CN107404244B - 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 PDFInfo
- Publication number
- CN107404244B CN107404244B CN201710559849.6A CN201710559849A CN107404244B CN 107404244 B CN107404244 B CN 107404244B CN 201710559849 A CN201710559849 A CN 201710559849A CN 107404244 B CN107404244 B CN 107404244B
- Authority
- CN
- China
- Prior art keywords
- phase
- triple
- modulating wave
- modulation
- photovoltaic inverter
- 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.)
- Active
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
- 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
Landscapes
- 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 is to inject the smooth triple-frequency harmonics of waveform in sinusoidal SPWM modulating wave and obtain SVPWM modulating wave, carries out PWM modulation using SVPWM modulating wave.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 brings, and can improve the harmonic characterisitic of output electric current, obtain more preferable modulation effect.
Description
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 technique
The existing common topological structure of three-phase string type photovoltaic combining inverter is T-type three-level topology, system structure
As shown in Fig. 1.
System is by DC input source Edc, T-type three-level topology, LC filter, power grid composition.Uan、Ubn、UcnIt is defeated for inverter
Voltage (also referred to as modulation voltage) out, Ia、Ib、IcFor inverter output current, L and C1 constitute output filter.Wherein, in order to press down
The neutral point of the filter capacitor C1 of output filter is connected to the midpoint of DC bus by the common mode current of photovoltaic DC-to-AC converter processed.
Available modulation system has carrier wave sine SPWM modulation and Space vector modulation SVPWM modulation.Wherein SPWM modulation system because
DC bus-bar voltage utilization rate is low, and there are DC bus-bar voltage height, and outputting inductance current ripples are big, and loss is big, and system effectiveness is low
The problem of, current less use.It is substantially commonly SVPWM modulation system, the working method of SVPWM is illustrated by taking Fig. 1 as an example.Figure
In 1, each bridge arm has totally 4 power tubes, and Sx1 pipe and Sx3 pipe therein are complementary, and Sx2 pipe and Sx4 pipe are complementary, and x is a or b or c,
Then there are three types of output states, respectively P, O, N for tool altogether.P-state indicates upper two pipes Sx1, Sx2 conducting, and O state indicates that intermediate two manage
Sx2, Sx3 conducting, N-state indicates following two pipes Sx3, Sx4 conducting, corresponding such as the following table 1.
The relationship of 1 three-level three-phase inverter switching device tubulose state of table and output voltage (by taking A phase as an example)
Three groups of switching variable S of T-type three-level three-phase inverterA、SB、SCCan distinguish value be P, O, N, i.e., 33=27
Group switch combination state.Again since 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, this 19 voltage vectors are known 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 in SPWM modulating wave:
Wherein, Varef、VbrefAnd VcrefFor the three phase sine modulating wave of inverter.
Triple-frequency harmonics indicates are as follows:
Voffset=-(max (Varef,Vbref,Vcref)+min(Varef,Vbref,Vcref))/2 (2)
Actual modulation waveform is by taking A phase as an example, as shown in Figure 3.U in figureao、Uon、UanRespectively sine SPWM modulating wave
(Varef), the third-harmonic component waveform (V of equivalent injectionoffset), practical SVPWM output modulating wave.In from the graph
It can be seen that triple-frequency harmonics UonThere is more violent slope variation at peak value, because of UonPractical is the common mode electricity of system
Pressure, this big slope variation of common-mode voltage will lead to common mode current increase, common mode current meeting actual influence to output electric current
Harmonic characterisitic.
Summary of the invention
And bring harmonic characterisitic excessive for the slope variation due to triple-frequency harmonics that the object of the present invention is to provide a kind of
Problem so as to improve work mould electric current, and then improves the PWM method of output current harmonics characteristic.
In order to achieve the above objectives, the technical solution adopted by the present invention is that:
A kind of PWM method 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 wave and obtains SVPWM modulating wave, is carried out using the SVPWM modulating wave
PWM modulation.
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、VcrefRespectively sine SPWM modulating wave described in three-phase；Uao、Ubo、UcoRespectively three-phase is being just
String modulation voltage；MAXPWMFor the maximum output modulation voltage of the three-phase photovoltaic inverter；Uaopeak、Ubopeak、UcopeakRespectively
For the peak value of three phase sine modulation voltage；UonFor the triple-frequency harmonics.
Due to the above technical solutions, the present invention has the following advantages over the prior art: the present invention solves altogether
The problem of mode voltage slope is mutated and brings can improve the harmonic characterisitic of output electric current, obtain more preferable modulation effect.
Detailed description of the invention
Attached drawing 1 is the T-type three-level topology schematic diagram of existing photovoltaic combining inverter.
Attached drawing 2 is basic voltage vectors figure in T-type three-level topology.
Attached drawing 3 is existing SVPWM modulation waveform figure (by taking A phase as an example).
Attached drawing 4 is PWM modulation waveform diagram of the invention (by taking A phase as an example).
Attached drawing 5 is the three-phase inversion current simulations figure of tradition SVPWM modulation.
Attached drawing 6 is the common mode current analogous diagram of tradition SVPWM modulation.
Attached drawing 7 is total harmonic distortion (THD) value schematic diagram of PWM modulation of the invention.
Attached drawing 8 is the three-phase inversion current simulations figure of PWM modulation of the invention.
Attached drawing 9 is the common mode current analogous diagram of PWM modulation of the invention.
Attached drawing 10 is total harmonic distortion (THD) value schematic diagram of PWM modulation of the invention.
Specific embodiment
The invention will be further described for embodiment shown in reference to the accompanying drawing.
Embodiment one: a kind of PWM method improving three-phase photovoltaic inverter output current harmonics characteristic, are as follows: pass through
Algorithm changes the waveform of the triple-frequency harmonics in injection SPWM modulating wave, i.e., three of waveform smoothly are injected in sinusoidal SPWM modulating wave
Subharmonic and obtain SVPWM modulating wave, utilize the SVPWM modulating wave carry out PWM modulation.Common-mode voltage slope is solved with this
Change big problem, improves work mould electric current, and then improve the harmonic characterisitic of output electric current.In general, making in the waveform of triple-frequency harmonics
Peak Slope, which tends to 0, can be obtained 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、VcrefRespectively sine SPWM modulating wave described in three-phase；Uao、Ubo、UcoRespectively three-phase
Sine Modulated voltage；MAXPWMFor the maximum output modulation voltage of the three-phase photovoltaic inverter；Uaopeak、Ubopeak、UcopeakPoint
Not Wei three phase sine modulation voltage peak value；UonFor the triple-frequency harmonics.Then each waveform is as shown in Fig. 4.There it can be seen that
UonSlope variation at peak value is more smooth.
Establish the validity of Validation of Simulation Models above scheme, simulation parameters such as the following table 2.
2 simulation parameter of table
| 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 |
| Network voltage frequency | fg=50Hz |
| Network voltage virtual value | eRMS=220V |
Traditional SVPWM modulation and the modulation system simulation result invented are compared as shown in Fig. 5 to Figure 10.
By the comparison of Fig. 5 to Figure 10 as can be seen that modulator approach of the invention is not only in total harmonic distortion (THD) value
Better than traditional SVPWM mode (3.49% comparison 3.75%), and there is also advantages on subharmonic.Traditional SVPWM mode,
Triple-frequency harmonics content 1.5%, and 5 times, 7 times, etc. odd harmonics it is relatively high, and modulator approach of the invention, triple-frequency harmonics
Content is 1.2%, other each harmonic contents will also be lower than SVPWM.Therefore the present invention solves the slope mutation of common-mode voltage,
Improve the harmonic characterisitic of output electric 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 cans understand the content of the present invention and implement it accordingly, and it is not intended to limit the scope of the present invention.It is all according to the present invention
Equivalent change or modification made by Spirit Essence, should be covered by the protection scope of the present invention.
Claims (2)
1. a kind of 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 wave and obtains modulating wave, carries out PWM modulation using the modulating wave；It is described
Triple-frequency harmonics is obtained by following three formula:
Formula one:
Formula two:
Formula three:Wherein: Varef、Vbref、VcrefRespectively sine SPWM tune described in three-phase
Wave processed；Uao、Ubo、UcoRespectively three phase sine modulation voltage；MAXPWMIt is modulated for the maximum output of the three-phase photovoltaic inverter
Voltage；Uaopeak、Ubopeak、UcopeakThe respectively peak value of three phase sine modulation voltage；UonFor the triple-frequency harmonics.
2. the PWM method according to claim 1 for improving three-phase photovoltaic inverter output current harmonics characteristic, special
Sign is: Peak Slope tends to 0 in the waveform of the triple-frequency harmonics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710559849.6A CN107404244B (en) | 2017-07-11 | 2017-07-11 | Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710559849.6A CN107404244B (en) | 2017-07-11 | 2017-07-11 | Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107404244A CN107404244A (en) | 2017-11-28 |
| CN107404244B true CN107404244B (en) | 2019-09-06 |
Family
ID=60404624
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710559849.6A Active CN107404244B (en) | 2017-07-11 | 2017-07-11 | Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107404244B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019081503A1 (en) * | 2017-10-27 | 2019-05-02 | 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 |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5221261B2 (en) * | 2008-09-24 | 2013-06-26 | トヨタ自動車株式会社 | Rotating electrical machine control system |
| CN102723889B (en) * | 2012-07-03 | 2014-11-05 | 华为技术有限公司 | Inverter and pulse width modulation (PWM) method thereof |
| JP6065790B2 (en) * | 2013-09-11 | 2017-01-25 | トヨタ自動車株式会社 | Electric motor control device |
| CN103545841B (en) * | 2013-10-23 | 2016-10-05 | 华为技术有限公司 | The control method of a kind of inverter, device and inverter system |
| JP6056778B2 (en) * | 2014-01-24 | 2017-01-11 | 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 |
-
2017
- 2017-07-11 CN CN201710559849.6A patent/CN107404244B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN107404244A (en) | 2017-11-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106100430B (en) | The carrier wave implementation method of the low common-mode voltage modulation of three-phase five-level inverter | |
| CN106981976B (en) | The method of T-type three-level three-phase inverter inhibition middle line common mode current | |
| CN105305863B (en) | A kind of three level NPC inverter neutral-point potential balance control methods | |
| CN103779874B (en) | The non-isolated grid-connected electricity generation system of single-stage boost inverter and control method thereof | |
| CN103532420B (en) | Dual-three-level online-topology switchable inverter | |
| CN105978374A (en) | Neutral-point voltage balance and common-mode voltage suppression method for three-level inverter | |
| CN107404244B (en) | Improve the PWM method of three-phase photovoltaic inverter output current harmonics characteristic | |
| CN105245123B (en) | Three-phase neutral-point-clamped three-level inverter one-dimensional modulation common mode current suppressing method | |
| CN106921306A (en) | The level three-phase inverter of T-shaped active clamp type five and parallel network reverse electricity generation system | |
| CN106169879A (en) | Revise VIENNA rectifier modulator approach, controller and the system injecting zero-sequence component | |
| CN105226982A (en) | A kind of three level NPC inverter midpoint potential balance control method based on mid point electric current | |
| CN106961225A (en) | discontinuous space vector pulse width modulation method and inverter | |
| CN107302317B (en) | The carrier wave implementation method of three-phase five-level inverter drain current suppressing | |
| CN104811071A (en) | Photovoltaic inverter and passive decoupling restraining method based on non-isolated LCL filtering | |
| CN104767365A (en) | T type three-level DC/AC converter direct voltage ripple compensation system and method | |
| CN108683351B (en) | Hybrid modulation method, controller and the system of a kind of source Z three-level inverter | |
| Waware et al. | A review of multilevel inverter based active power filter | |
| CN206547056U (en) | The T-shaped level three-phase inverter of active clamp type five and parallel network reverse electricity generation system | |
| CN106208131B (en) | Multilevel Inverters topological structure for new energy access and active distribution network | |
| Liu et al. | Neutral-point voltage balance control and oscillation suppression for VIENNA rectifier | |
| Moradi et al. | Improvement of the modulation method for single-phase transformerless photovoltaic conergy inverter for reactive power injection capability | |
| CN106505898A (en) | Z sources NPC three-level inverter invariable power grid-connection control systems based on SVPWM | |
| Ma et al. | A transformation method from conventional three phases full-bridge topology to conergy NPC topology | |
| Soomro et al. | Optimal design of a single-phase APF based on PQ theory | |
| CN104795980B (en) | Direct-current voltage ripple compensation system and method based on variable carrier SPWM (sinusoidal pulse width modulation) method |
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 | ||
| CP03 | Change of name, title or address |
Address after: 215000 No. 90, Zijin Road, high tech Zone, Suzhou, Jiangsu Patentee after: Goodway Technology Co.,Ltd. Address before: 215163 No. 189 Kunlun mountain road, hi tech Zone, Suzhou, Jiangsu Patentee before: JIANGSU GOODWE POWER SUPPLY TECHNOLOGY Co.,Ltd. |
|
| CP03 | Change of name, title or address |