CN107769257B - A kind of method for controlling frequency conversion of the photovoltaic combining inverter based on LCL filtering - Google Patents
A kind of method for controlling frequency conversion of the photovoltaic combining inverter based on LCL filtering Download PDFInfo
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- H02J3/383—
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
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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
- H02M7/53—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
- H02M7/5387—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 in a bridge configuration
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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
- H02M7/53—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
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- 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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- 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
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
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Abstract
The present invention provides a kind of method for controlling frequency conversion of photovoltaic combining inverter based on LCL filtering, comprising the following steps: acquisition network voltage eabc, grid-connected current iabc, the signal of acquisition is transformed into synchronous rotary dq axis coordinate system, Feedforward Decoupling is carried out to electric current loop under dq axis and obtains output reference signal, by the output electric current i of samplingaBy frequency controller, suitable current carrier frequency f is obtainedsw, finally by reference signalWith carrier frequency fswIt is sent to SVPWM generator, this method is applicable not only to Double closed-loop of voltage and current method as described herein, but also it is suitable for various other Grid-connected Control Strategies, different from general SVPWM method, the method can be according to the carrier frequency of the current output power selection SVPWM wave of inverter, simultaneously network electric energy quality is improved to greatest extent, especially in the generated output deficiency rated power of photovoltaic module, the preset parameter that LCL can be adapted to by frequency conversion finally significantly reduces output current harmonics content.
Description
Technical field
The invention belongs to photovoltaic DC-to-AC converter technical field more particularly to a kind of photovoltaic combining inverters based on LCL filtering
Method for controlling frequency conversion.
Background technique
In the photovoltaic combining inverter filtered based on LCL, filter parameter is usually specified according to gird-connected inverter
Power designs.However the generated output of photovoltaic module is closely related with intensity of solar radiation, due to intensity of solar radiation with
Time and season constantly changing, so inverter will not always work at rated power.When the output power of photovoltaic module
When gradually decreasing, by the LCL filter circuit that rated output power designs, filtering performance is decreased when exporting current reduction,
Output harmonic wave increases, and causes to export power quality significant decrease.
The presence of harmonic wave can be such that the loss of grid-connected transformer increases, and increase so as to cause the temperature of transformer, influence transformation
The service life of device.
In rated power, total percent harmonic distortion is mostly 3% or so for gird-connected inverter product work at present.According to
" grid-connected photovoltaic power generation special inverter technical conditions ", the current harmonics total harmonic distortion limit value for injecting power grid is 5%.When grid-connected inverse
Become the work of device product in lower-wattage, harmonic wave very likely exceeds the permitted range of national standard.
It is directed to grid-connected power quality problem at present, is mostly made up using complicated algorithm, however this also proposes controller
Higher requirement.
When inverter work is in rated power, in order to reduce the switching loss of power device, switching frequency generally compared with
It is low.However when inverter work is in lower-wattage, the switching loss of power device is no longer limiting factor, therefore can be led to
The switching frequency of raising power device is crossed to improve power quality.
Summary of the invention
The present invention is to provide a kind of light based on LCL filtering in order to avoid above-mentioned existing deficiencies in the technology
Lie prostrate the method for controlling frequency conversion of inverter.In photovoltaic module power variation, by changing the carrier frequency of SVPWM wave, to reach
To the purpose for improving electric energy.
To achieve the above object, the invention provides the following technical scheme:
The present invention discloses a kind of method for controlling frequency conversion of photovoltaic DC-to-AC converter based on LCL filtering, and the photovoltaic DC-to-AC converter is
It is controlled by parallel network reverse controller, the parallel network reverse controller uses convertible SVPWM wave to the photovoltaic DC-to-AC converter
The Double closed-loop of voltage and current strategy of frequency；The method for controlling frequency conversion of the photovoltaic DC-to-AC converter the following steps are included:
A kind of method for controlling frequency conversion of the photovoltaic DC-to-AC converter based on LCL filtering characterized by comprising
Step 1 initializes the system parameter of the photovoltaic DC-to-AC converter, the PI parameter including current inner loop, voltage
The PI parameter of outer ring, DC bus-bar voltage given valueInitial p WM frequency Fsw；
Step 2 samples the input, output, DC bus of the photovoltaic DC-to-AC converter, specifically acquisition network voltage
eabc, grid-connected current signal iabcWith DC bus-bar voltage Vdc(eabc=[ea eb ec]T, iabc=[ia ib ic]T)；
Step 3, using in step 2 to the input of photovoltaic DC-to-AC converter, output, the sampling of DC bus, it is inverse to the photovoltaic
Become device using the outer voltage of dq decoupler shaft, the double-loop control strategy of current inner loop, specifically:
Step 3.1, by current signal and voltage signal iabc、eabcClark coordinate transform is carried out, respectively by formulaObtain the i under α β coordinate systemαβ、eαβ, and pass throughObtain lock phase angle theta；
Step 3.2, by the i under α β coordinate systemβα、eβαPark transformation is carried out, respectively by formulaObtain the i under synchronous rotating frameqd、eqd, by iqdWith
Reference current signalIt is compared, after the result for being asked difference relatively to obtain passes through pi regulator, according under dq coordinate system
Mathematical model carries out Feedforward Decoupling, obtains the reference signal under dq coordinate systemBy reference signalPark inverse transformation is carried out,
By formulaObtain the reference signal under α β coordinate system In,For giving for reactive current
It is fixed,For the reference signal of watt current, (i is obtained after being adjusted by outer voltage by PIqd=[iq id]T, iβα=[iβiα]T, eβα=[eβeα]T)；
Step 4, the output electric current i obtained using samplinga, obtain current carrier frequency fsw, specific method can be to as follows
Two kinds of executive modes carry out selection execution:
Selection executes one, carries out carrier frequency f based on segmentation selectionswSelection, specifically include:
Step 4.1, the design method according to LCL, by the inductance summation formula of LCLIts
Middle udcIt is a steady state value, f for the DC bus-bar voltageswFor the PWM carrier frequency for controlling IGBT, iaElectricity is exported for inverter
Stream, required inductance total amount is only with fswiaVariation and change, therefore when output power variation i.e. output electric current iaWhen variation, pass through
Change frequency makes fswiaValue maintain within the set range, so that total inductance needed for making is basically unchanged, it is therefore desirable to determine
The output-current rating I of inverteraWith the carrier frequency F under rated powersw, and calculate its Product-factor M=Ia·Fsw；
Step 4.2 will export rated current IaDivided by 2n(n=0,1,2,3,4,5) is divided into 5 groups i.e.:
Step 4.3, the Product-factor M calculated using step 4.1 are by PWM carrier frequency fswCarry out equivalent grouping, corresponding step
Rapid 4.2 output rated current IaGrouping, can be by fswGrouping are as follows: Fsw, 2Fsw, 4Fsw, 8Fsw, 16Fsw；
The output electric current i that step 4.4, basis currently acquireaPlace grouping, selects corresponding PWM carrier frequency fsw；
Selection executes two, carries out carrier frequency f based on continuous selectionswSelection, particular by carrier frequency controller,
Pre-selected carriers frequency is obtained, then is limited carrier frequency within the set range by frequency limit device, obtains current carrier frequency
fsw, wherein carrier frequency selector is to utilize relational expressionObtain pre-selected frequency, FswFor the modulation under rated power
Frequency, IaFor the output electric current under rated power, iaCurrently to export electric current；
Reference signal under step 5, the α β coordinate system for obtaining step 3The current carrier frequency f obtained with step 4sw
It is sent to SVPWM generator.
The beneficial effects of the present invention are: the present invention is applicable not only to Double closed-loop of voltage and current, but also it is suitable for it
Its various Grid-connected Control Strategy, is different from general SVPWM method, and the method can be selected according to the current power of inverter
The carrier frequency of SVPWM wave is selected, simultaneously network electric energy quality is improved to greatest extent, especially in the generated output deficiency of photovoltaic module
When determining power, the preset parameter of LCL can be adapted to by frequency conversion, finally significantly reduce output current harmonics content.
Detailed description of the invention
Fig. 1 is photovoltaic inverting system structure chart according to the present invention.
Fig. 2 is the control strategy figure of photovoltaic inversion controller according to the present invention.
Fig. 3 is carrier frequency controller according to the present invention.
Fig. 4 is that PWM carrier frequency control mode harmonic contrast figure is chosen in Traditional control and segmentation.
Fig. 5 is control frequency partition figure.
Fig. 6 is the citing of grid-connected frequency partition.
Fig. 7 is Traditional control and continuous selection PWM carrier frequency control mode harmonic contrast figure.
Specific embodiment
The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawing, so that advantages and features of the invention energy
It is easier to be readily appreciated by one skilled in the art, apparent explicitly be defined to be made to protection scope of the present invention.
Present invention employs the topological circuits of attached drawing 1.Its specific control method is as shown in Figure 2.
This control method is applied to the parallel network reverse controller filtered based on LCL.Since total inductance of LCL filter is big
It is small can be by formula:It indicates, wherein DC bus-bar voltage udcFor definite value.When the carrier wave of SVPWM wave
Frequency fswWhen constant, total inductance amount LTSize and inverter output current iaIt is inversely proportional.The hardware device fixed for one,
Its total inductance amount is determined according to inverter output-current rating, exports electricity to solve inverter under non-rated power
The problem of energy quality is deteriorated, using the method for increasing SVPWM wave carrier signal frequency.
Specifically, it is a kind of based on LCL filtering photovoltaic DC-to-AC converter method for controlling frequency conversion, it the following steps are included:
Step 1 initializes the system parameter of the photovoltaic DC-to-AC converter, the PI parameter including current inner loop, voltage
The PI parameter of outer ring, DC bus-bar voltage given valueInitial p WM frequency Fsw；
Step 2 samples the input, output, DC bus of the photovoltaic DC-to-AC converter, specifically acquisition network voltage
eabc, grid-connected current signal iabcWith DC bus-bar voltage Vdc；
Step 3, using in step 2 to the input of photovoltaic DC-to-AC converter, output, the sampling of DC bus, it is inverse to the photovoltaic
Become device using the outer voltage of dq decoupler shaft, the double-loop control strategy of current inner loop, specifically:
Step 3.1, by current signal and voltage signal iabc、eabcClark coordinate transform is carried out, respectively by formulaObtain the i under α β coordinate systemαβ、eαβ, and pass throughObtain lock phase angle theta；
Step 3.2, by the i under α β coordinate systemαβ、eαβPark transformation is carried out, respectively by formulaObtain the i under synchronous rotating framedq、edq, by idqWith
Reference current signalIt is compared, after the result that work difference compares acquisition is passed through pi regulator, according to the number under dq coordinate system
It learns model and carries out Feedforward Decoupling, obtain the reference signal under dq coordinate systemBy reference signalPark inverse transformation is carried out, by
FormulaObtain the reference signal under α β coordinate systemWherein,For the given of reactive current,For the reference signal of watt current, (i is obtained after being adjusted by outer voltage by PIqd=[iq id]T, iβα=[iβ iα]T, eβα=[eβ eα]T)；
Step 4, the output electric current i obtained using samplinga, obtain current carrier frequency fsw, specifically carry out selection execution:
Selection executes one, carries out carrier frequency f based on segmentation selectionswSelection, specifically include:
Step 4.1, the design method according to LCL, by the inductance summation formula of LCLIts
Middle udcIt is a steady state value, f for the DC bus-bar voltageswFor the PWM carrier frequency for controlling IGBT, iaElectricity is exported for inverter
Stream, it can be seen that required inductance total amount is only with fswiaVariation and change, therefore when output power variation i.e. output electric current iaBecome
When change, f is made by change frequencyswiaValue be maintained within a certain range, so that total inductance needed for making is basically unchanged, therefore
It needs to be determined that the output-current rating I of inverteraWith the carrier frequency F under rated powersw, and calculate its Product-factor M=
Ia·Fsw；
Step 4.2 will export rated current IaDivided by 2n(n=0,1,2,3,4,5), is divided into 5 groups, as shown in Figure 5, it may be assumed that
The switching times primarily to reduction switching device are so divided, system caused by frequent switching frequency is avoided
Unstable；
Step 4.3, the Product-factor M calculated using step 4.1 are by PWM carrier frequency fswCarry out equivalent grouping, corresponding step
Rapid 4.2 output rated current IaGrouping, as shown in figure 5, can be by fswGrouping are as follows: Fsw, 2Fsw, 4Fsw, 8Fsw, 16Fsw；
The output electric current i that step 4.4, basis currently acquireaPlace grouping, selects corresponding PWM carrier frequency fsw；
Selection executes two, carries out carrier frequency f based on continuous selectionswSelection, particular by carrier frequency selector,
Pre-selected carriers frequency is obtained, then is limited carrier frequency within the set range by frequency limit device, obtains current carrier frequency
fsw, wherein carrier frequency selector is to utilize relational expressionObtain pre-selected frequency, FswFor the modulation under rated power
Frequency, IaFor the output electric current under rated power, iaCurrently to export electric current；
Reference signal under step 5, the α β coordinate system for obtaining step 3The current carrier frequency f obtained with step 4sw
It is sent to SVPWM generator.
Further, the photovoltaic combining inverter of rated power 38kW is emulated, structure chart as shown in Figure 1,
Control strategy figure is as shown in Fig. 2, DC bus-bar voltage is 850V, and rated output maximum phase current is 80A, and rated output voltage is
380V, initial p WM frequency Fsw=3150Hz；It compares fixed SVPWM frequency control and selects SVPWM carrier wave according to changed power
Control method for frequency, according to step 4 segmentation selection carry out carrier frequency selection as shown in fig. 6, its grid-connected current it is total humorous
For wave aberration rate as shown in figure 4, carrying out the selection of carrier frequency according to the continuous selection of step 4, total harmonic wave of grid-connected current is abnormal
Variability is as shown in fig. 7, in fixed SVPWM frequency (Fsw=3150Hz) under control method, with the reduction of power, grid-connected current
THD is increased rapidly, and under the method for controlling frequency conversion for adjusting SVPWM frequency according to changed power, although the THD of grid-connected current
Also increasing, but increasing speed and slow down and be greatly improved compared to fixed frequency method.
Single-phase grid-connected electric current i is obtained by acquisition grid-connected current as shown in figure 3, the invention reside in (1)a；(2) by grid-connected electricity
Flow iaPre-selected carriers frequency is obtained by carrier frequency selector, wherein carrier frequency selector is according to LCL filter parameter
Design method is designed, and meets relational expression(3) within the set range by carrier frequency limitation, frequency is prevented
The excessively high limit for reaching device receiving；(4) by carrier frequency fswIt is sent to SVPWM generator, generates the control waveform of corresponding frequencies,
Realize the frequency control of inverter.
Specific embodiment described herein is only an example for the spirit of the invention.The neck of technology belonging to the present invention
The technical staff in domain can make various modifications or additions to the described embodiments or replace by a similar method
In generation, however, it does not deviate from the spirit of the invention or beyond the scope of the appended claims.
Claims (1)
1. a kind of method for controlling frequency conversion of the photovoltaic DC-to-AC converter based on LCL filtering characterized by comprising
Step 1 initializes the system parameter of the photovoltaic DC-to-AC converter, PI parameter, outer voltage including current inner loop
PI parameter, DC bus-bar voltage given valueInitial p WM frequency Fsw；
Step 2 samples the input, output, DC bus of the photovoltaic DC-to-AC converter, specifically acquisition network voltage eabc、
Grid-connected current signal iabcWith DC bus-bar voltage Vdc, wherein
eabc=[ea eb ec]T, iabc=[ia ib ic]T；
Step 3, using in step 2 to the input of photovoltaic DC-to-AC converter, output, the sampling of DC bus, to the photovoltaic DC-to-AC converter
Using the double-loop control strategy of the outer voltage of dq decoupler shaft, current inner loop, specifically:
Step 3.1, by current signal and voltage signal iabc、eabcClark coordinate transform is carried out, respectively by formulaObtain the i under α β coordinate systemαβ、eαβ, and pass throughObtain lock phase angle theta；
Step 3.2, by the i under α β coordinate systemαβ、eαβPark transformation is carried out, respectively by formulaObtain the i under synchronous rotating framedq、edq, by idqWith
Reference current signalIt is compared, after the result that work difference compares acquisition is passed through pi regulator, according to the number under dq coordinate system
It learns model and carries out Feedforward Decoupling, obtain the reference signal under dq coordinate systemBy reference signalPark inverse transformation is carried out, by
FormulaObtain the reference signal under α β coordinate systemWherein,For the given of reactive current,For the reference signal of watt current, obtained after being adjusted by outer voltage by PI, iqd=[iq id]T,iβα=[iβ iα]T, eβα=[eβ eα]T；
Step 4, the output electric current i obtained using samplinga, obtain current carrier frequency fsw, specifically carry out selection execution:
Selection executes one, carries out carrier frequency f based on segmentation selectionswSelection, specifically include:
Step 4.1, the design method according to LCL, by the inductance summation formula of LCLWherein udc
It is a steady state value, f for the DC bus-bar voltageswFor the PWM carrier frequency for controlling IGBT, iaFor inverter output current, institute
Need inductance total amount only with fswiaVariation and change, therefore when output power variation i.e. output electric current iaWhen variation, pass through variation
Frequency makes fswiaValue maintain within the set range, so that total inductance needed for making is basically unchanged, it is therefore desirable to determine inversion
The output-current rating I of deviceaWith the carrier frequency F under rated powersw, and calculate its Product-factor M=Ia·Fsw；
Step 4.2 will export rated current IaDivided by 2n, wherein n=0,1,2,3,4,5 are divided into 5 groups, it may be assumed that
Step 4.3, the Product-factor M calculated using step 4.1 are by PWM carrier frequency fswCarry out equivalent grouping, corresponding step 4.2
Output rated current IaGrouping, by fswGrouping are as follows: Fsw, 2Fsw, 4Fsw, 8Fsw, 16Fsw；
The output electric current i that step 4.4, basis currently acquireaPlace grouping, selects corresponding PWM carrier frequency fsw；
Selection executes two, carries out carrier frequency f based on continuous selectionswSelection obtain particular by carrier frequency selector
Pre-selected carriers frequency, then limited carrier frequency within the set range by frequency limit device, obtain current carrier frequency fsw,
Middle carrier frequency selector is to utilize relational expressionObtain pre-selected frequency, FswFor the modulating frequency under rated power,
IaFor the output electric current under rated power, iaCurrently to export electric current；
Reference signal under step 5, the α β coordinate system for obtaining step 3The current carrier frequency f obtained with step 4swIt is sent to
SVPWM generator.
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| CN108539790A (en) * | 2018-05-09 | 2018-09-14 | 国网山东省电力公司德州供电公司 | A kind of grid-connected photovoltaic inverter electric current Optimal Control System and method |
| CN108879782B (en) * | 2018-08-01 | 2021-11-30 | 国网重庆市电力公司电力科学研究院 | Grid-connected inverter optimization control method based on dual-filtering power grid voltage feedforward |
| CN110311408A (en) * | 2019-06-21 | 2019-10-08 | 广东电网有限责任公司 | A kind of novel inverter parameter optimization method based on stuffing function algorithm |
| CN110880790B (en) * | 2019-12-23 | 2022-06-21 | 太原理工大学 | Control method of grid-connected power converter with LCL topological structure |
| CN112838777B (en) * | 2021-01-07 | 2022-03-25 | 山东大学 | Active power consumption cooperative control system and method for power switching devices of multi-grid-connected inverter |
| CN112564533B (en) * | 2021-02-23 | 2021-07-06 | 浙江艾罗网络能源技术股份有限公司 | Frequency conversion control method of grid-connected inverter and grid-connected inverter system |
| CN113179037B (en) * | 2021-05-08 | 2023-03-07 | 全球能源互联网研究院有限公司 | Switching frequency modulation method and device and storage medium |
| CN114050605B (en) * | 2021-11-18 | 2023-08-15 | 山东大学 | Variable frequency pulse width modulation synchronization system and method based on local power grid phase |
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|---|---|---|---|---|
| CN102638186A (en) * | 2012-05-18 | 2012-08-15 | 上海三一精机有限公司 | Three-phase voltage type rectifier and control method thereof |
| CN102751742B (en) * | 2012-07-25 | 2014-03-26 | 漳州科华技术有限责任公司 | Method for improving grid-connected performance by variable switching frequency |
| CN102946115B (en) * | 2012-10-22 | 2015-08-05 | 哈尔滨电机厂(镇江)有限责任公司 | Based on the Three-Phase PWM Converter control method of LCL filter amphiorentation coordinate transform |
| JP2015192515A (en) * | 2014-03-28 | 2015-11-02 | 株式会社日立製作所 | drive system |
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