CN102611341B - Photovoltaic inverter and method for tracking maximum power of same - Google Patents

Photovoltaic inverter and method for tracking maximum power of same Download PDF

Info

Publication number
CN102611341B
CN102611341B CN201210063464.8A CN201210063464A CN102611341B CN 102611341 B CN102611341 B CN 102611341B CN 201210063464 A CN201210063464 A CN 201210063464A CN 102611341 B CN102611341 B CN 102611341B
Authority
CN
China
Prior art keywords
battery
photovoltaic
voltage
inversion
converter
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
Application number
CN201210063464.8A
Other languages
Chinese (zh)
Other versions
CN102611341A (en
Inventor
刘亚军
迟屹楠
郑开科
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen yingweiteng Photovoltaic Technology Co. Ltd.
Original Assignee
Shenzhen Invt Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shenzhen Invt Electric Co Ltd filed Critical Shenzhen Invt Electric Co Ltd
Priority to CN201210063464.8A priority Critical patent/CN102611341B/en
Publication of CN102611341A publication Critical patent/CN102611341A/en
Application granted granted Critical
Publication of CN102611341B publication Critical patent/CN102611341B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • 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

Disclosed are a photovoltaic inverter and a method for tracking maximum power of the same. At least two batteries serve as input power sources of the photovoltaic inverter. The method includes the steps: sampling input voltage of one battery 1 of the batteries; judging whether the input voltage of the currently sampled battery 1 is larger than a preset first threshold value or not; if the input voltage of the currently sampled battery 1 is not larger than the preset first threshold value, judging whether the input voltage of the currently sampled battery 1 is smaller than a preset second threshold value or not, wherein the first threshold value is larger than the second threshold value; if the input voltage of the currently sampled battery 1 is not smaller than the preset second threshold value, judging whether an inverted maximum tracking mark of the battery 1 is effective or not; and tracking the inverted maximum power of the battery 1 if the inverted maximum tracking mark of the battery 1 is effective. By the aid of the technical scheme of the photovoltaic inverter and the method in the embodiment, accuracy rate of seeking a maximum power tracking point of the photovoltaic inverter can be effectively increased.

Description

A kind of maximum power tracking method of photovoltaic DC-to-AC converter and photovoltaic DC-to-AC converter
Technical field
The present invention relates to photovoltaic system field, relate in particular to a kind of maximum power tracking method and photovoltaic DC-to-AC converter of photovoltaic DC-to-AC converter.
Background technology
Photovoltaic DC-to-AC converter is a kind of power adjusting device being made up of semiconductor device, is mainly used in direct current power to convert alternating electromotive force to.Generally formed by boost loop and inversion bridge type return.The loop of boosting boosts to photovoltaic DC-to-AC converter output the direct voltage of solar cell and controls required direct voltage.Inversion bridge type return is of equal value the direct voltage after boosting the alternating voltage that converts conventional frequency to.
Be illustrated in figure 1 the topological structure of conventional at present a kind of three-phase photovoltaic DC-to-AC converter.Its input side joint two-way solar cell, as the solar cell 1 in Fig. 1 and solar cell 2, inversion side is public side.Because the output voltage of solar cell is along with the variation of intensity of illumination changes, and the relation of its power output and output voltage as shown in Figure 2, as seen from Figure 2, the power voltage curve difference of two-way input battery, wherein, V1 and V2 are respectively two-way input battery corresponding voltage in the time reaching maximum power.
In order to improve the service efficiency of solar cell, must search out the maximum power point of solar cell.Existing maximal power tracing technology is to ask the power sum of two-way input battery, then utilizes booster circuit to follow the tracks of the maximum of power sum.But, may there are multiple extreme values in the power voltage curve corresponding due to two-way power sum, prior art can only solve power can trace into certain extreme value, but the not necessarily maximum of system, the maximum power point that is its tracking may not be real maximum power point, and is certain extreme point of power.
Summary of the invention
The embodiment of the present invention provides a kind of maximum power tracking method and photovoltaic DC-to-AC converter of photovoltaic DC-to-AC converter, when take over the battery of meaning road different qualities at photovoltaic DC-to-AC converter, effectively improves the accuracy rate of the maximal power tracing point of finding photovoltaic DC-to-AC converter.
For solving the problems of the technologies described above, the embodiment of the present invention provides following technical scheme:
A maximum power tracking method for photovoltaic DC-to-AC converter, wherein, described photovoltaic DC-to-AC converter is by least two-way battery is as input power, and described maximum power tracking method comprises: the wherein input voltage of a road battery 1 to described at least two-way battery is sampled; Whether the input voltage that judges the battery 1 of current sampling is greater than the first preset threshold values; If the input voltage of the battery of described current sampling 1 is not more than the first preset threshold values, judge whether the input voltage of the battery 1 of described current sampling is less than the second preset threshold values, wherein, described the first threshold values is greater than described the second threshold values; If the input voltage of the battery of described current sampling 1 is not less than the second preset threshold values, judge that whether the maximum tracking mark of inversion of battery 1 is effective; And if the maximum tracking mark of the inversion of described battery 1 is effective, described battery 1 is carried out to inversion maximal power tracing.
Preferably, the step whether input voltage of the described battery 1 that judges current sampling is greater than the first preset threshold values also comprises afterwards: if the input voltage of the battery of described current sampling 1 is greater than described the first preset threshold values, maximum the inversion of described battery 1 tracking mark is set to effectively, and described battery 1 is carried out to inversion maximal power tracing.
Preferably, described sampling also comprises samples to the wherein input current of a road battery 1 of described at least two-way battery, wherein, the step of described battery 1 being carried out to inversion maximal power tracing also comprises: the boosted switch pipe that disconnects the loop of boosting at described battery 1 place; The busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the second threshold values; The input power of all batteries that the described input voltage obtaining according to described sampling and described input current calculate respectively the maximum tracking mark of current inversion while being effective, sues for peace to obtain inversion input power by the input power of described all batteries; According to described inversion input power, utilize method of perturbation to calculate the first disturbance voltage; And according to the busbar voltage initial value of described the first disturbance voltage and described photovoltaic DC-to-AC converter, the input voltage of described battery 1 is carried out to inversion control.
Preferably, the step that the described busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the second threshold values comprises: if the busbar voltage initial value of described photovoltaic DC-to-AC converter is greater than described the second threshold values, progressively the busbar voltage initial value of described photovoltaic DC-to-AC converter is decayed to described the second threshold values according to the first predetermined step-length.
Preferably, before described step of the input voltage of described battery 1 being carried out to inversion control, comprise: if described the first disturbance voltage exceedes the first preset maximum threshold, described the first disturbance voltage is carried out to amplitude limiting processing, if or described the first disturbance voltage is while being less than the first preset minimum threshold, described the first disturbance voltage is carried out to increasing degree processing.
Preferably, the described step that the input voltage of described battery 1 is carried out to inversion control comprises: the busbar voltage of current described photovoltaic DC-to-AC converter is deducted to the busbar voltage initial value of described the first disturbance voltage and described photovoltaic DC-to-AC converter, obtain the first difference; Described the first difference passing ratio integral adjustment is obtained to the first current value; By poor the current value of inductance on the inversion circuit of described the first current value and described photovoltaic DC-to-AC converter, obtain the first electric current difference; Will be described the first electric current difference passing ratio obtain the first output variable after regulating, utilize the ON time of the inverse switch pipe on the inversion circuit of photovoltaic DC-to-AC converter described in described the first output variable control, with this, input voltage of described battery 1 is carried out to inversion control.
Preferably, the step whether input voltage of the described battery 1 that judges described current sampling is less than the second preset threshold values also comprises afterwards: if the input voltage of the battery of described current sampling 1 is less than described the second preset threshold values, it is invalid maximum the inversion of battery 1 tracking mark to be set to, and described battery 1 is carried out to the maximal power tracing that boosts.
Preferably, the step whether input voltage of the described battery 1 that judges described current sampling is less than the second preset threshold values also comprises afterwards: if the input voltage of the battery of described current sampling 1 is not less than described the second preset threshold values, and when the maximum tracking mark of the inversion of described battery 1 is invalid, described battery 1 is carried out to the maximal power tracing that boosts.
Preferably, described sampling also comprises samples to the wherein input current of a road battery 1 of described at least two-way battery, wherein, the step that described battery 1 is carried out to the maximal power tracing that boosts also comprises: if the boosted switch pipe in the loop of boosting at current described battery 1 place in off-state, the boosted switch pipe in the loop of boosting at battery 1 place described in conducting; The busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the first threshold values; Obtain the input voltage of described battery 1 and input current and calculate the input power of described battery 1 according to described sampling; According to the input power of described battery 1, utilize method of perturbation to calculate the second disturbance voltage; And according to described the second disturbance voltage, the input voltage of described battery 1 is carried out to boosting rectifier control.
Preferably, the step that the described busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the first threshold values is specially: if the busbar voltage initial value of described photovoltaic DC-to-AC converter is less than described the first threshold values, progressively the busbar voltage initial value of described photovoltaic DC-to-AC converter is increased to described the first threshold values according to the second predetermined step-length.
Preferably, before described step of according to described the second disturbance voltage, the input voltage of described battery 1 being carried out boosting rectifier control, comprise: if described the second disturbance voltage exceedes the second preset maximum threshold, described the second disturbance voltage is carried out to amplitude limiting processing, if or described the second disturbance voltage is less than the second preset minimum threshold, described the second disturbance voltage is carried out to increasing degree processing.
Preferably, described step of the input voltage of described battery 1 being carried out to boosting rectifier control according to described the second disturbance voltage comprises: the current input voltage of described battery 1 is deducted to described the second disturbance voltage, obtain the second difference; Described the second difference passing ratio integral adjustment is obtained to the second current value; By poor the current value of inductance on the loop of boosting of described the second current value and described photovoltaic DC-to-AC converter, obtain the second electric current difference; Will be described the second electric current difference passing ratio obtain the second output variable after regulating, utilize the ON time of the boosted switch pipe on loop that boosts at battery 1 place described in described the second output variable control, with this, input voltage of described battery 1 is carried out to boosting rectifier control.
A kind of photovoltaic DC-to-AC converter, comprises sampling unit, the first judging unit, the second judging unit, the 3rd judging unit and inversion maximal power tracing unit, wherein, described photovoltaic DC-to-AC converter by two-way battery at least as input power.Sampling unit is for sampling to the wherein input voltage of a road battery 1 of described at least two-way battery.Whether the input voltage that the first judging unit is used for the battery 1 that judges the current sampling of described sampling unit is greater than the first preset threshold values.The second judging unit, for when the judged result of described the first judging unit is while being no, judges whether the input voltage of the battery 1 of described current sampling is less than the second preset threshold values, and wherein, described the first threshold values is greater than described the second threshold values.The 3rd judging unit, for when the judged result of described the second judging unit is while being no, judges that whether the inversion maximum tracking mark of described battery 1 is effective.Inversion maximal power tracing flow process, for when the judged result of described the 3rd judging unit is when being, is carried out to described battery 1 in inversion maximal power tracing unit.
Preferably, described photovoltaic DC-to-AC converter also comprises: trace labelling setup unit, for when the judged result of described the first judging unit is when being, maximum the inversion of described battery 1 tracking mark is set to effectively, wherein, described inversion maximal power tracing unit, also, at described trace labelling setup unit, maximum the inversion of described battery 1 tracking mark being set to when effective, carries out inversion maximal power tracing flow process to described battery 1.
Preferably, described sampling unit is also sampled for the wherein input current of a road battery 1 to described at least two-way battery, wherein, described inversion maximal power tracing unit specifically comprises: the first switch controlled unit, for disconnecting the boosted switch pipe in the loop of boosting at described battery 1 place; The first busbar voltage setting unit, equals described the second threshold values for the busbar voltage initial value of described photovoltaic DC-to-AC converter is set; The first computing unit, the input power of all batteries when to calculate respectively current inversion maximum tracking mark be effective for sample according to described the sampling unit described input voltage that obtains and described input current, the input power summation of described all batteries is obtained to inversion input power, and utilize method of perturbation to calculate the first disturbance voltage according to described inversion input power; Inversion control unit, for according to the busbar voltage initial value of described the first disturbance voltage and described photovoltaic DC-to-AC converter, carries out inversion control to the input voltage of described battery 1.
Preferably, if when described the first busbar voltage setting unit is also greater than described the second threshold values for the busbar voltage initial value of described photovoltaic DC-to-AC converter, progressively the busbar voltage initial value of described photovoltaic DC-to-AC converter is decayed to described the second threshold values according to the first predetermined step-length.
Preferably, described photovoltaic DC-to-AC converter also comprises: the first AM unit, for before described inversion control unit carries out inversion control to the input voltage of described battery 1, if described the first disturbance voltage exceedes the first preset maximum threshold, described the first disturbance voltage is carried out to amplitude limiting processing, if or described the first disturbance voltage is less than the first preset minimum threshold, described the first disturbance voltage is carried out to increasing degree processing.
Preferably, described inversion control unit comprises: first makes differential mode piece, for the busbar voltage of current described photovoltaic DC-to-AC converter being deducted to described the first disturbance voltage and the set busbar voltage initial value of described the first busbar voltage setting unit, obtains the first difference; The first proportional integral adjustment module, for described the first difference passing ratio integral adjustment is obtained to the first current value, wherein, described first makes differential mode piece also for by poor the current value of inductance on the inversion circuit of described the first current value and described photovoltaic DC-to-AC converter, obtains the first electric current difference; The first ratio adjustment module obtains the first output variable after described the first electric current difference passing ratio is regulated; Inversion control submodule, for utilizing the ON time of the inverse switch pipe on the inversion circuit of photovoltaic DC-to-AC converter described in described the first output variable control, carries out inversion control with this to the input voltage of described battery 1.
Preferably, described trace labelling setup unit is also for when the judged result of described the second judging unit is when being, it is invalid that maximum the inversion of described battery 1 tracking mark is set to, wherein, described photovoltaic DC-to-AC converter also comprises: maximal power tracing unit boosts, for when described trace labelling setup unit, maximum the inversion of described battery 1 tracking mark being set to when invalid, to the described battery 1 execution maximal power tracing flow process of boosting.
Preferably, described in the maximal power tracing unit that boosts, be also no for the judged result when described the second judging unit, and the judged result of described the 3rd judging unit is while be also no, to the described battery 1 execution maximal power tracing flow process of boosting.
Preferably, described sampling unit is also sampled for the wherein input current of a road battery 1 to described at least two-way battery, wherein, the described maximal power tracing unit that boosts specifically comprises: second switch pipe control unit, for the boosted switch pipe in the loop of boosting at current described battery 1 place during in off-state, the boosted switch pipe in the loop of boosting at battery 1 place described in conducting; The second busbar voltage setting unit, equals described the first threshold values for the busbar voltage initial value of described photovoltaic DC-to-AC converter is set; The second computing unit, described input voltage and the described input current of the described battery 1 obtaining for sampling according to described sampling unit calculate the input power of described battery 1, and utilize method of perturbation to calculate the second disturbance voltage according to the input power of described battery 1; Boosting rectifier control unit, for carrying out boosting rectifier control according to described the second disturbance voltage to the input voltage of described battery 1.
Preferably, described the second busbar voltage setting unit, also in the time that the busbar voltage initial value of described photovoltaic DC-to-AC converter is less than described the first threshold values, is progressively increased to described the first threshold values by the busbar voltage initial value of described photovoltaic DC-to-AC converter according to the second predetermined step-length.
Preferably, described photovoltaic DC-to-AC converter also comprises: the second AM unit, for before described boosting rectifier control unit carries out boosting rectifier control to the input voltage of described battery 1, if described the second disturbance voltage exceedes the second preset maximum threshold, described the second disturbance voltage is carried out to amplitude limiting processing, if or described the second disturbance voltage is while being less than the second preset minimum threshold, described the second disturbance voltage is carried out to increasing degree processing.
Preferably, described boosting rectifier control unit specifically comprises: second makes differential mode piece, for the current input voltage of described battery 1 being deducted to described the second disturbance voltage, obtains the second difference; The second proportional integral adjustment module, for described the second difference passing ratio integral adjustment is obtained to the second current value, wherein, described second makes differential mode piece also for by poor the current value of inductance on the loop of boosting of described the second current value and described photovoltaic DC-to-AC converter, obtains the second electric current difference; The second ratio adjustment module obtains the second output variable after described the second electric current difference passing ratio is regulated; Boosting rectifier control submodule, for utilizing the ON time of the boosted switch pipe on loop that boosts at battery 1 place described in described the second output variable control, carries out boosting rectifier control with this to the input voltage of described battery 1.
Therefore, in the embodiment of the present invention, set the first threshold values and the second threshold values, and the first threshold values is greater than the second threshold values, size by the cell voltage that relatively gathers and the first threshold values, the second threshold values is set the maximum tracking mark of inversion of this road battery, judges that according to the maximum tracking mark of inversion this road battery carries out inversion maximal power tracing or boosts maximal power tracing.By independently controlling two-way or multichannel battery, make the input of every road battery all reach maximal power tracing point, make photovoltaic DC-to-AC converter in the time taking over the battery of meaning road different qualities, can accurately search out the maximal power tracing point of photovoltaic DC-to-AC converter system.
Brief description of the drawings
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the topological structure schematic diagram of a kind of three-phase photovoltaic DC-to-AC converter of commonly using;
Fig. 2 is the schematic diagram that is related to of the power output of photovoltaic DC-to-AC converter and output voltage;
The maximum power tracking method schematic flow sheet of the photovoltaic DC-to-AC converter that Fig. 3 provides for the embodiment of the present invention;
The inversion maximal power tracing schematic flow sheet that Fig. 4 provides for the embodiment of the present invention;
The maximal power tracing schematic flow sheet that boosts that Fig. 5 provides for the embodiment of the present invention;
Photovoltaic DC-to-AC converter the first example structure schematic diagram that Fig. 6 provides for the embodiment of the present invention;
Photovoltaic DC-to-AC converter the second example structure schematic diagram that Fig. 7 provides for the embodiment of the present invention;
The inversion maximal power tracing cellular construction schematic diagram that Fig. 8 provides for the embodiment of the present invention;
Photovoltaic DC-to-AC converter the 3rd example structure schematic diagram that Fig. 9 provides for the embodiment of the present invention;
The maximal power tracing cellular construction schematic diagram that boosts that Figure 10 provides for the embodiment of the present invention.
Embodiment
The embodiment of the present invention provides a kind of maximum power tracking method and photovoltaic DC-to-AC converter of photovoltaic DC-to-AC converter.
For making goal of the invention of the present invention, feature, advantage can be more obvious and understandable, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, but not whole embodiment.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.
In embodiments of the present invention, photovoltaic DC-to-AC converter by two-way battery (as solar cell) at least as input power, be the topological structure as the three-phase photovoltaic DC-to-AC converter of input power as shown in Figure 1 by two-way battery, wherein, above-mentioned at least two-way battery can have identical characteristics, also can there is different qualities, be not construed as limiting herein.
Below the maximum power tracking method of a kind of photovoltaic DC-to-AC converter in the embodiment of the present invention is described, in the embodiment of the present invention, photovoltaic DC-to-AC converter carries out independent control to two-way or the multichannel battery of access, and, in the battery of Mei road, carry out identical flow processing, therefore, for convenience of description and understand, the embodiment of the present invention describes in the processing procedure in the loop at battery 1 place with photovoltaic DC-to-AC converter, wherein, battery 1 is a road wherein in above-mentioned at least two-way battery, concrete, photovoltaic DC-to-AC converter can be with reference to the description in the embodiment of the present invention in the processing procedure in the loop at other battery place.
Refer to Fig. 3, the maximum power tracking method schematic flow sheet of the photovoltaic DC-to-AC converter providing for the embodiment of the present invention, as shown in Figure 3, the maximum power tracking method of photovoltaic DC-to-AC converter comprises:
301, the input voltage of battery 1 is sampled.
In embodiments of the present invention, can by set the sampling period, make photovoltaic DC-to-AC converter periodically the input voltage of Dui Ge road battery sample, for example, if setting the sampling period is 50 milliseconds, photovoltaic DC-to-AC converter is sampled every the input voltage of 50 milliseconds of Dui Ge road batteries.
Further, photovoltaic DC-to-AC converter, when the input voltage of battery 1 is sampled, is also sampled to the input current of battery 1.
Whether the input voltage that 302, judges the battery 1 of current sampling is greater than the first preset threshold values.
Photovoltaic DC-to-AC converter judges whether the input voltage of the battery 1 of current sampling is greater than the first preset threshold values, wherein, the first threshold values can be set as the output voltage of photovoltaic DC-to-AC converter, modulation depth and tube voltage drop according to practical application, as being the photovoltaic DC-to-AC converter of 50 hertz, 220 volts alternating currents for output voltage, can set the first threshold values is 650.
In embodiments of the present invention, be greater than the first preset threshold values if judge the input voltage of the battery 1 of current sampling, execution step 303; Be not more than the first preset threshold values if judge the input voltage of the battery 1 of current sampling, execution step 304.
303, maximum the inversion of battery 1 tracking mark is set to effectively.
Illustrate, if the maximum tracking mark of definition inversion be 1 o'clock effective, the maximum tracking mark of inversion be 0 o'clock invalid, in the embodiment of the present invention in the time that the input voltage of battery 1 of judging current sampling is greater than the first preset threshold values, maximum the inversion of battery 1 tracking mark is set to 1.Certainly, in the embodiment of the present invention, also can define the maximum tracking mark of inversion and indicate it effectively with invalid with other value, be not construed as limiting herein.
In embodiments of the present invention, after maximum the inversion of battery 1 tracking mark is set to effectively, execution step 307.
Whether the input voltage that 304, judges the battery 1 of above-mentioned current sampling is less than the second preset threshold values.
In embodiments of the present invention, photovoltaic DC-to-AC converter is in the time that the input voltage of the battery 1 of the current sampling of judgement is not more than the first preset threshold values, also need further to judge whether the input voltage of the battery 1 of current sampling is less than the second preset threshold values, and wherein, the second threshold values is less than the first threshold values.The second threshold values can be set as the output voltage of photovoltaic DC-to-AC converter, modulation depth and tube voltage drop according to practical application, and as being the photovoltaic DC-to-AC converter of 50 hertz, 220 volts alternating currents for output voltage, can set the second threshold values is 610.
In embodiments of the present invention, be less than the second preset threshold values if judge the input voltage of the battery 1 of current sampling, perform step 305; Be not less than the second preset threshold values if judge the input voltage of the battery 1 of current sampling, keep the maximum tracking mark of the current inversion of battery 1, enter step 306.
305, maximum the inversion of battery 1 tracking mark is set to invalid.
Illustrate, if the maximum tracking mark of definition inversion be 1 o'clock effective, the maximum tracking mark of inversion be 0 o'clock invalid, in the embodiment of the present invention in the time that the input voltage of battery 1 of judging current sampling is less than the second preset threshold values, maximum the inversion of battery 1 tracking mark is set to 0.Certainly, in the embodiment of the present invention, also can define the maximum tracking mark of inversion and indicate it effectively with invalid with other value, be not construed as limiting herein.
In embodiments of the present invention, maximum the inversion of battery 1 tracking mark is set to invalid after, execution step 308.
306, judge that whether the maximum tracking mark of inversion of battery 1 is effective.
If the maximum tracking mark of the inversion of battery 1 is effective, perform step 307, if the maximum tracking mark of the inversion of battery 1 is invalid, perform step 308.
307, battery 1 is carried out to inversion maximal power tracing flow process.
In embodiments of the present invention, inversion maximal power tracing flow process as shown in Figure 4.
Refer to Fig. 4, the inversion maximal power tracing schematic flow sheet providing for the embodiment of the present invention.As shown in Figure 4, inversion maximal power tracing flow process comprises:
The boosted switch pipe in the loop of boosting at A1, disconnection battery 1 place.
In embodiments of the present invention, if photovoltaic DC-to-AC converter disconnects the boosted switch pipe in the loop of boosting at battery 1 place, now, the busbar voltage of photovoltaic DC-to-AC converter equals the input voltage of battery 1.
A2, the busbar voltage initial value that photovoltaic DC-to-AC converter is set equal above-mentioned the second threshold values.
In a kind of application scenarios, if when the busbar voltage initial value of photovoltaic DC-to-AC converter is greater than above-mentioned the second threshold values, the busbar voltage of system progressively the busbar voltage initial value of photovoltaic DC-to-AC converter decayed to above-mentioned the second threshold values according to the first predetermined step-length, so that can seamlessly transit when maximal power tracing algorithm changeover.
A3, the input voltage obtaining according to sampling and input current, calculate respectively the input power that the maximum tracking mark of current inversion is effective all batteries, and the input power summation of above-mentioned all batteries is obtained to inversion input power.
In embodiments of the present invention, the input voltage obtaining according to sampling and input current, by formula P (power)=U (voltage) * I (electric current), can calculate respectively the input power that the maximum tracking mark of current inversion is effective all batteries.Then the input power that is effective all batteries by maximum the current inversion calculating tracking mark is cumulative, can obtain inversion input power.
The inversion input power that A4, basis obtain, utilizes method of perturbation to calculate the first disturbance voltage.
From the curve in Fig. 2, the operating power in loop, battery place is along with the input voltage of this battery increases and gradually near maximum power point, arrive after maximum power point, along with the further increase of the input voltage of this battery, the operating power in loop, battery place will be gradually away from maximum power point.
The input voltage U of the battery 1 that more current sampling obtains of the method for perturbation in the embodiment of the present invention kwith the inversion input power P calculating kinput voltage U with last sampling period battery 1 k-1with input power P k-1if, P kbe greater than P k-1, and U kbe greater than U k-1, show P kbe positioned at maximum power point P on curve maxleft area, by U kadd predetermined change step Δ U, obtain the first disturbance voltage; If P kbe greater than P k-1, and U kbe less than U k-1, show P kbe positioned at maximum power point P on curve maxregion, the right, by U kdeduct Δ U, obtain the first disturbance voltage; If P kbe less than P k-1, and U kbe greater than U k-1, show P kbe positioned at maximum power point P on curve maxregion, the right, by U kdeduct Δ U, obtain the first disturbance voltage; If P kbe less than P k-1, and U kbe less than U k-1, show P kbe positioned at maximum power point P on curve maxleft area, by U kadd Δ U, obtain the first disturbance voltage.
A5, the first disturbance voltage obtaining according to steps A 4 and the busbar voltage initial value of photovoltaic DC-to-AC converter, carry out inversion control to the input voltage of battery 1.
Under a kind of application scenarios, if the input voltage of the inversion circuit of photovoltaic DC-to-AC converter is excessive, may cause the unstable even collapse of photovoltaic DC-to-AC converter place system, therefore, can be before the input voltage of battery 1 be carried out to inversion control in the embodiment of the present invention, detect above-mentioned the first disturbance voltage and whether exceed the first preset maximum threshold, if exceed, above-mentioned the first disturbance voltage is carried out to amplitude limiting processing; Further, can also, in the time detecting the first disturbance voltage and do not exceed the first preset maximum threshold, detect above-mentioned the first disturbance voltage and whether be less than the first preset minimum threshold, if be less than, above-mentioned the first disturbance voltage is carried out to increasing degree processing.
In embodiments of the present invention, the input voltage of battery 1 is carried out to the detailed process of inversion control as follows:
The busbar voltage initial value that the busbar voltage of current photovoltaic DC-to-AC converter is deducted to photovoltaic DC-to-AC converter set in the first disturbance voltage that steps A 4 obtains and steps A 2, obtains the first difference; Above-mentioned the first difference passing ratio integral adjustment is obtained to the first current value; By poor the current value of inductance on the inversion circuit of the first current value obtaining and photovoltaic DC-to-AC converter, obtain the first electric current difference; After being regulated, the first electric current difference passing ratio obtaining obtains the first output variable, the ON time of the inverse switch pipe on the inversion circuit of the first output variable control photovoltaic DC-to-AC converter that utilization obtains, with this, input voltage of battery 1 is carried out to inversion control, and then make the input power of battery 1 close towards the maximal power tracing point of battery 1.
Below please continue to refer to Fig. 3.
308, battery 1 is carried out to the maximal power tracing flow process of boosting.
In embodiments of the present invention, boost maximal power tracing flow process as shown in Figure 5.
Refer to Fig. 5, the maximal power tracing schematic flow sheet that boosts providing for the embodiment of the present invention.As shown in Figure 5, the maximal power tracing flow process of boosting comprises:
If the boosted switch pipe in the loop of boosting at the current battery of B1 1 place is in off-state, the boosted switch pipe in the loop of boosting at turn-on battery 1 place.
In embodiments of the present invention, if the boosted switch pipe in the loop of boosting at current battery 1 place, in conducting state, can not perform step B1.
B2, the busbar voltage initial value that photovoltaic DC-to-AC converter is set equal above-mentioned the first threshold values.
In a kind of application scenarios, if when the busbar voltage initial value of current photovoltaic DC-to-AC converter is less than above-mentioned the first threshold values, the busbar voltage of system progressively the busbar voltage initial value of photovoltaic DC-to-AC converter is increased to above-mentioned the first threshold values according to the second predetermined step-length, so that can seamlessly transit when maximal power tracing algorithm changeover.
Input voltage and the input current of B3, the battery 1 that obtains according to sampling, calculate the input power of battery 1.
Input voltage and the input current of the battery 1 obtaining according to sampling, by formula P (power)=U (voltage) * I (electric current), calculate the input power of battery 1.
The input power of the battery 1 that B4, basis obtain, utilizes method of perturbation to calculate the second disturbance voltage.
From the curve in Fig. 2, the operating power in loop, battery place is along with the input voltage of this battery increases and gradually near maximum power point, arrive after maximum power point, along with the further increase of the input voltage of this battery, the operating power in loop, battery place will be gradually away from maximum power point.
The input voltage U of the battery 1 that more current sampling obtains of the method for perturbation in the embodiment of the present invention kinput power P with the current battery calculating 1 kinput voltage U with last sampling period battery 1 k-1with input power P k-1if, P kbe greater than P k-1, and U kbe greater than U k-1, show P kbe positioned at maximum power point P on curve maxleft area, by U kadd predetermined change step Δ U, obtain the second disturbance voltage; If P kbe greater than P k-1, and U kbe less than U k-1, show P kbe positioned at maximum power point P on curve maxregion, the right, by U kdeduct Δ U, obtain the second disturbance voltage; If P kbe less than P k-1, and U kbe greater than U k-1, show P kbe positioned at maximum power point P on curve maxregion, the right, by U kdeduct Δ U, obtain the second disturbance voltage; If P kbe less than P k-1, and U kbe less than U k-1, show P kbe positioned at maximum power point P on curve maxleft area, by U kadd Δ U, obtain the second disturbance voltage.
B5, the second disturbance voltage obtaining according to step B4, carry out boosting rectifier control to the input voltage of battery 1.
Under a kind of application scenarios, if the input voltage of the inversion circuit of photovoltaic DC-to-AC converter is excessive, may cause the unstable even collapse of photovoltaic DC-to-AC converter place system, therefore, can be before carrying out boosting rectifier control in the embodiment of the present invention, detect above-mentioned the second disturbance voltage and whether exceed the second preset maximum threshold, if exceed, above-mentioned the second disturbance voltage is carried out to amplitude limiting processing; Further, can also, in the time detecting the second disturbance voltage and do not exceed the second preset maximum threshold, detect above-mentioned the second disturbance voltage and whether be less than the second preset minimum threshold, if be less than, above-mentioned the second disturbance voltage is carried out to increasing degree processing.
In embodiments of the present invention, the input voltage of battery 1 is carried out to the detailed process of boosting rectifier control as follows:
The current input voltage of battery 1 is deducted to the second disturbance voltage that step B4 obtains, obtain the second difference; Above-mentioned the second difference passing ratio integral adjustment is obtained to the second current value; By poor the current value of inductance on the loop of boosting of the second current value obtaining and photovoltaic DC-to-AC converter, obtain the second electric current difference; After being regulated, the second electric current difference passing ratio obtaining obtains the second output variable, the ON time of the boosted switch pipe on loop that boosts at the second output variable control battery 1 place that utilization obtains, with this, input voltage of battery 1 is carried out to boosting rectifier control, and then make the input power of battery 1 close towards the maximal power tracing point of battery 1.
The flow process of embodiment of the present invention Fig. 3 triggers in the time that photovoltaic inverter grid-connected is worked, it should be noted that, photovoltaic DC-to-AC converter will enter initialized process in the time of electrifying startup, just grid-connected work after initialization procedure finishes is invalid by maximum above-mentioned inversion tracking mark default setting in the embodiment of the present invention in above-mentioned initialization procedure.
The maximum power tracking method of the photovoltaic DC-to-AC converter in the embodiment of the present invention can be applied to single-phase photovoltaic DC-to-AC converter, also can be applied in three-phase photovoltaic DC-to-AC converter, battery in the embodiment of the present invention can be solar panel, or, also can be other battery that can realize opto-electronic conversion, be not construed as limiting herein.
Therefore, in the embodiment of the present invention, set the first threshold values and the second threshold values, and the first threshold values is greater than the second threshold values, size by the cell voltage that relatively gathers and the first threshold values, the second threshold values is set the maximum tracking mark of inversion of this road battery, judges that according to the maximum tracking mark of inversion this road battery carries out inversion maximal power tracing or boosts maximal power tracing.By independently controlling two-way or multichannel battery, make the input of every road battery all reach maximal power tracing point, make photovoltaic DC-to-AC converter in the time taking over the battery of meaning road different qualities, can accurately search out the maximal power tracing point of photovoltaic DC-to-AC converter system.And, because the maximum power tracking method of the photovoltaic DC-to-AC converter in the embodiment of the present invention optionally carries out maximal power tracing in inverter circuit, with respect to only using booster circuit to do the scheme of maximal power tracing, effectively increase the maximal power tracing scope of system.
Below the photovoltaic DC-to-AC converter in the embodiment of the present invention is described, wherein, photovoltaic DC-to-AC converter in the embodiment of the present invention as input power, refers to Fig. 6 by two-way battery at least, photovoltaic DC-to-AC converter the first example structure schematic diagram providing for the embodiment of the present invention.As shown in Figure 6, photovoltaic DC-to-AC converter 600 comprises: sampling unit 601, the first judging unit 602, the second judging unit 603, the 3rd judging unit 604 and inversion maximal power tracing unit 605.
Sampling unit 601, samples for the wherein input voltage of a road battery 1 to above-mentioned at least two-way battery.
In embodiments of the present invention, can by set the sampling period, make sampling unit 601 periodically the input voltage of Dui Ge road battery sample, for example, if setting the sampling period is 50 milliseconds, sampling unit 601 is sampled every the input voltage of 50 milliseconds of Dui Ge road batteries.Further, sampling unit 601, when the input voltage of battery 1 is sampled, is also sampled to the input current of battery 1.
Whether the first judging unit 602, be greater than the first preset threshold values for the input voltage of the battery that judges sampling unit 601 current samplings.In embodiments of the present invention, the first threshold values can be set as the output voltage of photovoltaic DC-to-AC converter, modulation depth and tube voltage drop according to practical application, as being the photovoltaic DC-to-AC converter of 50 hertz, 220 volts alternating currents for output voltage, can set the first threshold values is 650.
The second judging unit 603, when being no when the judged result of the first judging unit 602, judges whether the input voltage of the battery 1 of above-mentioned current sampling is less than the second preset threshold values, and wherein, above-mentioned the first threshold values is greater than above-mentioned the second threshold values.
In embodiments of the present invention, the first judging unit 602 is in the time that the input voltage of the battery 1 of the current sampling of judgement is not more than the first preset threshold values, also need the second judging unit 603 further to judge whether the input voltage of the battery 1 of current sampling is less than the second preset threshold values, wherein, the second threshold values is less than the first threshold values.The second threshold values can be set as the output voltage of photovoltaic DC-to-AC converter, modulation depth and tube voltage drop according to practical application, and as being the photovoltaic DC-to-AC converter of 50 hertz, 220 volts alternating currents for output voltage, can set the second threshold values is 610.
The 3rd judging unit 604, when being no when the judged result of the second judging unit 603, judges that whether the maximum tracking mark of inversion of battery 1 is effective.Illustrate, can define the maximum tracking mark of inversion and be 1 o'clock effective, the maximum tracking mark of inversion be 0 o'clock invalid, by judge the maximum tracking mark of inversion be 1 or 0 determine whether effective.
Inversion maximal power tracing unit 605, for when the judged result of the 3rd judging unit 604 is when being, carries out inversion maximal power tracing flow process to above-mentioned battery 1.Wherein, the detailed structure view of inversion maximal power tracing unit 605 as shown in Figure 8.
In embodiments of the present invention, to above-mentioned battery 1 carry out inversion maximal power tracing flow process with in Fig. 4, describe identical, just repeat no more at this.
Refer to Fig. 7, photovoltaic DC-to-AC converter the second example structure schematic diagram providing for the embodiment of the present invention.As shown in Figure 7, photovoltaic DC-to-AC converter 700 is on the basis of Fig. 6 photovoltaic DC-to-AC converter 600, to have increased trace labelling setup unit 606 and the first AM unit 607, and the function of unit 601～605 and Fig. 6 photovoltaic DC-to-AC converter 600 is identical, just repeats no more at this.
Trace labelling setup unit 606 is for when the judged result of the first judging unit 602 is when being, maximum the inversion of above-mentioned battery 1 tracking mark is set to effectively, and also for when the judged result of the second judging unit 603 is when being, it is invalid that maximum the inversion of above-mentioned battery 1 tracking mark is set to.Illustrate, if the maximum tracking mark of definition inversion be 1 o'clock effective, the maximum tracking mark of inversion be 0 o'clock invalid, in the embodiment of the present invention in the time that the input voltage of battery 1 of judging current sampling is greater than the first preset threshold values, maximum the inversion of battery 1 tracking mark is set to 1, or when being, maximum the inversion of above-mentioned battery 1 tracking mark is set to 0 in the judged result of the second judging unit 603.Certainly, in the embodiment of the present invention, also can define the maximum tracking mark of inversion and indicate it effectively with invalid with other value, be not construed as limiting herein.
Inversion maximal power tracing flow process also, at above-mentioned trace labelling setup unit 606, maximum the inversion of above-mentioned battery 1 tracking mark being set to when effective, is carried out to above-mentioned battery 1 in inversion maximal power tracing unit 605.In embodiments of the present invention, to above-mentioned battery 1 carry out inversion maximal power tracing flow process with in Fig. 4, describe identical, just repeat no more at this.
Refer to Fig. 8, inversion maximal power tracing unit 605 structural representations that provide for the embodiment of the present invention.As shown in Figure 8, inversion maximal power tracing unit 605 comprises: the first switch controlled unit 6051, the first busbar voltage setting unit 6052, the first computing unit 6053 and inversion control unit 6054.
The first switch controlled unit 6051, for disconnecting the boosted switch pipe in the loop of boosting at above-mentioned battery 1 place.In embodiments of the present invention, if photovoltaic DC-to-AC converter 700 disconnects the boosted switch pipe in the loop of boosting at battery 1 place, now, the busbar voltage of photovoltaic DC-to-AC converter 700 equals the input voltage of battery 1.
The first busbar voltage setting unit 6052, equals above-mentioned the second threshold values for the busbar voltage initial value of photovoltaic DC-to-AC converter 700 is set.In embodiments of the present invention, if when the busbar voltage initial value of photovoltaic DC-to-AC converter 700 is greater than above-mentioned the second threshold values, the busbar voltage of system progressively the busbar voltage initial value of photovoltaic DC-to-AC converter 700 decayed to above-mentioned the second threshold values according to the first predetermined step-length, so that can seamlessly transit when maximal power tracing algorithm changeover.
The first computing unit 6053, for sample according to sampling unit 601 input voltage and the input current that obtain, calculate respectively the input power that the maximum tracking mark of current inversion is effective all batteries, the input power summation of above-mentioned all batteries is obtained to inversion input power, and utilize method of perturbation to calculate the first disturbance voltage according to above-mentioned inversion input power.In embodiments of the present invention, the computational methods of the computational methods of inversion input power and the first disturbance voltage respectively with Fig. 4 in A3, A4 step identical, just repeat no more at this.
Inversion control unit 6054, for the first disturbance voltage of obtaining according to the first computing unit 6053 and the busbar voltage initial value of photovoltaic DC-to-AC converter 700, carries out inversion control to the input voltage of above-mentioned battery 1.
Concrete, inversion control unit 6054 can comprise that first makes differential mode piece, the first proportional integral adjustment module, the first ratio adjustment module and inversion control submodule (not shown in FIG. next).Wherein, first makes differential mode piece, and the busbar voltage initial value arranging for the busbar voltage of current photovoltaic DC-to-AC converter 700 being deducted to above-mentioned the first disturbance voltage and above-mentioned the first busbar voltage setting unit 6052, obtains the first difference; The first proportional integral adjustment module, obtains the first current value for making by first the first difference passing ratio integral adjustment that differential mode piece obtains; Above-mentioned first to make differential mode piece also poor for the current value of inductance on the inversion circuit of the first current value that the first proportional integral adjustment module is obtained and photovoltaic DC-to-AC converter 700, obtains the first electric current difference; The first ratio adjustment module, for doing after the first electric current difference passing ratio that differential mode piece obtains regulates to obtain the first output variable by above-mentioned first; Inversion control submodule, for utilizing the ON time of the inverse switch pipe on the inversion circuit of the first output variable control photovoltaic DC-to-AC converter 700 that the first ratio adjustment module obtains, with this, input voltage of above-mentioned battery 1 is carried out to inversion control, and then make the input power of battery 1 close towards the maximal power tracing point of battery 1.
Please continue to refer to Fig. 7, the first AM unit 607 is for before carrying out inversion control in inversion control unit 6054 to the input voltage of above-mentioned battery 1, if above-mentioned the first disturbance voltage exceedes the first preset maximum threshold, above-mentioned the first disturbance voltage is carried out to amplitude limiting processing, if or above-mentioned the first disturbance voltage is less than the first preset minimum threshold, above-mentioned the first disturbance voltage is carried out to increasing degree processing.In embodiments of the present invention, by the first AM unit 607 is set, can avoid the excessive phenomenon generation that may cause the unstable even collapse of photovoltaic DC-to-AC converter 700 place systems of input voltage because of the inversion circuit of photovoltaic DC-to-AC converter 700.
Refer to Fig. 9, photovoltaic DC-to-AC converter the 3rd example structure schematic diagram providing for the embodiment of the present invention.As shown in Figure 9, photovoltaic DC-to-AC converter 800 is on the basis of Fig. 7 photovoltaic DC-to-AC converter 700, to have increased boost maximal power tracing unit 608 and the second AM unit 609, and the function of unit 601～607 is identical with Fig. 7 photovoltaic DC-to-AC converter 700, just repeats no more at this.
Wherein, inversion maximal power tracing flow process also, at above-mentioned trace labelling setup unit 606, maximum the inversion of above-mentioned battery 1 tracking mark being set to when effective, is carried out to above-mentioned battery 1 in inversion maximal power tracing unit 605.In embodiments of the present invention, to above-mentioned battery 1 carry out inversion maximal power tracing flow process with in Fig. 4, describe identical, just repeat no more at this.
The maximal power tracing unit 608 that boosts, for when above-mentioned trace labelling setup unit 606, maximum the inversion of above-mentioned battery 1 tracking mark being set to when invalid, carries out to above-mentioned battery 1 the maximal power tracing flow process of boosting.Further, the maximal power tracing unit 608 that boosts, also for being no when the judged result of the second judging unit 603, and the judged result of the 3rd judging unit 604 is while be also no, to the above-mentioned battery 1 execution maximal power tracing flow process of boosting.In embodiments of the present invention, to above-mentioned battery 1 carry out boost maximal power tracing flow process with in Fig. 5, describe identical, just repeat no more at this.
Refer to Figure 10, maximal power tracing unit 608 structural representations that boost that provide for the embodiment of the present invention.As shown in figure 10, the maximal power tracing unit 608 that boosts comprises: second switch pipe control unit 6081, the second busbar voltage setting unit 6082, the second computing unit 6083 and boosting rectifier control unit 6084.
Second switch pipe control unit 6081, for the boosted switch pipe in the loop of boosting at current above-mentioned battery 1 place during in off-state, the boosted switch pipe in the loop of boosting at the above-mentioned battery of conducting 1 place.
The second busbar voltage setting unit 6082, equals above-mentioned the first threshold values for the busbar voltage initial value of photovoltaic DC-to-AC converter 800 is set.In embodiments of the present invention, if when the busbar voltage initial value of current photovoltaic DC-to-AC converter 800 is less than above-mentioned the first threshold values, the busbar voltage of system progressively the busbar voltage initial value of photovoltaic DC-to-AC converter 800 is increased to above-mentioned the first threshold values according to the second predetermined step-length, so that can seamlessly transit when maximal power tracing algorithm changeover.
The second computing unit 6083, for input voltage and the input current of the above-mentioned battery 1 obtaining of sampling according to sampling unit 601, calculates the input power of battery 1, and utilizes method of perturbation to calculate the second disturbance voltage according to the input power of battery 1.In embodiments of the present invention, the computational methods of the computational methods of the input power of battery 1 and the second disturbance voltage respectively with Fig. 5 in B3, B4 step identical, just repeat no more at this.
Boosting rectifier control unit 6084, carries out boosting rectifier control for the second disturbance voltage obtaining according to above-mentioned the second computing unit 6083 to the input voltage of above-mentioned battery 1.
Concrete, boosting rectifier control unit 6084 can comprise: second makes differential mode piece, the second proportional integral adjustment module, the second ratio adjustment module and boosting rectifier control submodule (not shown).Wherein, second makes differential mode piece, for the current input voltage of above-mentioned battery 1 being deducted to above-mentioned the second disturbance voltage, obtains the second difference; The second proportional integral adjustment module, obtains the second current value for making by second the second difference passing ratio integral adjustment that differential mode piece obtains; Above-mentioned second to make differential mode piece also poor for the current value of inductance on the loop of boosting of the second current value that the second proportional integral adjustment module is obtained and photovoltaic DC-to-AC converter 800, obtains the second electric current difference; The second ratio adjustment module, for doing after the second electric current difference passing ratio that differential mode piece obtains regulates to obtain the second output variable by above-mentioned second; Boosting rectifier control submodule, for utilizing the ON time of the boosted switch pipe on loop that boosts at the above-mentioned battery of the second output variable control 1 place that above-mentioned the second ratio adjustment module obtains, with this, input voltage of battery 1 is carried out to boosting rectifier control, and then make the input power of battery 1 close towards the maximal power tracing point of battery 1.
Please continue to refer to Fig. 9, the second AM unit 609 is for before carrying out boosting rectifier control in boosting rectifier control unit 6084 to the input voltage of above-mentioned battery 1, if above-mentioned the second disturbance voltage exceedes the second preset maximum threshold, above-mentioned the second disturbance voltage is carried out to amplitude limiting processing, if or above-mentioned the second disturbance voltage is less than the second preset minimum threshold, above-mentioned the second disturbance voltage is carried out to increasing degree processing.In embodiments of the present invention, by the second AM unit 609 is set, can avoid the excessive phenomenon generation that may cause the unstable even collapse of photovoltaic DC-to-AC converter 800 place systems of input voltage because of the inversion circuit of photovoltaic DC-to-AC converter 800.
It should be noted that, photovoltaic DC-to-AC converter 600,700,800 in the embodiment of the present invention can be for realizing the whole technical schemes in said method embodiment, the function of its each functional module can be according to the method specific implementation in said method embodiment, its specific implementation process can, with reference to the associated description in above-described embodiment, repeat no more herein.
Therefore, in the embodiment of the present invention, set the first threshold values and the second threshold values, and the first threshold values is greater than the second threshold values, size by the cell voltage that relatively gathers and the first threshold values, the second threshold values is set the maximum tracking mark of inversion of this road battery, judges that according to the maximum tracking mark of inversion this road battery carries out inversion maximal power tracing or boosts maximal power tracing.By independently controlling two-way or multichannel battery, make the input of every road battery all reach maximal power tracing point, make photovoltaic DC-to-AC converter in the time taking over the battery of meaning road different qualities, can accurately search out the maximal power tracing point of photovoltaic DC-to-AC converter system.And, because the maximum power tracking method of the photovoltaic DC-to-AC converter in the embodiment of the present invention optionally carries out maximal power tracing in inverter circuit, with respect to only using booster circuit to do the scheme of maximal power tracing, effectively increase the maximal power tracing scope of system.
Those skilled in the art can be well understood to, and for convenience and simplicity of description, the specific works process of the device of foregoing description and unit, can, with reference to the corresponding process in preceding method embodiment, not repeat them here.
In the several embodiment that provide in the application, should be understood that disclosed apparatus and method can realize by another way.For example, device embodiment described above is only schematic, for example, the division of described unit, be only that a kind of logic function is divided, when actual realization, can have other dividing mode, for example multiple unit or assembly can in conjunction with or can be integrated into another system, or some features can ignore, or do not carry out.Another point, shown or discussed coupling each other or direct-coupling or communication connection can be by some interfaces, indirect coupling or the communication connection of device or unit can be electrically, machinery or other form.
The described unit as separating component explanation can or can not be also physically to separate, and the parts that show as unit can be or can not be also physical locations, can be positioned at a place, or also can be distributed in multiple network element.Can select according to the actual needs some or all of unit wherein to realize the object of the present embodiment scheme.
In addition, the each functional unit in each embodiment of the present invention can be integrated in a processing unit, can be also that the independent physics of unit exists, and also can be integrated in a unit two or more unit.Above-mentioned integrated unit both can adopt the form of hardware to realize, and also can adopt the form of SFU software functional unit to realize.
If described integrated unit is realized and during as production marketing independently or use, can be stored in a computer read/write memory medium using the form of SFU software functional unit.Based on such understanding, the all or part of of the part that technical scheme of the present invention contributes to prior art in essence in other words or this technical scheme can embody with the form of software product, this computer software product is stored in a storage medium, comprise that some instructions (can be personal computers in order to make a computer equipment, server, or the network equipment etc.) carry out all or part of step of method described in each embodiment of the present invention.And aforesaid storage medium comprises: USB flash disk, portable hard drive, read-only memory (ROM, Read-Only Memory), the various media that can be program code stored such as random access memory (RAM, Random Access Memory), magnetic disc or CD.
Maximum power tracking method to a kind of photovoltaic DC-to-AC converter provided by the present invention and photovoltaic DC-to-AC converter are described in detail above, for one of ordinary skill in the art, according to the thought of the embodiment of the present invention, all will change in specific embodiments and applications, to sum up, this description should not be construed as limitation of the present invention.

Claims (22)

1. a maximum power tracking method for photovoltaic DC-to-AC converter, is characterized in that, described photovoltaic DC-to-AC converter is by least two-way battery is as input power, and described maximum power tracking method comprises:
Input voltage to each the road battery 1 in described at least two-way battery is sampled;
Whether the input voltage that judges the battery 1 of current sampling is greater than the first preset threshold values;
If the input voltage of the battery of described current sampling 1 is not more than the first preset threshold values, judge whether the input voltage of the battery 1 of described current sampling is less than the second preset threshold values, wherein, described the first threshold values is greater than described the second threshold values;
If the input voltage of the battery of described current sampling 1 is not less than the second preset threshold values, judge that whether the maximum tracking mark of inversion of battery 1 is effective; And if the maximum tracking mark of the inversion of described battery 1 is effective, described battery 1 is carried out to inversion maximal power tracing;
If the input voltage of the battery of described current sampling 1 is less than described the second preset threshold values, it is invalid maximum the inversion of battery 1 tracking mark to be set to, and described battery 1 is carried out to the maximal power tracing that boosts.
2. maximum power tracking method according to claim 1, is characterized in that, the step whether input voltage of the described battery 1 that judges current sampling is greater than the first preset threshold values also comprises afterwards:
If the input voltage of the battery of described current sampling 1 is greater than described the first preset threshold values, maximum the inversion of described battery 1 tracking mark is set to effectively, and described battery 1 is carried out to inversion maximal power tracing.
3. maximum power tracking method according to claim 1 and 2, it is characterized in that, described sampling also comprises samples to the wherein input current of a road battery 1 of described at least two-way battery, and wherein, the step that described battery 1 is carried out to inversion maximal power tracing also comprises:
Disconnect the boosted switch pipe in the loop of boosting at described battery 1 place;
The busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the second threshold values;
The input power of all batteries that the described input voltage obtaining according to described sampling and described input current calculate respectively the maximum tracking mark of current inversion while being effective, sues for peace to obtain inversion input power by the input power of described all batteries;
According to described inversion input power, utilize method of perturbation to calculate the first disturbance voltage; And
According to the busbar voltage initial value of described the first disturbance voltage and described photovoltaic DC-to-AC converter, the input voltage of described battery 1 is carried out to inversion control.
4. method according to claim 3, is characterized in that, the step that the described busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the second threshold values comprises:
If the busbar voltage initial value of described photovoltaic DC-to-AC converter is greater than described the second threshold values, progressively the busbar voltage initial value of described photovoltaic DC-to-AC converter is decayed to described the second threshold values according to the first predetermined step-length.
5. method according to claim 3, is characterized in that, before described step of the input voltage of described battery 1 being carried out to inversion control, comprises:
If described the first disturbance voltage exceedes the first preset maximum threshold, described the first disturbance voltage is carried out to amplitude limiting processing, if or described the first disturbance voltage be less than the first preset minimum threshold, described the first disturbance voltage is carried out to increasing degree processing.
6. method according to claim 3, is characterized in that, the described step that the input voltage of described battery 1 is carried out to inversion control comprises:
The busbar voltage initial value that the busbar voltage of current described photovoltaic DC-to-AC converter is deducted to described the first disturbance voltage and described photovoltaic DC-to-AC converter, obtains the first difference;
Described the first difference passing ratio integral adjustment is obtained to the first current value;
By poor the current value of inductance on the inversion circuit of described the first current value and described photovoltaic DC-to-AC converter, obtain the first electric current difference;
Will be described the first electric current difference passing ratio obtain the first output variable after regulating, utilize the ON time of the inverse switch pipe on the inversion circuit of photovoltaic DC-to-AC converter described in described the first output variable control, with this, input voltage of described battery 1 is carried out to inversion control.
7. maximum power tracking method according to claim 1, is characterized in that, the step whether input voltage of the described battery 1 that judges described current sampling is less than the second preset threshold values also comprises afterwards:
If the input voltage of the battery of described current sampling 1 is not less than described the second preset threshold values, and the maximum tracking mark of the inversion of described battery 1 is while being invalid, and described battery 1 is carried out to the maximal power tracing that boosts.
8. according to the maximum power tracking method described in claim 1 or 7, it is characterized in that, described sampling also comprises samples to the wherein input current of a road battery 1 of described at least two-way battery, and wherein, the step that described battery 1 is carried out to the maximal power tracing that boosts also comprises:
If the boosted switch pipe in the loop of boosting at current described battery 1 place is in off-state, the boosted switch pipe in the loop of boosting at battery 1 place described in conducting;
The busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the first threshold values;
Obtain the input voltage of described battery 1 and input current and calculate the input power of described battery 1 according to described sampling;
According to the input power of described battery 1, utilize method of perturbation to calculate the second disturbance voltage; And
According to described the second disturbance voltage, the input voltage of described battery 1 is carried out to boosting rectifier control.
9. method according to claim 8, is characterized in that, the step that the described busbar voltage initial value that described photovoltaic DC-to-AC converter is set equals described the first threshold values is specially:
If the busbar voltage initial value of described photovoltaic DC-to-AC converter is less than described the first threshold values, progressively the busbar voltage initial value of described photovoltaic DC-to-AC converter is increased to described the first threshold values according to the second predetermined step-length.
10. method according to claim 8, is characterized in that, before described step of according to described the second disturbance voltage, the input voltage of described battery 1 being carried out boosting rectifier control, comprises:
If described the second disturbance voltage exceedes the second preset maximum threshold, described the second disturbance voltage is carried out to amplitude limiting processing, if or described the second disturbance voltage while being less than the second preset minimum threshold, described the second disturbance voltage is carried out to increasing degree processing.
11. methods according to claim 8, is characterized in that, described step of the input voltage of described battery 1 being carried out to boosting rectifier control according to described the second disturbance voltage comprises:
The current input voltage of described battery 1 is deducted to described the second disturbance voltage, obtain the second difference;
Described the second difference passing ratio integral adjustment is obtained to the second current value;
By poor the current value of inductance on the loop of boosting of described the second current value and described photovoltaic DC-to-AC converter, obtain the second electric current difference;
Will be described the second electric current difference passing ratio obtain the second output variable after regulating, utilize the ON time of the boosted switch pipe on loop that boosts at battery 1 place described in described the second output variable control, with this, input voltage of described battery 1 is carried out to boosting rectifier control.
12. 1 kinds of photovoltaic DC-to-AC converters, is characterized in that, described photovoltaic DC-to-AC converter is by least two-way battery is as input power, and described photovoltaic DC-to-AC converter comprises:
Sampling unit, samples for the input voltage of each the road battery 1 to described at least two-way battery;
Whether the first judging unit, be greater than the first preset threshold values for the input voltage of the battery 1 that judges the current sampling of described sampling unit;
The second judging unit, when being no when the judged result of described the first judging unit, judges whether the input voltage of the battery 1 of described current sampling is less than the second preset threshold values, and wherein, described the first threshold values is greater than described the second threshold values;
The 3rd judging unit, when being no when the judged result of described the second judging unit, judges that whether the maximum tracking mark of inversion of described battery 1 is effective;
Inversion maximal power tracing unit, for when the judged result of described the 3rd judging unit is when being, carries out inversion maximal power tracing flow process to described battery 1;
Trace labelling setup unit, for when the judged result of described the second judging unit is when being, it is invalid that maximum the inversion of described battery 1 tracking mark is set to;
The maximal power tracing unit that boosts, for when described trace labelling setup unit, maximum the inversion of described battery 1 tracking mark being set to when invalid, carries out to described battery 1 the maximal power tracing flow process of boosting.
13. photovoltaic DC-to-AC converters according to claim 12, is characterized in that,
Trace labelling setup unit also, for when the judged result of described the first judging unit is when being, is set to maximum the inversion of described battery 1 tracking mark effectively;
Wherein, described inversion maximal power tracing unit, also, at described trace labelling setup unit, maximum the inversion of described battery 1 tracking mark being set to when effective, carries out inversion maximal power tracing flow process to described battery 1.
14. according to the photovoltaic DC-to-AC converter described in claim 12 or 13, it is characterized in that, described sampling unit is also sampled for the wherein input current of a road battery 1 to described at least two-way battery, and wherein, described inversion maximal power tracing unit specifically comprises:
The first switch controlled unit, for disconnecting the boosted switch pipe in the loop of boosting at described battery 1 place;
The first busbar voltage setting unit, equals described the second threshold values for the busbar voltage initial value of described photovoltaic DC-to-AC converter is set;
The first computing unit, the input power of all batteries when to calculate respectively current inversion maximum tracking mark be effective for sample according to described the sampling unit described input voltage that obtains and described input current, the input power summation of described all batteries is obtained to inversion input power, and utilize method of perturbation to calculate the first disturbance voltage according to described inversion input power;
Inversion control unit, for according to the busbar voltage initial value of described the first disturbance voltage and described photovoltaic DC-to-AC converter, carries out inversion control to the input voltage of described battery 1.
15. photovoltaic DC-to-AC converters according to claim 14, it is characterized in that, if when described the first busbar voltage setting unit is also greater than described the second threshold values for the busbar voltage initial value of described photovoltaic DC-to-AC converter, progressively the busbar voltage initial value of described photovoltaic DC-to-AC converter is decayed to described the second threshold values according to the first predetermined step-length.
16. photovoltaic DC-to-AC converters according to claim 14, it is characterized in that, described photovoltaic DC-to-AC converter also comprises: the first AM unit, for before described inversion control unit carries out inversion control to the input voltage of described battery 1, if described the first disturbance voltage exceedes the first preset maximum threshold, described the first disturbance voltage is carried out to amplitude limiting processing, if or described the first disturbance voltage be less than the first preset minimum threshold, described the first disturbance voltage is carried out to increasing degree processing.
17. photovoltaic DC-to-AC converters according to claim 14, is characterized in that, described inversion control unit comprises:
First makes differential mode piece, for the busbar voltage of current described photovoltaic DC-to-AC converter being deducted to described the first disturbance voltage and the set busbar voltage initial value of described the first busbar voltage setting unit, obtains the first difference;
The first proportional integral adjustment module, for described the first difference passing ratio integral adjustment is obtained to the first current value, wherein, described first makes differential mode piece also for by poor the current value of inductance on the inversion circuit of described the first current value and described photovoltaic DC-to-AC converter, obtains the first electric current difference;
The first ratio adjustment module obtains the first output variable after described the first electric current difference passing ratio is regulated;
Inversion control submodule, for utilizing the ON time of the inverse switch pipe on the inversion circuit of photovoltaic DC-to-AC converter described in described the first output variable control, carries out inversion control with this to the input voltage of described battery 1.
18. photovoltaic DC-to-AC converters according to claim 12, it is characterized in that, the described maximal power tracing unit that boosts, be also no for the judged result when described the second judging unit, and when the judged result of described the 3rd judging unit is also no, described battery 1 is carried out to the maximal power tracing flow process of boosting.
19. according to the photovoltaic DC-to-AC converter described in claim 12 or 18, it is characterized in that, described sampling unit is also sampled for the wherein input current of a road battery 1 to described at least two-way battery, wherein, described in the maximal power tracing unit that boosts specifically comprise:
Second switch pipe control unit, for the boosted switch pipe in the loop of boosting at current described battery 1 place during in off-state, the boosted switch pipe in the loop of boosting at battery 1 place described in conducting;
The second busbar voltage setting unit, equals described the first threshold values for the busbar voltage initial value of described photovoltaic DC-to-AC converter is set;
The second computing unit, described input voltage and the described input current of the described battery 1 obtaining for sampling according to described sampling unit calculate the input power of described battery 1, and utilize method of perturbation to calculate the second disturbance voltage according to the input power of described battery 1;
Boosting rectifier control unit, for carrying out boosting rectifier control according to described the second disturbance voltage to the input voltage of described battery 1.
20. photovoltaic DC-to-AC converters according to claim 19, it is characterized in that, described the second busbar voltage setting unit, also in the time that the busbar voltage initial value of described photovoltaic DC-to-AC converter is less than described the first threshold values, is progressively increased to described the first threshold values by the busbar voltage initial value of described photovoltaic DC-to-AC converter according to the second predetermined step-length.
21. photovoltaic DC-to-AC converters according to claim 19, it is characterized in that, described photovoltaic DC-to-AC converter also comprises: the second AM unit, for before described boosting rectifier control unit carries out boosting rectifier control to the input voltage of described battery 1, if described the second disturbance voltage exceedes the second preset maximum threshold, described the second disturbance voltage is carried out to amplitude limiting processing, if or described the second disturbance voltage be less than the second preset minimum threshold, described the second disturbance voltage is carried out to increasing degree processing.
22. photovoltaic DC-to-AC converters according to claim 19, is characterized in that, described boosting rectifier control unit specifically comprises:
Second makes differential mode piece, for the current input voltage of described battery 1 being deducted to described the second disturbance voltage, obtains the second difference;
The second proportional integral adjustment module, for described the second difference passing ratio integral adjustment is obtained to the second current value, wherein, described second makes differential mode piece also for by poor the current value of inductance on the loop of boosting of described the second current value and described photovoltaic DC-to-AC converter, obtains the second electric current difference;
The second ratio adjustment module obtains the second output variable after described the second electric current difference passing ratio is regulated;
Boosting rectifier control submodule, for utilizing the ON time of the boosted switch pipe on loop that boosts at battery 1 place described in described the second output variable control, carries out boosting rectifier control with this to the input voltage of described battery 1.
CN201210063464.8A 2012-03-12 2012-03-12 Photovoltaic inverter and method for tracking maximum power of same Active CN102611341B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201210063464.8A CN102611341B (en) 2012-03-12 2012-03-12 Photovoltaic inverter and method for tracking maximum power of same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201210063464.8A CN102611341B (en) 2012-03-12 2012-03-12 Photovoltaic inverter and method for tracking maximum power of same

Publications (2)

Publication Number Publication Date
CN102611341A CN102611341A (en) 2012-07-25
CN102611341B true CN102611341B (en) 2014-07-30

Family

ID=46528545

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201210063464.8A Active CN102611341B (en) 2012-03-12 2012-03-12 Photovoltaic inverter and method for tracking maximum power of same

Country Status (1)

Country Link
CN (1) CN102611341B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9459139B2 (en) * 2011-09-06 2016-10-04 Morgan Solar Inc. Photovoltaic generating system with control unit for controlling output power conversion and actuation of photovoltaic tracker units
CN102857094A (en) * 2012-08-20 2013-01-02 无锡山亿新能源科技有限公司 Boost task switching method and system based on hysteresis control
CN103116383B (en) * 2012-12-25 2015-01-07 深圳创动科技有限公司 Two-way boost photovoltaic inverter and control method thereof
CN104868764B (en) * 2014-02-26 2017-08-04 全汉企业股份有限公司 Inverter and its power conversion method
CN104111691A (en) * 2014-07-08 2014-10-22 安徽金峰新能源股份有限公司 Photovoltaic inverter MPPT control method based on three-point comparison method
CN108628385A (en) * 2018-05-08 2018-10-09 上海电力学院 Based on the maximum photovoltaic power point tracking and controlling method for improving conductance increment method
CN111049188A (en) * 2020-01-02 2020-04-21 阳光电源股份有限公司 Multi-input photovoltaic inverter system centralized mode MPPT method and application device thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7248946B2 (en) * 2004-05-11 2007-07-24 Advanced Energy Conversion, Llc Inverter control methodology for distributed generation sources connected to a utility grid
CN101630171A (en) * 2009-08-05 2010-01-20 华南理工大学 Segmentation self-adapting hill climbing method and system applied for tracing maximum power of photovoltaic cell
CN201450012U (en) * 2009-08-05 2010-05-05 华南理工大学 Segmented adaptive hill climbing method applied for tracking photovoltaic battery maximum power
CN102111086A (en) * 2009-12-25 2011-06-29 比亚迪股份有限公司 Method and device for tracking maximum power point of solar battery
CN102135783A (en) * 2011-04-06 2011-07-27 广东美的电器股份有限公司 Method for tracking maximum power of solar cell
CN102185534A (en) * 2011-05-26 2011-09-14 广东金华达电子有限公司 Maximum power tracking method and device of photovoltaic cell

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100997990B1 (en) * 2008-06-24 2010-12-03 삼성전기주식회사 Power supply having maximum power point tracking function

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7248946B2 (en) * 2004-05-11 2007-07-24 Advanced Energy Conversion, Llc Inverter control methodology for distributed generation sources connected to a utility grid
CN101630171A (en) * 2009-08-05 2010-01-20 华南理工大学 Segmentation self-adapting hill climbing method and system applied for tracing maximum power of photovoltaic cell
CN201450012U (en) * 2009-08-05 2010-05-05 华南理工大学 Segmented adaptive hill climbing method applied for tracking photovoltaic battery maximum power
CN102111086A (en) * 2009-12-25 2011-06-29 比亚迪股份有限公司 Method and device for tracking maximum power point of solar battery
CN102135783A (en) * 2011-04-06 2011-07-27 广东美的电器股份有限公司 Method for tracking maximum power of solar cell
CN102185534A (en) * 2011-05-26 2011-09-14 广东金华达电子有限公司 Maximum power tracking method and device of photovoltaic cell

Also Published As

Publication number Publication date
CN102611341A (en) 2012-07-25

Similar Documents

Publication Publication Date Title
CN102611341B (en) Photovoltaic inverter and method for tracking maximum power of same
JP5857193B2 (en) Current collection box
CN104917413A (en) Inverting apparatus and control method thereof
US20050110454A1 (en) Methods and apparatuses for tracking maximum power point of solar electricity generating system
CN103715924B (en) There is the three-level inverter of two direct-current chains and control apparatus and method
KR102318326B1 (en) Power conversion device and three-phase ac power supply device
JP2014241715A (en) Inverter device
KR20170071491A (en) Converting device
CN109713714B (en) Maximum power point tracking method and equipment
EP2658109A1 (en) Power converting apparatus, operating method thereof, and solar power generation system
CN102591399A (en) Perturbation and observation method for tracking maximum power point of photovoltaic grid-connected generating system
CN105074604A (en) Solar cell control device
CN103078475B (en) The two edge constant off-time modulation voltage type control method of switch converters and device thereof
US9541587B2 (en) Inverting apparatus for avoiding misjudgement of maximum power point tracking operation and control method thereof
CN103427687B (en) The maximum power tracking method of photovoltaic DC-to-AC converter when constant pressure source inputs
CN103677067B (en) A kind of method, device and photovoltaic generating system realizing MPPT maximum power point tracking
CN110572067B (en) Island energy storage type power unit series micro-grid structure and control method
Kamnarn et al. Design and simulation of DC distributed power supply with power balance control technique
CN103885522A (en) Maximum power tracking method based on direct-current bus voltage control
CN106981882A (en) A kind of photovoltaic generating system MPPT perturbation motion methods
CN103606955B (en) A kind of micro-grid power source based on half-sinusoid
US9564830B2 (en) Control method of inverting apparatus for achieving MPPT and inverting apparatus thereof
CN104656736B (en) Power supply control system and method
KR101398679B1 (en) Photovoltaic power inverting system for utility interconnection
JPH08171430A (en) Inverter device

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
TR01 Transfer of patent right
TR01 Transfer of patent right

Effective date of registration: 20180125

Address after: 518055 Guangdong city of Shenzhen province Nanshan District Taoyuan streets Beihuan Industrial Zone in the high mountain cat No. 7 Building 5 layer 504

Patentee after: Shenzhen yingweiteng Photovoltaic Technology Co. Ltd.

Address before: 518055 Nanshan District, Shenzhen Province, Longjing high tech Industrial Park, No. 4 plant on the ground floor, No.

Patentee before: Shenzhen Yingweiteng Electric Co., Ltd.