CN104753379B - Mid-point voltage adjusting method for three-phase tri-level inverter - Google Patents

Mid-point voltage adjusting method for three-phase tri-level inverter Download PDF

Info

Publication number
CN104753379B
CN104753379B CN201510170375.7A CN201510170375A CN104753379B CN 104753379 B CN104753379 B CN 104753379B CN 201510170375 A CN201510170375 A CN 201510170375A CN 104753379 B CN104753379 B CN 104753379B
Authority
CN
China
Prior art keywords
msub
mrow
mtr
mtd
mfrac
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN201510170375.7A
Other languages
Chinese (zh)
Other versions
CN104753379A (en
Inventor
李丹
郑洪涛
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.)
Shanghai Zhaoneng Electric & Electronic Technology Co Ltd
Original Assignee
Shanghai Zhaoneng Electric & Electronic Technology 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 Shanghai Zhaoneng Electric & Electronic Technology Co Ltd filed Critical Shanghai Zhaoneng Electric & Electronic Technology Co Ltd
Priority to CN201510170375.7A priority Critical patent/CN104753379B/en
Publication of CN104753379A publication Critical patent/CN104753379A/en
Application granted granted Critical
Publication of CN104753379B publication Critical patent/CN104753379B/en
Expired - Fee Related 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
    • H02M7/487—Neutral point clamped inverters
    • 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
    • H02M7/53—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 using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/539—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with automatic control of output wave form or frequency
    • H02M7/5395—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 using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters with automatic control of output wave form or frequency by pulse-width modulation

Landscapes

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

Abstract

The present invention relates to a kind of mid-point voltage adjusting method for three-phase tri-level inverter, according to the maximum and minimum value and the difference of DC voltage of the three-phase bridge arm voltage of three-level inverter, the numerical value that the voltage vector of the corresponding three-phase bridge arm of PWM cycle can be increased or decreased simultaneously is calculated；A mid-point voltage adjustment factor is given, to solve the control time for obtaining switching device in three-phase bridge arm；By the control time according to PWM rule and the carrier wave ratio of three-level inverter compared with and generating the control instruction to drive switching device in the three-level inverter.The present invention realizes that the regulation of alignment voltage is controlled by the selection of switching variable, it is easy to accomplish, operation efficiency can be effectively improved.

Description

Neutral point voltage regulating method for three-phase three-level inverter
Technical Field
The invention relates to the field of inverter control, in particular to a method for adjusting midpoint voltage of a three-phase three-level inverter.
Background
The multi-level inverter is suitable for occasions with large capacity and high voltage and is applied more and more. The three-level inverter has a plurality of switching elements, the switching combination of which is configured as the output voltage of the inverter. The topological structure is characterized in that the maximum voltage borne by each power switch tube is 1/2 of the direct-current side voltage, and in addition, the phase voltage has three level states, and the phase voltage has one level more than that of a traditional two-level inverter, so the output waveform quality is high. Therefore, the converter with the structure has wide application in the fields of high-performance, medium-high voltage variable frequency speed regulation, active power filter devices, reactive power compensation of power systems and the like. However, this kind of converter adopts two capacitors connected in series to generate three levels, and due to the inconsistent characteristics of the switching devices and the fact that the midpoint potential participates in energy transmission during the energy conversion of the converter, the problem of voltage division of the two capacitors is not uniform, i.e. the midpoint balance problem is generated. If the neutral point potential is unbalanced, low-order harmonic waves can be generated on the alternating current output side, so that the output efficiency of the inverter is low, and meanwhile, the harmonic waves can also generate pulsating torque on the motor to influence the speed regulation performance of the motor; in addition, the voltage born by some switching tubes of the inverter is increased, so that the reliability of the system is reduced; finally, the midpoint potential fluctuation reduces the life of the dc side capacitor.
Disclosure of Invention
The invention aims to provide a simple and easily-realized adjusting method for neutral point voltage balance of a three-phase three-level inverter, which adopts special coordinate transformation and a specific vector transformation rule and realizes adjustment of neutral point voltage through selection of switching variables.
In order to achieve the above object, the technical solution of the present invention is to provide a midpoint voltage adjusting method for a three-phase three-level inverter, including the following steps:
according to three-phase bridge arm voltage V of three-level inverterA,VB,VCDefining the variable M as VA,VB,VCMaximum value of (1) and DC side voltage VdcThe difference of (a) represents the voltage vector of the three-phase arm corresponding to the PWM period by the variable MA number that can be increased simultaneously;
defining variable N as three-phase bridge arm voltage VA,VB,VCMinimum value of (1) and DC side voltage VdcBy the variable N, the voltage vectorA value that can be reduced simultaneously;
M＝Vdc-max(VA,VB,VC)
N＝Vdc-min(VA,VB,VC)
solving the control time T of the switching devices in the three-phase bridge arm according to the given midpoint voltage regulating coefficient kA,TB,TCWherein:
when the midpoint voltage does not need to be adjusted, taking k as 0:
when the midpoint voltage needs to be adjusted to be high, taking k epsilon (0, 1):
when the midpoint voltage needs to be adjusted to be low, k epsilon (-1,0) is taken:
the obtained control time TA,TB,TCAnd comparing the PWM modulation rule of the three-level inverter with a carrier wave to generate a control command for driving a switching device in the three-level inverter.
The three-phase three-level voltage vector in the three-level inverter satisfies the following relation:
wherein,for the current input reference voltage vector, TPWMIs the pulse width modulation period.
According to a given reference voltage UrCalculating to obtain the three-phase bridge arm voltage VA,VB,VCSo that its range satisfies [ -V ]dc,+Vdc]：
The invention solves the problem of midpoint balance by providing a midpoint voltage adjusting method for a three-level inverter. The invention only processes the modulation wave of the output PWM slightly, does not influence the integral control of the inverter, has simple digital realization and can effectively improve the operation efficiency.
Drawings
FIG. 1 is a typical circuit topology of a three-phase, three-level inverter of the present invention;
FIG. 2 is an analysis diagram illustrating that k taken (-1,1) does not affect the output voltage vector in the present invention;
FIG. 3 is a flow chart of the midpoint voltage balancing algorithm of the present invention;
fig. 4 shows a PWM waveform when k is 0 under certain input conditions;
fig. 5 is a PWM waveform of the present invention when k is 1 under the same input conditions as fig. 4;
fig. 6 shows the PWM waveform of the present invention when k is-1 under the same input conditions as in fig. 4.
Detailed Description
The following describes embodiments of the present invention with reference to the drawings.
The example of fig. 1 provides a typical circuit topology of a three-phase three-level inverter, and the neutral point voltage adjusting method of the invention is suitable for the three-phase three-level inverter and a similar power electronic system with three direct current input levels and outputting three-phase voltage.
In the output relation of the three-level inverter, the three-phase three-level voltage vector satisfies the following relation:
wherein,for the current vector of the input reference voltage,the calculated voltage vector of the three-phase bridge arm of the inverter corresponding to the PWM (pulse width modulation) period. T isPWMIs the pulse width modulation period, TA,TB,TCThe control time of three voltage bridge arms of the three-phase three-level inverter is respectively corresponding to the control time of the switching tube.
An example of a voltage vector composite graph is shown in FIG. 2, where A, B, C are three phase voltage coordinate axes, VrefIs an input reference voltage vector; lines of T1, T2 represent one set of vectors, lines of T1 ', T3' represent another set of vectors. According to the plane geometry principle, the vector synthesized by T1 and T2 and the vector synthesized by T1 'and T3' are both Vref. This means that the synthetic vector approach is not unique for a given reference vector.
That is to say that the first and second electrodes,forming an output according to vector combinational logicAs can be seen from this figure 2 of the drawings,increase simultaneouslyBy making large or small pairs of the same valueAre all identical. I.e. calculated for any instantIncreasing or decreasing the same value at the same time does not affect the output, however, this simultaneous increase or decrease value causes a change in the midpoint voltage; also, the value of this simultaneous increase or decrease is not arbitrary, but is limited by the characteristics of the inverter.
The flow chart of the point adjusting logic of the method for adjusting the midpoint voltage is shown in fig. 3, and the method directly adds an operation step in the original modulation mode without changing the modulation mode.
The calculation method comprises the following steps:
step 1, calculating V according to a modulation method of a three-level inverterA，VB，VC；
I.e. according to a given reference voltage UrCalculating to obtain three-phase bridge arm voltage V of corresponding three-level inverterA，VB，VC(ii) a Limited by the output relationship of the actual inverter, VA，VB，VCMust satisfy the range of [ -V ]dc,+Vdc]。
Thus, according to the SPWM (sinusoidal pulse Width modulation) modulation mode, obtaining
Step 2, defining two variables M and N which are respectively VA，VB，VCMaximum/minimum value of (1) and DC side voltage VdcA difference of (d);
that is, the numerical values obtained by the equations (4) and (5) are respectively defined asThe maximum value M, which may be increased at the same time, and the minimum value N, which may be decreased at the same time.
M＝Vdc-max(VA,VB,VC) (4)
N＝Vdc-min(VA,VB,VC) (5)
And 3, defining a middle point voltage regulating coefficient k, wherein the k range is (-1, 1). The k coefficient is given artificially, and corresponds to three conditions of midpoint voltage regulation, when k >0(0,1) needs to be regulated positively, k <0(-1,0) needs to be regulated negatively, and k is 0 and does not need to be regulated. The rule defined by k is that the closer the absolute value is to 0, the smaller the effect of the regulation, the closer the absolute value is to 1, and the faster the regulation speed.
Step 4, controlling according to the coefficient kThe three variables are simultaneously increased or decreased in numerical value, and are processed in three different conditions through formulas (6) to (8), so that the control time T of three voltage bridge arms of the corresponding three-phase three-level inverter is solvedA,TB,TCThereby achieving the purpose of controlling the midpoint voltage.
When no adjustment is required:
when the midpoint voltage is low, the voltage needs to be adjusted up:
when the midpoint voltage is high, the voltage needs to be adjusted down:
TA,TB,TCand comparing the modulation rule of the three-level inverter with the carrier to generate PWM driving. Thereby generating a control command for driving a plurality of switching devices of the three-level inverter according to a PWM modulation method of the inverter.
Fig. 4 shows a PWM waveform when k is 0 under certain input conditions of the present invention, where the portion filled with oblique lines is the effective portion of the PWM waveform. From the figure it can be seen that PWMA, PWMB is greater than 0 and PWMC is less than 0.
Fig. 5 shows the PWM waveform of the present invention under the same input condition as fig. 4, where the wave point filling part is the effective part added to the PWM waveform on the basis of fig. 4, and the grid filling part is the part reduced from the PWM waveform on the basis of fig. 4. The waveform differs from that of fig. 4 in that PWMA, PWMB, PWMC are simultaneously increased by M-Vdc-max(VA,VB,VC)。
Fig. 6 is a PWM waveform of the present invention at the same input condition as fig. 4 where k is-1 (negative regulation), wherein the part of the wave point filling is an effective part of the PWM waveform increased on the basis of fig. 4, and the part of the grid filling is a part of the PWM waveform decreased on the basis of fig. 4. The waveform differs from that of fig. 4 in that PWMA, PWMB, PWMC are reduced by N-V at the same timedc-min(VA,VB,VC)。
In summary, the midpoint voltage adjusting method of the present invention adopts a special coordinate transformation and a specific vector transformation rule, adjusts the midpoint voltage by selecting the switching variable, and is suitable for a three-phase three-level inverter system. The invention only processes the modulation wave of the output PWM slightly, does not influence the integral control of the inverter, has simple digital realization and can effectively improve the operation efficiency.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.

Claims (3)

1. A method for midpoint voltage regulation for a three-phase three-level inverter, comprising the steps of:
according to three-phase bridge arm voltage V of three-level inverterA,VB,VCDefining the variable M as VA,VB,VCMaximum value of (1) and DC side voltage VdcThe difference of (a) represents the voltage vector of the three-phase bridge arm corresponding to the pulse width modulation period by the variable MA number that can be increased simultaneously;
defining variable N as three-phase bridge arm voltage VA,VB,VCMinimum value of (1) and DC side voltage VdcBy the variable N, the voltage vectorA value that can be reduced simultaneously;
M＝Vdc-max(VA,VB,VC)
N＝Vdc-min(VA,VB,VC)
solving the control time T of the switching devices in the three-phase bridge arm according to the given midpoint voltage regulating coefficient kA,TB,TCWherein:
when the midpoint voltage does not need to be adjusted, taking k as 0:
<mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>A</mi> </msub> <mo>=</mo> <mfrac> <msub> <mi>V</mi> <mi>A</mi> </msub> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>B</mi> </msub> <mo>=</mo> <mfrac> <msub> <mi>V</mi> <mi>B</mi> </msub> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>C</mi> </msub> <mo>=</mo> <mfrac> <msub> <mi>V</mi> <mi>C</mi> </msub> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> </mtable> </mfenced>
when the midpoint voltage needs to be adjusted to be high, taking k epsilon (0, 1):
<mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>A</mi> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>V</mi> <mi>A</mi> </msub> <mo>+</mo> <mi>k</mi> <mo>&amp;times;</mo> <mi>M</mi> </mrow> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>B</mi> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>V</mi> <mi>B</mi> </msub> <mo>+</mo> <mi>k</mi> <mo>&amp;times;</mo> <mi>M</mi> </mrow> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>C</mi> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>V</mi> <mi>C</mi> </msub> <mo>+</mo> <mi>k</mi> <mo>&amp;times;</mo> <mi>M</mi> </mrow> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> </mtable> </mfenced>
when the midpoint voltage needs to be adjusted to be low, k epsilon (-1,0) is taken:
<mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>A</mi> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>V</mi> <mi>A</mi> </msub> <mo>+</mo> <mi>k</mi> <mo>&amp;times;</mo> <mi>M</mi> </mrow> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>B</mi> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>V</mi> <mi>B</mi> </msub> <mo>+</mo> <mi>k</mi> <mo>&amp;times;</mo> <mi>M</mi> </mrow> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>T</mi> <mi>C</mi> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>V</mi> <mi>C</mi> </msub> <mo>+</mo> <mi>k</mi> <mo>&amp;times;</mo> <mi>M</mi> </mrow> <msub> <mi>V</mi> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mfrac> </mrow> </mtd> </mtr> </mtable> </mfenced>
the obtained control time TA,TB,TCAnd comparing the PWM modulation rule of the three-level inverter with a carrier wave to generate a control command for driving a switching device in the three-level inverter.
2. The midpoint voltage adjustment method of claim 1,
the three-phase three-level voltage vector in the three-level inverter satisfies the following relation:
wherein,for the current input reference voltage vector, TPWMIs the pulse width modulation period.
3. The midpoint voltage adjustment method of claim 1,
according to a given reference voltage UrCalculating to obtain the three-phase bridge arm voltage VA,VB,VCSo that its range satisfies [ -V ]dc,+Vdc]：
<mrow> <mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <msub> <mi>V</mi> <mi>A</mi> </msub> <mo>=</mo> <msub> <mi>U</mi> <mi>r</mi> </msub> <mo>*</mo> <mi>s</mi> <mi>i</mi> <mi>n</mi> <mrow> <mo>(</mo> <mi>&amp;omega;</mi> <mi>t</mi> <mo>)</mo> </mrow> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>V</mi> <mi>B</mi> </msub> <mo>=</mo> <msub> <mi>U</mi> <mi>r</mi> </msub> <mo>*</mo> <mi>sin</mi> <mrow> <mo>(</mo> <mi>&amp;omega;</mi> <mi>t</mi> <mo>-</mo> <mfrac> <mrow> <mn>2</mn> <mi>&amp;pi;</mi> </mrow> <mn>3</mn> </mfrac> <mo>)</mo> </mrow> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>V</mi> <mi>C</mi> </msub> <mo>=</mo> <msub> <mi>U</mi> <mi>r</mi> </msub> <mo>*</mo> <mi>sin</mi> <mrow> <mo>(</mo> <mi>&amp;omega;</mi> <mi>t</mi> <mo>+</mo> <mfrac> <mrow> <mn>2</mn> <mi>&amp;pi;</mi> </mrow> <mn>3</mn> </mfrac> <mo>)</mo> </mrow> </mrow> </mtd> </mtr> </mtable> </mfenced> <mo>.</mo> </mrow>2
CN201510170375.7A 2015-04-10 2015-04-10 Mid-point voltage adjusting method for three-phase tri-level inverter Expired - Fee Related CN104753379B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510170375.7A CN104753379B (en) 2015-04-10 2015-04-10 Mid-point voltage adjusting method for three-phase tri-level inverter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510170375.7A CN104753379B (en) 2015-04-10 2015-04-10 Mid-point voltage adjusting method for three-phase tri-level inverter

Publications (2)

Publication Number Publication Date
CN104753379A CN104753379A (en) 2015-07-01
CN104753379B true CN104753379B (en) 2017-09-01

Family

ID=53592606

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510170375.7A Expired - Fee Related CN104753379B (en) 2015-04-10 2015-04-10 Mid-point voltage adjusting method for three-phase tri-level inverter

Country Status (1)

Country Link
CN (1) CN104753379B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109510496B (en) * 2018-12-03 2020-01-03 华中科技大学 Neutral point voltage balance control method and system for NPC three-level inverter without electrolytic capacitor

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7196919B2 (en) * 2005-03-25 2007-03-27 Tyco Electronics Power Systems, Inc. Neutral point controller, method of controlling and rectifier system employing the controller and the method
JP5176710B2 (en) * 2008-06-13 2013-04-03 株式会社安川電機 Neutral point clamp power converter and control method thereof
CN103401457B (en) * 2013-07-09 2015-07-01 西安交通大学 Carrier wave modulation method of voltage type three-level neutral point clamped converter

Also Published As

Publication number Publication date
CN104753379A (en) 2015-07-01

Similar Documents

Publication Publication Date Title
CN108123639B (en) Pulse width modulation method, pulse width modulation system and controller
US8471514B2 (en) Adaptive harmonic reduction apparatus and methods
EP3024132B1 (en) System and method for unified common mode voltage injection
JP6289675B2 (en) Power converter
CN111740635A (en) Double-loop control method of single-phase LC inverter
CN104410311B (en) Discontinuous PWM modulation midpoint balance method of three-level inverter
Banaei et al. Analysis of a generalized symmetrical multilevel inverter
GHolinezhad et al. Application of cascaded H-bridge multilevel inverter in DTC-SVM based induction motor drive
CN110912436B (en) Three-level converter synchronous carrier DPWM control method
CN113746108B (en) T-type three-level SAPF open circuit fault sequence model prediction fault tolerance control method
Yilmaz et al. FPGA-based space vector PWM and closed loop controllers design for the Z source inverter
CN110994964A (en) Modulation method for reducing alternating current voltage low-order harmonic waves of modular multilevel converter
JP4893151B2 (en) Space vector modulation method for AC-AC direct conversion device
CN104753379B (en) Mid-point voltage adjusting method for three-phase tri-level inverter
CN112787529A (en) Direct current prediction control method and system for T-type three-level converter
CN109600061B (en) Novel fixed-frequency model prediction current control method based on dynamic weight
Salari et al. A novel 49-level asymmetrical modular multilevel inverter: analysis, comparison and validation
CN105119314B (en) A kind of dynamic switching method that control is balanced for power unit direct voltage
CN109039124B (en) MMC capacitor voltage balance control method based on phase-shift space vector modulation
Votava et al. Improved model predictive control with extended horizon for dual inverter with real-time minimization of converter power losses
CN103715875A (en) Switching frequency adjusting method and device and inverters
WO2015005471A1 (en) Power conversion device, power storage system, and power conversion method
CN111682786A (en) Improved control method of cascaded PWM rectifier
Ghosh et al. A simplified space vector PWM technique of three-level diode clamped inverter with rectifier side direct power control topology
Nordin et al. Fuzzy-PI Torque and Flux Controllers for DTC with Multilevel Inverter of Induction Machines

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20170901

CF01 Termination of patent right due to non-payment of annual fee