CN112803808B - Control method for reducing high-frequency pulsating current on direct current side of modular multilevel converter - Google Patents

Control method for reducing high-frequency pulsating current on direct current side of modular multilevel converter Download PDF

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CN112803808B
CN112803808B CN202011619429.0A CN202011619429A CN112803808B CN 112803808 B CN112803808 B CN 112803808B CN 202011619429 A CN202011619429 A CN 202011619429A CN 112803808 B CN112803808 B CN 112803808B
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phase
bridge arm
carriers
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CN112803808A (en
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邓富金
喻强
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Southeast University
Liyang Research Institute of Southeast University
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Liyang Research Institute of Southeast University
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • 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
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices

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Abstract

The invention discloses a control method for reducing high-frequency pulsating current at the direct current side of a modular multilevel converterM2, obtaining the number of modules required to be input by the bridge arm; and finally, obtaining a driving signal of each module by a sequencing voltage-sharing method. In each carrier period, the carrier phase of each phase is adjusted, so that voltage pulses on three-phase bridge arm inductors are mutually offset, corresponding current zero-sequence components are eliminated, the current zero-sequence components cannot flow into a direct current bus, and high-frequency current harmonics on the direct current bus are reduced. The invention improves the problem of high-frequency pulsating current at the direct current side of the MMC caused by double-frequency loop control, and improves the current and power quality at the direct current side of the MMC.

Description

Control method for reducing high-frequency pulsating current on direct current side of modular multilevel converter
Technical Field
The invention relates to a control method for reducing high-frequency pulsating current on a direct current side of a modular multilevel converter, and belongs to the technical field of high-power multilevel power electronic converters.
Background
The Modular Multilevel Converter (MMC) adopts a multi-module cascade structure, compared with the traditional two-level converter and three-level converter, the MMC is more convenient to expand, the efficiency is higher, and the output harmonic wave is smaller, so that the modular multilevel converter is very suitable for the power electronic conversion application occasions with medium-high voltage and large capacity, and has great application prospect in the fields of medium-voltage motor driving, medium-voltage power distribution networks, static synchronous compensators, unified power flow controllers and the like.
Double frequency circulating current is an important operating feature inside an MMC. The double frequency circulation controller has become a necessary control structure for normal operation of the MMC for the purpose of reducing internal loss or optimizing loss distribution, among other purposes. Generally, the circulation controller obtains a frequency-doubled voltage reference wave y through internal calculation according to an input electrical quantityj2Then respectively adding the fundamental frequency reference wave-y to the upper and lower bridge arms of each phasej1And yjAnd the later modulation and control process is participated. However, due to the frequency-doubled voltage reference wave y in the post modulation and controlj2So that the sum of the number of modules thrown into each phase upper and lower bridge arm is no longer always equal to the number N of bridge arm modules in each carrier cycle. When y isj2>When 0, the number of the input modules of the upper bridge arm and the lower bridge arm of each phase is N or N-1; when y isj2<And when 0, the number of the input modules of the upper bridge arm and the lower bridge arm of each phase is N or N + 1. If the voltage of the direct current bus is kept constant, when the number of the input modules of the upper bridge arm and the lower bridge arm of each phase changes between N-1, N and N +1, the inductance of the bridge arm can correspondingly bear positive or negative voltage pulses, the pulse height is equal to the capacitance voltage of 1 module, and then current is generated, the zero sequence component of three-phase current can flow into the direct current side, so that the problem of high-frequency pulsating current of the direct current bus is caused, and the quality of the direct current side current and the power is deteriorated.
To solve this problem, an existing control method divides N carriers of each bridge arm into two parts, N-1 and 1, where N-1 carriers are used to modulate a fundamental frequency reference wave and the remaining 1 is used to modulate a frequency-doubled reference wave. And then the three-phase voltage pulse is counteracted in a mode of adjusting the carrier phase. Although the method can restrain direct current ripple current, the maximum active power and reactive power which can be transmitted by the MMC are obviously reduced due to the arrangement and the modulation process of the carrier, and the application occasions of the MMC are greatly limited.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the control method for reducing the high-frequency pulsating current on the direct current side of the modular multilevel converter is provided, and the capability of the converter for transmitting active power and reactive power is not influenced. Two groups of carriers are arranged on each A, B, C three-phase bridge arm and are respectively used for modulating fundamental frequency reference waves and double frequency reference waves, the number and the overall modulation mode of each group of carriers are given, and the phase of each phase of carrier is adjusted in each carrier period, so that the sum of voltage pulses on bridge arm inductors is always equal to zero, zero sequence current of the bridge arms is eliminated, and the aim of reducing high-frequency pulsating current on a direct current side is fulfilled.
The invention adopts the following technical scheme for solving the technical problems:
the invention provides a control method for reducing high-frequency pulsating current on a direct current side of a modular multilevel converter, wherein A, B, C three phases of the modular multilevel converter MMC respectively comprise an upper bridge arm and a lower bridge arm, each bridge arm comprises N identical modules, and the control method comprises the following steps:
(1) 2 groups of isosceles triangle carriers with the same frequency are arranged for the upper bridge arm and the lower bridge arm of each phase:
for the upper bridge arm, the 1 st group comprises N carriers with the same phase, the N carriers are uniformly distributed in the range of [ -1,1] from bottom to top, and the N carriers have the same amplitude and are equal to 2/N; the 2 nd group contains M carriers with the same phase, the carriers are uniformly distributed in the range of [ -1,1] from bottom to top, the amplitudes are the same and equal to 2/M, and the phase difference between the 2 nd group and the 1 st group is 180 degrees; when N is an even number, M ═ N; when N is an odd number, M ═ N + 1;
for the lower bridge arm, the phase difference between the 1 st group of carrier waves of the lower bridge arm and the 1 st group of carrier waves of the upper bridge arm is 180 degrees, and the rest settings are the same; the phase difference between the 2 nd group of carrier waves and the 2 nd group of carrier waves of the upper bridge arm is 180 degrees, and the rest settings are the same;
(2) dividing the reference wave of the upper bridge arm and the lower bridge arm of each phase into two parts according to the frequency:
the first part is a fundamental frequency sinusoidal reference wave, wherein the reference waves of the upper and lower bridge arms are-y respectivelyj1And yj1Comparing the voltage with the 1 st group of carriers of the upper and lower bridge arms respectively to obtain n levelsuj1And nlj1Subscript j ═ a, b, c, each representing A, B, C three phases;
the second part is a frequency-doubled sinusoidal reference wave y output by the circulation controllerj2Comparing the two signals with the 2 nd group of carriers of the upper and lower bridge arms respectively to obtain n levelsuj2And nlj2；
Then obtaining the final input module numbers of the j-phase upper bridge arm and the j-phase lower bridge arm which are n respectivelyujAnd nljWherein n isuj＝nuj1+nuj2-M/2，nlj＝nlj1+nlj2-M/2；
(3) According to a voltage-sharing method based on capacitor voltage sequencing and according to the final input module number of each bridge arm and all modulesThe result of the capacitor voltage sequencing and the direction of the bridge arm current respectively obtain the PWM driving signal of each module of the upper bridge arm and the lower bridge arm, and finally respectively input nujAnd nljAnd (4) a module.
Further, in the control method provided by the present invention, the phases of the two sets of carriers of the A, B, C three-phase upper and lower bridge arms are obtained by a control algorithm, which specifically includes the following steps:
(101) in each carrier period, obtaining a normalized A, B, C three-phase secondary sinusoidal reference wave signal output by the double-frequency loop controller, and recording the signal as ya2、yb2、yc2；
(102) Calculating the absolute value of the width of the voltage pulse | theta of the three-phase bridge arm inductora|、|θb|、|θcL, where θj＝-yj2·M·π；
(103) To | θa|、|θb|、|θcI carries out ascending sequencing to obtain a serial number Kθa、Kθb、KθcWhere | θa|、|θb|、|θcThe serial number corresponding to the largest one in | is equal to 1, the serial number corresponding to the smallest one is equal to 3, otherwise, the serial number is equal to 2;
(104) and A, B, C, calculating the phase angle positions of the carrier waves when the three-phase sequencing serial numbers are respectively 1, 2 and 3, and according to the serial number K in the step (103)θa、Kθb、KθcAnd respectively moving the two groups of carriers of the upper bridge arm and the lower bridge arm of each phase to corresponding phase positions.
In the control method, in the step (104), for the carrier phase angle positions of A, B, C three phases, it is defined that in one carrier cycle, the horizontal phase distances from the starting point of the upper bridge arm group 1 triangular carrier to the negative peak point of the carrier are respectively θsa、θsb、θscThe specific calculation method comprises the following steps:
for the phase A, the phase A is selected,
Kθawhen 1, θsa＝π；
KθaWhen the number is equal to 2, the alloy is put into a container,
Figure BDA0002875762260000031
Kθawhen the number is 3,
Figure BDA0002875762260000032
for the phase B, the phase B is selected,
Kθbwhen 1, θsb＝π；
KθbWhen the number is equal to 2, the alloy is put into a container,
Figure BDA0002875762260000033
Kθbwhen the number is 3,
Figure BDA0002875762260000034
for the phase C, the phase C is selected,
Kθcwhen 1, θsc＝π；
KθcWhen the number is equal to 2, the alloy is put into a container,
Figure BDA0002875762260000035
Kθcwhen the number is 3,
Figure BDA0002875762260000036
further, in the control method provided by the present invention, in step (2), the bridge arm reference wave is compared with each group of carriers to obtain the number of levels, specifically:
comparing the size of the reference wave with that of each triangular carrier wave respectively, and if the reference wave is greater than or equal to a certain carrier wave, the result is equal to 1; if the reference wave is smaller than a certain carrier wave, the result is equal to 0; and summing the comparison results of the reference wave and all the carriers in the group, namely the number of the levels after the reference wave and the carriers in the group are compared.
Compared with the prior art, the invention adopting the technical scheme has the following technical effects:
1. the traditional circulation control causes the problem of high-frequency pulsating current generated on the direct current side of the MMC, the quality of electric energy on the direct current side is deteriorated, high-frequency noise is increased, and the path loss is increased. The invention provides a simple control method, which can remarkably reduce the high-frequency harmonic current on the direct current side without influencing the circulation control and greatly improve the current and power quality on the direct current side.
2. Although a research focuses on the problem of high-frequency pulsating current on the direct current side of the MMC at present, and a corresponding method is provided, the carrier setting and modulation process of the method can cause the amplitude of the reference wave to be greatly influenced by the number of bridge arm modules, so that the maximum allowable transmission active power and reactive power of the MMC are obviously reduced. The method provided by the invention provides a new carrier setting and modulating method, and can solve the problem. Therefore, the invention has wider application occasions and higher practical value.
Drawings
FIG. 1 is a three-phase MMC topology and module structure diagram.
Fig. 2 is a schematic diagram of the control method proposed by the present invention in phase j.
FIG. 3 shows the method proposed by the present invention in one carrier period yj2>Modulation results at 0 are shown.
FIG. 4 shows the method proposed by the present invention in one carrier period yj2<Modulation results at 0 are shown.
Fig. 5 is a schematic diagram of A, B, C three-phase carrier phase shift and voltage pulse phase shift on the bridge arm inductance in the method provided by the invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
The invention provides a control method for reducing high-frequency pulsating current at the direct current side of an MMC (modular multilevel converter), which is characterized in that two groups of different triangular carriers are arranged for each bridge arm of a three-phase MMC and are respectively used for modulating a fundamental frequency reference wave and a double frequency reference wave, the number and the overall modulation mode of each group of carriers are given, and the phase of each phase of carrier is adjusted in each carrier period according to the result of a control algorithm, so that the sum of voltage pulses on bridge arm inductors is always equal to zero, the zero-sequence current of the bridge arms is eliminated, and the purpose of reducing the high-frequency pulsating current at the direct current side is achieved.
The invention provides a control method for reducing high-frequency pulsating current on a direct-current side of an MMC (modular multilevel converter), wherein the topology and the sub-module structure of the MMC are shown in figure 1. The A, B, C three phases of the MMC respectively comprise an upper bridge arm and a lower bridge arm, and each bridge arm comprises N identical modules. Fig. 2 shows a schematic diagram of the proposed control method in phase j (j ═ a, b, c). The upper and lower bridge arms of each phase are provided with two groups of isosceles triangle carriers with the same frequency: for the upper bridge arm, the 1 st group contains N carriers, the phases are all the same and are obtained by a control algorithm and are uniformly distributed on [ -1,1] from bottom to top]Within the range, the amplitudes are the same and equal to 2/N; the 2 nd group contains M carriers, the phases are all the same, and are uniformly distributed in [ -1,1] from bottom to top]Within the range, the amplitude is equal and equal to 2/M and the phase differs by 180 from the first group. When N is an even number, M ═ N; when N is an odd number, M is N + 1. For the lower bridge arm, the phase difference between the 1 st group of carrier waves of the lower bridge arm and the 1 st group of carrier waves of the upper bridge arm is 180 degrees, and the rest settings are the same; the phase difference between the 2 nd group of carrier waves and the 2 nd group of carrier waves of the upper bridge arm is 180 degrees, and the rest settings are the same; the reference wave of the upper and lower bridge arms of each phase is divided into two parts according to the frequency: part 1 is a fundamental frequency sinusoidal reference wave, where the reference waves of the upper and lower arms are-y, respectivelyj1And yj1Comparing with the first group of carriers of the upper and lower bridge arms respectively to obtain n levelsuj1And nlj1(ii) a Part 2 is a frequency-doubled sinusoidal reference wave y output by the circulation controllerj2Comparing with the 2 nd group carrier of the upper and lower bridge arms respectively to obtain n levelsuj2And nlj2(ii) a Then obtaining the final input module numbers of the j-phase upper bridge arm and the j-phase lower bridge arm which are n respectivelyujAnd nljWherein n isuj＝nuj1+nuj2-M/2，nlj＝nlj1+nlj2-M/2; finally, according to a general voltage-sharing method based on capacitor voltage sequencing, the voltage-sharing method is carried out according to the number of finally-input modules of each bridge arm,The sequencing result of the capacitor voltage of all the modules and the direction of the current of the bridge arm, the upper bridge arm and the lower bridge arm can respectively obtain the PWM driving signal of each module, so that n is finally inputujAnd nljAnd (4) a module.
The phase calculation of the two groups of carriers of the A, B, C three-phase upper and lower bridge arms comprises the following steps:
(1) in each carrier period, a normalized A, B, C three-phase secondary sinusoidal reference wave signal output by the double-frequency loop controller is obtained through sampling and is marked as ya2、yb2、yc2；
(2) Calculating absolute value of width of voltage pulse | theta of three-phase bridge arm inductora|、|θb|、|θcL, where θj＝-yj2·M·π；
(3) For | thetaa|、|θb|、|θcI carries out ascending sequencing to obtain a serial number Kθa、Kθb、KθcWhere | θa|、|θb|、|θcThe serial number corresponding to the largest one in | is equal to 1, the serial number corresponding to the smallest one is equal to 3, otherwise, equal to 2.
(4) Calculating A, B, C the phase angle position of carrier wave when the three-phase sequencing serial numbers are 1, 2 and 3 respectively, and according to the serial number K in (3)θa、Kθb、KθcRespectively moving the two groups of carriers of the upper bridge arm and the lower bridge arm of each phase to corresponding phase positions;
in the step (4), for the A, B, C three-phase carrier phase angle positions, it is defined that in one carrier period, the horizontal phase distance from the starting point of the 1 st group of triangular carriers of the upper bridge arm to the negative peak point of the carrier is θsa、θsb、θscThe specific calculation method comprises the following steps:
for the phase A, the phase A is selected,
Kθawhen 1, θsa＝π；
KθaWhen the number is equal to 2, the alloy is put into a container,
Figure BDA0002875762260000061
Kθawhen the number is 3,
Figure BDA0002875762260000062
for the phase B, the phase B is selected,
Kθbwhen 1, θsb＝π；
KθbWhen the number is equal to 2, the alloy is put into a container,
Figure BDA0002875762260000063
Kθbwhen the number is 3,
Figure BDA0002875762260000064
for the phase C, the phase C is selected,
Kθcwhen 1, θsc＝π；
KθcWhen the number is equal to 2, the alloy is put into a container,
Figure BDA0002875762260000065
Kθcwhen the number is 3,
Figure BDA0002875762260000066
comparing the defined bridge arm reference wave with each group of carrier waves to obtain the number of levels, which specifically comprises the following steps: comparing the size of the reference wave with that of each triangular carrier wave respectively, and if the reference wave is greater than or equal to a certain carrier wave, the result is equal to 1; if the reference wave is smaller than a certain carrier wave, the result is equal to 0; and summing the comparison results of the reference wave and all the carriers in the group, namely the number of the levels after the reference wave and the carriers in the group are compared.
Y as shown in FIGS. 3 and 4, respectivelyj2>0 and yj2<And (3) a modulation result of j phase at 0. Taking FIG. 3 as an example, for the upper bridge arm, the fundamental frequency reference wave-yj1With W in group 1 carrierI_ujKIntersect, nuj1Between K-1 and K, a frequency-doubled reference wave yj2With W in the 2 nd group carrierII_uj(M/2+S)Intersect, nuj2At M/2+ SBetween-1 and M/2+ S. Thus, nujBetween K + S-2 and K + S-1. For the lower arm, fundamental reference wave yj1With W in group 1 carrierI_lj(N-K+1)Intersect, nlj1Between N-K and N-K +1, a frequency-doubled reference wave yj2With W in the 2 nd group carrierII_lj(M/2+S)Intersect, nlj2Between M/2+ S-1 and M/2+ S. Thus, nljBetween N-K + S-1 and N-K + S. The sum n of the numbers of the upper bridge arm and the lower bridge arm input modulesuj+nljIs not always equal to N. Thus, in each carrier period, two negative pulses appear on the bridge arm inductance, and the distance between the two pulses is always pi. By the same token, y can be obtainedj2<At 0, two positive pulses with a distance of pi appear on the bridge arm inductance. For the three-phase MMC, the analysis is easy to obtain, and the width of the three-phase pulse satisfies thetaa+θb+θ c0. Therefore, the three-phase carrier wave is moved to a specific phase, so that the pulses on the three-phase inductors are mutually offset, and the aims of eliminating zero-sequence voltage, further eliminating zero-sequence current and reducing high-frequency pulsating current on the direct current side are fulfilled.
Fig. 5 shows a case where the pulse voltage at A, B, C three-phase bridge arm inductance is shifted when the present invention is applied. WII_ua1、WII_ub1And WII_uc1The 1 st carrier wave in the 2 nd group of carrier waves of the three-phase upper bridge arm is used for the three-phase carrier wave phase displacement indication. In this case, the width of the three-phase pulse has a magnitude relation of | θa|>|θb|>|θcL, thus Kθa＝1，Kθb＝2，Kθc3. So the A phase carrier wave is kept still and the B phase carrier wave is moved to the left to pi- (| theta)a|-|θbI)/2, shift the C-phase carrier to the right to pi + (| theta)a|-|θcI))/2. At this time, the pulse voltages on the three-phase bridge arm inductors are mutually offset, and the sum of the pulse voltages is equal to zero. The zero sequence voltage is then eliminated. Therefore, zero sequence current can not be generated to flow into the direct current side, and therefore high-frequency pulsating current on the direct current side is reduced.
The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modifications made on the basis of the technical scheme according to the technical idea of the present invention fall within the protection scope of the present invention.

Claims (4)

1. A control method for reducing high-frequency pulsating current on a direct current side of a Modular Multilevel Converter (MMC), wherein A, B, C three phases of the Modular Multilevel Converter (MMC) respectively comprise an upper bridge arm and a lower bridge arm, and each bridge arm comprises N identical modules, is characterized by comprising the following steps of:
(1) 2 groups of isosceles triangle carriers with the same frequency are arranged for the upper bridge arm and the lower bridge arm of each phase:
for the upper bridge arm, the 1 st group comprises N carriers with the same phase, the N carriers are uniformly distributed in the range of [ -1,1] from bottom to top, and the N carriers have the same amplitude and are equal to 2/N; the 2 nd group contains M carriers with the same phase, the carriers are uniformly distributed in the range of [ -1,1] from bottom to top, the amplitudes are the same and equal to 2/M, and the phase difference between the 2 nd group and the 1 st group is 180 degrees; when N is an even number, M ═ N; when N is an odd number, M ═ N + 1; n represents a natural number;
for the lower bridge arm, the phase difference between the 1 st group of carrier waves of the lower bridge arm and the 1 st group of carrier waves of the upper bridge arm is 180 degrees, and the rest settings are the same; the phase difference between the 2 nd group of carrier waves and the 2 nd group of carrier waves of the upper bridge arm is 180 degrees, and the rest settings are the same;
(2) dividing the reference wave of the upper bridge arm and the lower bridge arm of each phase into two parts according to the frequency:
the first part is a fundamental frequency sinusoidal reference wave, wherein the reference waves of the upper and lower bridge arms are-y respectivelyj1And yj1Comparing the voltage with the 1 st group of carriers of the upper and lower bridge arms respectively to obtain n levelsuj1And nlj1Subscript j ═ a, b, c, each representing A, B, C three phases;
the second part is a frequency-doubled sinusoidal reference wave y output by the circulation controllerj2Comparing the two signals with the 2 nd group of carriers of the upper and lower bridge arms respectively to obtain n levelsuj2And nlj2；
Then obtaining the final input module numbers of the j-phase upper bridge arm and the j-phase lower bridge arm which are n respectivelyujAnd nljWherein n isuj＝nuj1+nuj2-M/2，nlj＝nlj1+nlj2-M/2；
(3) According to a voltage-sharing method based on capacitor voltage sequencing, PWM (pulse-width modulation) driving signals of each module of an upper bridge arm and a lower bridge arm are respectively obtained according to the number of finally-input modules of each bridge arm, the result of capacitor voltage sequencing of all modules and the direction of current of the bridge arm, and finally n are respectively inputujAnd nljAnd (4) a module.
2. The control method according to claim 1, wherein the phases of the two groups of carriers of the A, B, C three-phase upper and lower bridge arms are obtained by a control algorithm, and the method specifically comprises the following steps:
(101) in each carrier period, obtaining a normalized A, B, C three-phase double-frequency sine reference wave output by the double-frequency circulation controller, and recording the wave as ya2、yb2、yc2；
(102) Calculating the absolute value of the width of the voltage pulse | theta of the three-phase bridge arm inductora|、|θb|、|θcL, where θj＝-yj2·M·π；
(103) To | θa|、|θb|、|θcI carries out ascending sequencing to obtain a serial number Kθa、Kθb、KθcWhere | θa|、|θb|、|θcThe serial number corresponding to the largest one in | is equal to 1, the serial number corresponding to the smallest one is equal to 3, otherwise, the serial number is equal to 2;
(104) and A, B, C, calculating the phase angle positions of the carrier waves when the three-phase sequencing serial numbers are respectively 1, 2 and 3, and according to the serial number K in the step (103)θa、Kθb、KθcAnd respectively moving the two groups of carriers of the upper bridge arm and the lower bridge arm of each phase to corresponding phase positions.
3. The control method according to claim 2, characterized in that, in the step (104), for A, B, C three-phase carrier phase angle positions, a carrier period from the starting point of the 1 st group of triangular carriers of the upper bridge arm to the carrier is definedThe horizontal phase distance of the negative peak point of the wave is thetasa、θsb、θscThe specific calculation method comprises the following steps:
for the phase A, the phase A is selected,
Kθawhen 1, θsa＝π；
KθaWhen the number is equal to 2, the alloy is put into a container,
Figure FDA0003439219450000021
Kθawhen the number is 3,
Figure FDA0003439219450000022
for the phase B, the phase B is selected,
Kθbwhen 1, θsb＝π；
KθbWhen the number is equal to 2, the alloy is put into a container,
Figure FDA0003439219450000023
Kθbwhen the number is 3,
Figure FDA0003439219450000024
for the phase C, the phase C is selected,
Kθcwhen 1, θsc＝π；
KθcWhen the number is equal to 2, the alloy is put into a container,
Figure FDA0003439219450000025
Kθcwhen the number is 3,
Figure FDA0003439219450000026
4. the control method according to claim 1, wherein in step (2), the fundamental frequency sinusoidal reference wave and the frequency-doubled sinusoidal reference wave are respectively compared with each group of carriers to obtain the number of levels, specifically:
respectively comparing the reference wave with each triangular carrier, and if the reference wave is greater than or equal to the carrier, the result is equal to 1; if the reference wave is smaller than the carrier wave, the result is equal to 0; and summing the comparison results of the reference wave and all the carriers in the group, namely the number of the levels after the reference wave and the carriers in the group are compared.
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* Cited by examiner, † Cited by third party
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CN101951162A (en) * 2010-09-06 2011-01-19 东北电力大学 Pulse width control method of modular multilevel converter
JP2014096969A (en) * 2012-11-12 2014-05-22 Hitachi Ltd Power conversion apparatus and power conversion method
CN109149916A (en) * 2018-07-23 2019-01-04 东南大学 Modularization multi-level converter DC side pulsation of current suppressing method

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101951162A (en) * 2010-09-06 2011-01-19 东北电力大学 Pulse width control method of modular multilevel converter
JP2014096969A (en) * 2012-11-12 2014-05-22 Hitachi Ltd Power conversion apparatus and power conversion method
CN109149916A (en) * 2018-07-23 2019-01-04 东南大学 Modularization multi-level converter DC side pulsation of current suppressing method

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