CN107134930B - Power electronics distribution transformer and its control method based on MMC - Google Patents
Power electronics distribution transformer and its control method based on MMC Download PDFInfo
- Publication number
- CN107134930B CN107134930B CN201710525852.6A CN201710525852A CN107134930B CN 107134930 B CN107134930 B CN 107134930B CN 201710525852 A CN201710525852 A CN 201710525852A CN 107134930 B CN107134930 B CN 107134930B
- Authority
- CN
- China
- Prior art keywords
- voltage
- phase
- mmc
- inverter
- bridge arm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- 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
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
- H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
- H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
- H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M5/4585—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only having a rectifier with controlled elements
-
- 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
-
- 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
- H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses the power electronics distribution transformer based on MMC and its control method, its transformer includes MMC rectifier module, DC DC isolators and the DC AC inverters being sequentially connected, the input of MMC rectifier module is connected with High-voltage AC Network, and the output end of DC AC inverters is connected with low-voltage alternating-current power network;Its method includes step:First, the rectification of High Level AC Voltage;Then, the decompression of the output high-voltage dc voltage of MMC rectifier module;Finally, the inversion of low-voltage dc voltage;The quantity that IGBT of the present invention is used is few, cost is low, reliability is high, it is convenient to extend capacity, High-voltage AC Network occurs three-phase imbalance or during voltage dip failure, and power electronics distribution transformer long-term safety and can reliably be run, and power supply quality is high, small, efficiency high is fluctuated in the impact that low-voltage alternating-current power network breaks down to High-voltage AC Network.
Description
Technical field
The invention belongs to electrical equipment technical field, and in particular to a kind of power electronics distribution transformer based on MMC and
Its control method.
Background technology
Due to the energy-saving adjustment for promoting energy resource structure so that the regenerative resource such as wind energy, solar energy is in electric power energy
Role is increasingly heavier in source, and therefore, the requirement of intellectuality, flexibility for following power network, interactive etc. is also to get over
Come higher.China's power network proposes the target of the development of intelligent grid, and whether the realization of this target will primarily depend upon electricity
The performance and intelligent level of the smart machine used in net.In numerous electrical equipments that current power network uses, distribution transformer
Device is one of most widely used, electrical equipment that status is mostly important in power distribution network, and its major function is realized 6kV-
35kV voltages are converted to 380V voltages supply user and used.And the l/3 of China's transformer year production total capacity is distribution transformer
Device.So the performance indications and intelligent level of distribution transformer will have a strong impact on that following China's intelligent grid is intelligent
Horizontal and power supply quality.
Block combiner multi-level converter (Modular Multilevel Convert), abbreviation MMC, is a kind of new
More level topology, the advantages of except with traditional multi-level rectifier, MMC uses Modular Structure Design, is easy to System Expansion
And redundancy of effort, there is fault traversing and recovery capability, system reliability height.However, the control of the distribution transformer based on MMC
Element is more, and system control is complicated, expensive, limits its application to a certain extent.In addition, in power system, three-phase
Imbalance can be divided into uneven two classes of fault uneven and non-faulting.For non-faulting three-phase imbalance, though allow
Long-term existence under operating mode, but as long as transmission line of electricity three-phase imbalance be more than to a certain degree, may result in circuit transmission capacity deficiency,
The problems such as line loss increase and false protection, harm is produced to power system;Long-term existence can then have a strong impact on power network
Safety, economy, stable operation.
The content of the invention
It is based in view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is that providing one kind
MMC power electronics distribution transformer and its control method, the quantity that its IGBT is used is few, and cost is low, and reliability is high, and extension is held
Amount is convenient, and when three-phase imbalance or voltage dip failure occur for High-voltage AC Network (4), power electronics distribution transformer can
Safely and reliably run, power supply quality is high, the shock wave that low-voltage alternating-current power network (5) breaks down to High-voltage AC Network (4)
Move small, efficiency high.
In order to solve the above technical problems, the technical solution adopted by the present invention is:Power electronics distribution transformer based on MMC
Device, it is characterised in that:It is whole including MMC rectifier module, DC-DC isolators and the DC-AC inverter being sequentially connected, the MMC
The input of stream device module is connected with High-voltage AC Network, and the output end of the DC-AC inverter is connected with low-voltage alternating-current power network;
The DC-DC isolators include multiple DC-DC isolation subelements, the voltage input ends of multiple DC-DC isolation subelements according to
Secondary to be connected in series between the DC output end of MMC rectifier module, the output end of multiple DC-DC isolation subelements is in parallel
It is connected between the direct-flow input end of DC-AC inverter;Sub- inverter that DC-DC isolation subelement includes being sequentially connected,
Sub- intermediate-frequency transformer and sub- rectifier, the sub- inverter include by upper bridge arm electric capacity, upper bridge arm IGBT, lower bridge arm electric capacity and under
The single-phase full bridge inverter circuit of bridge arm IGBT compositions, the input parallel connection of the single-phase full bridge inverter circuit are connected to derided capacitors,
The sub- rectifier is that diode does not control bridge rectifier.
The above-mentioned power electronics distribution transformer based on MMC, it is characterised in that:The DC-AC inverter is that three-phase is complete
Bridge inverter, filter inductance is connected between the three-phase full-bridge inverter and the low-voltage alternating-current power network.
The above-mentioned power electronics distribution transformer based on MMC, it is characterised in that:The diode does not control bridge rectifier
Including diode-bridge circuit and the filter capacitor in parallel with the output end of the diode-bridge circuit.
The above-mentioned power electronics distribution transformer based on MMC, it is characterised in that:The MMC rectifier module is three-phase
Six bridge arm circuits, per mutually including upper bridge arm and lower bridge arm, the upper bridge arm and the lower bridge in the bridge arm circuit of three-phase six
Arm includes a current-limiting reactor and the M MMC submodules being connected in series, one end of the M submodules being connected in series
Connect with one end of current-limiting reactor, the other end of the current-limiting reactor connects with the High-voltage AC Network, the series connection
The other end of the MMC submodules of connection connects with the sub- inverter, and the MMC submodules include half-bridge circuit and submodule electricity
Hold, the submodule electric capacity is in parallel with the half-bridge circuit signal output part.
The above-mentioned power electronics distribution transformer based on MMC, it is characterised in that:The half-bridge circuit is by half-bridge on MMC
Half-bridge IGBT is formed under IGBT and MMC.
Can in the case where High-voltage AC Network exports three-phase imbalance or voltage dip failure present invention also offers one kind
Operation steady in a long-term, power attenuation is small, the power electronics distribution transformer control method of efficiency high, it is characterised in that the controlling party
Method comprises the following steps:
Step 1: the rectification of High Level AC Voltage, process are as follows:
The A phase current instantaneous values i of step 101, in real time measurement High-voltage AC NetworkA, A phase voltage instantaneous values uSA, B phase currents
Instantaneous value iB, B phase voltage instantaneous values uSB, C phase current instantaneous values iCWith C phase voltage instantaneous values uSC;
Step 102, according to formulaCalculate High-voltage AC Network
The positive-sequence component i of A phase transient currentsA +, B phase transient currents positive-sequence component iB +With the positive-sequence component i of C phase transient currentsC +;
According to formulaCalculate the A phase currents of High-voltage AC Network
Negative sequence component iA -, B phase currents negative sequence component iB -With the negative sequence component i of C phase currentsC -;
According to formulaCalculate the A of High-voltage AC Network
The positive-sequence component u of phase instantaneous voltageSA +, B phase instantaneous voltages positive-sequence component uSB +With the positive-sequence component u of C phase instantaneous voltagesSC +;Its
In, ω is the angular frequency of High-voltage AC Network voltage;
According to formulaCalculate the A of High-voltage AC Network
The negative sequence component u of phase instantaneous voltageSA -, B phase instantaneous voltages negative sequence component uSB -With the negative sequence component u of C phase instantaneous voltagesSC -;
Step 103, to iA +、iB +And iC +Q axle forward-order currents i can be obtained by carrying out dq conversionq +With d axle forward-order currents id +, to iA -、
iB -And iC -Q axle negative-sequence currents i can be obtained by carrying out dq conversionq -With d axle negative-sequence currents id -;
To uSA +、uSB +And uSC +Q axle positive sequence High-voltage AC Network instantaneous voltages u can be obtained by carrying out dq conversionSq +It is high with d axles positive sequence
Press AC network instantaneous voltage uSd +, to uSA -、uSB -And uSC -Q axle negative phase-sequence High-voltage AC Network instantaneous voltages can be obtained by carrying out dq conversion
uSq -With d axle negative phase-sequence High-voltage AC Network instantaneous voltages uSd -;
Step 104, using the first pi regulator to MMC rectifier module output high-voltage dc voltage be adjusted, obtain d
Axle forward-order current reference valueWherein,uDC *For MMC rectifier mould
Block exports high-voltage dc voltage setting value, uDCHigh-voltage dc voltage real-time measurement values, K are exported for MMC rectifier modulep 1For institute
State the proportionality coefficient of the first pi regulator, Ki 1For the integral coefficient of first pi regulator;
The MMC rectifier module is the bridge arm circuit of three-phase six, often mutually includes upper bridge in the bridge arm circuit of three-phase six
Arm and lower bridge arm, the upper bridge arm and the lower bridge arm include a current-limiting reactor and the M MMC submodules being connected in series
Block, the M one end of submodule being connected in series connect with one end of current-limiting reactor, the other end of the current-limiting reactor
Connect with the High-voltage AC Network, the other end of the submodule being connected in series connects with the sub- inverter, the son
Module includes half-bridge circuit and submodule electric capacity, and the submodule electric capacity is in parallel with the half-bridge circuit signal output part;
Step 105, using the second pi regulator to d axle forward-order currents reference value, q axle forward-order currents reference value, d axle negative phase-sequences
Current reference value and q axle negative-sequence current reference values are adjusted, and according to formulaCalculate the input of MMC rectifier module d axles positive sequence
Voltage uMd +With MMC rectifier module q axle positive sequence input voltages uMq +, according to formulaCalculate the input of d axle negative phase-sequence MMC rectifiers module
Voltage uMd -With q axle negative phase-sequence MMC rectifier module input voltages uMq -, wherein,Reference value for q axle forward-order currents and Reference value for d axle negative-sequence currents and Reference value for q axle negative-sequence currents andKp 2For
The proportionality coefficient of second pi regulator, Ki 2For the integral coefficient of the second pi regulator, L is the inductance value of the current-limiting reactor;
Step 106, to uMd +And uMq +Carry out dq inverse transformations and obtain MMC rectifier modules A phase positive sequence input voltage uMA +, B phases
Positive sequence input voltage uMB +With C phase positive sequence input voltages uMC +;To uMd -And uMq -Carry out dq inverse transformations and obtain MMC rectifier modules A
Phase negative phase-sequence input voltage uMA -, B phases negative sequence voltage input uMB -With C phase negative phase-sequence input voltages uMC -;According to formulaCalculate MMC rectifier modules A phase input voltage uMA, MMC rectifier module B phases input electricity
Press uMBWith MMC rectifier module C phase input voltages uMC;
Step 107, the quantity for obtaining each bridge arm input MMC submodules of the bridge arm circuit of three-phase six:To the bridge arm circuit of three-phase six
In be determined respectively per the MMC submodule input quantities of phase, and MMC submodules in the bridge arm circuit of three-phase six in any one phase
The determination method all same of input quantity;
When being determined to the MMC submodule input quantities in the bridge arm circuit of three-phase six per phase, process is as follows:
Step I, according to formulaCalculate the input number under every phase on bridge arm in the bridge arm circuit of three-phase six
D1, wherein, ceil () is rounds up function, uMFor any one phase input voltage in MMC rectifier module three-phase voltage, ummc
For submodule electric capacity rated voltage;
Step II, according to formula D2=M-D1, calculate the input number D in every phase on bridge arm in the bridge arm circuit of three-phase six2;
The output high-voltage dc voltage real-time measurement values u of step 108, MMC rectifier moduleDCVoltage stabilizing:Pass through MMC submodules
Block capacitance voltage ranking method determines that the submodule that each bridge arm is put into completes the output high-voltage dc voltage to MMC rectifier module
uDCVoltage stabilizing;
Step 109, circulation step 101 to step 108, the output high-voltage dc voltage to MMC rectifier module are surveyed in real time
Value uDCExported;
Step 2: the decompression of the output high-voltage dc voltage of MMC rectifier module, process are as follows:
Step 201, partial pressure:Using output high-voltage dc voltage of multiple DC-DC isolation subelements to MMC rectifier module
Partial pressure is carried out, utilizes the output high pressure of the derided capacitors in sub- inverter and the bridge arm electric capacity to MMC rectifier module
DC voltage carries out two-stage partial pressure, obtains partial pressure DC voltage uFC;
Step 202, inversion:50% couple of partial pressure DC voltage u is respectively turned on using two IGBT in sub- inverterFCCarry out
Inversion, obtain square wave alternating voltage;
Step 203, decompression:Sub- intermediate-frequency transformer other side alternating current wave pressure is depressured to obtain low pressure square wave alternating voltage;
Step 204, rectification and filtering:Sub- rectifier carries out rectification to the low pressure square wave alternating voltage and obtains low-voltage direct
Voltage, and denoising is filtered to low-voltage dc voltage;
Step 3: the inversion of low-voltage dc voltage, process are as follows:
Step 301, using DC-AC inverter to low-voltage dc voltage carry out inversion, while measure DC-AC inverter output
Side A phase instantaneous voltages uva, B phase instantaneous voltages uvbWith C phase instantaneous voltages uvc;
The DC-AC inverter is three-phase full-bridge inverter, the three-phase full-bridge inverter and the low-voltage alternating-current power network
Between be connected with filter inductance;
Step 302, to A phase instantaneous voltages uva, B phase instantaneous voltages uvbWith C phase instantaneous voltages uvcDq is carried out to convert to obtain
DC-AC inverter d axle output voltages uvdWith DC-AC inverter q axle output voltages uvq;
Step 303, using the 3rd pi regulator to DC-AC inverter d axle output voltages uvdIt is defeated with DC-AC inverter q axles
Go out voltage uvqIt is adjusted, obtains DC-AC inverter d axle output voltage adjusted values uvd' and DC-AC inverter q axle output voltages
Adjusted value uvq', wherein,uvd *For DC-AC inverter d axle output voltages
Set reference value, uvq* reference value, K are set for DC-AC inverter q axles output voltagep 3For the proportionality coefficient of the 3rd pi regulator,
Ki 3For the integral coefficient of the 3rd pi regulator;
Step 304, to uvd' and uvq' dq inverse transformations are carried out, obtain three phase sine modulating wave;
Step 305, Frequency conversion control is carried out to the three phase sine modulating wave, obtained in three-phase full-bridge inverting circuit
Trigger pulse, IGBT in three-phase full-bridge inverter is controlled according to the trigger pulse, exports symmetrical three phase sine alternating voltage;
Step 306, circulation step 301 to step 305, realize the inversion of low-voltage dc voltage.
The present invention has advantages below compared with prior art:
1st, the power electronics distribution transformer that the present invention uses is by setting DC-DC isolators to reduce the number that IGBT is used
Amount, the structure of power electronics distribution transformer is simplified, reduce the cost of power electronics distribution transformer, improve electric power electricity
The reliability of sub- distribution transformer.
2nd, the equalizing capacitance and bridge arm electric capacity that the power electronics distribution transformer that the present invention uses is set are to MMC rectifier mould
The high-voltage dc voltage of block output carries out step pressure reducing, simple in construction, reasonable in design, and extension capacity is convenient.
3rd, the control method that uses of the present invention by by the reference value of q axle forward-order currents forWith the ginseng of q axle negative-sequence currents
Examine valueIt is disposed as 0 so that power electronics distribution transformer is in the case where rated capacity is constant, it is possible to achieve specific work
Rate factor is controlled, and the active power of power electronics distribution transformer transmission is improved, and reduces power electronics distribution transformer
Loss.
4th, the control method that uses of the present invention carries out the control based on phase component method to MMC rectifier module, by by d axles
The reference value of negative-sequence currentWith the reference value of q axle negative-sequence currentsIt is disposed as 0, it is suppressed that High-voltage AC Network is input to
The negative sequence component of MMC rectifier module input mouth so that MMC rectifier module can stablize output high-voltage dc voltage, enter
And make it that, when three-phase imbalance or voltage dip failure occur for High-voltage AC Network, power electronics distribution transformer can be grown
Phase is safely and reliably run, and improves power supply quality.
5th, the control method that the present invention uses is by setting DC-DC isolators and having carried out electricity to MMC rectifier module
Flow closed-loop control so that the isolation between High-voltage AC Network and low-voltage alternating-current power network is high, and low-voltage alternating-current power network breaks down
Impact fluctuation to High-voltage AC Network is small.
6th, the control method that the present invention uses improves voltage by carrying out Frequency conversion control to DC-AC inverter
Utilization rate, and then the efficiency high of power electronics distribution transformer.
In summary, the quantity that IGBT of the present invention is used is few, and cost is low, and reliability is high, and extension capacity is convenient, high-voltage alternating
Power network occurs three-phase imbalance or during voltage dip failure, and power electronics distribution transformer long-term safety and can be transported reliably
OK, power supply quality is high, and small, efficiency high is fluctuated in the impact that low-voltage alternating-current power network breaks down to High-voltage AC Network.
Below by drawings and examples, technical scheme is described in further detail.
Brief description of the drawings
Fig. 1 is the circuit theory diagrams of power electronics distribution transformer of the present invention.
Fig. 2 is the circuit theory diagrams of DC-DC transformers in power electronics distribution transformer of the present invention.
Fig. 3 is the circuit theory diagrams of half-bridge circuit in power electronics distribution transformer of the present invention.
Fig. 4 is the FB(flow block) of control method of the present invention.
Description of reference numerals:
1-MMC rectifier module;2-DC-DC isolators;3-DC-AC inverter;
1-1-half-bridge circuit;1-2-MMC submodule electric capacity;2-1-sub- inverter;
2-2-sub- intermediate-frequency transformer;2-3-sub- rectifier, 4-High-voltage AC Network;
5-low-voltage alternating-current power network.
Embodiment
As depicted in figs. 1 and 2, including the MMC rectifier module 1, DC-DC isolators 2 and the DC-AC inverter that are sequentially connected
3, the input of the MMC rectifier module 1 is connected with High-voltage AC Network 4, the output end of the DC-AC inverter 3 with it is low
Pressure AC network 5 connects;The DC-DC isolators 2 include multiple DC-DC isolation subelements, multiple DC-DC separaants lists
The voltage input end of member is sequentially connected in series between the DC output end of MMC rectifier module 1, multiple DC-DC isolation
The output end of subelement is connected in parallel between the direct-flow input end of DC-AC inverter 3;The DC-DC isolation subelement includes
Sub- inverter 2-1, sub- intermediate-frequency transformer 2-2 and the sub- rectifier 2-3 being sequentially connected, the sub- inverter 2-1 are included by upper bridge
The single-phase full bridge inverter circuit that arm electric capacity, upper bridge arm IGBT, lower bridge arm electric capacity and lower bridge arm IGBT are formed, the single-phase full bridge are inverse
The input parallel connection for becoming circuit is connected to derided capacitors, and the sub- rectifier 2-3 is that diode does not control bridge rectifier.
It should be noted that the setting of the MMC rectifier module 1 is in order to by the ac high-voltage of High-voltage AC Network 4
High direct voltage is converted to, the MMC rectifier module 1 has the advantages of high output voltage quality, efficiency high;The DC-DC every
Setting from device 2 is in order to which the high direct voltage is converted into DC low-voltage, and DC-DC isolators 2 effectively reduce IGBT's
Usage quantity, the cost of power electronics distribution transformer is reduced, and because the IGBT quantity for needing to control is few, and then reduce
The difficulty of the control of DC-DC isolators 2, improve the reliability of DC-DC isolators 2;Multiple DC-DC isolation subelements use
The frame mode of series connection input Parallel opertation effectively simplifies the control difficulty of DC-DC isolators 2, improves power electronics distribution
Transformer reliability;The setting of DC-AC inverter 3 is the DC-AC inverter in order to be AC low-tension by the DC low-voltage inversion
3 controls are simple, efficiency high;The setting of derided capacitors and the bridge arm electric capacity in order to carry out partial pressure step by step to the high direct voltage,
It is easy to realize, simple in construction;The sub- inverter 2-1, sub- intermediate-frequency transformer 2-2 and sub- rectifier 2-3 are corresponded;It is described
Sub- inverter 2-1 setting is the sub- inverter in order to which the high direct voltage inversion for exporting MMC rectifier module 1 is square-wave voltage
The full-bridge circuit structure that 2-1 is made up of two groups of bridge arm electric capacity and IGBT, with the full-bridge circuit structure phase being made up of four IGBT
Than, the IGBT quantity that sub- inverter 2-1 is used is few, and cost is low, wherein, C1、C2……CNFor the equal derided capacitors of capacitance, C21、
C31、C22、C32……C2N、C3NFor the equal bridge arm electric capacity of capacitance;The sub- rectifier 2-3 is that diode does not control bridge rectifier
Device, simple in construction, cost is low, reduces the difficulty of power electronics distribution transformer control.In the present embodiment, the high-voltage alternating
The output voltage of power network 4 is 10KV, and frequency 50Hz, the output voltage of low-voltage alternating-current power network 5 is 380V, frequency 50Hz, DC-DC
The quantity for isolating subelement is 10, and sub- intermediate-frequency transformer 2-2 frequency is 5KHz, sub- intermediate-frequency transformer 2-2 primary side winding
No-load voltage ratio with vice-side winding is 1500:1000, sub- intermediate-frequency transformer 2-2 have the advantages of small volume, metal material usage amount are few.
The DC-AC inverter 3 is three-phase full-bridge inverter, the three-phase full-bridge inverter and the low-voltage alternating-current power network
Filter inductance is connected between 5.
As shown in figure 1, in the present embodiment, three-phase full-bridge inverter is by six IGBT groups of S3, S4, S5, S6, S7 and S8
Into being connected with filter inductance L7, L8 and L9, the filtering between the three-phase full-bridge inverter and the low-voltage alternating-current power network 5
The setting of inductance improves the quality of the output voltage of DC-AC inverter 3.
The diode do not control bridge rectifier include diode-bridge circuit and with the diode-bridge circuit simultaneously
The filter capacitor of connection, the both ends of the filter capacitor isolate the low-pressure side of subelement for the DC-DC.
As shown in Fig. 2 in the present embodiment, sub- rectifier 2-3 includes two-by-two being connected by four diodes the bridge-type electricity formed
Road, the both ends of the bridge circuit are connected in parallel with the filter capacitor, and the diode is not controlled bridge rectifier and will can handed over
Stream voltage commutation is DC voltage, without individually being controlled, it is easy to accomplish, reliability is high.
The MMC rectifier module 1 is the bridge arm circuit of three-phase six, often mutually includes upper bridge in the bridge arm circuit of three-phase six
Arm and lower bridge arm, the upper bridge arm and the lower bridge arm include a current-limiting reactor and the M MMC submodules being connected in series
Block, the M one end of submodule being connected in series connect with one end of current-limiting reactor, the other end of the current-limiting reactor
Connecting with the High-voltage AC Network, the other end of the MMC submodules being connected in series connects with the sub- inverter 2-1,
The MMC submodules include half-bridge circuit 1-1 and submodule electric capacity 1-2, the submodule electric capacity 1-2 and the half-bridge circuit 1-
1 signal output part is in parallel.
As shown in figure 1, A phases bridge arm includes bridge arm under bridge arm in A phases and A phases, bridge arm is by MMC submodules SM in A phasesp1a、
MMC submodules SMp2a... MMC submodules SMpMaIt is connected in series, bridge arm is by MMC submodules SM under A phasesn1a, MMC submodules
SMn2a... MMC submodules SMnMaIt is connected in series;B phases bridge arm includes in B phases bridge arm under bridge arm and B phases, in B phases bridge arm by
MMC submodules SMp1b, MMC submodules SMp2b... MMC submodules SMpMbIt is connected in series, bridge arm is by MMC submodules under B phases
SMn1b, MMC submodules SMn2b... MMC submodules SMnMbIt is connected in series;C phases bridge arm includes bridge under bridge arm in C phases and C phases
Arm, bridge arm is by MMC submodules SM in C phasesp1c, MMC submodules SMp2c... MMC submodules SMpMcIt is connected in series, under C phases
Bridge arm is by MMC submodules SMn1c, MMC submodules SMn2c... MMC submodules SMnMcIt is connected in series;The MMC submodules
SMp1a, MMC submodules SMp1bWith MMC submodules SMp1cConnection end and the MMC submodules SMnMa, MMC submodules SMnMbWith
MMC submodules SMnMcConnection end between voltage be MMC rectifier module 1 output high-voltage dc voltage;MMC submodules are adopted
With the mode being connected in series so that it is convenient, fast to expand capacity;Connect in the A phases between bridge arm and the High-voltage AC Network 4
It is connected in current-limiting reactor L1, B phase and current-limiting reactor L2 is connected between bridge arm and the High-voltage AC Network 4, in the C phase
Current-limiting reactor L3 is connected between bridge arm and the High-voltage AC Network 4;Bridge arm and the High-voltage AC Network under the A phases
Current-limiting reactor L4 is connected between 4, current-limiting reactor is connected between bridge arm and the High-voltage AC Network 4 under the B phases
L5, current-limiting reactor L6 is connected between bridge arm and the High-voltage AC Network 4 under the C phases;The current-limiting reactor is set
It is impact in order to reduce the DC output end of MMC rectifier module 1 in the case of failure to MMC submodules to put, and improves electric power
The reliability of electrical power distribution transformer;As shown in figure 3, the MMC submodules include half-bridge circuit 1-1 and MMC submodule electric capacity
1-2, the half-bridge circuit 1-1 are in parallel with the MMC submodules electric capacity 1-2.In the present embodiment, 1 each bridge arm of MMC rectifier module
The MMC submodules number being connected in series is 12, and the capacitance of multiple MMC submodules electric capacity is 0.018F, multiple described
The rated voltage of MMC submodule electric capacity is 2500V, and the capacitance of multiple derided capacitors is 0.012F, multiple bridges
The capacitance of arm electric capacity is 0.006F, and the inductance value of multiple current-limiting reactors is 0.005mH.
The half-bridge circuit 1-1 is made up of two groups of IGBT and fly-wheel diode, and IGBT described in two groups and fly-wheel diode connect
It is connected into half-H-bridge structure.
As shown in figure 3, half-bridge circuit 1-1 is made up of two groups of IGBT and fly-wheel diode, IGBT described in two groups and afterflow two
Pole pipe connects into half-H-bridge structure.
As shown in figure 4, the control method of power electronics distribution transformer of the present invention, it is characterised in that the controlling party
Method comprises the following steps:
Step 101, in real time measurement High-voltage AC Network 4A phase current instantaneous values iA, A phase voltage instantaneous values uSA, B phase currents
Instantaneous value iB, B phase voltage instantaneous values uSB, C phase current instantaneous values iCWith C phase voltage instantaneous values uSC;
Step 102, according to formulaCalculate High-voltage AC Network 4
A phase transient currents positive-sequence component iA +, B phase transient currents positive-sequence component iB +With the positive-sequence component i of C phase transient currentsC +;
According to formulaCalculate the A phase currents of High-voltage AC Network 4
Negative sequence component iA -, B phase currents negative sequence component iB -With the negative sequence component i of C phase currentsC -;
According to formulaCalculate the A of High-voltage AC Network 4
The positive-sequence component u of phase instantaneous voltageSA +, B phase instantaneous voltages positive-sequence component uSB +With the positive-sequence component u of C phase instantaneous voltagesSC +;Its
In, ω is the angular frequency of the voltage of High-voltage AC Network 4;
According to formulaCalculate the A of High-voltage AC Network 4
The negative sequence component u of phase instantaneous voltageSA -, B phase instantaneous voltages negative sequence component uSB -With the negative sequence component u of C phase instantaneous voltagesSC -;
Step 103, to iA +、iB +And iC +Q axle forward-order currents i can be obtained by carrying out dq conversionq +With d axle forward-order currents id +, to iA -、
iB -And iC -Q axle negative-sequence currents i can be obtained by carrying out dq conversionq -With d axle negative-sequence currents id -;
To uSA +、uSB +And uSC +Q axle positive sequence High-voltage AC Network instantaneous voltages u can be obtained by carrying out dq conversionSq +It is high with d axles positive sequence
Press AC network instantaneous voltage uSd +, to uSA -、uSB -And uSC -Q axle negative phase-sequence High-voltage AC Network instantaneous voltages can be obtained by carrying out dq conversion
uSq -With d axle negative phase-sequence High-voltage AC Network instantaneous voltages uSd -;
It should be noted that the instantaneous value of the three-phase current exported to High-voltage AC Network 4 carries out symmetrical separation and Extraction electric current
Positive and negative order components method, without individually calculating the amplitude and phase of three-phase current, method is simple and convenient;The uSA +、uSB +
And uSC +According to formulaDq is carried out to convert to obtain uSq +And uSd +, the uSA -、uSB -And uSC -According to formulaCarry out dq conversion
Obtain uSq -And uSd -;In the present embodiment, the angular frequency of High-voltage AC Network 4 is 314;
Step 104, using the first pi regulator to MMC rectifier module output high-voltage dc voltage be adjusted, obtain d
Axle forward-order current reference valueWherein,uDC *For MMC rectifier mould
Block exports high-voltage dc voltage setting value, uDCHigh-voltage dc voltage real-time measurement values, K are exported for MMC rectifier modulep 1For institute
State the proportionality coefficient of the first pi regulator, Ki 1For the integral coefficient of first pi regulator;
The MMC rectifier module 1 is the bridge arm circuit of three-phase six, often mutually includes upper bridge in the bridge arm circuit of three-phase six
Arm and lower bridge arm, the upper bridge arm and the lower bridge arm include a current-limiting reactor and the M MMC submodules being connected in series
Block, the M one end of submodule being connected in series connect with one end of current-limiting reactor, the other end of the current-limiting reactor
Connect with the High-voltage AC Network, the other end of the submodule being connected in series connects with the sub- inverter 2-1, described
Submodule includes half-bridge circuit 1-1 and submodule electric capacity 1-2, the submodule electric capacity 1-2 and the half-bridge circuit 1-1 signals are defeated
It is in parallel to go out end;
Step 105, using the second pi regulator to d axle forward-order currents reference value, q axle forward-order currents reference value, d axle negative phase-sequences
Current reference value and q axle negative-sequence current reference values are adjusted, and according to formulaCalculate the input of MMC rectifier module d axles positive sequence
Voltage uMd +With MMC rectifier module q axle positive sequence input voltages uMq +, according to formulaCalculate the input of d axle negative phase-sequence MMC rectifiers module
Voltage uMd -With q axle negative phase-sequence MMC rectifier module input voltages uMq -, wherein,Reference value for q axle forward-order currents and Reference value for d axle negative-sequence currents and Reference value for q axle negative-sequence currents andKp 2For
The proportionality coefficient of second pi regulator, Ki 2For the integral coefficient of the second pi regulator, L is the inductance value of the current-limiting reactor;
It should be noted that the reference value by q axle forward-order currentsWith the reference value of q axle negative-sequence currentsIt is disposed as 0
Be in order to MMC rectifier module 1 carry out unity power factor control so that power electronics distribution transformer in rated capacity not
In the case of change, the active power of transformer transmission is improved, and reduces the loss of power electronics distribution transformer;Passing through will
The reference value of d axle negative-sequence currents isWith the reference value of q axle negative-sequence currentsBeing disposed as 0 realizes to MMC rectifier mould
Block 1 carries out the control based on phase component method, it is suppressed that the High-voltage AC Network 4 is input to the input port of MMC rectifier module 1
Negative sequence component so that MMC rectifier module 1 can stablize output high-voltage dc voltage, and then cause in the high-voltage alternating
When three-phase imbalance or voltage dip failure occur for power network 4, power electronics distribution transformer can safely and reliably be run,
Improve power supply quality;In the present embodiment, L 0.005mH;
Step 106, to uMd +And uMq +Carry out dq inverse transformations and obtain MMC rectifier modules A phase positive sequence input voltage uMA +, B phases
Positive sequence input voltage uMB +With C phase positive sequence input voltages uMC +;To uMd -And uMq -Carry out dq inverse transformations and obtain MMC rectifier modules A
Phase negative phase-sequence input voltage uMA -, B phases negative sequence voltage input uMB -With C phase negative phase-sequence input voltages uMC -;According to formulaCalculate MMC rectifier modules A phase input voltage uMA, MMC rectifier module B phases input electricity
Press uMBWith MMC rectifier module C phase input voltages uMC;
It should be noted that according to formulaTo uMd +
And uMq +Carry out dq inverse transformations and obtain uMA +、uMB +And uMC +, according to formulaTo uMd -And uMq -Carry out dq inverse transformations and obtain uMA -、uMB -With
uMC -, further according to formulaTry to achieve uMA、uMBAnd uMC, wherein, uMAFor MMC submodules SMpMaWith limit
Flow the voltage at reactor L1 connection end points, uMBFor MMC submodules SMpMbWith the voltage at current-limiting reactor L2 connection end points,
uMCFor MMC submodules SMpMcWith the voltage at current-limiting reactor L3 connection end points;
Step 107, the quantity for obtaining each bridge arm input MMC submodules of the bridge arm circuit of three-phase six:To the bridge arm circuit of three-phase six
In be determined respectively per the MMC submodule input quantities of phase, and MMC submodules in the bridge arm circuit of three-phase six in any one phase
The determination method all same of input quantity;
When being determined to the MMC submodule input quantities in the bridge arm circuit of three-phase six per phase, process is as follows:
Step I, according to formulaCalculate the input number under every phase on bridge arm in the bridge arm circuit of three-phase six
D1, wherein, ceil () is rounds up function, uMTo be any one mutually defeated in the input port three-phase voltage of MMC rectifier module 1
Inbound port voltage, ummcFor submodule electric capacity rated voltage;
Step II, according to formula D2=M-D1, calculate the input number D in every phase on bridge arm in the bridge arm circuit of three-phase six2;
The output high-voltage dc voltage real-time measurement values u of step 108, MMC rectifier module 1DCVoltage stabilizing:Pass through submodule
Capacitance voltage ranking method determines that the submodule that each bridge arm is put into completes the output high-voltage dc voltage to MMC rectifier module 1
uDCVoltage stabilizing;
It should be noted that in the present embodiment, bridge arm is according to formula under A phasesLower bridge arm is calculated
The MMC submodule numbers for needing to put into are D1AIt is individual, according to D2A=M-D1A, the input number being calculated in A phases on bridge arm is 12-
D1AIt is individual, the rated value u of MMC submodule electric capacitymmcFor 2500V;The side that the MMC submodule input quantities of B phases and C phases are determined
Method is identical with A phases, will not be repeated here;
Step 109, circulation step 101 to step 108, the output high-voltage dc voltage to MMC rectifier module 1 are surveyed in real time
Value uDCExported;
It should be noted that in the present embodiment, the use MMC submodule capacitor voltages ranking method process of A phase bridge arms
It is as follows:First, bridge arm current i in A phases in measurement MMC rectifier module 1 in real timeapWith lower bridge arm current ian, and measure in real time
Each MMC submodules in the size of each MMC submodules electric capacity both end voltage and lower bridge arm in the upper bridge arm of A phases in MMC rectifier module 1
The size of block electric capacity both end voltage;Then, if ian>0, then bridge arm chooses MMC submodule electric capacity both end voltage minimum under A phases
D1AIndividual MMC submodules come into operation, if ian<0, then bridge arm chooses the maximum D of MMC submodule electric capacity both end voltage under A phases1A
Individual MMC submodules come into operation;Finally, if iap>0, then bridge arm chooses MMC submodule electric capacity both end voltage minimum in A phases
12-D1AIndividual MMC submodules come into operation, if iap<0, then bridge arm chooses MMC submodule electric capacity both end voltage maximum in A phases
12-D1AIndividual MMC submodules come into operation;By that analogy, the B phases bridge arm and C phases bridge arm use MMC submodule capacitor voltages
Ranking method determines that the MMC submodules used will be put into, will not be repeated here;The MMC submodule capacitor voltages ranking method
Setting is in order to ensure that capacitance voltage is equal in the cycle, so as to realize the equilibrium of MMC submodule capacitor voltages so that MMC rectifications
The high-voltage dc voltage that device module 1 exports is stable and reliable, and this method and step is simple, it is easy to accomplish;
Step 2: the decompression of the output high-voltage dc voltage of MMC rectifier module, process are as follows:
Step 201, partial pressure:Using output high voltage direct current of multiple DC-DC isolation subelements to MMC rectifier module 1
Pressure carries out partial pressure, using the derided capacitors in sub- inverter 2-1 and the bridge arm electric capacity to the defeated of MMC rectifier module 1
Go out high-voltage dc voltage and carry out two-stage partial pressure, obtain partial pressure DC voltage uFC;
Step 202, inversion:50% couple of partial pressure DC voltage u is respectively turned on using two IGBT in sub- inverter 2-1FC
Inversion is carried out, obtains square wave alternating voltage;
Step 203, decompression:Sub- intermediate-frequency transformer 2-2 other side alternating current wave pressure is depressured to obtain low pressure square wave alternating-current electricity
Pressure;
Step 204, rectification and filtering:Sub- rectifier 2-3 carries out rectification to the low pressure square wave alternating voltage and obtains low pressure
DC voltage, and denoising is filtered to low-voltage dc voltage;
In the present embodiment, the quantity of derided capacitors is 10, and the voltage at 10 derided capacitors both ends is 2520V,
The quantity of the bridge arm electric capacity is 20, the partial pressure DC voltage u at 20 bridge arm electric capacity both endsFCFor 1260V, uFCBy
Two IGBT are respectively turned on the square wave alternating voltage that 50% inversion is ± 1260V, sub- intermediate-frequency transformer 2-2 no-load voltage ratio 1500:
1000, ± 1260V square wave alternating voltage are depressured to obtain ± 840V low pressure square wave alternating voltage through sub- intermediate-frequency transformer 2-2;
The low pressure square wave alternating voltage of ± 840V obtains 840V low-voltage dc voltage after sub- rectifier 2-3 rectifications;
Step 3: the inversion of low-voltage dc voltage, process are as follows:
Step 301, inversion carried out to low-voltage dc voltage using DC-AC inverter 3, while it is defeated to measure DC-AC inverter 3
Go out side A phase instantaneous voltages uva, B phase instantaneous voltages uvbWith C phase instantaneous voltages uvc;
The DC-AC inverter 3 is three-phase full-bridge inverter, the three-phase full-bridge inverter and the low-voltage alternating-current power network
Between be connected with filter inductance;
Step 302, to A phase instantaneous voltages uva, B phase instantaneous voltages uvbWith C phase instantaneous voltages uvcDq is carried out to convert to obtain
DC-AC inverter d axle output voltages uvdWith DC-AC inverter q axle output voltages uvq;
Step 303, using the 3rd pi regulator to DC-AC inverter d axle output voltages uvdIt is defeated with DC-AC inverter q axles
Go out voltage uvqIt is adjusted, obtains DC-AC inverter d axle output voltage adjusted values uvd' and DC-AC inverter q axle output voltages
Adjusted value uvq', wherein,uvd *For DC-AC inverter d axle output voltages
Set reference value, uvq* reference value, K are set for DC-AC inverter q axles output voltagep 3For the proportionality coefficient of the 3rd pi regulator,
Ki 3For the integral coefficient of the 3rd pi regulator;
Step 304, to uvd' and uvq' dq inverse transformations are carried out, obtain three phase sine modulating wave;
Step 305, Frequency conversion control is carried out to the three phase sine modulating wave, obtained in three-phase full-bridge inverting circuit
Trigger pulse, IGBT in three-phase full-bridge inverter is controlled according to the trigger pulse, exports symmetrical three phase sine alternating voltage;
Step 306, circulation step 301 to step 305, realize the inversion of low-voltage dc voltage.
In the present embodiment, according to formula
Set uvd *And uvq *, wherein, ω takes 314, and the aberration rate of three phase sine alternating voltage is 2.1%, meets national standard.
It is described above, only it is presently preferred embodiments of the present invention, not the present invention is imposed any restrictions, it is every according to the present invention
Any simple modification, change and the equivalent structure change that technical spirit is made to above example, still fall within skill of the present invention
In the protection domain of art scheme.
Claims (4)
1. the control method of the power electronics distribution transformer based on MMC, the power electronics distribution transformer bag based on MMC
Include the MMC rectifier module (1) being sequentially connected, DC-DC isolators (2) and DC-AC inverter (3), the MMC rectifier module
(1) input is connected with High-voltage AC Network (4), output end and the low-voltage alternating-current power network (5) of the DC-AC inverter (3)
Connection;The DC-DC isolators (2) include multiple DC-DC isolation subelements, the voltage of multiple DC-DC isolation subelements
Input is sequentially connected in series between the DC output end of MMC rectifier module (1), multiple DC-DC isolation subelements
Output end be connected in parallel between the direct-flow input end of DC-AC inverter (3);The DC-DC isolation subelement is included successively
Connection sub- inverter (2-1), sub- intermediate-frequency transformer (2-2) and sub- rectifier (2-3), the sub- inverter (2-1) including by
The single-phase full bridge inverter circuit that upper bridge arm electric capacity, upper bridge arm IGBT, lower bridge arm electric capacity and lower bridge arm IGBT are formed is described single-phase complete
The input parallel connection of bridge inverter circuit is connected to derided capacitors, and the sub- rectifier (2-3) is that diode does not control bridge rectifier, its
It is characterised by, the control method comprises the following steps:
Step 1: the rectification of High Level AC Voltage, process are as follows:
Step 101, the A phase current instantaneous values i for measuring High-voltage AC Network (4) in real timeA, A phase voltage instantaneous values uSA, B phase currents
Instantaneous value iB, B phase voltage instantaneous values uSB, C phase current instantaneous values iCWith C phase voltage instantaneous values uSC;
Step 102, according to formulaCalculate the A of High-voltage AC Network (4)
The positive-sequence component i of phase transient currentA +, B phase transient currents positive-sequence component iB +With the positive-sequence component i of C phase transient currentsC +;
According to formulaThe A phase currents for calculating High-voltage AC Network (4) are born
Order components iA -, B phase currents negative sequence component iB -With the negative sequence component i of C phase currentsC -;
According to formulaCalculate the A phases of High-voltage AC Network (4)
The positive-sequence component u of instantaneous voltageSA +, B phase instantaneous voltages positive-sequence component uSB +With the positive-sequence component u of C phase instantaneous voltagesSC +;Its
In, ω is the angular frequency of High-voltage AC Network (4) voltage;
According to formulaCalculate the A phases of High-voltage AC Network (4)
The negative sequence component u of instantaneous voltageSA -, B phase instantaneous voltages negative sequence component uSB -With the negative sequence component u of C phase instantaneous voltagesSC -;
Step 103, to iA +、iB +And iC +Q axle forward-order currents i can be obtained by carrying out dq conversionq +With d axle forward-order currents id +, to iA -、iB -With
iC -Q axle negative-sequence currents i can be obtained by carrying out dq conversionq -With d axle negative-sequence currents id -;
To uSA +、uSB +And uSC +Q axle positive sequence High-voltage AC Network instantaneous voltages u can be obtained by carrying out dq conversionSq +Handed over d axle positive sequences high pressure
Flow power network instantaneous voltage uSd +, to uSA -、uSB -And uSC -Q axle negative phase-sequence High-voltage AC Network instantaneous voltages u can be obtained by carrying out dq conversionSq -
With d axle negative phase-sequence High-voltage AC Network instantaneous voltages uSd -;
Step 104, using the first pi regulator MMC rectifier module output high-voltage dc voltage is adjusted, is obtaining d axles just
Sequence current reference value i* d +, wherein,uDC *Exported for MMC rectifier module
High-voltage dc voltage setting value, uDCHigh-voltage dc voltage real-time measurement values, K are exported for MMC rectifier modulep 1For described first
The proportionality coefficient of pi regulator, Ki 1For the integral coefficient of first pi regulator;
The MMC rectifier module (1) is the bridge arm circuit of three-phase six, often mutually includes upper bridge arm in the bridge arm circuit of three-phase six
With lower bridge arm, the upper bridge arm and the lower bridge arm include a current-limiting reactor and the M MMC submodules being connected in series,
One end of submodule that the M is connected in series connect with one end of current-limiting reactor, the other end of the current-limiting reactor with
The High-voltage AC Network connects, and the other end of the submodule being connected in series connects with the sub- inverter (2-1), described
Submodule includes half-bridge circuit (1-1) and submodule electric capacity (1-2), the submodule electric capacity (1-2) and the half-bridge circuit (1-
1) signal output part is in parallel;
Step 105, using the second pi regulator to d axle forward-order currents reference value, q axle forward-order currents reference value, d axle negative-sequence currents
Reference value and q axle negative-sequence current reference values are adjusted, and according to formulaCalculate the input of MMC rectifier module d axles positive sequence
Voltage uMd +With MMC rectifier module q axle positive sequence input voltages uMq +, according to formulaCalculate the input of d axle negative phase-sequence MMC rectifiers module
Voltage uMd -With q axle negative phase-sequence MMC rectifier module input voltages uMq -, wherein, iq +*For the reference value and i of q axle forward-order currentsq +*=
0, id -*For the reference value and i of d axle negative-sequence currentsd -*=0, iq -*For the reference value and i of q axle negative-sequence currentsq -*=0, Kp 2For second
The proportionality coefficient of pi regulator, Ki 2For the integral coefficient of the second pi regulator, L is the inductance value of the current-limiting reactor;
Step 106, to uMd +And uMq +Carry out dq inverse transformations and obtain MMC rectifier modules A phase positive sequence input voltage uMA +, B phase positive sequences
Input voltage uMB +With C phase positive sequence input voltages uMC +;To uMd -And uMq -Progress dq inverse transformations obtain MMC rectifier modules A and mutually born
Sequence input voltage uMA -, B phases negative sequence voltage input uMB -With C phase negative phase-sequence input voltages uMC -;According to formulaCalculate MMC rectifier modules A phase input voltage uMA, MMC rectifier module B phases input electricity
Press uMBWith MMC rectifier module C phase input voltages uMC;
Step 107, the quantity for obtaining each bridge arm input MMC submodules of the bridge arm circuit of three-phase six:To every in the bridge arm circuit of three-phase six
The MMC submodule input quantities of phase are determined respectively, and the MMC submodules input in the bridge arm circuit of three-phase six in any one phase
Number determination method all same;
When being determined to the MMC submodule input quantities in the bridge arm circuit of three-phase six per phase, process is as follows:
Step I, according to formulaCalculate the input number D under every phase on bridge arm in the bridge arm circuit of three-phase six1,
Wherein, ceil () is rounds up function, uMFor any one phase input voltage in MMC rectifier module three-phase voltage, ummcFor
Submodule electric capacity rated voltage;
Step II, according to formula D2=M-D1, calculate the input number D in every phase on bridge arm in the bridge arm circuit of three-phase six2;
The output high-voltage dc voltage real-time measurement values u of step 108, MMC rectifier module (1)DCVoltage stabilizing:Pass through MMC submodules
Block capacitance voltage ranking method determines that the submodule that each bridge arm is put into completes the output HVDC to MMC rectifier module (1)
Voltage uDCVoltage stabilizing;
Step 109, circulation step 101 to step 108, the output high-voltage dc voltage of MMC rectifier module (1) is measured in real time
Value uDCExported;
Step 2: the decompression of the output high-voltage dc voltage of MMC rectifier module, process are as follows:
Step 201, partial pressure:Isolate output high-voltage dc voltage of the subelement to MMC rectifier module (1) using multiple DC-DC
Partial pressure is carried out, using the derided capacitors in sub- inverter (2-1) and the bridge arm electric capacity to MMC rectifier module (1)
Export high-voltage dc voltage and carry out two-stage partial pressure, obtain partial pressure DC voltage uFC;
Step 202, inversion:50% couple of partial pressure DC voltage u is respectively turned on using two IGBT in sub- inverter (2-1)FCEnter
Row inversion, obtains square wave alternating voltage;
Step 203, decompression:Sub- intermediate-frequency transformer (2-2) other side's alternating current wave pressure is depressured to obtain low pressure square wave alternating voltage;
Step 204, rectification and filtering:Sub- rectifier (2-3) carries out rectification to the low pressure square wave alternating voltage and obtains low-pressure direct
Voltage is flowed, and denoising is filtered to low-voltage dc voltage;
Step 3: the inversion of low-voltage dc voltage, process are as follows:
Step 301, inversion carried out to low-voltage dc voltage using DC-AC inverter (3), while it is defeated to measure DC-AC inverter (3)
Go out side A phase instantaneous voltages uva, B phase instantaneous voltages uvbWith C phase instantaneous voltages uvc;
Step 302, to A phase instantaneous voltages uva, B phase instantaneous voltages uvbWith C phase instantaneous voltages uvcDq is carried out to convert to obtain DC-AC
Inverter d axle output voltages uvdWith DC-AC inverter q axle output voltages uvq;
Step 303, using the 3rd pi regulator to DC-AC inverter d axle output voltages uvdElectricity is exported with DC-AC inverter q axles
Press uvqIt is adjusted, obtains DC-AC inverter d axle output voltage adjusted values uvd' and the adjustment of DC-AC inverter q axles output voltage
Value uvq', wherein,uvd *Set for DC-AC inverter d axles output voltage
Reference value, uvq* reference value, K are set for DC-AC inverter q axles output voltagep 3For the proportionality coefficient of the 3rd pi regulator, Ki 3For
The integral coefficient of 3rd pi regulator;
Step 304, to uvd' and uvq' dq inverse transformations are carried out, obtain three phase sine modulating wave;
Step 305, Frequency conversion control is carried out to the three phase sine modulating wave, obtain the triggering in three-phase full-bridge inverting circuit
Pulse, IGBT in three-phase full-bridge inverter is controlled according to the trigger pulse, exports symmetrical three phase sine alternating voltage;
Step 306, circulation step 301 to step 305, realize the inversion of low-voltage dc voltage.
2. according to the control method of the power electronics distribution transformer based on MMC described in claim 1, it is characterised in that:Institute
It is three-phase full-bridge inverter to state DC-AC inverter (3), between the three-phase full-bridge inverter and the low-voltage alternating-current power network (5)
It is connected with filter inductance.
3. according to the control method of the power electronics distribution transformer based on MMC described in claim 1, it is characterised in that:Institute
Stating diode and not controlling bridge rectifier includes diode-bridge circuit and in parallel with the output end of the diode-bridge circuit
Filter capacitor.
4. according to the control method of the power electronics distribution transformer based on MMC described in claim 1, it is characterised in that:Institute
Half-bridge circuit (1-1) is stated to be made up of half-bridge IGBT under half-bridge IGBT and MMC on MMC.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201710525852.6A CN107134930B (en) | 2017-06-30 | 2017-06-30 | Power electronics distribution transformer and its control method based on MMC |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201710525852.6A CN107134930B (en) | 2017-06-30 | 2017-06-30 | Power electronics distribution transformer and its control method based on MMC |
Publications (2)
Publication Number | Publication Date |
---|---|
CN107134930A CN107134930A (en) | 2017-09-05 |
CN107134930B true CN107134930B (en) | 2018-02-16 |
Family
ID=59736815
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201710525852.6A Expired - Fee Related CN107134930B (en) | 2017-06-30 | 2017-06-30 | Power electronics distribution transformer and its control method based on MMC |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN107134930B (en) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107645178B (en) * | 2017-09-08 | 2020-09-08 | 许继电气股份有限公司 | Virtual synchronous machine control system and method based on power electronic transformer |
CN109029407A (en) * | 2018-06-25 | 2018-12-18 | 内江海德科技有限公司 | A kind of airborne vertical gyroscope of miniaturization |
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 |
WO2021016742A1 (en) * | 2019-07-26 | 2021-02-04 | Abb Schweiz Ag | Voltage converter |
CN112467997B (en) * | 2019-09-06 | 2021-12-31 | 中国科学院电工研究所 | Flexible substation topology circuit and control method thereof |
CN111030483A (en) * | 2019-12-30 | 2020-04-17 | 上海科梁信息工程股份有限公司 | Power electronic transformer and control method |
CN113824345A (en) * | 2020-06-18 | 2021-12-21 | 中国电力科学研究院有限公司 | Optimization device and control method of power electronic transformer |
CN114094833B (en) * | 2021-10-29 | 2023-12-29 | 深圳供电局有限公司 | Switch capacitor access type direct current transformer and control method thereof |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103098329A (en) * | 2010-09-21 | 2013-05-08 | Abb技术有限公司 | An apparatus for controlling the electric power transmission in a HVDC power transmission system |
CN104638940A (en) * | 2015-03-02 | 2015-05-20 | 东南大学 | Modular multi-level power electronic transformer based on cascading |
CN106033931B (en) * | 2015-03-18 | 2019-09-03 | 山特电子(深圳)有限公司 | Bidirectional DC-DC converter and its control method |
CN105553304B (en) * | 2016-01-15 | 2018-10-02 | 湖南大学 | A kind of modular multilevel type solid-state transformer and its internal model control method |
-
2017
- 2017-06-30 CN CN201710525852.6A patent/CN107134930B/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
CN107134930A (en) | 2017-09-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN107134930B (en) | Power electronics distribution transformer and its control method based on MMC | |
CN102832841B (en) | Modularized multi-level converter with auxiliary diode | |
CN107230983B (en) | Power spring application system based on power control and control method thereof | |
CN103607032B (en) | Renewable energy power generation, power transmission and transformation and electrical network access integral system | |
CN106374830B (en) | High-power high step-up ratio photovoltaic DC converter device and control method | |
CN104682390A (en) | Alternating current (AC) hybrid active power filter system for high-voltage direct current (DC) transmission, and control method thereof | |
CN105406748B (en) | A kind of control method of suppression module Multilevel Inverters output current harmonics | |
CN102064712A (en) | Power electronic transformer based on simple PFC (Power Factor Correction) | |
CN106533189A (en) | Power electronic transformer and control method thereof | |
CN106411161B (en) | Three-Phase PWM Converter and its optimal control method under the conditions of a kind of Voltage unbalance | |
CN110350792A (en) | A kind of power master-slave control method of DC transformer | |
CN104410256A (en) | Active filter system containing modular multilevel converter and control method thereof | |
CN104980047A (en) | 24 pulse aviation self-coupling transformer rectifier based on star-shaped primary-side winding phase shift | |
CN109980948A (en) | A kind of five port electric power electric transformer of three Coupling Between Phases | |
WO2015143744A1 (en) | Multi-port dc-dc autotransformer and application therefor | |
CN105006982A (en) | P-type 24-pulse aviation self-coupling transformation rectifier | |
CN109378788A (en) | Novel SVG type DC de-icing device | |
CN108306324B (en) | Modularized centralized energy storage system | |
CN106712054B (en) | A kind of STATCOM device inhibiting capacitance voltage pulsation based on modular multilevel | |
CN107546983B (en) | A kind of high-power high no-load voltage ratio modularization two-way DC converter of isolated form | |
CN102820666B (en) | Three-phase power electronic transformer capable of balancing asymmetric load | |
CN109728581A (en) | A kind of composite energy router and control method | |
CN210405078U (en) | Three-phase multiple power frequency isolation type photovoltaic grid-connected inverter | |
CN111313424A (en) | Three-phase four-wire system universal power quality controller and control method thereof | |
CN204031006U (en) | A kind of power model group of three-phase power electronic transformer |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20180216 Termination date: 20180630 |
|
CF01 | Termination of patent right due to non-payment of annual fee |