CN101567567A - Carrier shifting inversion large power photovoltaic grid-connection system and control method thereof - Google Patents
Carrier shifting inversion large power photovoltaic grid-connection system and control method thereof Download PDFInfo
- Publication number
- CN101567567A CN101567567A CNA2009101170189A CN200910117018A CN101567567A CN 101567567 A CN101567567 A CN 101567567A CN A2009101170189 A CNA2009101170189 A CN A2009101170189A CN 200910117018 A CN200910117018 A CN 200910117018A CN 101567567 A CN101567567 A CN 101567567A
- Authority
- CN
- China
- Prior art keywords
- inversion
- parallel
- unit
- grid
- carrier
- 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.)
- Pending
Links
Images
Classifications
-
- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/60—Planning or developing urban green infrastructure
-
- 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
Abstract
The invention relates to a carrier shifting inversion large power photovoltaic grid-connection system and a control method thereof. The system is characterized in that a plurality of parallelly connected inverter units having the same internal structure is disposed, a DC bus is shared thereby, and the AC output terminals of all inversion units are parallelly connected, and connected to the electric grid through an output transformer; each inversion unit parallelly disposed is in three phase inversion structure, the inversion output side is parallelly connected through a three-phase inductor L. The switch modulation of each grid-connection inversion unit is controlled by carrier shifting PWM control, as a result output current pulse ripple of each inversion unit is shifted by a defined angle, and current ripple of each unit counteracts with each other during integration, so that current ripple content is greatly reduced after integration.
Description
Technical field
The present invention relates to the control method of large power photovoltaic grid-connection system and system, more specifically the say so a kind of large power photovoltaic grid-connection system of carrier shifting inversion control and the control method of system thereof.
Background technology
Along with new forms of energy more and more are subject to people's attention, solar power generation has also welcome the more wide development world.The pv grid-connected plant of MW class is development trend and the direction that following solar energy utilizes, therefore the supporting with it high-power parallel network reverse device emphasis that is present photovoltaic area research.
For high-power photovoltaic synchronization contravariant device, reduce the percent harmonic distortion of grid-connected current, improving the fail safe and the efficient of system and reducing system cost is the key of system design.
High-power photovoltaic synchronization contravariant device can be by selecting high-power switch device for use, or device is organized mode in parallel more and is realized dilatation, but the switching frequency of high power device is generally not high, if guarantee the grid-connected current quality, must strengthen the ac filter inductance value, therefore increase the volume and the design difficulty of system; If according to existing method design filter inductance, along with the increase of power system capacity, the corresponding minimizing of filter inductance value meeting, thus cause the pulsation ripple of grid-connected current to increase.
Summary of the invention
The present invention is for avoiding above-mentioned existing in prior technology weak point, a kind of carrier shifting inversion large power photovoltaic grid-connection system and control method thereof being provided, with the increase power system capacity, to improve the grid-connected current quality of grid-connected system.
Technical solution problem of the present invention adopts following technical scheme:
The design feature of carrier shifting inversion large power photovoltaic grid-connection system of the present invention is:
It is parallel with one another that a plurality of inversion units with identical inner structure are set, the shared dc bus of described each inversion unit, and the ac output end of each inversion unit is parallel with one another, and is connected on the electrical network through output transformer;
Each inversion unit of described parallel connection is the three-phase inversion structure, and the inversion outlet side is in parallel behind three pole reactor L.
The characteristics of large power photovoltaic grid-connection system carrier shifting inversion control method of the present invention are:
The switch modulation of described each parallel network reverse unit is to adopt carrier phase PWM control, in order to eliminate output current ripple; For the grid-connected system with n parallel inverter unit, wherein the carrier phase angle θ of i inversion unit calculates according to following formula and receives:
θ＝(2*π*i)/n*k
Wherein, n is a unit in parallel number; K is a carrier wave ratio; The scope of i is 0≤i＜n.
Each inversion unit has identical modulating wave in the system of the present invention, and the carrier phase proper angle, because every total mutually output current of grid-connected system equals the electric current sum of a plurality of parallel inverters unit of corresponding output phase, carrier phase makes the also phase shift certain angle of output current pulsation ripple of each inversion unit, each cell current ripple is cancelled each other when synthetic, thereby has significantly reduced the current ripples content after synthesizing.This method is compared with traditional scheme, under same carrier frequency, same filter inductance condition, can significantly reduce current ripples, and the total capacity of device do not increase, and is good, safe than the direct parallel current-sharing of power model.
Compared with the prior art, beneficial effect of the present invention is embodied in:
1, the present invention is applicable to the high-power grid-connecting apparatus that inversion unit is parallel extended, inversion unit adopts the control of phase-shifting carrier wave switch, make the fundametal compoment of output current in parallel equal the fundametal compoment sum of unit output current, and the harmonic component of unit in parallel output current is cancelled out each other, thereby reduces the percent harmonic distortion of output current in parallel.Compare with the system of direct use high-power switch device, even under identical modulating frequency, output current harmonics aberration rate of the present invention also has significantly reduction.
2, the equivalent switching frequency height of system of the present invention, the circuit structure of each unit is consistent with the live load of device, the output inductor simplicity of design, thereby reduced system cost, improved the reliability of system.
Description of drawings
Fig. 1 is a circuit system schematic diagram of the present invention
Fig. 2 is a parallel inverter cellular construction schematic diagram of the present invention, and (in 1～n), T1, T2 are brachium pontis a, and T3, T4 are brachium pontis b, and T5, T6 are brachium pontis c at inversion unit.
Fig. 3 a is a phase Unit four of the present invention phase-shifting carrier wave SPWM in parallel schematic diagram.
Fig. 3 b is an inversion unit Bridge 1 arm a output voltage waveforms of the present invention.
Fig. 3 c is an inversion unit Bridge 2 arm a output voltage waveforms of the present invention.
Fig. 3 d is inversion unit 3 brachium pontis a output voltage waveforms of the present invention.
Fig. 3 e is inversion unit 4 brachium pontis a output voltage waveforms of the present invention.
Fig. 4 a is the current waveform after the parallel connection of four inversion unit phase-shifting carrier wave of the present invention.
Fig. 4 b is the humorous analysis schematic diagram of electric wave waveform after the parallel connection of four inversion unit phase-shifting carrier wave of the present invention.
Fig. 5 a is a three-phase bridge current waveform of the present invention.
Fig. 5 b is the humorous wavelength-division plates of three invention three-phase bridge current waveforms.
Below by embodiment, the invention will be further described in conjunction with the accompanying drawings.
Embodiment
Referring to Fig. 1, Fig. 2, it is parallel with one another that a plurality of inversion units with identical inner structure are set, the shared dc bus of each inversion unit, and the ac output end of each inversion unit is parallel with one another, and is connected on the electrical network through output transformer; Each inversion unit in parallel is the three-phase inversion structure, and the inversion outlet side is in parallel behind three pole reactor L.
In the present embodiment, the switch modulation of each parallel network reverse unit is to adopt carrier phase PWM control, in order to eliminate output current ripple; For the grid-connected system with n parallel inverter unit, wherein the carrier phase angle θ of i inversion unit calculates according to following formula and receives:
θ＝(2*π*i)/n*k
Wherein, n is a unit in parallel number; K is a carrier wave ratio; The scope of i is 0≤i＜n
In the present embodiment system, as shown in Figure 1 and Figure 2, the main circuit of grid-connecting apparatus adopts a plurality of inversion unit parallel connections, and each inversion unit adopts identical topological structure; Direct and the solar cell array of the DC side of parallel inverter unit, it is identical to exchange outlet side filter inductance value, and the filter inductance output of corresponding phase is connected to each other and forms ac bus together, is connected with electrical network by output transformer.
In the present embodiment control method, detect solar cell array voltage U dc, compare, regulate, obtain grid-connected current set-point i through voltage regulator with the direct voltage set-point
a *, i
b *, i
c *Grid-connected current set-point i
a *, i
b *, i
c *With ac bus output current i
a, i
b, i
cThrough current tracing controller, regulate the desired output voltage V that obtains grid-connected system by closed-loop control to electric current
a *, V
b *, V
c *Thereby, control ac bus grid-connected current i
a, i
b, i
cFollow the tracks of output reference current value i
a *, i
b *, i
c *
The command voltage of inversion unit is the desired output voltage V of system
a *, V
b *, V
c *, therefore the modulating wave of every group of inversion unit is identical, and the output phase fundamental current of system equals the electric current sum of the corresponding output of a plurality of inversion units phase; The switch modulation of power device adopts the carrier phase control strategy, triangular carrier moves respective angles according to the phase shift rule, feasible pulsation ripple mutual deviation phase shift angle, thus make every phase current when synthetic, the current harmonics component is cancelled each other, and significantly reduces the ripple amplitude of output current.
In the present embodiment, compare with the voltage-type three-phase grid-connected inverting system and the conventional voltage-type three-phase grid-connected inverting system of four inversion unit parallel connections.
With a in the three-phase is example mutually, shown in Fig. 3 a, Fig. 3 b, Fig. 3 c, Fig. 3 d, Fig. 3 e, describes the basic control principle of phase-shifting carrier wave SPWM, and wherein Z1, Z2, Z3, Z4 are respectively the triangular carrier waveform of Unit four among the 3a.Fig. 4 a and Fig. 4 b are respectively current waveform, THD and the Harmonic Distribution thereof after the four unit parallel connections of phase shift carrier frequency fload when being 1kHZ.The switching frequency of parallel inverter unit is 1KHz, and the carrier phase angle is 90 °.Fig. 5 a and Fig. 5 b are respectively under same inductance and the fundamental current condition, simple unit output current wave, THD and the Harmonic Distribution thereof that improves SPWM carrier frequency (carrier frequency is 4kHZ) and capacity that rely on.
From Fig. 4 and Fig. 5 more as can be seen, under same inductance and fundamental current condition, adopt system of the present invention output current ripple significantly to reduce, the fft analysis of current waveform has also been verified this conclusion.
Claims (2)
1, carrier shifting inversion large power photovoltaic grid-connection system is characterized in that:
It is parallel with one another that a plurality of inversion units with identical inner structure are set, the shared dc bus of each inversion unit of described parallel connection, and the ac output end of each inversion unit is parallel with one another, and is connected on the electrical network through output transformer;
Each inversion unit of described parallel connection is the three-phase inversion structure, and the inversion outlet side is in parallel behind three pole reactor L.
2, the described large power photovoltaic grid-connection system carrier shifting inversion of a kind of claim 1 control method is characterized in that:
The switch modulation of described each parallel network reverse unit is to adopt carrier phase PWM control, in order to eliminate output current ripple; For the grid-connected system with n parallel inverter unit, wherein the carrier phase angle θ of i inversion unit calculates according to following formula and receives:
θ＝(2*π*i)/n*k
Wherein, n is a unit in parallel number; K is a carrier wave ratio; The scope of i is 0≤i＜n.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2009101170189A CN101567567A (en) | 2009-06-05 | 2009-06-05 | Carrier shifting inversion large power photovoltaic grid-connection system and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2009101170189A CN101567567A (en) | 2009-06-05 | 2009-06-05 | Carrier shifting inversion large power photovoltaic grid-connection system and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101567567A true CN101567567A (en) | 2009-10-28 |
Family
ID=41283592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2009101170189A Pending CN101567567A (en) | 2009-06-05 | 2009-06-05 | Carrier shifting inversion large power photovoltaic grid-connection system and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101567567A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710716A (en) * | 2009-11-13 | 2010-05-19 | 南京航空航天大学 | Grid-connected inverter capable of reducing electrolytic capacitance |
| CN101702523B (en) * | 2009-11-20 | 2011-08-24 | 南京航空航天大学 | Control method of distributed modular grid-connected power generation system |
| CN103023060A (en) * | 2012-09-14 | 2013-04-03 | 深圳市汇川技术股份有限公司 | Photovoltaic inverter and harmonic suppression method |
| CN103368427A (en) * | 2012-04-05 | 2013-10-23 | 艾默生网络能源有限公司 | Single-phase inverter and system thereof and three-phase inverter and system thereof |
| CN103414361A (en) * | 2013-07-26 | 2013-11-27 | 常州佳讯光电产业发展有限公司 | Main circuit topological structure of single megawatt photovoltaic grid-connected inverter |
| CN103490652A (en) * | 2013-08-27 | 2014-01-01 | 国电南瑞吉电新能源（南京）有限公司 | Carrier phase-shifting pulse width modulation method |
| CN104716851A (en) * | 2013-12-17 | 2015-06-17 | 北车大连电力牵引研发中心有限公司 | Converter control method and device |
| CN106292634A (en) * | 2016-08-27 | 2017-01-04 | 上海科梁信息工程股份有限公司 | Switching power amplifying device and simulation Variable flow control method |
| CN108923408A (en) * | 2018-08-07 | 2018-11-30 | 威胜集团有限公司 | The method for reducing multichannel inversion system DC ripple |
| CN110752751A (en) * | 2019-10-25 | 2020-02-04 | 中国科学院电工研究所 | Control method of direct-current photovoltaic wide-range input high-transformation-ratio boosting device |
-
2009
- 2009-06-05 CN CNA2009101170189A patent/CN101567567A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710716A (en) * | 2009-11-13 | 2010-05-19 | 南京航空航天大学 | Grid-connected inverter capable of reducing electrolytic capacitance |
| CN101702523B (en) * | 2009-11-20 | 2011-08-24 | 南京航空航天大学 | Control method of distributed modular grid-connected power generation system |
| CN103368427A (en) * | 2012-04-05 | 2013-10-23 | 艾默生网络能源有限公司 | Single-phase inverter and system thereof and three-phase inverter and system thereof |
| CN103023060A (en) * | 2012-09-14 | 2013-04-03 | 深圳市汇川技术股份有限公司 | Photovoltaic inverter and harmonic suppression method |
| CN103414361A (en) * | 2013-07-26 | 2013-11-27 | 常州佳讯光电产业发展有限公司 | Main circuit topological structure of single megawatt photovoltaic grid-connected inverter |
| CN103490652A (en) * | 2013-08-27 | 2014-01-01 | 国电南瑞吉电新能源（南京）有限公司 | Carrier phase-shifting pulse width modulation method |
| CN104716851A (en) * | 2013-12-17 | 2015-06-17 | 北车大连电力牵引研发中心有限公司 | Converter control method and device |
| WO2015089870A1 (en) * | 2013-12-17 | 2015-06-25 | 北车大连电力牵引研发中心有限公司 | Converter control method and device |
| CN106292634A (en) * | 2016-08-27 | 2017-01-04 | 上海科梁信息工程股份有限公司 | Switching power amplifying device and simulation Variable flow control method |
| CN108923408A (en) * | 2018-08-07 | 2018-11-30 | 威胜集团有限公司 | The method for reducing multichannel inversion system DC ripple |
| CN110752751A (en) * | 2019-10-25 | 2020-02-04 | 中国科学院电工研究所 | Control method of direct-current photovoltaic wide-range input high-transformation-ratio boosting device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101567567A (en) | Carrier shifting inversion large power photovoltaic grid-connection system and control method thereof | |
| Buticchi et al. | A nine-level grid-connected converter topology for single-phase transformerless PV systems | |
| CN102255529B (en) | Comprehensive control method for high-power efficient energy consuming high-frequency switching power supply | |
| Kim et al. | Design and control of a grid-connected three-phase 3-level NPC inverter for building integrated photovoltaic systems | |
| CN105450059B (en) | Inhibit the modulator approach of two H bridge cascaded inverter leakage currents | |
| US20040223348A1 (en) | Power converter with ripple current cancellation using skewed switching techniques | |
| CN102856916A (en) | Reactive power control method and circuit of single-phase photovoltaic inverter | |
| EP3637611B1 (en) | Voltage-type single-stage multi-input high frequency link inverter having built-in parallel time-sharing selection switches | |
| CN103312184A (en) | Power circuit, current transformer structure and wind generator system comprising both | |
| CN212660115U (en) | Rectifying system for grid-connected water electrolysis hydrogen production | |
| CN102769291B (en) | Active power filter based on multiphase converter structure | |
| CN103580048A (en) | Chained battery energy storage system integrated with active power filter | |
| CN116260348B (en) | MMC-based high-capacity electrolytic hydrogen production hybrid rectifier and control method | |
| CN104795981A (en) | Current ripple active restraining method of DC-grid-connection-operation hybrid micro-grid bidirectional transducers | |
| CN102013690A (en) | MMC (multimedia controller)-based modular multi-level transformerless inductive energy storage topological structure | |
| CN202085085U (en) | Large power efficient energy-consuming high frequency switch power supply | |
| Chen et al. | A buck type multi-input distributed generation system with parallel-timesharing power supply | |
| Zhu et al. | Partial power conversion and high voltage ride-through scheme for a PV-battery based multiport multi-bus power router | |
| CN203574386U (en) | Multilevel multiport power generation and energy storage hybrid apparatus | |
| US20060034103A1 (en) | Utility grid-interactive power converter with ripple current cancellation using skewed switching techniques | |
| CN108023497B (en) | Series simultaneous power supply forward cycle conversion type single-stage multi-input high-frequency link inverter | |
| CN108023496B (en) | Series simultaneous selection switch voltage type single-stage multi-input low-frequency link inverter | |
| CN108199602B (en) | Multi-winding time-sharing power supply forward direct current chopper type single-stage multi-input high-frequency chain inverter | |
| CN105281364B (en) | A kind of photovoltaic generating system based on multi-phase inverter unit | |
| CN203057066U (en) | Feedforward compensation energy-saving control converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Open date: 20091028 |