
Difference after flowing d axis components relatively, obtains d axle output valves after PI is reconciled；The q shaft current ring a reference values of setting are intersected with three
Difference after flowing electric current q axis components relatively, obtains q axle output valves after PI is reconciled；It is defeated to resulting d axles output valve and q axles
Go out value decoupling computing and obtain the d axles and q axis components of basic modulated signal, the basic modulated signal of three-phase is obtained through dq inverse transformations；
High-frequency square-wave signal is injected in the basic modulated signal of three-phase and obtains the modulated signal of modular multi-level converter；
According to the capacitance voltage of modular multi-level converter submodule in the high-voltage alternating level of sampling respectively with given base
Accurate value is compared, and by the output after comparison after PI is adjusted and the obtained modulated signal of modular multi-level converter
It is added, as the final modulated signal of the submodule, with balanced submodule capacitor voltage and adjusts electric power electric transformer output.
Further, as a preferred technical solution of the present invention：Also include carrying out loop current suppression to high-voltage alternating level.
Further, as a preferred technical solution of the present invention：It is described that loop current suppression, tool are carried out to high-voltage alternating level
Body is：
The electric current of three-phase bridge arm and output port to modular multi-level converter is sampled and handled, and determines bridge arm
Circulation control input；Computing is carried out according to the circulation control input of identified bridge arm and conversion obtains three-phase bridge arm modulation letter
Number loop current suppression thermal compensation signal；
The basic modulated signal of three-phase bridge arm obtained using modular multi-level converter progress double-closed-loop control subtracts ring
Stream suppresses thermal compensation signal and obtains the three-phase bridge arm modulated signal with loop current suppression effect.
The present invention uses above-mentioned technical proposal, can produce following technique effect：
A kind of multiport electric power electric transformer topology and its control method based on MMC provided by the invention, reduce
The electric energy of HVDC to low-voltage direct in original electric power electric transformer is changed, and only has two from high-voltage alternating to low-voltage direct
Level structure, big metering device is saved, be favorably improved transformer whole efficiency and reliability, reduce cost；And electric power electricity
Sub- transformer also has HVDC port, can provide high-voltage dc voltage.In addition, low-voltage direct level H bridges can realize zero
Switch off current, the current stress of low-voltage direct level switching device is reduced, improves efficiency of transmission.
Brief description of the drawings
Fig. 1 is the circuit topology figure of the multiport electric power electric transformer topology proposed by the present invention based on MMC.
Fig. 2 a are a kind of single submodule topological diagram of modular multi-level converter proposed by the present invention.
Fig. 2 b are another single submodule topological diagram of modular multi-level converter proposed by the present invention.
Fig. 3 is the novel electric power electric transformer topology proposed by the present invention with low-voltage alternating-current port.
Fig. 4 is the principle schematic of the control method of novel electric power electric transformer proposed by the present invention.
Fig. 5 a are that the present invention proposes that submodule presses a kind of method of policy control.
Fig. 5 b are that the present invention proposes that the submodule with loop current suppression effect presses a kind of method of policy control.
Fig. 6 is the H bridge controlling parties of the novel electric power electric transformer topology proposed by the present invention with low-voltage alternating-current port
Method.
Fig. 7 is the low-voltage direct level output voltage waveforms of novel electric power electric transformer proposed by the present invention.
Fig. 8 is the high-voltage alternating side A phase voltage current waveforms of novel electric power electric transformer proposed by the present invention.
Fig. 9 is that the high-voltage alternating level of novel electric power electric transformer proposed by the present invention exports H1H2Port voltage waveform.
Embodiment
Embodiments of the present invention are described with reference to Figure of description.
As shown in figure 1, the present invention proposes a kind of multiport electric power electric transformer topology based on MMC, including by inputting
Level and two output stages form, wherein the input stage be high-voltage alternating level, for by high pressure industrial frequency AC to HVDC and
The transformation of electrical energy of low-voltage high-frequency exchange；Described two output stages are respectively HVDC level and low-voltage direct level, for respectively will
HVDC after the conversion of high-voltage alternating level is converted further into high-voltage dc voltage and low-pressure direct with low-voltage high-frequency AC energy
Stream voltage simultaneously exports.
Wherein, the high-voltage alternating level is by half-bridge submodule and full-bridge submodule hybrid type type modular multi-level converter
Composition, the sub-module types of its modular multi-level converter are not fixed, can be by part full-bridge submodule and part half-bridge
Submodule mixing composition, its structure is respectively as shown in Figure 2 a and 2 b, but be not secured to a kind of sub-module types；The present embodiment
In, Modular multilevel converter shares the bridge arm of three-phase six, and every phase bridge arm is made up of upper and lower two and half bridge arm and each half bridge arm
By N number of half-bridge submodule or full-bridge submodule SM1~SMNWith a bridge arm inductance LarmIt is in series；It is described upper per phase bridge arm
Intermediate point A, B, C of lower bridge arm are respectively connecting to mesohigh AC network, and by two port H after three-phase bridge arm in parallel1、H2
As high-voltage alternating level output port.
The HVDC level includes trapper and HVDC storage capacitor Coh, a port of the trapper
Connect, and will make between the another port of another output port of high-voltage alternating level and trapper with an output port of high-voltage alternating level
For HVDC level output port, the parallel high voltage DC energy storage electric capacity between HVDC level output port.Preferably, trapper
By filter inductance LfWith filter capacitor CfCompose in parallel, trapper acts the low-voltage high-frequency point filtered out in HVDC level output electric energy
The effect of amount.HVDC storage capacitor CohPlay a part of stable high voltage DC port voltage.By one by filter inductance
LfWith filter capacitor CfThe trapper that parallel connection is formed, filters out the high frequency square wave in modular multi-level converter output waveform, is obtaining
Obtain HVDC port and obtain a high-voltage dc voltage.
The low-voltage direct level includes capacitance Cr, high-frequency isolation transformer, H-bridge circuit and low-voltage direct storage capacitor
Col, wherein described two high-voltage alternating level output port H1、H2Connect capacitance CrThe one of high-frequency isolation transformer is connected to afterwards
Secondary side ports Y1、N1, and the secondary port Y of high-frequency isolation transformer2、N2Connect first and second bridge arm intermediate point of H-bridge circuit
M、N；The H-bridge circuit output port parallel connection low-voltage direct storage capacitor ColIt is low-voltage direct level output port afterwards.Wherein, it is described
H-bridge circuit can be composed in parallel by some groups of H bridges, and single H bridges structure is used in the present embodiment, by the paralleled power switches of two pairs of series connection
Composition；Capacitance CrOn the one hand play a part of filtering out the HVDC component in the output of high-voltage alternating level, on the other hand with
High-voltage alternating level bridge arm inductance LarmResonance circuit is formed, auxiliary low pressure direct current level H-bridge circuit realizes zero-current switching；High frequency every
From the voltage transformation that transformer plays a part of electrical isolation and high-frequency ac voltage；H-bridge circuit has then realized low-voltage high-frequency
Exchange the conversion of low-voltage dc voltage；Low-voltage direct storage capacitor ColPlay a part of stabilizing low voltage DC port voltage.
Pass through low-voltage direct level capacitance CrMultilevel Inverters mesohigh DC voltage is filtered out, in high frequency transformer one
Secondary side obtains low-voltage high-frequency voltage waveform.By low-voltage direct level H-bridge circuit rectification, low-pressure direct can be obtained in low-voltage direct port
Flow voltage.Also, resonance circuit is formed by the bridge arm inductance and low-voltage direct level capacitance of Modular multilevel converter, controlled
Low-voltage direct level H-bridge circuit processed produces the square wave with frequency same-phase with high frequency transformer primary side square wave so that low-voltage direct level H
The switching device of bridge circuit is operated under zero-current switching pattern, can effectively reduce the switching loss of switching device.
Described electric power electric transformer mesolow direct current level capacitance CrWith modular multi-level converter bridge arm electricity
Anti- composition series resonant circuit, HVDC level filter inductance form trapper with filter capacitor.Bridge arm reactance LarmWith blocking electricity
Hold CrResonant frequency frNeed to meet the high-frequency square-wave signal u with injecting in modular multi-level converter modulated signalsqu's
Frequency fsquIt is equal, that is, meet formula (1).
The present invention can also use other modules or device to replace bridge arm reactance LarmWith capacitance CrIt is humorous to form series connection
Shaken circuit, and other modules or method can also be used to realize the filter action of HVDC stage notch device.
The individual module of modular multi-level converter example is opened up used by electric power electric transformer of the present invention
Flutter as shown in Figure 2 a, be half-bridge structure, by two switching tube Q1、Q2Formed with storage capacitor.Or full bridge structure, such as Fig. 2 b
It is shown, by four switching tube Q1、Q2、Q3、Q4Formed with storage capacitor.
The topological structure of described electric power electric transformer can also do following improvement, increase extra low-voltage alternating-current end
Mouthful.I.e. described two output stages also include low-voltage alternating-current level, and the low-voltage alternating-current level includes bandwidth-limited circuit and low-voltage alternating-current level
Circuit.
As shown in figure 3, adding extra low-voltage alternating-current level in low-voltage direct level, low-pressure stage is collectively referred to as, it is necessary to original
Following improvement is done in circuit topology：In the secondary port Y of high-frequency isolation transformer2、N2The resonant inductance L for connecting extrar2With
Resonant capacitance Cr2Bandwidth-limited circuit is formed, in the bridge arm of low-pressure stage H-bridge circuit first and low pressure in parallel at the second bridge arm intermediate point
Exchange level circuit.Low-voltage alternating-current level circuit is mainly by low-voltage alternating-current filter inductance Lf_aclWith low-voltage alternating-current filter capacitor Co_aclString
Connection is formed, electric capacity Co_aclBoth ends are as low-voltage alternating-current output port.
On this basis, the present invention also proposes a kind of controlling party of the multiport electric power electric transformer topology based on MMC
Method, described control method are divided into two control sections of high-voltage alternating level and low-voltage direct level, comprised the following steps：
It is anti-as outer voltage using low-voltage direct level output voltage or submodule capacitor averaging voltage to the high-voltage alternating level
Feedback amount, double-closed-loop control is carried out as inner loop feedback amount using high-voltage alternating level electric current and obtains the basic modulated signal of three-phase bridge arm, and
Overlapped high-frequency square wave signal component in the basic modulated signal of three-phase bridge arm, to cause high-voltage alternating level to export high-voltage dc voltage
With low-voltage high-frequency DC voltage；The HVDC that high-voltage alternating level is exported respectively is converted into high pressure with low-voltage high-frequency AC energy
DC voltage and low-voltage dc voltage simultaneously export.
Also, when power transmits between high-voltage alternating level and low-voltage direct level, the low-voltage direct level is controlled to produce
Voltage waveform with institute's overlapped high-frequency square wave signal component with frequency same-phase.That is the generation of low-pressure direct stream level control H-bridge circuit and institute
Overlapped high-frequency square-wave signal passes through the reactance of modular multi-level converter bridge arm and capacitance with the voltage waveform of frequency same-phase
The resonant tank of composition, high frequency sinusoidal electric current is produced in high-frequency isolation transformer both sides, H bridge switch Guan Jun is worked in zero current
Off state.
As shown in figure 4, specifically control comprises the steps of this method：
Step (1)：High-voltage alternating level three-phase voltage is sampled with three-phase current, by being carried out to three-phase alternating voltage
PLL locks mutually obtain phase angle θ.It is u to carry out dq to three-phase alternating voltage to convert to obtain the d axles of three-phase voltage and q axis componentsd、uq,
It is i to carry out dq to three-phase alternating current to convert to obtain the d axles of three-phase current and q axis componentsd、iq。
By low-voltage direct level output level udclOr submodule capacitor voltage average value uc_averageFor the feedback of outer voltage
Amount, with given voltage udcl_refIt is compared, a reference value value i after Voltage loop PI regulations as d shaft current ringsd_ref；Will
The d shaft current ring a reference values i arrivedd_refWith three-phase alternating current d axis components idDifference after comparing, exported after PI is reconciled
Value id_PI；Q shaft current ring a reference values are set to 0, with three-phase alternating current q axis components iqDifference after comparing, after PI is reconciled
To output valve iq_PI。
To gained id_PIWith iq_PIValue carries out decoupling computing, shown in its decoupling method such as formula (2), (3), is modulated substantially
The d axles of signal and q axis components id_outWith iq_out.Wherein ω is the angular frequency of line voltage, is that 100 π rad/s, L hand over for high pressure
Flow the filter inductance of side.To id_outWith iq_outCarry out dq inverse transformations and obtain the basic modulated signal u of three-phase bridge arma0、ub0、uc0。
id_out=-id_PI+iq*ωL+ud (2)
iq_out=-iq_PI-id*ωL+uq (3)
Step (2)：The basic modulated signal u of three-phase bridge arm of gained in (1)a0、ub0、uc0Middle injection high-frequency square-wave signal
usquObtain the modulated signal u of modular multi-level convertera_ref、ub_ref、uc_ref, inject square wave frequency amplitude size determine
The voltage output of low-voltage direct port, HVDC port voltage and the submodule of high-voltage alternating level Modular multilevel converter
Number of blocks and type, and submodule capacitor voltage are relevant.
Step (3)：As shown in Figure 5 a, the capacitance voltage in high-voltage alternating level modular multi-level converter submodule is entered
Row sampling, respectively ua1、ua2……uaN, ub1、ub2……ubN, uc1、uc2……ucN, by submodule capacitor voltage respectively with to
Determine a reference value uaveIt is compared, exports the modulating wave u with modular multi-level converter after PI is adjusteda_ref、ub_ref、
uc_refIt is added, the final modulated signal u as the submodulea1_m、ua2_m……uaN_m, ub1_m、ub2_m……ubN_m, uc1_m、
uc2_m……ucN_m.The PWM drive signal of each submodule is obtained with reference to phase-shifting carrier wave control, with balanced submodule capacitor voltage
And adjust electric power electric transformer output.
Step (4)：It is as follows to low-pressure direct stream level control, its step：When power is transmitted to low-voltage direct side by high-voltage alternating side
When, low-voltage direct level H bridge switch devices are closed, and are carried out rectification using the antiparallel diodes of H bridges IGBT, are made transformation
Device secondary side square wave voltage waveform and (2) medium-high frequency square-wave signal usquWith frequency same-phase；When power is transmitted to height by low-voltage direct side
When pressure exchange is surveyed, low-voltage direct level H bridges are controlled using 50% dutycycle is fixed, equally make Circuit Fault on Secondary Transformer square wave electric
Pressure and (2) medium-high frequency square-wave signal usquWith frequency same-phase.
Following method can also be used in the control method of described electric power electric transformer, substitutes or adds in above-mentioned steps
In：
Method mesohigh exchange level half-bridge submodule and the full-bridge submodule hybrid type modular multilevel unsteady flow of the present invention
Extra loop current suppression step can be added in the control of device.Its step is as follows：
The electric current of six and half bridge arms of modular multilevel is sampled, respectively iau、ial、ibu、ibl、icu、icl, adopt
Sample high-voltage alternating level output port H1、H2The electric current at place is iac.By iau、ial1/2 is multiplied by after summation as the control of A phase bridge arms circulation
Input ia_cir, by ibu、ibl1/2 is multiplied by after summation as B phase bridge arm circulation control inputs ib_cir, by icu、iclIt is multiplied by after summation
1/2 as C phase bridge arm circulation control inputs ic_cir.By ia_cir、ib_cir、ic_cirSubtract 1/3 iacDq conversion is carried out afterwards, and dq becomes
The phase angle θ changedcirFor 2 times of high-voltage alternating side phase angle, dq conversion outputs are id_cir、iq_cir.Circulation d in loop current suppression ring
The a reference value of axis component and q axis components is 0, by d axles with q axis components compared with a reference value, the output by PI regulations is
id_cir_PI、iq_cir_PI.To the i of gainedd_cir_PI、iq_cir_PIAmount carries out decoupling computing, shown in its decoupling method such as formula (4), (5).
To the output i after decouplingd_cir_outWith iq_cir_outThe loop current suppression benefit of three-phase bridge arm modulated signal is obtained after carrying out dq inverse transformations
Repay signal, respectively ia_cir_add、ib_cir_add、ic_cir_add.In the modulated signal u of modular multi-level convertera_ref、
ub_ref、uc_refIn subtract loop current suppression thermal compensation signal i accordinglya_cir_add、ib_cir_add、ic_cir_addIt can obtain pressing down with circulation
The three-phase bridge arm modulated signal u of effect processeda_last、ub_last、uc_last, reach suppress three-phase bridge arm between circulation effect.
id_cir_out=id_cir_PI+iq_cir*2ωLarm (4)
iq_cir_out=iq_cir_PI-id_cir*2ωLarm (5)
If using the loop current suppression strategy, the content of above-mentioned steps (3) should be changed to：As shown in Figure 5 b, to high-voltage alternating
Capacitance voltage in level modular multi-level converter submodule is sampled, respectively ua1、ua2……uaN, ub1、ub2……
ubN, uc1、uc2……ucN, by submodule capacitor voltage respectively with given a reference value uaveIt is compared, exports after PI is adjusted
With the modulating wave u of modular multi-level convertera_last、ub_last、uc_lastIt is added, the final modulated signal as the submodule
ua1_m、ua2_m……uaN_m, ub1_m、ub2_m……ubN_m, uc1_m、uc2_m……ucN_m.Obtained with reference to phase-shifting carrier wave control per height
The PWM drive signal of module.
Also, for the improvement described above that extra low-voltage alternating-current level is added in low-voltage direct level, corresponding controlling party
Method is as shown in fig. 6, comprise the following steps that：
To the basic modulated signal u of three-phase bridge arm in step (2)a0、ub0、uc0Middle injection high frequency ac signal uac_high；
The control mode of low-pressure stage H-bridge circuit in step (4) is：As shown in fig. 6, to low-voltage direct output voltage
udclSampled, be multiplied by and fold into high frequency ac signal u after PI is adjusted after being made the difference with voltage DC given voltageac_high
With the unit AC signal of frequency same-phase.By result and transformer secondary side current isAdjusted after making the difference by PI, export low-pressure direct
Flow level modulated signal.Alternating voltage is given into uacl_refWith low-voltage alternating-current output voltage uaclMake the difference, electric current is used as after PI is adjusted
iaclIt is given, both differences adjust to obtain low-voltage alternating-current modulated signal through PI.Low-voltage alternating-current modulated signal is subtracted into low-pressure direct
Modulated signal is flowed, obtains low-pressure stage H bridge modulated signals uH。
When being controlled using this method, extra low pressure can be obtained in the case where not increasing extra switch pipe
Alternating voltage exports, and is advantageous to reduce switching tube quantity.
As shown in Fig. 7, Fig. 8, Fig. 9, emulated through matlab, high power density electric power electric transformer proposed by the invention
Low-voltage direct level output voltage stabilization can be kept and maintain the High Power Factor of high-voltage alternating level.Using the control method
When, high-voltage alternating level output H1H2Voltage waveform as shown in figure 9, subtracting waveform obtained by voltage on bridge arm reactor for square wave.
To sum up, The present invention reduces the electric energy of the HVDC in original electric power electric transformer to low-voltage direct to change,
Only have two-layer configuration from high-voltage alternating to low-voltage direct, save big metering device, be favorably improved transformer whole efficiency with can
By property, cost is reduced.And the electric power electric transformer also has HVDC port, can provide high-voltage dc voltage.This
Outside, low-voltage direct level H bridges can realize zero-current switching, reduce the current stress of low-voltage direct level switching device, improve
Efficiency of transmission.
Embodiments of the present invention are explained in detail above in conjunction with accompanying drawing, but the present invention is not limited to above-mentioned implementation
Mode, can also be on the premise of present inventive concept not be departed from those of ordinary skill in the art's possessed knowledge
Make a variety of changes.
Claims (10)
1. the multiport electric power electric transformer topology based on MMC, it is characterised in that including by input stage and two output stage groups
Into wherein the input stage is high-voltage alternating level, for the electricity exchanged by high pressure industrial frequency AC to HVDC with low-voltage high-frequency
Can conversion；Described two output stages are respectively HVDC level and low-voltage direct level, after high-voltage alternating level is converted respectively
HVDC and low-voltage high-frequency AC energy be converted into high-voltage dc voltage and low-voltage dc voltage and export；Wherein, it is described
High-voltage alternating level is made up of the modular multi-level converter of use three-phase bridge arm, and every phase bridge arm is by upper and lower two half-bridges
Arm forms and each half bridge arm is in series by N number of half-bridge submodule or full-bridge submodule and a bridge arm inductance；Every phase
The intermediate point of the upper and lower bridge arm of bridge arm distinguishes filtered inductance connection to mesohigh AC network, and by after three-phase bridge arm in parallel
Two ports are as high-voltage alternating level output port.
2. the multiport electric power electric transformer topology based on MMC according to claim 1, it is characterised in that：The high pressure
Direct current level includes trapper and HVDC storage capacitor, a port of the trapper and high-voltage alternating level one of them
Output port is connected, and is exported between the another port of another output port of high-voltage alternating level and trapper as HVDC level
Port, and the parallel high voltage DC energy storage electric capacity between HVDC level output port.
3. the multiport electric power electric transformer topology based on MMC according to claim 2, it is characterised in that：The trap
Device is composed in parallel by filter inductance and filter capacitor.
4. the multiport electric power electric transformer topology based on MMC according to claim 1, it is characterised in that：The low pressure
Direct current level includes capacitance, high-frequency isolation transformer, H-bridge circuit and low-voltage direct storage capacitor, wherein described two high pressures
A side ports of high-frequency isolation transformer, and high-frequency isolation transformer are connected to after exchange level output port series connection capacitance
Secondary port connection H-bridge circuit first and second bridge arm intermediate point；The H-bridge circuit output port parallel connection low-voltage direct storage
Can be low-voltage direct level output port after electric capacity.
5. the multiport electric power electric transformer topology based on MMC according to claim 4, it is characterised in that：It is described two
Output stage also includes low-voltage alternating-current level, and the low-voltage alternating-current level includes bandwidth-limited circuit and low-voltage alternating-current level circuit；The high frequency
The secondary port series connection bandwidth-limited circuit of isolating transformer, and at first and second bridge arm intermediate point of H-bridge circuit simultaneously
Join low-voltage alternating-current level circuit；The low-voltage alternating-current level circuit is connected structure by low-voltage alternating-current filter inductance with low-voltage alternating-current filter capacitor
Into, and using the both ends of low-voltage alternating-current filter capacitor as low-voltage alternating-current output port.
6. the multiport electric power electric transformer topology based on MMC according to claim 4, it is characterised in that：The H bridges electricity
The paralleled power switches composition of two pairs of series connection of route.
A kind of 7. controlling party based on the multiport electric power electric transformer topology based on MMC described in any of the above-described claim
Method, it is characterised in that comprise the following steps：
To the high-voltage alternating level using low-voltage direct level output voltage or submodule capacitor averaging voltage as outer voltage feedback quantity,
Double-closed-loop control is carried out as inner loop feedback amount using high-voltage alternating level electric current and obtains the basic modulated signal of three-phase bridge arm, and in the three-phase
Basic modulated signal overlapped high-frequency square wave signal component, to cause high-voltage alternating level output high-voltage dc voltage and low-voltage high-frequency electricity
Pressure；The HVDC that high-voltage alternating level is exported respectively is converted into high-voltage dc voltage and low-pressure direct with low-voltage high-frequency AC energy
Stream voltage simultaneously exports；
Also, when power transmits between high-voltage alternating level and low-voltage direct level, control the low-voltage direct level generation and institute
Voltage waveform of the overlapped high-frequency square wave signal component with frequency same-phase.
8. the control method of the multiport electric power electric transformer topology based on MMC, its feature exist according to claim 7
In：Double-closed-loop control is carried out in methods described, is specially：
PLL locks are carried out with three-phase alternating current according to the three-phase alternating voltage of the high-voltage alternating level of sampling and mutually obtain phase angle, and
Respectively three-phase alternating voltage and three-phase alternating current are converted to obtain each comfortable d axles and q axis components；
It is outer voltage feedback quantity by low-voltage direct level output voltage or submodule capacitor averaging voltage, compared with given voltage,
A reference value after Voltage loop PI regulations as d shaft current rings；The a reference value and three-phase alternating current d of d shaft current rings will be obtained
Axis component relatively after difference, d axle output valves are obtained after PI is reconciled；By the q shaft current ring a reference values and three-phase alternating current of setting
Electric current q axis components relatively after difference, q axle output valves are obtained after PI is reconciled；Resulting d axles output valve and q axles are exported
Value decoupling computing obtains the d axles and q axis components of basic modulated signal, and the basic modulated signal of three-phase bridge arm is obtained through dq inverse transformations；
High-frequency square-wave signal is injected in the basic modulated signal of three-phase bridge arm and obtains the submodule tune of modular multi-level converter
Signal processed;
Meanwhile according to the capacitance voltage of modular multi-level converter submodule in the high-voltage alternating level of sampling respectively with given base
Accurate value is compared, and by the output after comparison after PI is adjusted and the obtained modulated signal of modular multi-level converter
It is added, as the final modulated signal of the submodule, with balanced submodule capacitor voltage and adjusts electric power electric transformer output.
9. the control method of the multiport electric power electric transformer topology based on MMC, its feature exist according to claim 7
In：Also include carrying out loop current suppression to high-voltage alternating level.
10. the control method of the multiport electric power electric transformer topology based on MMC, its feature exist according to claim 9
In：It is described that loop current suppression is carried out to high-voltage alternating level, be specially：
The electric current of three-phase bridge arm and output port to modular multi-level converter is sampled and handled, and determines the ring of bridge arm
Flow control inputs；Computing is carried out according to the circulation control input of identified bridge arm and conversion obtains loop current suppression thermal compensation signal；
The basic modulated signal of three-phase bridge arm that the double-closed-loop control of modular multi-level converter obtains is subtracted into loop current suppression to mend
Signal is repaid, the basic modulated signal of three-phase bridge arm with loop current suppression effect can be obtained.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108832825A (en) * | 2018-07-06 | 2018-11-16 | 华北电力大学 | A kind of multiport electric power electric transformer topology of high power density |
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| CN110022077A (en) * | 2019-04-10 | 2019-07-16 | 南京师范大学 | The compound modular multilevel solid-state transformer topological structure of power towards alternating current-direct current mixing power distribution network |
| CN110492721A (en) * | 2019-08-23 | 2019-11-22 | 西安西电电力系统有限公司 | A kind of multiport electric power electric transformer |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204835971U (en) * | 2015-06-04 | 2015-12-02 | 广西电网有限责任公司电力科学研究院 | Multiport power electronic transformer |
| CN105610336A (en) * | 2016-01-27 | 2016-05-25 | 东南大学 | Dual-capacitor module based MMC type multi-port power electronic transformer |
| CN106452136A (en) * | 2016-06-20 | 2017-02-22 | 清华大学 | Multi-port power electronic converter for energy internet |
| CN106533189A (en) * | 2016-11-25 | 2017-03-22 | 中国科学院电工研究所 | Power electronic transformer and control method thereof |
-
2017
- 2017-09-29 CN CN201710904472.3A patent/CN107623456A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204835971U (en) * | 2015-06-04 | 2015-12-02 | 广西电网有限责任公司电力科学研究院 | Multiport power electronic transformer |
| CN105610336A (en) * | 2016-01-27 | 2016-05-25 | 东南大学 | Dual-capacitor module based MMC type multi-port power electronic transformer |
| CN106452136A (en) * | 2016-06-20 | 2017-02-22 | 清华大学 | Multi-port power electronic converter for energy internet |
| CN106533189A (en) * | 2016-11-25 | 2017-03-22 | 中国科学院电工研究所 | Power electronic transformer and control method thereof |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108832825A (en) * | 2018-07-06 | 2018-11-16 | 华北电力大学 | A kind of multiport electric power electric transformer topology of high power density |
| CN108832825B (en) * | 2018-07-06 | 2020-01-24 | 华北电力大学 | High power density's multiport power electronic transformer topology |
| CN109378788A (en) * | 2018-11-08 | 2019-02-22 | 国网湖南省电力有限公司 | Novel SVG type DC de-icing device |
| CN111404409A (en) * | 2019-01-03 | 2020-07-10 | 南京南瑞继保工程技术有限公司 | Multi-port power electronic transformer topology based on MMC and control method thereof |
| CN110022077A (en) * | 2019-04-10 | 2019-07-16 | 南京师范大学 | The compound modular multilevel solid-state transformer topological structure of power towards alternating current-direct current mixing power distribution network |
| CN110492721A (en) * | 2019-08-23 | 2019-11-22 | 西安西电电力系统有限公司 | A kind of multiport electric power electric transformer |
| CN110492764A (en) * | 2019-08-27 | 2019-11-22 | 中国科学院电工研究所 | The single-phase AC and DC power electronic transformer of capacitor isolated |
| CN113258801A (en) * | 2020-02-12 | 2021-08-13 | 新疆金风科技股份有限公司 | Direct current gets electric installation, system and wind generating set's start control system |
| CN111711219A (en) * | 2020-06-24 | 2020-09-25 | 全球能源互联网研究院有限公司 | Alternating current-direct current power supply configuration structure and flexible transformer substation |
| CN111711219B (en) * | 2020-06-24 | 2022-06-28 | 全球能源互联网研究院有限公司 | Alternating current-direct current power supply configuration structure and flexible transformer substation |
| CN115189588A (en) * | 2022-06-14 | 2022-10-14 | 国网江苏省电力有限公司常州供电分公司 | Control method and device for electromagnetic induction type steam boiler power supply circuit |
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