CN106787883A - The pressure modulator approach approached based on nearest level and press modulating device - Google Patents

The pressure modulator approach approached based on nearest level and press modulating device Download PDF

Info

Publication number
CN106787883A
CN106787883A CN201710053899.7A CN201710053899A CN106787883A CN 106787883 A CN106787883 A CN 106787883A CN 201710053899 A CN201710053899 A CN 201710053899A CN 106787883 A CN106787883 A CN 106787883A
Authority
CN
China
Prior art keywords
bridge arm
module
submodule
diff
ban2
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.)
Granted
Application number
CN201710053899.7A
Other languages
Chinese (zh)
Other versions
CN106787883B (en
Inventor
于向恩
刘韬
郝翔
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TBEA Xinjiang Sunoasis Co Ltd
Original Assignee
TBEA Xinjiang Sunoasis Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by TBEA Xinjiang Sunoasis Co Ltd filed Critical TBEA Xinjiang Sunoasis Co Ltd
Priority to CN201710053899.7A priority Critical patent/CN106787883B/en
Publication of CN106787883A publication Critical patent/CN106787883A/en
Application granted granted Critical
Publication of CN106787883B publication Critical patent/CN106787883B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H02M7/4835—Converters with outputs that each can have more than two voltages levels comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage

Landscapes

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

Abstract

The present invention provides a kind of pressure modulator approach approached based on nearest level, including：Predeterminated voltage limit Δ U and Dynamic gene h, if Umax‑Umin<Δ U, then according to Non (k), Non (k 1) and each bridge arm current i in this controlling cyclearmEach bridge arm Neutron module of direction controlling switching with equal pressure drop frequently；If Umax‑Umin>=Δ U, then according to each bridge arm Neutron module capacitance voltage minimum value Umin, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding first additional adjusting module number N of each bridge arm respectivelyBAN1, according to each bridge arm Neutron module capacitance voltage maximum Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding second additional adjusting module number N of each bridge arm respectivelyBAN2, then according to N in this controlling cycleBAN1、NBAN2, Non (k) and Non (k 1) control the switching of each bridge arm Neutron module with equal pressure drop frequently.Correspondingly, there is provided one kind presses modulating device.The present invention on the premise of equal pressure request is met, can reduce the on-off times of power device, reduce switching loss.

Description

The pressure modulator approach approached based on nearest level and press modulating device
Technical field
The present invention relates to flexible T ＆ D Technology field, and in particular to a kind of pressure modulation methods approached based on nearest level Method, and a kind of pressure modulating device approached based on nearest level.
Background technology
Compared with the transverter of conventional voltage source, modularization multi-level converter (Modular Multilever Converter, MMC) have the advantages that favorable expandability, harmonic wave are small, switching frequency is low, few to the consistent triggering requirement of device, in height Pressure application field is with the obvious advantage, is particularly suited for direct current transportation application scenario.Technology of HVDC based Voltage Source Converter based on MMC extensively should For fields such as new energy submitting, city dilatation, regional power grid interconnection, and island with power, compared to Traditional DC transmission of electricity skill Art, the advantage of Technology of HVDC based Voltage Source Converter is gradually highlighted.The country has carried out multinomial flexible DC power transmission demonstration project, more next More power transmission engineerings promote the development of Technology of HVDC based Voltage Source Converter using the Technology of HVDC based Voltage Source Converter based on MMC.
In the flexible direct current power transmission system based on MMC, valve level control is a very crucial technology, for converter valve (NLM) method is approached more than the more system of bridge arm number of modules using nearest level to be modulated.Specifically, by adjusting each phase The switching of submodule, makes the staircase waveform being made up of the voltage sum of varying number submodule of output approach default reference electricity Corrugating.
For MMC, DC side energy storage is to be connected to maintain by multiple submodule capacitance voltage, when energy variation, electricity Holding voltage will necessarily have a certain degree of fluctuation；In addition, loss, the size of capacitance of the submodule electric capacity in same bridge arm Not equal factor can also make the capacitance voltage of each submodule uneven, influence the normal operation of MMC.Therefore must be to each height Module capacitance voltage carries out Balance route, to ensure the stable operation of system.
However, in traditional Pressure and Control strategy, needing constantly according to the capacitance voltage and bridge arm current after sequence Direction determines the switching situation of each submodule, even if submodule capacitor voltage change is little, it is also possible to which frequent switching is changed, Cause that the on-off times of IGBT in each bridge arm are more, switching loss is big.
The content of the invention
The technical problems to be solved by the invention are directed to the drawbacks described above in the presence of prior art, there is provided a kind of full Foot is on the premise of pressure request, reduce power device on-off times, reduce switching loss based on nearest level approach it is equal Press modulator approach and press modulating device.
Solving the technical scheme that is used of present invention problem is：
The present invention provides a kind of pressure modulator approach approached based on nearest level, and it comprises the following steps：
In Real-time Collection each controlling cycle in each bridge arm all submodules capacitance voltage value and switching state information, with And each bridge arm current iarmDirectional information；
Obtain conducting number Non (k) of each bridge arm Neutron module and each bridge arm in last controlling cycle in this controlling cycle Conducting number Non (k-1) of Neutron module, wherein k is the integer more than 1；
Calculate each bridge arm Neutron module capacitance voltage maximum U in this controlling cyclemaxWith capacitance voltage minimum value Umin, And the difference between the two；
Predeterminated voltage limit Δ U and Dynamic gene h, if Umax-Umin<Δ U, then according to Non in this controlling cycle (k), Non (k-1) and each bridge arm current iarmEach bridge arm Neutron module of direction controlling switching with equal pressure drop frequently；If Umax-Umin >=Δ U, then according to each bridge arm Neutron module capacitance voltage minimum value Umin, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding first additional adjusting module number N of each bridge arm respectivelyBAN1, and according to each bridge arm Neutron module electricity Hold voltage max Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain each bridge arm correspondence respectively The second additional adjusting module number NBAN2, then according to N in this controlling cycleBAN1、NBAN2, Non (k) and Non (k-1) control The switching of each bridge arm Neutron module is made with equal pressure drop frequently.
The present invention also provides a kind of pressure modulating device approached based on nearest level, and it includes：
Collecting unit, capacitance voltage value and switching shape for gathering all submodules in each bridge arm in each controlling cycle State information, and each bridge arm current iarmDirectional information；
Acquiring unit, conducting number Non (k) and last control for obtaining each bridge arm Neutron module in this controlling cycle Conducting number Non (k-1) of each bridge arm Neutron module in cycle, wherein k is the integer more than 1；
Computing unit, for calculating each bridge arm Neutron module capacitance voltage maximum U in this controlling cyclemaxAnd electric capacity Voltage minimum Umin, and the difference between the two；
Control unit, is preset with voltage limits Δ U and Dynamic gene h, in U in itmax-Umin<During Δ U, at this According to Non (k), Non (k-1) and each bridge arm current i in controlling cyclearmEach bridge arm Neutron module of direction controlling switching with Equal pressure drop is frequently；And in Umax-UminDuring >=Δ U, according to each bridge arm Neutron module capacitance voltage minimum value Umin, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding first additional adjusting module number N of each bridge arm respectivelyBAN1, with And according to each bridge arm Neutron module capacitance voltage maximum Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarm's Direction obtains the corresponding second additional adjusting module number N of each bridge arm respectivelyBAN2, then according to N in this controlling cycleBAN1、 NBAN2, Non (k) and Non (k-1) control the switching of each bridge arm Neutron module with equal pressure drop frequently.
Beneficial effect：
The pressure modulator approach approached based on nearest level of the present invention and pressure modulating device are applied to flexible direct current When in the MMC of transmission system, by the capacitance voltage maximum U to each bridge arm Neutron module in this controlling cyclemaxAnd electric capacity Voltage minimum UminDifference be compared with default voltage limits Δ U, for Umax-Umin<The situation of Δ U, according to this secondary control Conducting number Non (k) of each bridge arm Neutron module in cycle processed, in last controlling cycle each bridge arm Neutron module conducting number Non And each bridge arm current i (k-1)armEach bridge arm Neutron module of direction controlling switching with equal pressure drop frequently；For Umax-Umin≥ΔU Situation, according to the capacitance voltage minimum value U of all submodules in each bridge armminWith capacitance voltage maximum Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding first additional adjusting module number N of each bridge armBAN1With Two additional adjusting module number NBAN2, further according to NBAN1、NBAN2, Non (k) and Non (k-1) control the switching of each bridge arm Neutron module With equal pressure drop frequently, so as to both ensure that submodule capacitor voltage control near limit value, and submodule is reduced to greatest extent Average frequency of switching.
Brief description of the drawings
Fig. 1 is the topological diagram of MMC in the flexible direct current power transmission system that the present invention is applied；
Fig. 2 is a kind of flow chart for pressing modulator approach approached based on nearest level that the embodiment of the present invention 1 is provided；
Fig. 3 is another flow chart for pressing modulator approach approached based on nearest level that the embodiment of the present invention 1 is provided；
Fig. 4 is the schematic diagram for pressing modulating device approached based on nearest level that the embodiment of the present invention 2 is provided；
Fig. 5 is the part-structure schematic diagram of control unit in Fig. 4；
Fig. 6 is another part structural representation of control unit in Fig. 4；
The waveform that each submodule capacitor voltage in bridge arm in the A phases for drawing is emulated through PSCAD that Fig. 7 is provided for the present invention Figure.
In figure：SM- submodules；100- collecting units；200- acquiring units；300- computing units；400- controls are single Unit；The computing modules of 401- first；The order modules of 402- first；403- keeps module；The order modules of 404- second；405- First switching module；The switching modules of 406- second；The order modules of 407- the 3rd；The acquisition modules of 408- first；409- second Acquisition module；The computing modules of 410- second；The acquisition modules of 411- the 3rd；The correcting modules of 412- first；413- second is corrected Module；The switching modules of 414- the 3rd；The switching modules of 415- the 4th；The order modules of 416- the 4th；The order modules of 417- the 5th.
Specific embodiment
To make those skilled in the art more fully understand technical scheme, with reference to the accompanying drawings and examples to this Invention is described in further detail.
Pressure modulator approach of the present invention and pressure modulating device can be applied to flexible direct current power transmission system, wherein MMC The topological structure of (modularization multi-level converter) refers to Fig. 1.As shown in figure 1, MMC includes three facies units, respectively A phases are single Unit, B facies units and C facies units, each facies unit include upper bridge arm and lower bridge arm, altogether 6 bridge arms.The structure of each bridge arm It is identical, reactor and N number of submodule SM including being sequentially connected in series.
The quantity of the submodule of each facies unit be by system design at the beginning of by DC bus-bar voltage, electronic device is pressure-resistant What the factors such as the type of grade and submodule were together decided on.In the present embodiment, the quantity 2N=of the submodule of each facies unit Udc/USM, wherein UdcIt is the voltage between positive and negative dc bus, USMIt is the capacitance voltage of each submodule, during N is each bridge arm Submodule quantity, and N>1.
Specifically, as shown in figure 1, for the upper bridge arm of A facies units, ac output end A is sequentially connected reactor, N number of son The positive pole Vdc+ of DC bus-bar voltage is accessed after module SM, wherein, submodule SM1Output terminals A 1 and DC bus-bar voltage just Pole Vdc+ connections, output end B1 and adjacent submodule SM2Output terminals A 2 connect, submodule SMNOutput terminals A n with it is adjacent Submodule SM(N-1)Output end B (n-1) connection, submodule SMNOutput end Bn be connected with one end of reactor, reactor The other end is connected with A cross streams output terminals As, and other submodules of the upper bridge arm of A facies units (remove submodule SM1With submodule SMN Submodule in addition) output terminals A i previous submodules adjacent thereto output end B (i-1) connections, A facies units it is upper The latter output terminals A of submodule (i+1) the connection output end Bi of other submodules of bridge arm adjacent thereto, 2≤i≤ (N-1).Here, the previous submodule adjacent with a certain submodule refers to adjacent with the submodule and in circuit connecting relation It is upper than the submodule closer to the positive pole Vdc+ of DC bus-bar voltage submodule, such as submodule SM2It is and submodule SM3Phase Adjacent previous submodule；The latter submodule adjacent with a certain submodule is referred to adjacent with the submodule and connected in circuit Connect in relation than the submodule closer to A cross streams output terminals As submodule, such as submodule SM3It is and submodule SM2It is adjacent Latter submodule.As shown in figure 1, bridge arm current i on A facies unitsarmDirection it is downward when be defined as positive direction, work as bridge arm The sense of current is just (iarm>0) when, the electric capacity of the submodule put into upper bridge arm charges, conversely, upper bridge arm current iarmSide To it is upward when be defined as negative direction, when bridge arm current direction is negative (iarm<0) when, the electric capacity of the submodule put into upper bridge arm Electric discharge.
As for the lower bridge arm of A facies units, its structure is differed only in the structure of the upper bridge arm of A facies units, is exchanged defeated Go out to hold A to be sequentially connected the negative pole Vdc- of access DC bus-bar voltage after reactor, N number of submodule SM.As shown in figure 1, A facies units Lower bridge arm current iarmDirection it is downward when be defined as positive direction, the electric capacity of the submodule for now having been put into lower bridge arm charges, instead It, lower bridge arm current iarmDirection it is upward when be defined as negative direction, the electric capacity of the submodule for now having been put into lower bridge arm is put Electricity.
And the structure of the upper and lower bridge arm of B facies units and C facies units can respectively refer to the knot of the upper and lower bridge arm of A facies units Structure, here is omitted.As can be seen that the symmetrical configuration of the structure of the upper bridge arm of each facies unit and lower bridge arm.
In the present embodiment, the structure all same of each submodule is half-bridge submodule, it include transistor VT1 and with Diode VD1, the transistor VT2 of its reverse parallel connection and diode VD2 and electric capacity C with its reverse parallel connection.
Below with submodule SM1Structure as a example by describe in detail half-bridge submodule concrete structure.
The colelctor electrode of transistor VT1 is connected with the negative pole of diode VD1, the connection of the positive pole of emitter stage and diode VD1, brilliant The colelctor electrode of body pipe VT2 is connected with the negative pole of diode VD2, the connection of the positive pole of emitter stage and diode VD2, transistor VT1's Colelctor electrode of the emitter stage also with transistor VT2 is connected, and output terminals A 1 and transistor VT1 emitter stage and the collection of transistor VT2 The tie point of electrode is connected；The positive pole of electric capacity C is connected with the colelctor electrode of transistor VT1, and the negative pole of electric capacity C is with transistor VT2's Emitter stage is connected.
In the embodiment of the present invention, the power device in each submodule can use IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, Metal-Oxide Semiconductor field-effect transistor) or IGCT (Integrated Gate Commutated Thyristors, integrated gate commutated thyristor).
Below by specific embodiment 1 and 2 in detail technical scheme is described in detail.
Embodiment 1：
The present embodiment provides a kind of pressure modulator approach approached based on nearest level.As shown in Fig. 2 pressure modulation Method comprises the following steps S101 to S104.
S101. the capacitance voltage value of all submodules and switching state are believed in each bridge arm in each controlling cycle of Real-time Collection Breath, and each bridge arm current iarmDirectional information.
In the present embodiment, bridge arm current iarmDirection it is downward when be positive direction (iarm>0), i.e., each bridge arm current iarmFrom straight It is positive direction when the positive pole Vdc+ for flowing busbar voltage flows to the negative pole Vdc- of DC bus-bar voltage, now to having been put into the bridge arm Submodule electric capacity charge；Conversely, bridge arm current iarmDirection it is upward when be negative direction (iarm<0), now in the bridge arm The electric capacity electric discharge of the submodule for having put into.
S102. conducting number Non (k) of each bridge arm Neutron module in this controlling cycle is obtained each with last controlling cycle Conducting number Non (k-1) of bridge arm Neutron module, wherein k is the integer more than 1.
S103. each bridge arm Neutron module capacitance voltage maximum U in this controlling cycle is calculatedmaxIt is minimum with capacitance voltage Value Umin, and the difference between the two.
Specifically, in this controlling cycle, according to the electric capacity of all submodules in each bridge arm obtained in step S101 Magnitude of voltage, can calculate each bridge arm Neutron module capacitance voltage maximum UmaxWith capacitance voltage minimum value Umin, and two The difference of person.
S104. predeterminated voltage limit Δ U and Dynamic gene h, if Umax-Umin<Δ U, the then basis in this controlling cycle Non (k), Non (k-1) and each bridge arm current iarmEach bridge arm Neutron module of direction controlling switching with equal pressure drop frequently；
If Umax-Umin>=Δ U, then according to the capacitance voltage minimum value U of all submodules in each bridge armmin, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding first additional adjusting module number N of each bridge arm respectivelyBAN1, with And according to the capacitance voltage maximum U of all submodules in each bridge armmax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding second additional adjusting module number N of each bridge arm respectivelyBAN2, the then basis in this controlling cycle NBAN1、NBAN2, Non (k) and Non (k-1) control the switching of each bridge arm Neutron module with equal pressure drop frequently.
Wherein, voltage limits Δ U and Dynamic gene h can be set by those skilled in the art according to actual conditions, and Dynamic gene h is settable variable, and its preferred scope is (0,1).
In this step, according to each bridge arm Neutron module capacitance voltage maximum U that step S103 drawsmaxWith electric capacity electricity Pressure minimum value Umin, the difference between the two (U can be calculatedmax-Umin), this difference can be divided into the relation of default voltage limits Δ U Two kinds of situations, one of which situation is Umax-Umin<Δ U, another situation is Umax-Umin≥ΔU。
In Umax-Umin<During Δ U, the step S104 comprises the following steps S104-1 to S104-4.
S104-1. the difference N of the quantity of this controlling cycle of each bridge arm and last time controlling cycle input submodule is calculateddiff= Non(k)-Non(k-1)。
Wherein, NdiffAlternatively referred to as this controlling cycle and the submodule conducting change number of last time controlling cycle, specifically may be used It is divided into three kinds of situations：Ndiff>0, Ndiff=0, and Ndiff<0。
If S104-2. Ndiff>0, the then capacitance voltage of the submodule to having been cut off in each bridge arm in this controlling cycle (as sorted from small to large) is ranked up respectively, further according to ranking results and each bridge arm current iarmEach bridge arm of direction controlling in The switching of the submodule for having cut off.
The step S104-2 is specifically included：If bridge arm current iarmDirection be just (iarm>0), then in the bridge arm Submodule charges, and puts into the N of capacitance voltage minimum in the submodule cut off in the bridge armdiffIndividual submodule, i.e., from this The minimum N of capacitance voltage is chosen in the submodule cut off in bridge armdiffIndividual submodule puts into；If bridge arm current iarm's Direction is negative (iarm<0), then discharged to the submodule in the bridge arm, and put into electric capacity in the submodule cut off in the bridge arm The maximum N of voltagediffIndividual submodule, i.e., choose the maximum N of capacitance voltage from the submodule cut off in the bridge armdiffIt is individual Submodule puts into.
If S104-3. Ndiff=0, then make in this controlling cycle the switching state of each submodule and upper secondary control in each bridge arm Cycle processed keeps identical, i.e., the drive signal in this controlling cycle to submodule keeps constant, to the switching state of submodule Any switching is not done.
If S104-4. Ndiff<0, the then capacitance voltage of the submodule to being had been put into each bridge arm in this controlling cycle (as sorted from small to large) is ranked up respectively, further according to ranking results and each bridge arm current iarmEach bridge arm of direction controlling in The switching of the submodule having been put into.
The step S104-4 is specifically included：If bridge arm current iarmDirection be just (iarm>0), then in the bridge arm Submodule charges, and cuts off the N of capacitance voltage maximum in the submodule being had been put into the bridge armdiffIndividual submodule, i.e., from this The maximum N of capacitance voltage is chosen in the submodule being had been put into bridge armdiffIndividual submodule cuts off；If bridge arm current iarm's Direction is negative (iarm<0), then discharged to the submodule in the bridge arm, and cut off electric capacity in the submodule being had been put into the bridge arm The minimum N of voltagediffIndividual submodule, i.e., choose the minimum N of capacitance voltage from the submodule being had been put into the bridge armdiffIt is individual Submodule cuts off.
In Umax-UminDuring >=Δ U, the step S104 also comprises the following steps S104-5 to S104-7.
S104-5. the capacitance voltage to all submodules in each bridge arm in this controlling cycle be ranked up respectively (such as from It is small to be sorted to big).
If S104-6. bridge arm current iarmDirection be just (iarm>0), then charged to the submodule in the bridge arm, and obtained Capacitance voltage value is not less than (U in the bridge armmin+ h* Δ U) submodule quantity, the quantity is the bridge arm corresponding first Additional adjusting module number NBAN1。
If S104-7. bridge arm current iarmDirection be negative (iarm<0), then discharged to the submodule in the bridge arm, and obtained Capacitance voltage value is not more than (U in the bridge armmax- h* Δ U) submodule quantity, the quantity is the bridge arm corresponding second Additional adjusting module number NBAN2。
Obtaining the first additional adjusting module number NBAN1Adjusting module number N additional with secondBAN2Afterwards, the step S104 may also include the steps of S104-8 to S104-12.
S104-8. the difference N of the quantity of this controlling cycle of each bridge arm and last time controlling cycle input submodule is calculateddiff= Non(k)-Non(k-1).Wherein, Non (k) is alternatively referred to as the submodule number that each bridge arm is currently at input state, Non (k-1) The previous submodule number in input state of alternatively referred to as each bridge arm.
S104-9. excision number Noff (k) of each bridge arm Neutron module in this controlling cycle is obtained.Wherein, Noff (k) Can be described as the submodule number that each bridge arm is currently at excision state.
S104-10. according to Ndiff, Non (k) and Noff (k) correct NBAN1To obtain N'BAN1, so as to avoid putting into or turn on The not enough situation of submodule quantity.
The step S104-10 includes：
If Ndiff=0, then N'BAN1=Min (NBAN1, Non (k), Noff (k)), that is, take NBAN1, Non (k) and Noff (k) Minimum value corrects NBAN1To obtain N'BAN1；If Ndiff>0, then N'BAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff), i.e., Take NBAN1, Non (k) and (Noff (k)-Ndiff) minimum value correct NBAN1To obtain N'BAN1；If Ndiff<0, then N'BAN1= Min(NBAN1,Non(k)+Ndiff, Noff (k)), that is, take NBAN1、(Non(k)+Ndiff) and the minimum value of Noff (k) correct NBAN1 To obtain N'BAN1。
S104-11. according to Ndiff, Non (k) and Noff (k) correct NBAN2To obtain N'BAN2, so as to avoid putting into or turn on The not enough situation of submodule quantity.
The step S104-11 includes：
If Ndiff=0, then N'BAN2=Min (NBAN2, Non (k), Noff (k)), that is, take NBAN2, Non (k) and Noff (k) Minimum value corrects NBAN2To obtain N'BAN2；If Ndiff>0, then N'BAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff), i.e., Take NBAN2, Non (k) and (Noff (k)-Ndiff) minimum value correct NBAN2To obtain N'BAN2；If Ndiff<0, then N'BAN2= Min(NBAN2,Non(k)+Ndiff, Noff (k)), that is, take NBAN2、(Non(k)+Ndiff) and the minimum value of Noff (k) correct NBAN2 To obtain N'BAN2。
S104-12. according to revised N'BAN1And N'BAN2Control the switching of each bridge arm Neutron module.
The step S104-12 includes：
The capacitance voltage of the submodule to having been cut off in each bridge arm in this controlling cycle is ranked up (such as from small respectively To big sequence), to obtain the corresponding excision state subgroup module sorted lists of each bridge arm；
The capacitance voltage of the submodule to being had been put into each bridge arm in this controlling cycle is ranked up (such as from small respectively To big sequence), to obtain the corresponding input state subgroup module sorted lists of each bridge arm；
If N'BAN1=Min (NBAN1, Non (k), Noff (k)), then select voltage in state subgroup module sorted lists are cut off Minimum N'BAN1Individual submodule input, and the maximum N' of voltage is selected in state subgroup module sorted lists are put intoBAN1Height Module cuts off；
If N'BAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff), then selected in state subgroup module sorted lists are cut off Select the minimum (N' of voltageBAN1+Ndiff) individual submodule input, and select voltage most in state subgroup module sorted lists are put into Big N'BAN1Individual submodule excision；
If N'BAN1=Min (NBAN1,Non(k)+Ndiff, Noff (k)), then selected in state subgroup module sorted lists are cut off Select the minimum N' of voltageBAN1Individual submodule input, and voltage maximum is selected in state subgroup module sorted lists are put into (N'BAN1-Ndiff) individual submodule excision；
If N'BAN2=Min (NBAN2, Non (k), Noff (k)), then select voltage in state subgroup module sorted lists are cut off Maximum N'BAN2Individual submodule input, and the minimum N' of voltage is selected in state subgroup module sorted lists are put intoBAN2Height Module cuts off；
If N'BAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff), then selected in state subgroup module sorted lists are cut off Select the maximum (N' of voltageBAN2+Ndiff) individual submodule input, and select voltage most in state subgroup module sorted lists are put into Small N'BAN2Individual submodule excision；
If N'BAN2=Min (NBAN2,Non(k)+Ndiff, Noff (k)), then selected in state subgroup module sorted lists are cut off Select the maximum N' of voltageBAN2Individual submodule input, and voltage minimum is selected in state subgroup module sorted lists are put into (N'BAN2-Ndiff) individual submodule excision.
The present embodiment also provides a kind of pressure modulator approach more approached based on nearest level in detail.As shown in figure 3, The pressure modulator approach comprises the following steps S201 to S233.
S201. the capacitance voltage value of all submodules and switching state are believed in each bridge arm in each controlling cycle of Real-time Collection Breath, and each bridge arm current iarmDirectional information.
S202. conducting number Non (k), the submodule capacitor voltage of each bridge arm Neutron module in this controlling cycle are obtained most Big value UmaxWith capacitance voltage minimum value Umin, and in last controlling cycle each bridge arm Neutron module conducting number Non (k-1), Wherein k is the integer more than 1.
S203. each bridge arm Neutron module capacitance voltage maximum U in this controlling cycle is calculatedmaxIt is minimum with capacitance voltage Value UminDifference, if Umax-Umin<Δ U, then perform step S204；If Umax-Umin>=Δ U, then perform step S214.Wherein, Δ U It is default voltage limits.
S204. the difference N of the quantity of this controlling cycle of each bridge arm and last time controlling cycle input submodule is calculateddiff= Non (k)-Non (k-1), i.e., calculate in each bridge arm this controlling cycle son in submodule conducting number and last controlling cycle respectively Module turns on the difference N of numberdiff, so that the submodule conducting change number of adjacent controlling cycle is obtained, if Ndiff>0, then perform step Rapid S205；If Ndiff=0, then perform step S209；If Ndiff<0, then perform step S210.
S205. the capacitance voltage of the submodule to having been cut off in each bridge arm in this controlling cycle carry out respectively from it is small to Big sequence.In other words, to cut off in each bridge arm in this controlling cycle submodule (i.e. in excision state submodule Block) capacitance voltage sorted from small to large.
S206. bridge arm current i is judgedarmDirection, if bridge arm current iarmDirection be just (i.e. iarm>0) step, is then performed Rapid S207；If bridge arm current iarmDirection be negative (i.e. iarm<0) step S208, is then performed.
S207. the N of capacitance voltage minimum in the submodule cut off in the bridge arm is put intodiffIndividual submodule, i.e., from N is put into the submodule of excision statediffThe minimum submodule of individual capacitance voltage, so as to the submodule put into the bridge arm The electric capacity of block charges.
S208. the N of capacitance voltage maximum in the submodule cut off in the bridge arm is put intodiffIndividual submodule, i.e., from N is put into the submodule of excision statediffThe maximum submodule of individual capacitance voltage, so as to the electricity of each submodule in the bridge arm Discharge capacitor.
S209. the switching state of each submodule and last time controlling cycle in each bridge arm is made in this controlling cycle to keep phase Together.In other words, the switching state of holding submodule is constant, and the drive signal to submodule is also constant, i.e., submodule does not do any Switching, so that it is constant to maintain a bat to drive.
S210. the capacitance voltage of the submodule to being had been put into each bridge arm in this controlling cycle carry out respectively from it is small to Big sequence.In other words, to had been put into each bridge arm in this controlling cycle submodule (i.e. in input state submodule Block) capacitance voltage sorted from small to large.
S211. bridge arm current i is judgedarmDirection, if bridge arm current iarmDirection be just (i.e. iarm>0) step, is then performed Rapid S212；If bridge arm current iarmDirection be negative (i.e. iarm<0) step S213, is then performed.
S212. the N of capacitance voltage maximum in the submodule being had been put into the bridge arm is cut offdiffIndividual submodule, i.e., from N is cut off in the submodule of input statediffThe maximum submodule of individual capacitance voltage, so as to the submodule put into the bridge arm The electric capacity of block charges.
S213. the N of capacitance voltage minimum in the submodule being had been put into the bridge arm is cut offdiffIndividual submodule, i.e., from N is cut off in the submodule of input statediffThe minimum submodule of individual capacitance voltage, so as to the electricity of each submodule in the bridge arm Discharge capacitor.
S214. the capacitance voltage to all submodules in each bridge arm in this controlling cycle is arranged from small to large respectively Sequence, so as to obtain the submodule block sequencing of each bridge arm.
S215. the capacitance voltage of the submodule to having been cut off in each bridge arm in this controlling cycle carry out respectively from it is small to Big sequence, to obtain the corresponding excision state subgroup module sorted lists of each bridge arm；And in each bridge arm in this controlling cycle The capacitance voltage of the submodule having been put into is sorted from small to large respectively, to obtain the corresponding input state submodule of each bridge arm Block sequencing list.
S216. difference (the i.e. submodule of the quantity of this controlling cycle of each bridge arm and last time controlling cycle input submodule is calculated Block turns on the difference of number) Ndiff=Non (k)-Non (k-1).
S217. bridge arm current i is judgedarmDirection, if bridge arm current iarmDirection be just (i.e. iarm>0) bridge arm, is given Submodule charge, then perform step S218；If bridge arm current iarmDirection be negative (i.e. iarm<0), to the submodule of the bridge arm Electric discharge, then perform step S225.
S218. capacitance voltage value >=(U in the bridge arm is obtainedmin+ h* Δ U) submodule quantity, the quantity is the bridge The corresponding first additional adjusting module number N of armBAN1, and the excision number for obtaining each bridge arm Neutron module in this controlling cycle Noff(k).Wherein, h is default Dynamic gene, and h is settable variable, and its preferred scope is (0,1).
S219. N is judgeddiffValue, if Ndiff=0, then perform step S220；If Ndiff>0, then perform step S222；If Ndiff<0, then perform step S224.
S220. N' is madeBAN1=Min (NBAN1, Non (k), Noff (k)), that is, correct NBAN1, with the son for avoiding putting into or turning on The not enough situation of module number occurs.
S221. the minimum N' of voltage is selected in state subgroup module sorted lists are cut offBAN1Individual submodule input, Yi Ji The maximum N' of voltage is selected in input state subgroup module sorted listsBAN1Individual submodule excision.
S222. N' is madeBAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff), that is, correct NBAN1, to avoid putting into or lead The not enough situation of logical submodule quantity occurs.
S223. minimum (the N' of voltage is selected in state subgroup module sorted lists are cut offBAN1+Ndiff) individual submodule input, And the maximum N' of voltage is selected in state subgroup module sorted lists are put intoBAN1Individual submodule excision.
S224. N' is madeBAN1=Min (NBAN1,Non(k)+Ndiff, Noff (k)), that is, correct NBAN1, to avoid putting into or lead The not enough situation of logical submodule quantity occurs.
S225. the minimum N' of voltage is selected in state subgroup module sorted lists are cut offBAN1Individual submodule input, Yi Ji Maximum (the N' of voltage is selected in input state subgroup module sorted listsBAN1-Ndiff) individual submodule excision.
S226. capacitance voltage value≤(U in the bridge arm is obtainedmax- h* Δ U) submodule quantity, the quantity is the bridge The corresponding second additional adjusting module number N of armBAN2, and the excision number for obtaining each bridge arm Neutron module in this controlling cycle Noff(k).Wherein, h is default Dynamic gene, and h is settable variable, and its preferred scope is (0,1).
S227. N is judgeddiffValue, if Ndiff=0, then perform step S228；If Ndiff>0, then perform step S230；If Ndiff<0, then perform step S232.
S228. N' is madeBAN2=Min (NBAN2, Non (k), Noff (k)), that is, correct NBAN2, with the son for avoiding putting into or turning on The not enough situation of module number occurs.
S229. the maximum N' of voltage is selected in state subgroup module sorted lists are cut offBAN2Individual submodule input, Yi Ji The minimum N' of voltage is selected in input state subgroup module sorted listsBAN2Individual submodule excision.
S230. N' is madeBAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff), that is, correct NBAN2, to avoid putting into or lead The not enough situation of logical submodule quantity occurs.
S231. maximum (the N' of voltage is selected in state subgroup module sorted lists are cut offBAN2+Ndiff) individual submodule input, And the minimum N' of voltage is selected in state subgroup module sorted lists are put intoBAN2Individual submodule excision.
S232. N' is madeBAN2=Min (NBAN2,Non(k)+Ndiff, Noff (k)), that is, correct NBAN2, to avoid putting into or lead The not enough situation of logical submodule quantity occurs.
S233. the maximum N' of voltage is selected in state subgroup module sorted lists are cut offBAN2Individual submodule input, Yi Ji Minimum (the N' of voltage is selected in input state subgroup module sorted listsBAN2-Ndiff) individual submodule excision.
It should be noted that during above two presses modulator approach, the order of steps involved is simply to illustrate that this hair Bright and two kinds of instantiations proposing, the present invention is not limited the order of above-mentioned steps, and those skilled in the art actually should It can be adjusted on demand in.
Embodiment 2：
The present embodiment provides a kind of pressure modulating device approached based on nearest level.As shown in figure 4, pressure modulation Device includes collecting unit 100, acquiring unit 200, computing unit 300 and control unit 400.
Wherein, collecting unit 100 is used to gather the capacitance voltage value of all submodules in each bridge arm in each controlling cycle With switching state information, and each bridge arm current iarmDirectional information；Acquiring unit 200 is used to obtain in this controlling cycle Conducting number Non (k-1) of each bridge arm Neutron module in conducting number Non (k) of each bridge arm Neutron module and last controlling cycle, its Middle k is the integer more than 1；It is maximum that computing unit 300 is used to calculate each bridge arm Neutron module capacitance voltage in this controlling cycle Value UmaxWith capacitance voltage minimum value Umin, and the difference between the two；Be preset with control unit 400 voltage limits Δ U and adjustment because Sub- h, in Umax-Umin<During Δ U, according to Non (k), Non (k-1) and each bridge arm current i in this controlling cyclearm's The switching of each bridge arm Neutron module of direction controlling with equal pressure drop frequently；And in Umax-UminDuring >=Δ U, according to submodule in each bridge arm Block capacitance voltage minimum value Umin, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain each bridge arm respectively Corresponding first additional adjusting module number NBAN1, and according to each bridge arm Neutron module capacitance voltage maximum Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain the corresponding second additional adjusting module number N of each bridge arm respectivelyBAN2, Then according to N in this controlling cycleBAN1、NBAN2, Non (k) and Non (k-1) control the switching of each bridge arm Neutron module with equal Pressure drop is frequently.
Specifically, as shown in figure 5, control unit 400 includes：
First computing module 401, for calculating this controlling cycle of each bridge arm with last time controlling cycle input submodule The difference N of quantitydiff=Non (k)-Non (k-1)；
First order module 402, in Ndiff>When 0, to the submodule cut off in each bridge arm in this controlling cycle The capacitance voltage of block is ranked up respectively；
First switching module 405, for the ranking results according to the first order module 402 and each bridge arm current iarmSide To the switching of the submodule for controlling to have been cut off in each bridge arm；
Module 403 is kept, in NdiffWhen=0, make the switching shape of each submodule in each bridge arm in this controlling cycle State is identical with last time controlling cycle holding；
Second order module 404, in Ndiff<When 0, to the submodule being had been put into each bridge arm in this controlling cycle The capacitance voltage of block is ranked up respectively；
Second switching module 406, for the ranking results according to the second order module 404 and each bridge arm current iarmSide To the switching of the submodule for controlling to be had been put into each bridge arm.
Wherein, the first switching module 405 is specifically in bridge arm current iarmDirection be timing, put into the bridge arm The minimum N of capacitance voltage in submodule through cutting offdiffIndividual submodule；In bridge arm current iarmDirection for it is negative when, put into the bridge The maximum N of capacitance voltage in the submodule cut off in armdiffIndividual submodule；Second switching module 406 is specifically in bridge Arm electric current iarmDirection be timing, cut off the maximum N of capacitance voltage in the submodule being had been put into the bridge armdiffIndividual submodule Block；In bridge arm current iarmDirection for it is negative when, cut off the minimum N of capacitance voltage in the submodule being had been put into the bridge armdiff Individual submodule.
As shown in fig. 6, control unit 400 also includes：
3rd order module 407, for the capacitance voltage difference to all submodules in each bridge arm in this controlling cycle It is ranked up；
First acquisition module 408, in bridge arm current iarmDirection be timing, obtain capacitance voltage value in the bridge arm Not less than (Umin+ h* Δ U) submodule quantity, the quantity is the corresponding first additional adjusting module number N of the bridge armBAN1；
Second acquisition module 409, in bridge arm current iarmDirection for it is negative when, obtain capacitance voltage value in the bridge arm No more than (Umax- h* Δ U) submodule quantity, the quantity is the corresponding second additional adjusting module number N of the bridge armBAN2；
Second computing module 410, for calculating this controlling cycle of each bridge arm with last time controlling cycle input submodule The difference N of quantitydiff=Non (k)-Non (k-1)；
3rd acquisition module 411, excision number Noff (k) for obtaining each bridge arm Neutron module in this controlling cycle；
First correcting module 412, for according to Ndiff, Non (k) and Noff (k) correct NBAN1To obtain N'BAN1；
3rd switching module 414, for according to revised N'BAN1Control the switching of each bridge arm Neutron module；
Second correcting module 413, for according to Ndiff, Non (k) and Noff (k) correct NBAN2To obtain N'BAN2；
4th switching module 415, for according to revised N'BAN2Control the switching of each bridge arm Neutron module；
4th order module 416, for the electricity of the submodule to having been cut off in each bridge arm in this controlling cycle Hold voltage to be ranked up respectively, to obtain the corresponding excision state subgroup module sorted lists of each bridge arm；
5th order module 417, for the electricity of the submodule to being had been put into each bridge arm in this controlling cycle Hold voltage to be ranked up respectively, to obtain the corresponding input state subgroup module sorted lists of each bridge arm.
Wherein, the first correcting module 412 is specifically in NdiffWhen=0, make N'BAN1=Min (NBAN1,Non(k),Noff (k))；In Ndiff>When 0, make N'BAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff)；In Ndiff<When 0, make N'BAN1=Min (NBAN1,Non(k)+Ndiff,Noff(k))；
Second correcting module 413 is specifically in NdiffWhen=0, make N'BAN2=Min (NBAN2,Non(k),Noff(k))； In Ndiff>When 0, make N'BAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff)；In Ndiff<When 0, make N'BAN2=Min (NBAN2, Non(k)+Ndiff,Noff(k))；
3rd switching module 414 specifically for：
In N'BAN1=Min (NBAN1, Non (k), Noff (k)) when, select voltage in state subgroup module sorted lists are cut off Minimum N'BAN1Individual submodule input, and the maximum N' of voltage is selected in state subgroup module sorted lists are put intoBAN1Height Module cuts off；
In N'BAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff) when, selected in state subgroup module sorted lists are cut off Select the minimum (N' of voltageBAN1+Ndiff) individual submodule input, and select voltage most in state subgroup module sorted lists are put into Big N'BAN1Individual submodule excision；
In N'BAN1=Min (NBAN1,Non(k)+Ndiff, Noff (k)) when, selected in state subgroup module sorted lists are cut off Select the minimum N' of voltageBAN1Individual submodule input, and voltage maximum is selected in state subgroup module sorted lists are put into (N'BAN1-Ndiff) individual submodule excision；
4th switching module 417 specifically for：
In N'BAN2=Min (NBAN2, Non (k), Noff (k)) when, select voltage in state subgroup module sorted lists are cut off Maximum N'BAN2Individual submodule input, and the minimum N' of voltage is selected in state subgroup module sorted lists are put intoBAN2Height Module cuts off；
In N'BAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff) when, selected in state subgroup module sorted lists are cut off Select the maximum (N' of voltageBAN2+Ndiff) individual submodule input, and select voltage most in state subgroup module sorted lists are put into Small N'BAN2Individual submodule excision；
In N'BAN2=Min (NBAN2,Non(k)+Ndiff, Noff (k)) when, selected in state subgroup module sorted lists are cut off Select the maximum N' of voltageBAN2Individual submodule input, and voltage minimum is selected in state subgroup module sorted lists are put into (N'BAN2-Ndiff) individual submodule excision.
In order to verify that pressure modulator approach of the present invention is implemented on the superior function of flexible direct-current transmission field, inventor MMC simulation models are built using PSCAD, and the tactful and of the present invention pressure modulator approach of existing both of which pressure respectively should The switching frequency (switching frequency) and capacitance voltage that each submodule in bridge arm in A phases is observed for the simulation model are uneven The situation of degree.
One of foregoing existing both of which pressure strategy (can be described as Existing policies 1) is, only by each bridge arm Neutron module electricity Hold the sequence of voltage and the direction of the bridge arm current to realize Pressure and Control so that the switching frequency of each bridge arm Neutron module still has Larger optimization space；Two (can be described as Existing policies 2) of foregoing existing both of which pressure strategy are to avoid to submodule in each bridge arm Pressure and Control are realized in the sequence of block capacitance voltage, such press strategy to think that to the sequence of submodule capacitor voltage control can be increased The burden of processing procedure sequence, however, in currently practical engineering, module presses strategy mainly to be realized by the FPGA in bridge arm control panel , it is easy to quicksort program is processed, hence it is demonstrated that voltage sequence will not turn into the bottleneck in Pressure and Control, is made in pressing Electricity consumption pressure sequence can be more accurately monitored and controlled to module voltage.
The simulation model be using the both-end flexible direct current power transmission system of bipolar mode of operation, wherein, each MMC include three Individual facies unit, each facies unit includes upper bridge arm and lower bridge arm, and each bridge arm includes 126 submodules, wherein 6 submodules Block is redundant module, and the rated operational voltage of submodule is 1667V.One end fortune in the both-end flexible direct current power transmission system In the case where voltage mode is controlled (Udc/Q ends), i.e., the end controls DC voltage and reactive power to row；The other end operates in control power mode Under (P/Q ends), i.e., the end control active power and reactive power.
Existing both of which pressure strategy and this are observed in the case where the both-end flexible direct current power transmission system is fully loaded with active ruuning situation The feelings of the modulator approach switching frequency of each submodule and capacitance voltage degree of unbalancedness in bridge arm in A phases are pressed described in embodiment Condition, is specifically shown in Table 1.
Table 1
As it can be seen from table 1 in the case where not higher than 8% submodule capacitor voltage degree of unbalancedness is met, compared to Existing both of which pressure strategy, pressure modulator approach of the present invention, by Reasonable adjustment voltage limits Δ U and Dynamic gene h, makes Average frequency of switching decline it is obvious, so as to reach relatively reasonably pressure, frequency reducing effect.
Meanwhile, through each submodule capacitor voltage in bridge arm in A phases under systematic steady state full load condition that PSCAD emulation draws Waveform as shown in fig. 7, it can be seen from figure 7 that submodule capacitor voltage degree of unbalancedness is within 8%, submodule is averagely opened Frequency is closed in 150Hz or so, system run all right.
In sum, the present invention is being met on the basis of flexible direct-current transmission valve control system presses, and reduces submodule Switching frequency, reduces the switching loss of power device (such as IGBT) in submodule, directly enhances power transmission efficiency.The present invention exists On the basis of nearest level approximation Strategy, it is ranked up by the capacitance voltage to submodule, Reasonable adjustment voltage limits Δ U and tune Integral divisor h, realizes the Reasonable adjustment to pressure and the switching frequency of submodule, to submodule capacitor voltage maximum/minimum difference Situation not less than voltage limits Δ U only carries out necessary switching, when submodule capacitor voltage maximum/minimum difference exceedes voltage In the case of limit Δ U, additional pressure adjusting module number (N is calculatedBAN1And NBAN2), farthest reduce factor module The unnecessary switching pressed and produce, had both met equal pressure request, the frequency of submodule switching was reduced again, so as to effectively drop The switching loss of power device in low submodule, meets the increasingly harsh requirement proposed to drop loss in engineer applied, The drop loss of flexible DC power transmission industry is significant.
It is understood that the embodiment of above principle being intended to be merely illustrative of the present and the exemplary implementation for using Mode, but the invention is not limited in this.For those skilled in the art, essence of the invention is not being departed from In the case of god and essence, various changes and modifications can be made therein, and these variations and modifications are also considered as protection scope of the present invention.

Claims (12)

1. a kind of pressure modulator approach approached based on nearest level, it is characterised in that comprise the following steps：
In Real-time Collection each controlling cycle in each bridge arm all submodules capacitance voltage value and switching state information, and respectively Bridge arm current iarmDirectional information；
Obtain conducting number Non (k) of each bridge arm Neutron module and each bridge arm neutron in last controlling cycle in this controlling cycle Conducting number Non (k-1) of module, wherein k is the integer more than 1；
Calculate each bridge arm Neutron module capacitance voltage maximum U in this controlling cyclemaxWith capacitance voltage minimum value Umin, and The difference between the two；
Predeterminated voltage limit Δ U and Dynamic gene h, if Umax-Umin<Δ U, then according to Non (k), Non in this controlling cycle And each bridge arm current i (k-1)armEach bridge arm Neutron module of direction controlling switching with equal pressure drop frequently；If Umax-Umin>=Δ U, Then according to each bridge arm Neutron module capacitance voltage minimum value Umin, voltage limits Δ U, Dynamic gene h and each bridge arm current iarm's Direction obtains the corresponding first additional adjusting module number N of each bridge arm respectivelyBAN1, and according to each bridge arm Neutron module capacitance voltage Maximum Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection obtain each bridge arm corresponding second respectively Additional adjusting module number NBAN2, then according to N in this controlling cycleBAN1、NBAN2, Non (k) and Non (k-1) control each bridge The switching of arm Neutron module with equal pressure drop frequently.
2. it is according to claim 1 to press modulator approach, it is characterised in that it is described in this controlling cycle according to Non (k), Non (k-1) and each bridge arm current iarmEach bridge arm Neutron module of direction controlling switching the step of include：
Calculate the difference N of the quantity of this controlling cycle of each bridge arm and last time controlling cycle input submodulediff=Non (k)-Non (k-1)；
If Ndiff>0, then the capacitance voltage of the submodule to having been cut off in each bridge arm in this controlling cycle be ranked up respectively, Further according to ranking results and each bridge arm current iarmEach bridge arm of direction controlling in the switching of submodule that has cut off；
If Ndiff=0, then the switching state of each submodule and last time controlling cycle in each bridge arm is kept phase Together；
If Ndiff<0, then the capacitance voltage of the submodule to being had been put into each bridge arm in this controlling cycle be ranked up respectively, Further according to ranking results and each bridge arm current iarmEach bridge arm of direction controlling in the switching of submodule that has been put into.
It is 3. according to claim 2 to press modulator approach, it is characterised in that
It is described according to ranking results and each bridge arm current iarmEach bridge arm of direction controlling in the switching of submodule that has cut off Step includes：
If bridge arm current iarmDirection for just, then put into the minimum N of capacitance voltage in the submodule cut off in the bridge armdiff Individual submodule；If bridge arm current iarmDirection be negative, then put into capacitance voltage in the submodule cut off in the bridge arm maximum NdiffIndividual submodule；
It is described according to ranking results and each bridge arm current iarmEach bridge arm of direction controlling in the switching of submodule that has been put into Step includes：
If bridge arm current iarmDirection for just, then cut off the maximum N of capacitance voltage in the submodule being had been put into the bridge armdiff Individual submodule；If bridge arm current iarmDirection be negative, then cut off capacitance voltage in the submodule being had been put into the bridge arm minimum NdiffIndividual submodule.
4. it is according to claim 1 to press modulator approach, it is characterised in that the additional adjusting module number of the acquisition first NBAN1The step of include：
Capacitance voltage to all submodules in each bridge arm in this controlling cycle is ranked up respectively；
If bridge arm current iarmDirection for just, then capacitance voltage value is not less than (U in obtaining the bridge armmin+ h* Δ U) submodule Quantity, the quantity is the corresponding first additional adjusting module number N of the bridge armBAN1；
The second additional adjusting module number N of the acquisitionBAN2The step of include：
Capacitance voltage to all submodules in each bridge arm in this controlling cycle is ranked up respectively；
If bridge arm current iarmDirection be negative, then obtain capacitance voltage value no more than (U in the bridge armmax- h* Δ U) submodule Quantity, the quantity is the corresponding second additional adjusting module number N of the bridge armBAN2。
5. the pressure modulator approach according to any one of claim 1-4, it is characterised in that described in this controlling cycle It is interior according to NBAN1、NBAN2, Non (k) and Non (k-1) include the step of control the switching of each bridge arm Neutron module：
Calculate the difference N of the quantity of this controlling cycle of each bridge arm and last time controlling cycle input submodulediff=Non (k)-Non (k-1)；
Obtain excision number Noff (k) of each bridge arm Neutron module in this controlling cycle；
According to Ndiff, Non (k) and Noff (k) correct NBAN1To obtain N'BAN1, and according to Ndiff, Non (k) and Noff (k) repair Positive NBAN2To obtain N'BAN2；
According to revised N'BAN1And N'BAN2Control the switching of each bridge arm Neutron module.
It is 6. according to claim 5 to press modulator approach, it is characterised in that
It is described according to Ndiff, Non (k) and Noff (k) correct NBAN1To obtain N'BAN1The step of include：
If Ndiff=0, then N'BAN1=Min (NBAN1,Non(k),Noff(k))；If Ndiff>0, then N'BAN1=Min (NBAN1,Non (k),Noff(k)-Ndiff)；If Ndiff<0, then N'BAN1=Min (NBAN1,Non(k)+Ndiff,Noff(k))；
It is described according to Ndiff, Non (k) and Noff (k) correct NBAN2To obtain N'BAN2The step of include：
If Ndiff=0, then N'BAN2=Min (NBAN2,Non(k),Noff(k))；If Ndiff>0, then N'BAN2=Min (NBAN2,Non (k),Noff(k)-Ndiff)；If Ndiff<0, then N'BAN2=Min (NBAN2,Non(k)+Ndiff,Noff(k))；
It is described according to revised N'BAN1And N'BAN2The step of switching for controlling each bridge arm Neutron module, includes：
The capacitance voltage of the submodule to having been cut off in each bridge arm in this controlling cycle is ranked up respectively, to obtain each bridge The corresponding excision state subgroup module sorted lists of arm；
The capacitance voltage of the submodule to being had been put into each bridge arm in this controlling cycle is ranked up respectively, to obtain each bridge The corresponding input state subgroup module sorted lists of arm；
If N'BAN1=Min (NBAN1, Non (k), Noff (k)), then select voltage minimum in state subgroup module sorted lists are cut off N'BAN1Individual submodule input, and the maximum N' of voltage is selected in state subgroup module sorted lists are put intoBAN1Individual submodule Excision；
If N'BAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff), then electricity is selected in state subgroup module sorted lists are cut off Press minimum (N'BAN1+Ndiff) individual submodule input, and voltage maximum is selected in state subgroup module sorted lists are put into N'BAN1Individual submodule excision；
If N'BAN1=Min (NBAN1,Non(k)+Ndiff, Noff (k)), then electricity is selected in state subgroup module sorted lists are cut off Press minimum N'BAN1Individual submodule input, and the maximum (N' of voltage is selected in state subgroup module sorted lists are put intoBAN1- Ndiff) individual submodule excision；
If N'BAN2=Min (NBAN2, Non (k), Noff (k)), then select voltage maximum in state subgroup module sorted lists are cut off N'BAN2Individual submodule input, and the minimum N' of voltage is selected in state subgroup module sorted lists are put intoBAN2Individual submodule Excision；
If N'BAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff), then electricity is selected in state subgroup module sorted lists are cut off Press maximum (N'BAN2+Ndiff) individual submodule input, and voltage minimum is selected in state subgroup module sorted lists are put into N'BAN2Individual submodule excision；
If N'BAN2=Min (NBAN2,Non(k)+Ndiff, Noff (k)), then electricity is selected in state subgroup module sorted lists are cut off Press maximum N'BAN2Individual submodule input, and the minimum (N' of voltage is selected in state subgroup module sorted lists are put intoBAN2- Ndiff) individual submodule excision.
7. a kind of pressure modulating device approached based on nearest level, it is characterised in that including：
Collecting unit, capacitance voltage value and the switching state letter for gathering all submodules in each bridge arm in each controlling cycle Breath, and each bridge arm current iarmDirectional information；
Acquiring unit, for obtaining conducting number Non (k) of each bridge arm Neutron module and last controlling cycle in this controlling cycle Conducting number Non (k-1) of interior each bridge arm Neutron module, wherein k is the integer more than 1；
Computing unit, for calculating each bridge arm Neutron module capacitance voltage maximum U in this controlling cyclemaxAnd capacitance voltage Minimum value Umin, and the difference between the two；
Control unit, is preset with voltage limits Δ U and Dynamic gene h, in U in itmax-Umin<During Δ U, in this secondary control According to Non (k), Non (k-1) and each bridge arm current i in cyclearmEach bridge arm Neutron module of direction controlling switching pressing Frequency reducing；And in Umax-UminDuring >=Δ U, according to each bridge arm Neutron module capacitance voltage minimum value Umin, voltage limits Δ U, adjust Integral divisor h and each bridge arm current iarmDirection obtain the corresponding first additional adjusting module number N of each bridge arm respectivelyBAN1, Yi Jigen According to each bridge arm Neutron module capacitance voltage maximum Umax, voltage limits Δ U, Dynamic gene h and each bridge arm current iarmDirection The corresponding second additional adjusting module number N of each bridge arm is obtained respectivelyBAN2, then according to N in this controlling cycleBAN1、NBAN2、 Non (k) and Non (k-1) control the switching of each bridge arm Neutron module with equal pressure drop frequently.
8. it is according to claim 7 to press modulating device, it is characterised in that described control unit includes：
First computing module, the difference of the quantity for calculating this controlling cycle of each bridge arm and last time controlling cycle input submodule Ndiff=Non (k)-Non (k-1)；
First order module, in Ndiff>When 0, the electric capacity of the submodule to having been cut off in each bridge arm in this controlling cycle Voltage is ranked up respectively；
First switching module, for the ranking results according to the first order module and each bridge arm current iarmEach bridge of direction controlling The switching of the submodule cut off in arm；
Module is kept, in NdiffWhen=0, make in this controlling cycle the switching state of each submodule and last time in each bridge arm Controlling cycle keeps identical；
Second order module, in Ndiff<When 0, the electric capacity of the submodule to being had been put into each bridge arm in this controlling cycle Voltage is ranked up respectively；
Second switching module, for the ranking results according to the second order module and each bridge arm current iarmEach bridge of direction controlling The switching of the submodule being had been put into arm.
9. it is according to claim 8 to press modulating device, it is characterised in that first switching module specifically for, Bridge arm current iarmDirection be timing, put into the minimum N of capacitance voltage in the submodule cut off in the bridge armdiffHeight Module；In bridge arm current iarmDirection for it is negative when, put into capacitance voltage in the submodule cut off in the bridge arm maximum NdiffIndividual submodule；
Second switching module is specifically in bridge arm current iarmDirection be timing, cut off what is had been put into the bridge arm The maximum N of capacitance voltage in submodulediffIndividual submodule；In bridge arm current iarmDirection for it is negative when, cut off in the bridge arm The minimum N of capacitance voltage in the submodule of inputdiffIndividual submodule.
10. it is according to claim 7 to press modulating device, it is characterised in that described control unit includes：
3rd order module, arranges respectively for the capacitance voltage to all submodules in each bridge arm in this controlling cycle Sequence；
First acquisition module, in bridge arm current iarmDirection be timing, capacitance voltage value is not less than in obtaining the bridge arm (Umin+ h* Δ U) submodule quantity, the quantity is the corresponding first additional adjusting module number N of the bridge armBAN1；
Second acquisition module, in bridge arm current iarmDirection for it is negative when, capacitance voltage value is not more than in obtaining the bridge arm (Umax- h* Δ U) submodule quantity, the quantity is the corresponding second additional adjusting module number N of the bridge armBAN2。
The 11. pressure modulating device according to any one of claim 7-10, described control unit includes：
Second computing module, the difference of the quantity for calculating this controlling cycle of each bridge arm and last time controlling cycle input submodule Ndiff=Non (k)-Non (k-1)；
3rd acquisition module, excision number Noff (k) for obtaining each bridge arm Neutron module in this controlling cycle；
First correcting module, for according to Ndiff, Non (k) and Noff (k) correct NBAN1To obtain N'BAN1；
3rd switching module, for according to revised N'BAN1Control the switching of each bridge arm Neutron module；
Second correcting module, for according to Ndiff, Non (k) and Noff (k) correct NBAN2To obtain N'BAN2；
4th switching module, for according to revised N'BAN2Control the switching of each bridge arm Neutron module.
12. according to claim 11 press modulating device, it is characterised in that
First correcting module specifically for,
In NdiffWhen=0, make N'BAN1=Min (NBAN1,Non(k),Noff(k))；In Ndiff>When 0, make N'BAN1=Min (NBAN1, Non(k),Noff(k)-Ndiff)；In Ndiff<When 0, make N'BAN1=Min (NBAN1,Non(k)+Ndiff,Noff(k))；
Second correcting module specifically for,
In NdiffWhen=0, make N'BAN2=Min (NBAN2,Non(k),Noff(k))；In Ndiff>When 0, make N'BAN2=Min (NBAN2, Non(k),Noff(k)-Ndiff)；In Ndiff<When 0, make N'BAN2=Min (NBAN2,Non(k)+Ndiff,Noff(k))；
Described control unit also includes the 4th order module and the 5th order module,
4th order module is used for, the capacitance voltage point of the submodule to having been cut off in each bridge arm in this controlling cycle It is not ranked up, to obtain the corresponding excision state subgroup module sorted lists of each bridge arm；
5th order module is used for, the capacitance voltage point of the submodule to being had been put into each bridge arm in this controlling cycle It is not ranked up, to obtain the corresponding input state subgroup module sorted lists of each bridge arm；
3rd switching module specifically for,
In N'BAN1=Min (NBAN1, Non (k), Noff (k)) when, select voltage minimum in state subgroup module sorted lists are cut off N'BAN1Individual submodule input, and the maximum N' of voltage is selected in state subgroup module sorted lists are put intoBAN1Individual submodule Excision；
In N'BAN1=Min (NBAN1,Non(k),Noff(k)-Ndiff) when, electricity is selected in state subgroup module sorted lists are cut off Press minimum (N'BAN1+Ndiff) individual submodule input, and voltage maximum is selected in state subgroup module sorted lists are put into N'BAN1Individual submodule excision；
In N'BAN1=Min (NBAN1,Non(k)+Ndiff, Noff (k)) when, electricity is selected in state subgroup module sorted lists are cut off Press minimum N'BAN1Individual submodule input, and the maximum (N' of voltage is selected in state subgroup module sorted lists are put intoBAN1- Ndiff) individual submodule excision；
4th switching module specifically for,
In N'BAN2=Min (NBAN2, Non (k), Noff (k)) when, select voltage maximum in state subgroup module sorted lists are cut off N'BAN2Individual submodule input, and the minimum N' of voltage is selected in state subgroup module sorted lists are put intoBAN2Individual submodule Excision；
In N'BAN2=Min (NBAN2,Non(k),Noff(k)-Ndiff) when, electricity is selected in state subgroup module sorted lists are cut off Press maximum (N'BAN2+Ndiff) individual submodule input, and voltage minimum is selected in state subgroup module sorted lists are put into N'BAN2Individual submodule excision；
In N'BAN2=Min (NBAN2,Non(k)+Ndiff, Noff (k)) when, electricity is selected in state subgroup module sorted lists are cut off Press maximum N'BAN2Individual submodule input, and the minimum (N' of voltage is selected in state subgroup module sorted lists are put intoBAN2- Ndiff) individual submodule excision.
CN201710053899.7A 2017-01-24 2017-01-24 The pressure modulator approach approached based on nearest level and press modulating device Active CN106787883B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710053899.7A CN106787883B (en) 2017-01-24 2017-01-24 The pressure modulator approach approached based on nearest level and press modulating device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710053899.7A CN106787883B (en) 2017-01-24 2017-01-24 The pressure modulator approach approached based on nearest level and press modulating device

Publications (2)

Publication Number Publication Date
CN106787883A true CN106787883A (en) 2017-05-31
CN106787883B CN106787883B (en) 2019-11-08

Family

ID=58941881

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710053899.7A Active CN106787883B (en) 2017-01-24 2017-01-24 The pressure modulator approach approached based on nearest level and press modulating device

Country Status (1)

Country Link
CN (1) CN106787883B (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108574288A (en) * 2018-05-31 2018-09-25 湖南五凌电力科技有限公司 The pressure method for handover control of capacitance in a kind of voltage-type high-voltage reactive generator
CN108897908A (en) * 2018-05-25 2018-11-27 华北电力大学 A kind of MMC real-time simulation modeling method of the function containing Pressure and Control
CN109067147A (en) * 2018-07-24 2018-12-21 上海交通大学 Cascade converter submodule capacitor voltage disturbance quantity and degree of unbalancedness extracting method
CN109274285A (en) * 2018-10-24 2019-01-25 南方电网科学研究院有限责任公司 Capacitance voltage balancing method of hybrid modular multilevel converter
CN112134477A (en) * 2020-09-14 2020-12-25 湖南大学 Frequency reduction control method of modular multilevel converter with auxiliary sub-modules
CN112152495A (en) * 2019-06-28 2020-12-29 新疆金风科技股份有限公司 Control method and controller of modular multilevel converter
CN112350596A (en) * 2020-11-19 2021-02-09 中国南方电网有限责任公司超高压输电公司 Flexible direct current transmission system power module switching frequency closed-loop control method and system
CN113765419A (en) * 2021-09-27 2021-12-07 中国南方电网有限责任公司超高压输电公司柳州局 Circuit control method, circuit control device, computer equipment and readable storage medium
CN115549439A (en) * 2022-11-29 2022-12-30 东南大学 MMC (Modular multilevel converter) switching loss optimization method and equipment under low-power operation

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103312208A (en) * 2013-05-06 2013-09-18 浙江大学 Zero-error recent level modulating method of modularized multi-level current converter
CN105897025A (en) * 2016-05-05 2016-08-24 上海电机学院 Modular multilevel converter sub-module voltage equalization method

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103312208A (en) * 2013-05-06 2013-09-18 浙江大学 Zero-error recent level modulating method of modularized multi-level current converter
CN105897025A (en) * 2016-05-05 2016-08-24 上海电机学院 Modular multilevel converter sub-module voltage equalization method

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108897908A (en) * 2018-05-25 2018-11-27 华北电力大学 A kind of MMC real-time simulation modeling method of the function containing Pressure and Control
CN108897908B (en) * 2018-05-25 2022-05-17 华北电力大学 MMC real-time simulation modeling method with voltage-sharing control function
CN108574288B (en) * 2018-05-31 2021-06-25 湖南五凌电力科技有限公司 Voltage-sharing switching control method for capacitor in voltage type high-voltage reactive generator
CN108574288A (en) * 2018-05-31 2018-09-25 湖南五凌电力科技有限公司 The pressure method for handover control of capacitance in a kind of voltage-type high-voltage reactive generator
CN109067147A (en) * 2018-07-24 2018-12-21 上海交通大学 Cascade converter submodule capacitor voltage disturbance quantity and degree of unbalancedness extracting method
CN109274285A (en) * 2018-10-24 2019-01-25 南方电网科学研究院有限责任公司 Capacitance voltage balancing method of hybrid modular multilevel converter
CN109274285B (en) * 2018-10-24 2020-04-03 南方电网科学研究院有限责任公司 Capacitance voltage balancing method of hybrid modular multilevel converter
CN112152495A (en) * 2019-06-28 2020-12-29 新疆金风科技股份有限公司 Control method and controller of modular multilevel converter
CN112152495B (en) * 2019-06-28 2023-03-31 新疆金风科技股份有限公司 Control method and controller of modular multilevel converter
CN112134477A (en) * 2020-09-14 2020-12-25 湖南大学 Frequency reduction control method of modular multilevel converter with auxiliary sub-modules
CN112350596A (en) * 2020-11-19 2021-02-09 中国南方电网有限责任公司超高压输电公司 Flexible direct current transmission system power module switching frequency closed-loop control method and system
CN112350596B (en) * 2020-11-19 2023-08-08 中国南方电网有限责任公司超高压输电公司 Closed-loop control method for switching frequency of power module of flexible direct-current transmission system
CN113765419A (en) * 2021-09-27 2021-12-07 中国南方电网有限责任公司超高压输电公司柳州局 Circuit control method, circuit control device, computer equipment and readable storage medium
CN115549439A (en) * 2022-11-29 2022-12-30 东南大学 MMC (Modular multilevel converter) switching loss optimization method and equipment under low-power operation

Also Published As

Publication number Publication date
CN106787883B (en) 2019-11-08

Similar Documents

Publication Publication Date Title
CN106787883B (en) The pressure modulator approach approached based on nearest level and press modulating device
CN106787884B (en) The pressure modulator approach and press modulating device that nearest level approaches
CN104917406B (en) Common-mode-injection-based nearest level modulation method for MMC
CN103633871A (en) Full-bridge module and half-bridge module-based mixed multi-level converter and control method thereof
CN107834867B (en) A kind of accurate two level PWM control methods of module multi-level converter based on SIC devices
CN103620942A (en) Converter
CN108631633A (en) A kind of mixing capacitance voltage type Shuangzi block coupled in series topological structure based on MMC
CN104836457B (en) A kind of modularization multi-level converter capacitance voltage is grouped balance optimizing algorithm
CN105356778A (en) Modularized multi-level inverter and dead-beat control method therefor
CN108631628B (en) Capacitor voltage balance control method for H-bridge cascade rectifier
CN106911260A (en) A kind of control method of multi-electrical level inverter, device and inverter
CN107834868A (en) A kind of capacitor voltage balance method of the MMC submodules mixed based on double half-bridges and full-bridge in parallel
CN104821734A (en) Sub module circuit of modular multi-level converter
CN203590069U (en) Mixed type multi-level converter based on full-bridge module and half-bridge module
CN108429477A (en) A kind of MMC submodules optimization method for equalizing voltage based on double half-bridges and full-bridge mixing in parallel
Shatshat et al. Artificial intelligent controller for current source converter-based modular active power filters
CN106100412A (en) A kind of based on critical current mode continuous control strategy inverter light load efficiency optimization method
CN113794393B (en) Hybrid MMC device loss optimization method based on module decoupling control
CN112564529B (en) Boost seven-level inverter
CN102437575A (en) Medium-and-high-voltage unified power quality controller (UPQC) without transformer
CN204597805U (en) A kind of submodular circuits for block combiner multi-level converter
CN106452146A (en) Multi-level converter submodule circuit and multi-level converter
CN117559496A (en) Hybrid energy storage system, control method, electronic device and storage medium
CN206195648U (en) Sub - module circuit of many level converter and many level converter
CN105024578A (en) Three-phase modular multilevel converter parallel system and control method thereof

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