CN107769257A - 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 PDF

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CN107769257A
CN107769257A CN201711207717.3A CN201711207717A CN107769257A CN 107769257 A CN107769257 A CN 107769257A CN 201711207717 A CN201711207717 A CN 201711207717A CN 107769257 A CN107769257 A CN 107769257A
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current
carrier frequency
frequency
output
abc
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CN107769257B (en
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潘健
李坤
熊亦舟
冯雨丝
黎家成
马浩
梁佳成
张慧
成玉爽
廖冬初
张子蓬
许章茁
尤润川
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Hubei University of Technology
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    • H02J3/383—
    • 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
    • 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
    • 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
    • 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
    • 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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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

The present invention provides a kind of method for controlling frequency conversion of the photovoltaic combining inverter based on LCL filtering, comprises the following steps：Gather line voltage eabc, grid-connected current iabc, the signal of collection is transformed into synchronous rotary dq axis coordinate systems, Feedforward Decoupling is carried out to electric current loop under dq axles and obtains exporting reference signal, by the output current i of samplingaBy frequency controller, suitable current carrier frequency f is obtainedsw, finally by reference signalWith carrier frequency fswIt is sent to SVPWM generators, this method is applicable not only to Double closed-loop of voltage and current method as described herein, but also it is applied to other various Grid-connected Control Strategies, different from general SVPWM method, the method can select the carrier frequency of SVPWM ripples according to the current power output of inverter, simultaneously network electric energy quality is improved to greatest extent, especially in the generated output deficiency rated power of photovoltaic module, LCL preset parameter can be adapted to by frequency conversion, finally significantly reduces output current harmonics content.

Description

Frequency conversion control method of photovoltaic grid-connected inverter based on LCL filtering
Technical Field
The invention belongs to the technical field of photovoltaic inverters, and particularly relates to a variable frequency control method of a photovoltaic grid-connected inverter based on LCL filtering.
Background
In a photovoltaic grid-connected inverter based on LCL filtering, the filter parameters are usually designed according to the rated power of the grid-connected inverter. However, the generated power of the photovoltaic module is closely related to the intensity of solar radiation, and since the intensity of solar radiation is continuously changed along with time and seasons, the inverter does not always work at the rated power. When the output power of the photovoltaic module is gradually reduced, the filtering performance of the LCL filtering circuit designed according to the rated output power is reduced when the output current is reduced, the output harmonic wave is increased, and the quality of the output electric energy is obviously reduced.
The existence of the harmonic wave can increase the loss of the grid-connected transformer, thereby causing the temperature rise of the transformer and influencing the service life of the transformer.
When the existing grid-connected inverter product works at rated power, the total harmonic distortion rate is mostly about 3 percent. According to technical conditions of inverters special for grid-connected photovoltaic power generation, the limit value of the total distortion rate of current harmonics injected into a power grid is 5%. When the grid-connected inverter product works at lower power, the harmonic waves of the grid-connected inverter product are most likely to exceed the range allowed by national standards.
At present, for grid-connected power quality problems, complex algorithms are mostly adopted to make up for the grid-connected power quality problems, however, higher requirements are provided for controllers.
When the inverter operates at rated power, its switching frequency is generally low in order to reduce the switching losses of the power devices. However, when the inverter operates at a lower power, the switching loss of the power device is no longer a limiting factor, and thus the power quality can be improved by increasing the switching frequency of the power device.
Disclosure of Invention
In order to avoid the defects in the prior art, the invention provides a variable frequency control method of a photovoltaic inverter based on LCL filtering. When the power of the photovoltaic module changes, the purpose of improving the electric energy is achieved by changing the carrier frequency of the SVPWM wave.
In order to achieve the purpose, the invention provides the following technical scheme:
the invention discloses a variable frequency control method of a photovoltaic inverter based on LCL filtering, wherein the photovoltaic inverter is controlled by a grid-connected inverter controller, and the grid-connected inverter controller adopts a voltage and current double-closed-loop control strategy capable of converting SVPWM wave frequency for the photovoltaic inverter; the frequency conversion control method of the photovoltaic inverter comprises the following steps:
a variable frequency control method of a photovoltaic inverter based on LCL filtering is characterized by comprising the following steps:
step 1, initializing system parameters of the photovoltaic inverter, including a PI parameter of a current inner ring, a PI parameter of a voltage outer ring and a given value of a direct-current bus voltageInitial PWM frequency Fsw；
Step 2, sampling the input, output and direct current bus of the photovoltaic inverter, specifically collecting the voltage e of the power gridabcGrid-connected current signal iabcAnd DC bus voltage Vdc(eabc＝[eaebec]T，iabc＝[iaibic]T)；
And 3, sampling the input and output of the photovoltaic inverter and the direct current bus in the step 2, and adopting a double closed loop control strategy of a dq axis decoupling voltage outer loop and a dq axis decoupling current inner loop for the photovoltaic inverter, wherein the double closed loop control strategy specifically comprises the following steps:
step 3.1, current signal and voltage signal iabc、eabcClark coordinate transformation is carried out, and the Clark coordinate transformation is respectively represented by the formulaobtaining i under alpha and beta coordinate systemαβ、eαβAnd throughObtaining a phase locking angle theta;
step 3.2, i in α β coordinate systemβα、eβαPerforming Park transformation, respectively using the formulasObtaining i under a synchronous rotating coordinate systemqd、eqdI is toqdAnd a reference current signalComparing, passing the result obtained by difference comparison through PI regulator, performing feedforward decoupling according to mathematical model under dq coordinate system to obtain reference signal under dq coordinate systemReference signalInverse Park transform is carried out according to the formulaobtaining a reference signal under α β coordinate system In (1),for a given amount of reactive current,the reference signal is an active current and is obtained by a voltage outer ring after PI regulationqd＝[iqid]T， iβα＝[iβiα]T，eβα＝[eβeα]T)；
Step 4, utilizing the output current i obtained by samplingaObtaining the current carrier frequency fswThe specific method can be selectively executed in the following two execution modes:
selection execution one, carrier frequency f based on segment selectionswThe selection specifically comprises the following steps:
step 4.1, according to the design method of the LCL, the inductance sum formula of the LCL is usedWherein u isdcFor the DC bus voltage to be a constant value, fswTo control the PWM carrier frequency, i, of the IGBTaThe total amount of inductance required for the inverter to output current follows only fswiaSo that when the output power changes, i.e. the output current i changesaWhen varied, by varying the frequency of fswiaSo that the required total inductance is substantially constant, and therefore the rated output of the inverter needs to be determinedOutput current IaAnd carrier frequency F at rated powerswAnd calculating the product factor M ═ Ia·Fsw；
Step 4.2, outputting rated current IaIs divided by 2n(n is 0,1,2,3,4,5), and is divided into 5 groups:
step 4.3, PWM carrier frequency f is carried by product factor M calculated in step 4.1swPerforming equivalent grouping corresponding to the output rated current I of the step 4.2aCan be divided into fswThe grouping is as follows: fsw，2Fsw，4Fsw，8Fsw，16Fsw；
Step 4.4, according to the currently collected output current iaIn the group, selecting corresponding PWM carrier frequency fsw；
Selection execution two, carrier frequency f based on successive selectionsswThe selection is that a pre-selected carrier frequency is obtained through a carrier frequency controller, and then the carrier frequency is limited in a set range through a frequency limiter to obtain the current carrier frequency fswWherein the carrier frequency selector is based on a relational expressionObtaining a preselected frequency, FswFor the modulation frequency at rated power, IaIs the output current at rated power, iaIs the current output current;
step 5, the reference signal under the α β coordinate system obtained in the step 3 is usedAnd the current carrier frequency f obtained in step 4swTo the SVPWM generator.
The invention has the beneficial effects that: the method is not only suitable for voltage and current double closed-loop control, but also suitable for other various grid-connected control strategies, is different from a common SVPWM modulation method, can select the carrier frequency of SVPWM waves according to the current power of an inverter, improves the grid-connected electric energy quality to the maximum extent, can adapt to the fixed parameters of the LCL through frequency conversion particularly when the generated power of a photovoltaic module is less than the rated power, and finally obviously reduces the harmonic content of the output current.
Drawings
Fig. 1 is a structural view of a photovoltaic inverter system according to the present invention.
Fig. 2 is a control strategy diagram of a photovoltaic inverter controller according to the present invention.
Fig. 3 is a carrier frequency controller according to the present invention.
Fig. 4 is a harmonic comparison diagram of the conventional control and the sectional selection PWM carrier frequency control method.
Fig. 5 is a control frequency division diagram.
Fig. 6 is an example of photovoltaic grid connection frequency division.
FIG. 7 is a graph showing the harmonic comparison between the conventional control and the continuous selection PWM carrier frequency control.
Detailed Description
The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the invention easier to understand by those skilled in the art, and thus will clearly and clearly define the scope of the invention.
The present invention employs the topology circuit of fig. 1. The specific control method is shown in fig. 2.
The control method is applied to the grid-connected inverter controller based on LCL filtering. Since the total inductance of the LCL filter can be given by:is shown, wherein the DC bus voltage udcIs a constant value. When carrier frequency f of SVPWM waveswWhen not changed, the total inductance LTAnd the inverter output current iaIn inverse proportion. For a fixed hardware device, the total inductance value is determined according to the rated output current of the inverter, and in order to solve the problem that the quality of the output power of the inverter is poor under the non-rated power, a method for increasing the carrier frequency of the SVPWM wave is adopted.
Specifically, the variable frequency control method of the photovoltaic inverter based on LCL filtering comprises the following steps:
step 1, initializing system parameters of the photovoltaic inverter, including a PI parameter of a current inner ring, a PI parameter of a voltage outer ring and a given value of a direct-current bus voltageInitial PWM frequency Fsw；
Step 2, sampling the input, output and direct current bus of the photovoltaic inverter, specifically collecting the voltage e of the power gridabcGrid-connected current signal iabcAnd DC bus voltage Vdc；
And 3, sampling the input and output of the photovoltaic inverter and the direct current bus in the step 2, and adopting a double closed loop control strategy of a dq axis decoupling voltage outer loop and a dq axis decoupling current inner loop for the photovoltaic inverter, wherein the double closed loop control strategy specifically comprises the following steps:
step 3.1, current signal and voltage signal iabc、eabcClark coordinate transformation is carried out, and the Clark coordinate transformation is respectively represented by the formulaobtaining i under alpha and beta coordinate systemαβ、eαβAnd throughObtaining a phase locking angle theta;
step 3.2, i in α β coordinate systemαβ、eαβPerforming Park transformation, respectively using the formulasObtaining i under a synchronous rotating coordinate systemdq、edqI is todqAnd a reference current signalComparing, passing the result obtained by difference comparison through PI regulator, performing feedforward decoupling according to mathematical model under dq coordinate system to obtain reference signal under dq coordinate systemReference signalInverse Park transform is carried out according to the formulaobtaining a reference signal under α β coordinate systemWherein,for a given amount of reactive current,the reference signal is an active current and is obtained by a voltage outer ring after PI regulationqd＝[iqid]T， iβα＝[iβiα]T，eβα＝[eβeα]T)；
Step 4, utilizing the output current i obtained by samplingaObtaining the current carrier frequency fswSpecifically, the selection execution is performed:
selection execution one, carrier frequency f based on segment selectionswThe selection specifically comprises the following steps:
step 4.1, according to the design method of the LCL, the inductance sum formula of the LCL is usedWherein u isdcFor the DC bus voltage to be a constant value, fswTo control the PWM carrier frequency, i, of the IGBTaFor the inverter output current, it can be seen that the total amount of inductance required only follows fswiaSo that when the output power changes, i.e. the output current i changesaWhen varied, by varying the frequency of fswiaIs maintained within a range such that the required total inductance is substantially constant, and therefore the rated output current I of the inverter needs to be determinedaAnd carrier frequency F at rated powerswAnd calculating the product factor M ═ Ia·Fsw；
Step 4.2, outputting rated current IaIs divided by 2n(n ═ 0,1,2,3,4,5), into 5 groups, as shown in fig. 5, i.e.:
the division is mainly used for reducing the switching times of the switching devices and avoiding unstable systems caused by frequent switching frequency;
step 4.3, utilizing the step 4.1 to countThe calculated product factor M will be the PWM carrier frequency fswPerforming equivalent grouping corresponding to the output rated current I of the step 4.2aMay be grouped into f as shown in FIG. 5swThe grouping is as follows: fsw，2Fsw，4Fsw，8Fsw，16Fsw；
Step 4.4, according to the currently collected output current iaIn the group, selecting corresponding PWM carrier frequency fsw；
Selection execution two, carrier frequency f based on successive selectionsswThe selection is that a carrier frequency selector is used for obtaining a preselected carrier frequency, a frequency limiter is used for limiting the carrier frequency within a set range, and a current carrier frequency f is obtainedswWherein the carrier frequency selector is based on a relational expressionObtaining a preselected frequency, FswFor the modulation frequency at rated power, IaIs the output current at rated power, iaIs the current output current;
step 5, the reference signal under the α β coordinate system obtained in the step 3 is usedAnd the current carrier frequency f obtained in step 4swTo the SVPWM generator.
Furthermore, a photovoltaic grid-connected inverter with the rated power of 38kW is simulated, the structure diagram is shown in FIG. 1, the control strategy diagram is shown in FIG. 2, the direct-current bus voltage is 850V, the rated output maximum phase current is 80A, the rated output voltage is 380V, and the initial PWM frequency F is obtainedsw3150 Hz; comparing the fixed SVPWM frequency control method with the SVPWM carrier frequency control method selected according to the power change, the carrier frequency selection is carried out according to the sectional selection of the step 4 as shown in FIG. 6, the total harmonic distortion of the grid-connected current is shown in FIG. 4, the carrier frequency selection is carried out according to the continuous selection of the step 4, and the total harmonic distortion of the grid-connected current is shown in FIG. 4FIG. 7 shows that at a fixed SVPWM frequency (F)sw3150Hz), the THD of the grid-connected current increases rapidly as the power decreases, and in the variable frequency control method of adjusting the SVPWM frequency according to the power variation, although the THD of the grid-connected current increases, the increase rate becomes slower and is much improved compared to the fixed frequency method.
As shown in FIG. 3, the invention lies in (1) obtaining single-phase grid-connected current i by collecting grid-connected currenta(ii) a (2) Will be connected to the grid current iaObtaining a preselected carrier frequency through a carrier frequency selector, wherein the carrier frequency selector is designed according to the LCL filter parameter design method and meets the relational expression(3) The carrier frequency is limited within a set range, so that the frequency is prevented from reaching the limit borne by a device; (4) carrier frequency fswAnd sending the voltage to an SVPWM generator to generate a control waveform with corresponding frequency, so as to realize the frequency conversion control of the inverter.
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims (1)

1. A variable frequency control method of a photovoltaic inverter based on LCL filtering is characterized by comprising the following steps:
step 1, initializing system parameters of the photovoltaic inverter, including a PI parameter of a current inner ring, a PI parameter of a voltage outer ring and a given value of a direct-current bus voltageInitial PWM frequency Fsw；
Step 2, inputting, outputting and straightening the photovoltaic inverterSampling the current bus, specifically, collecting the voltage e of the power gridabcGrid-connected current signal iabcAnd DC bus voltage Vdc(eabc＝[eaebec]T，iabc＝[iaibic]T)；
And 3, sampling the input and output of the photovoltaic inverter and the direct current bus in the step 2, and adopting a double closed loop control strategy of a dq axis decoupling voltage outer loop and a dq axis decoupling current inner loop for the photovoltaic inverter, wherein the double closed loop control strategy specifically comprises the following steps:
step 3.1, current signal and voltage signal iabc、eabcClark coordinate transformation is carried out, and the Clark coordinate transformation is respectively represented by the formulaobtaining i under alpha and beta coordinate systemαβ、eαβAnd throughObtaining a phase locking angle theta;
step 3.2, i in α β coordinate systemαβ、eαβPerforming Park transformation, respectively using the formulasObtaining i under a synchronous rotating coordinate systemdq、edqI is todqAnd a reference current signalComparing, passing the result obtained by difference comparison through PI regulator, performing feedforward decoupling according to mathematical model under dq coordinate system to obtain reference signal under dq coordinate systemReference signalCarrying out Park reactionTransformation by the formulaobtaining a reference signal under α β coordinate systemWherein,for a given amount of reactive current,the reference signal is an active current and is obtained by a voltage outer ring after PI regulationqd＝[iqid]T，iβα＝[iβiα]T，eβα＝[eβeα]T)；
Step 4, utilizing the output current i obtained by samplingaObtaining the current carrier frequency fswSpecifically, the selection execution is performed:
selection execution one, carrier frequency f based on segment selectionswThe selection specifically comprises the following steps:
step 4.1, according to the design method of the LCL, the inductance sum formula of the LCL is usedWherein u isdcFor the DC bus voltage to be a constant value, fswTo control the PWM carrier frequency, i, of the IGBTaThe total amount of inductance required for the inverter to output current follows only fswiaSo that when the output power changes, i.e. the output current i changesaWhen varied, by varying the frequency of fswiaSo that the required total inductance is substantially constant, and therefore the inverter must be ratedConstant output current IaAnd carrier frequency F at rated powerswAnd calculating the product factor M ═ Ia·Fsw；
Step 4.2, outputting rated current IaIs divided by 2n(n is 0,1,2,3,4,5), and is divided into 5 groups:
step 4.3, PWM carrier frequency f is carried by product factor M calculated in step 4.1swPerforming equivalent grouping corresponding to the output rated current I of the step 4.2aCan be divided into fswThe grouping is as follows: fsw，2Fsw，4Fsw，8Fsw，16Fsw；
Step 4.4, according to the currently collected output current iaIn the group, selecting corresponding PWM carrier frequency fsw；
Selection execution two, carrier frequency f based on successive selectionsswThe selection is that a carrier frequency selector is used for obtaining a preselected carrier frequency, a frequency limiter is used for limiting the carrier frequency within a set range, and a current carrier frequency f is obtainedswWherein the carrier frequency selector is based on a relational expressionObtaining a preselected frequency, FswFor the modulation frequency at rated power, IaIs the output current at rated power, iaIs the current output current;
step 5, the reference signal under the α β coordinate system obtained in the step 3 is usedAnd the current carrier frequency f obtained in step 4swTo the SVPWM generator.
CN201711207717.3A 2017-11-27 2017-11-27 A kind of method for controlling frequency conversion of the photovoltaic combining inverter based on LCL filtering Expired - Fee Related CN107769257B (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
CN108879782A (en) * 2018-08-01 2018-11-23 国网重庆市电力公司电力科学研究院 Gird-connected inverter optimal control method based on double-smoothing voltage feed-forward control
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
CN110445163A (en) * 2019-09-10 2019-11-12 北京金茂绿建科技有限公司 A kind of self-adjustable energy accumulation current converter of switching frequency
CN110880790A (en) * 2019-12-23 2020-03-13 太原理工大学 Control method of grid-connected power converter with LCL topological structure
CN112564533A (en) * 2021-02-23 2021-03-26 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
CN112838777A (en) * 2021-01-07 2021-05-25 山东大学 Active power consumption cooperative control system and method for power switching devices of multi-grid-connected inverter
CN113179037A (en) * 2021-05-08 2021-07-27 全球能源互联网研究院有限公司 Switching frequency modulation method and device and storage medium
CN114050605A (en) * 2021-11-18 2022-02-15 山东大学 Frequency conversion pulse width modulation synchronization system and method based on local power grid phase

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
CN102751742A (en) * 2012-07-25 2012-10-24 漳州科华技术有限责任公司 Method for improving grid-connected performance by variable switching frequency
CN102946115A (en) * 2012-10-22 2013-02-27 哈电通用风能（江苏）有限公司 Control method of three-phase PWM (Pulse-Width Modulation) converter based on bidirectional coordinate conversion of LCL filter
JP2015192515A (en) * 2014-03-28 2015-11-02 株式会社日立製作所 drive system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
CN102751742A (en) * 2012-07-25 2012-10-24 漳州科华技术有限责任公司 Method for improving grid-connected performance by variable switching frequency
CN102946115A (en) * 2012-10-22 2013-02-27 哈电通用风能（江苏）有限公司 Control method of three-phase PWM (Pulse-Width Modulation) converter based on bidirectional coordinate conversion of LCL filter
JP2015192515A (en) * 2014-03-28 2015-11-02 株式会社日立製作所 drive system

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
CN108879782A (en) * 2018-08-01 2018-11-23 国网重庆市电力公司电力科学研究院 Gird-connected inverter optimal control method based on double-smoothing voltage feed-forward control
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
CN110445163A (en) * 2019-09-10 2019-11-12 北京金茂绿建科技有限公司 A kind of self-adjustable energy accumulation current converter of switching frequency
CN110880790A (en) * 2019-12-23 2020-03-13 太原理工大学 Control method of grid-connected power converter with LCL topological structure
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
CN112838777A (en) * 2021-01-07 2021-05-25 山东大学 Active power consumption cooperative control system and method for power switching devices of multi-grid-connected inverter
CN112564533A (en) * 2021-02-23 2021-03-26 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
CN113179037A (en) * 2021-05-08 2021-07-27 全球能源互联网研究院有限公司 Switching frequency modulation method and device and storage medium
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
CN114050605A (en) * 2021-11-18 2022-02-15 山东大学 Frequency conversion pulse width modulation synchronization system and method based on local power grid phase
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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