CN107404244A - Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic - Google Patents

Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic Download PDF

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Publication number
CN107404244A
CN107404244A CN201710559849.6A CN201710559849A CN107404244A CN 107404244 A CN107404244 A CN 107404244A CN 201710559849 A CN201710559849 A CN 201710559849A CN 107404244 A CN107404244 A CN 107404244A
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China
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output current
triple
phase
pwm
photovoltaic inverter
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CN201710559849.6A
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CN107404244B (en
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曾维波
蒋峰
杨勇
黄敏
方刚
卢进军
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Goodwe Technologies Co Ltd
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JIANGSU GOODWE POWER SUPPLY TECHNOLOGY Co Ltd
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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
    • H02M1/12—Arrangements for reducing harmonics from ac input or output
    • 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
    • H02M1/12—Arrangements for reducing harmonics from ac input or output
    • H02M1/123—Suppression of common mode voltage or current
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

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

Abstract

The present invention relates to a kind of PWM method for improving three-phase photovoltaic inverter output current harmonics characteristic, this method obtains SVPWM modulating waves to inject the smooth triple-frequency harmonics of waveform in sinusoidal SPWM modulating waves, and PWM is carried out using SVPWM modulating waves.Peak Slope tends to 0 in the waveform of triple-frequency harmonics.The present invention solves the problems, such as the mutation of common-mode voltage slope and brought, and can improve the harmonic characterisitic of output current, obtain more preferable modulation effect.

Description

Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic
Technical field
The invention belongs to field of photovoltaic power generation, and in particular to one kind can improve three-phase photovoltaic inverter output current harmonics The PWM method of characteristic.
Background technology
The conventional topological structure of existing three-phase group string data photovoltaic combining inverter is T-shaped three-level topology, system architecture As shown in Figure 1.
System is by DC input sources Edc, T-shaped three-level topology, LC wave filters, power network composition.Uan、Ubn、UcnIt is defeated for inverter Go out voltage (also referred to as modulation voltage), Ia、Ib、IcFor inverter output current, L and C1 form output filter.Wherein, in order to press down The common mode current of photovoltaic DC-to-AC converter processed, the filter capacitor C1 of output filter neutral point is connected to the midpoint of dc bus. Available modulation system has carrier wave sine SPWM modulation and Space vector modulation SVPWM modulation.Wherein SPWM modulation systems because DC bus-bar voltage utilization rate is low, DC bus-bar voltage height be present, and outputting inductance current ripples are big, and loss is big, and system effectiveness is low The problem of, current less use.Conventional substantially SVPWM modulation systems, SVPWM working method is illustrated by taking Fig. 1 as an example.Figure In 1, each bridge arm has totally 4 power tubes, and Sx1 pipes and Sx3 pipes therein are complementary, and Sx2 pipes and Sx4 pipes are complementary, and x is a or b or c, Then there are three kinds of output states, respectively P, O, N altogether.P-state represents upper two pipes Sx1, Sx2 conducting, and O state represents that middle two manage Sx2, Sx3 are turned on, and N-state represents following two pipes Sx3, Sx4 conducting, corresponding such as table 1 below.
The relation of the three-level three-phase inverter switching device tubulose state of table 1 and output voltage (by taking A phases as an example)
Three groups of switching variable S of T-shaped three-level three-phase inverterA、SB、SCIt is P, O, N, i.e., 3 that value, which can be distinguished,3=27 Group switch combination state.Again because a voltage vector can correspond to multiple combinations of states, so this 27 output state combinations, 19 voltage vectors have only been corresponded to altogether, and this 19 voltage vectors are referred to as basic voltage vectors.As Fig. 2 is three-level inverter Voltage vector distribution map, 19 basic voltage vectors all illustrate out in fig. 2.
SVPWM modulation is actually equivalent to be filled with third-harmonic component among SPWM modulating waves：
Wherein, Varef、VbrefAnd VcrefFor the three phase sine modulating wave of inverter.
Triple-frequency harmonics is expressed as：
Voffset=-(max (Varef,Vbref,Vcref)+min(Varef,Vbref,Vcref))/2 (2)
Actual modulation waveform is by taking A phases as an example, as shown in Figure 3.U in figureao、Uon、UanRespectively sinusoidal SPWM modulating waves (Varef), the third-harmonic component waveform (V of equivalent injectionoffset), actual SVPWM output modulating wave.In from the graph As can be seen that triple-frequency harmonics UonMore violent slope variation at peak value be present, because UonThe actual common mode electricity for system Pressure, this big slope variation of common-mode voltage can cause common mode current to increase, and common mode current meeting actual influence arrives output current Harmonic characterisitic.
The content of the invention
It is an object of the invention to provide a kind of harmonic characterisitic brought for excessive due to the slope variation of triple-frequency harmonics Problem, so as to improve work mould electric current, and then improve the PWM method of output current harmonics characteristic.
To reach above-mentioned purpose, the technical solution adopted by the present invention is：
A kind of PWM method for improving three-phase photovoltaic inverter output current harmonics characteristic, this method are in sine The smooth triple-frequency harmonics of waveform is injected in SPWM modulating waves and obtains SVPWM modulating waves, is carried out using the SVPWM modulating waves PWM.
Preferably, Peak Slope tends to 0 in the waveform of the triple-frequency harmonics.
Preferably, the triple-frequency harmonics is obtained by following three formula：
Formula one：
Formula two：
Formula three：
Wherein：Varef、Vbref、VcrefSinusoidal SPWM modulating waves respectively described in three-phase；Uao、Ubo、UcoRespectively three phase sine is adjusted Voltage processed；MAXPWMFor the maximum output modulation voltage of the three-phase photovoltaic inverter；Uaopeak、Ubopeak、UcopeakRespectively three The peak value of phase Sine Modulated voltage；UonFor the triple-frequency harmonics.
Because above-mentioned technical proposal is used, the present invention has following advantages compared with prior art：The present invention solves altogether The problem of mode voltage slope is mutated and brought, can improve the harmonic characterisitic of output current, obtain more preferable modulation effect.
Brief description of the drawings
Accompanying drawing 1 is the T-shaped three-level topology schematic diagram of existing photovoltaic combining inverter.
Accompanying drawing 2 is basic voltage vectors figure in T-shaped three-level topology.
Accompanying drawing 3 is existing SVPWM modulation waveforms figure (by taking A phases as an example).
Accompanying drawing 4 is PWM oscillogram of the invention (by taking A phases as an example).
Accompanying drawing 5 is the three-phase inversion current simulations figure of traditional SVPWM modulation.
Accompanying drawing 6 is the common mode current analogous diagram of traditional SVPWM modulation.
Accompanying drawing 7 is total harmonic distortion (THD) value schematic diagram of the PWM of the present invention.
Accompanying drawing 8 is the three-phase inversion current simulations figure of the PWM of the present invention.
Accompanying drawing 9 is the common mode current analogous diagram of the PWM of the present invention.
Accompanying drawing 10 is total harmonic distortion (THD) value schematic diagram of the PWM of the present invention.
Embodiment
The invention will be further described for shown embodiment below in conjunction with the accompanying drawings.
Embodiment one：A kind of PWM method for improving three-phase photovoltaic inverter output current harmonics characteristic, it is：Pass through Algorithm changes the waveform of the triple-frequency harmonics in injection SPWM modulating waves, i.e., three of waveform smoothly are injected in sinusoidal SPWM modulating waves Subharmonic and obtain SVPWM modulating waves, utilize the SVPWM modulating waves carry out PWM.Solves common-mode voltage slope with this Change the problem of big, improve work mould electric current, and then improve the harmonic characterisitic of output current.Generally, make in the waveform of triple-frequency harmonics Peak Slope tends to 0 and can obtain the smooth triple-frequency harmonics of waveform.
For example, the triple-frequency harmonics is obtained by following three formula：
Formula one：
Formula two：
Formula three：
In above formula：Varef、Vbref、VcrefSinusoidal SPWM modulating waves respectively described in three-phase；Uao、Ubo、UcoRespectively three phase sine Modulation voltage；MAXPWMFor the maximum output modulation voltage of the three-phase photovoltaic inverter；Uaopeak、Ubopeak、UcopeakRespectively The peak value of three phase sine modulation voltage；UonFor the triple-frequency harmonics.Then each waveform is as shown in Figure 4.There it can be seen that Uon Slope variation at peak value is more smooth.
Establish the validity of Validation of Simulation Models such scheme, simulation parameters such as table 2 below.
The simulation parameter of table 2
Rated power P=30kw
Filter inductance L=0.5mH
Filter capacitor C=5 μ F
Bus filter capacitor Cp=CN=300uF
Inverter switching frequency fs=20kHz
Line voltage frequency fg=50Hz
Line voltage virtual value eRMS=220V
The modulation system simulation result that traditional SVPWM is modulated and invented is to such as shown in Fig. 5 to Figure 10.
By Fig. 5 to Figure 10 contrast as can be seen that the modulator approach of the present invention is not only in total harmonic distortion (THD) value Better than traditional SVPWM modes (3.49% contrast 3.75%), and there is also advantage on subharmonic.Traditional SVPWM modes, Triple-frequency harmonics content 1.5%, and 5 times, it is 7 times, higher etc. odd harmonics, and the modulator approach of the present invention, triple-frequency harmonics Content is 1.2%, and other each harmonic contents will also be less than SVPWM.Therefore the present invention solves the slope mutation of common-mode voltage, Improve the harmonic characterisitic of output current.
The above embodiments merely illustrate the technical concept and features of the present invention, and its object is to allow person skilled in the art Scholar can understand present disclosure and implement according to this, and it is not intended to limit the scope of the present invention.It is all according to the present invention The equivalent change or modification that Spirit Essence is made, it should all be included within the scope of the present invention.

Claims (3)

  1. A kind of 1. PWM method for improving three-phase photovoltaic inverter output current harmonics characteristic, it is characterised in that：In sine The smooth triple-frequency harmonics of waveform is injected in SPWM modulating waves and obtains SVPWM modulating waves, is carried out using the SVPWM modulating waves PWM.
  2. 2. the PWM method according to claim 1 for improving three-phase photovoltaic inverter output current harmonics characteristic, it is special Sign is：Peak Slope tends to 0 in the waveform of the triple-frequency harmonics.
  3. 3. the PWM method according to claim 1 or 2 for improving three-phase photovoltaic inverter output current harmonics characteristic, It is characterized in that：The triple-frequency harmonics is obtained by following three formula：
    Formula one：
    Formula two：
    Formula three：
    Wherein：Varef、Vbref、VcrefSinusoidal SPWM modulating waves respectively described in three-phase；Uao、Ubo、UcoRespectively three phase sine is adjusted Voltage processed；MAXPWMFor the maximum output modulation voltage of the three-phase photovoltaic inverter；Uaopeak、Ubopeak、UcopeakRespectively three The peak value of phase Sine Modulated voltage；UonFor the triple-frequency harmonics.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111342677A (en) * 2018-12-18 2020-06-26 协欣电子工业股份有限公司 Power converter
CN111446874A (en) * 2020-05-06 2020-07-24 西南交通大学 Single-phase boost common-mode inverter and modulation method thereof
US20200244184A1 (en) * 2017-10-27 2020-07-30 Abb Schweiz Ag Control of delta-connected converter

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100072927A1 (en) * 2008-09-24 2010-03-25 Denso Corporation Rotary electric machine control system
CN102723889A (en) * 2012-07-03 2012-10-10 华为技术有限公司 Inverter and pulse width modulation (PWM) method thereof
CN103545841A (en) * 2013-10-23 2014-01-29 华为技术有限公司 Control method and device of inverter and inverter system
CN104578807A (en) * 2015-01-13 2015-04-29 台安科技(无锡)有限公司 Three-phase output voltage balance adjusting method based on phrase voltage control
JP2015139345A (en) * 2014-01-24 2015-07-30 トヨタ自動車株式会社 non-contact power transmission system
CN105556830A (en) * 2013-09-11 2016-05-04 丰田自动车株式会社 Electric motor control apparatus and electric motor control method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100072927A1 (en) * 2008-09-24 2010-03-25 Denso Corporation Rotary electric machine control system
CN102723889A (en) * 2012-07-03 2012-10-10 华为技术有限公司 Inverter and pulse width modulation (PWM) method thereof
CN105556830A (en) * 2013-09-11 2016-05-04 丰田自动车株式会社 Electric motor control apparatus and electric motor control method
CN103545841A (en) * 2013-10-23 2014-01-29 华为技术有限公司 Control method and device of inverter and inverter system
JP2015139345A (en) * 2014-01-24 2015-07-30 トヨタ自動車株式会社 non-contact power transmission system
CN104578807A (en) * 2015-01-13 2015-04-29 台安科技(无锡)有限公司 Three-phase output voltage balance adjusting method based on phrase voltage control

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200244184A1 (en) * 2017-10-27 2020-07-30 Abb Schweiz Ag Control of delta-connected converter
CN111342677A (en) * 2018-12-18 2020-06-26 协欣电子工业股份有限公司 Power converter
CN111446874A (en) * 2020-05-06 2020-07-24 西南交通大学 Single-phase boost common-mode inverter and modulation method thereof

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