CN105824347A - Improved control method for variable-step-length maximum power point tracking on basis of beta parameter - Google Patents
Improved control method for variable-step-length maximum power point tracking on basis of beta parameter Download PDFInfo
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- CN105824347A CN105824347A CN201610310384.6A CN201610310384A CN105824347A CN 105824347 A CN105824347 A CN 105824347A CN 201610310384 A CN201610310384 A CN 201610310384A CN 105824347 A CN105824347 A CN 105824347A
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- power point
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/66—Regulating electric power
- G05F1/67—Regulating electric power to the maximum power available from a generator, e.g. from solar cell
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The invention discloses an improved control method for variable-step-length maximum power point tracking on the basis of beta parameter. The improved control method comprises the following steps: sampling voltage and current output by a photovoltaic module, thus obtaining a sampling voltage value V(k) and a sampling current value I(k), and then calculating an instantaneous value betaa of beta; defining the value range of beta according to the range of temperature and illumination, wherein a minimum value is betamin, the maximum value is betamax, and if betaa is more than or equal to betamin and less than or equal to betamax, the tracking step length is a fixed step length; if betaa is more than betamax, adjusting the step length, and adopting smaller proportionality coefficient value N1, wherein the step length deltaD is equal to N1 multiplied by (betaa-betag), betag is a reference value, and an intermediate value between betamax and betamin is taken; if betaa is less than betamin, adjusting the step length, and adopting larger proportionality coefficient value N2, wherein the step length deltaD is equal to N2 multiplied by (betaa-betag). The improved control method disclosed by the invention has the advantages that two kinds of different proportionality coefficients N are adopted for rising and falling of illumination, so that fast dynamic tracking is realized and the phenomenon of misjudgment is avoided.
Description
Technical field
The present invention relates to a kind of variable step maximum power point-tracing control method, more particularly to the variable step maximum power point-tracing control method based on β parameter of a kind of improvement.
Background technology
Solar energy is widely regarded as a kind of very important sustainable energy by the whole world.But owing to photovoltaic array is affected by outside environmental elements such as illumination or temperature, its output voltage, electric current present obvious nonlinear characteristic.Regulate the output of photovoltaic module the most in real time, under any external environment, realize MPPT maximum power point tracking (maximumpowerpointtracking, MPPT) seem particularly significant.
Existing MPPT technique mainly includes fixed step size and variable step two kinds.Common fixed step size MPPT algorithm has observation method of perturbation, conductance method and climbing method.It is simple, with low cost, easy to implement that the advantage of fixed step algorithm essentially consists in algorithm, preferable in the situation effect that weather conditions are stable.But, its shortcoming essentially consists in tracking accuracy and cannot take into account with response speed.Meanwhile, when illumination occurs acutely to convert, its algorithm can occur erroneous judgement thus cause following the trail of the decline of speed.
In order to can overcome the disadvantages that this defect, based on said method, variable step MPPT method is suggested, and its method main thought is exactly: when operating point is away from maximum power point (MPP), uses big step-length to go to follow the trail of；When near MPP, little step-length is used to go to follow the tracks of.Although variable step size method overcomes tracking accuracy and response speed well, but shortcoming essentially consists in and determines that the method for variable step size is the most complicated；Near MPP time step-length too small thus cause follow the trail of speed decline；System complexity is high.Meanwhile, when illumination occurs acutely to convert, its algorithm can occur erroneous judgement thus cause following the trail of the decline of speed.
For problems, in recent years, a kind of mixing step-length MPPT method, i.e. Beta method is suggested.Its method is mainly in combination with fixed step size and the mentality of designing of variable step, because the method is broadly divided into two benches: the first stage uses variable step, position near the MPP that quickly furthered by quiescent potential, thus realizes quickly response；Then second stage uses fixed step size, thus realizes tracking accuracy.Essentially consist in 2 points in place of the key of mixing MPPT method: first, how to determine the step sizes of variable step；Second, switch two kinds of methods the most exactly, the most how to determine the operation interval of two kinds of methods.The MPPT method of great majority mixing at present is that the trend according to photovoltaic voltage electric current determines variable step size and working range.But its shortcoming essentially consists in: need a large amount of, complicated calculating to determine step-length and operation interval；Logic is complicated simultaneously, and implementation is poor.
How to determine that algorithm is a major issue at the proportionality coefficient N of first stage variable step size.Although the least N value can ensure that system working stability, but follow the trail of speed and can decline；Relative, the biggest N value can ensure that tracking speed, but the instability that system likely works, as shown in Figure 1.
Fig. 2 is that light impinges upon 1000W/m
2
And 400W/m
2
Under I-V curve and β-V curve.When illumination is 1000W/m
2
Time, make photovoltaic module be operated in its maximum power point by the size controlling photovoltaic converter (inverter) duty cycle of switching, i.e. put A.Meanwhile, some A is in β in β-V curve
min
And β
max
Between.
When illumination suddenly falls to 400W/m
2
Time at that moment, it is assumed that the dutycycle of photovoltaic converter does not also change, now operating point should be switched to a B from an A.Meanwhile, some B is positioned at β in β-V curve
max
Top, the most from this moment on, Beta method switches to movement segment, and step-length can be calculated by following formula:
ΔD=N×(β
B
–β
g
)
Wherein β
g
For reference value, typically take β
max
With β
min
Intermediate value.
In like manner, when illumination is from 400W/m
2
Rise to 1000W/m
2
Time, operating point should switch to rapidly a D from a C.As shown in Figure 2, this time point D is positioned at β in β-V curve
min
Lower section, the most from this moment on, Beta method switches to movement segment, and step-length can be calculated by following formula:
ΔD=N×(β
D
–β
g
)
As shown in Figure 2, due to β
B
–β
g
β to be compared
D
–β
g
Greatly, if N value is relatively big, then causes system unstable when can drop under light illumination, whereas if N value is less, then system tracks speed can be caused when illumination rises slower.As can be seen here, same N value is used to be difficult to solve this contradiction.
Summary of the invention
In order to overcome fixed step size and the shortcoming of Variable Step Algorithm and effectively utilize its advantage, set forth herein the variable step maximum power point-tracing control method based on β parameter of a kind of improvement.Compared to traditional Beta method, the Beta method of improvement, based on to β-V tracing analysis, uses two kinds of different size of proportionality coefficient N to illumination raising and lowering, thus realizes quick dynamic tracing and avoid misjudgment phenomenon.
The technical scheme is that
The variable step maximum power point-tracing control method based on β parameter of a kind of improvement, it is characterised in that comprise the following steps:
S01: sample photovoltaic module output voltage, electric current, obtains sample voltage value V (k) and sampled current value I (k), then calculates instantaneous value β of β
a
；
S02: define the span of β according to the scope of temperature and illumination, minima is β min ,Maximum is β max If, β min ≤β a ≤β max , then following the trail of step-length is fixed step size；
S03: if β
a
>β
max
, adjusting step-length, use less scalefactor value N1, scope is [Isosorbide-5-Nitrae], step delta D=N1 × (β
a
–β
g
), wherein, β
g
For reference value, take β
max
With β
min
Intermediate value；
S04: if β
a
<β
min
, adjusting step-length, use bigger scalefactor value N2, scope is [5,7], step delta D=N2 × (β
a
–β
g
)。
Preferably, β in described step S01
a
Computing formula be:
β
a
=ln(I(k)/V(k))–c×V(k)
Wherein c=q/ (N
s
AKT) it is photovoltaic property parameter.
Preferably, the span of described scalefactor value is relevant to actual environment temperature and illumination.
The invention also discloses the variable step MPPT maximum power point tracking control system based on β parameter of a kind of improvement, it is characterised in that include photovoltaic module, dcdc converter and MPPT control module；Described dcdc converter is as the power interface between photovoltaic module and load, for providing the conversion of voltage or electric current, described MPPT control module uses the variable step maximum power point-tracing control method based on β parameter of the improvement described in any one of claim 1-3 to carry out MPPT maximum power point tracking.
Compared with prior art, the invention have the advantage that
Compared to traditional Beta method, the Beta method of improvement, based on to β-V tracing analysis, uses two kinds of different size of proportionality coefficient N to illumination raising and lowering, thus realizes quick dynamic tracing and avoid misjudgment phenomenon.Can determine compensation and operation interval by simple calculating, it is convenient to implement.
Accompanying drawing explanation
Below in conjunction with the accompanying drawings and embodiment the invention will be further described:
Fig. 1 is the traditional B eta method the using different N value simulation result figure when illumination acute variation；
Fig. 2 is that light impinges upon 1000W/m
2
And 400W/m
2
Under I-V curve and β-V curve chart；
Fig. 3 is the flow chart of the variable step maximum power point-tracing control method based on β parameter that the present invention improves；
Fig. 4 is the schematic diagram of the variable step MPPT maximum power point tracking control system based on β parameter that the present invention improves；
Fig. 5 a be fixed step size MPPT(observe method of perturbation) simulation result figure；
Fig. 5 b is the simulation result figure that traditional B eta method uses less N value；
Fig. 5 c is the simulation result figure that traditional B eta method uses bigger N value；
Fig. 5 d is the simulation result figure of the variable step maximum power point-tracing control method based on β parameter that the present invention improves.
Detailed description of the invention
For making the object, technical solutions and advantages of the present invention of greater clarity, below in conjunction with detailed description of the invention and referring to the drawings, the present invention is described in more detail.It should be understood that these describe the most exemplary, and it is not intended to limit the scope of the present invention.Additionally, in the following description, the description to known features and technology is eliminated, to avoid unnecessarily obscuring idea of the invention.
Embodiment:
The mixing MPPT method of the Beta method that the present invention improves is mainly illumination raising and lowering and uses two kinds of different size of N values, and its algorithm flow chart is as shown in Figure 3.
First, sampled voltage current value V (k) and I (k), then calculate instantaneous value β of beta
a
:
β
a
=ln(I(k)/V(k))–c×V(k)
Wherein c=q/ (NsAKT) is photovoltaic property parameter.
When calculating β a After, the span of β is defined according to the scope of temperature and illumination, minima is β min ,Maximum is β max , use this β a With β min And β max Compare: if β a In this interval, then illustrate that current quiescent potential, near MPP, thus switches into fixed step size method, such as climbing method；If β a Not in this interval, illustrate that work at present point voltage away from MPP, then enters next branch, i.e. judges β a At β min Lower section still at β max Top.If β a At β max Top, then explanation illumination decline, now use less N value, represent with N1 herein；Whereas if β a At β min Lower section, then explanation illumination rise, now use bigger N value, represent with N2 herein.
As shown in Figure 4, the system construction drawing of the present invention, which includes photovoltage model, dcdc converter and its load, also MPPT control module.Photovoltaic module mainly provides output, and its output characteristics is closely related with ambient temperature and illumination etc.；DCDC current transformer is as the power interface between photovoltaic module and load, it is provided that voltage or the conversion of electric current；MPPT control module is carried out concrete maximum power point-tracing control method, and then the dutycycle of regulation DCDC current transformer is so that photovoltaic module Maximum Power Output all the time under any working condition.
Experimental result is as shown in Fig. 5 a-5d.
Fig. 5 a be fixed step size MPPT(observe method of perturbation) simulation result figure；It can be seen that follow the trail of speed slowly, erroneous judgement easily occurs.
Fig. 5 b is the simulation result figure that traditional B eta method uses less N value；When illumination occurs acutely to convert, its algorithm can occur erroneous judgement thus cause following the trail of the decline of speed.
Fig. 5 c is the simulation result figure that traditional B eta method uses bigger N value；It can be seen that cause system unstable when can drop under light illumination.
Fig. 5 d is the simulation result figure of the variable step maximum power point-tracing control method based on β parameter that the present invention improves.Follow the trail of speed and soon and there is no misjudgment phenomenon.
It should be appreciated that the above-mentioned detailed description of the invention of the present invention is used only for exemplary illustration or explains the principle of the present invention, and it is not construed as limiting the invention.Therefore, any modification, equivalent substitution and improvement etc. done in the case of without departing from the spirit and scope of the present invention, should be included within the scope of the present invention.Additionally, claims of the present invention be intended to fall in the equivalents on scope and border or this scope and border whole change and modifications example.
Claims (4)
1. the variable step maximum power point-tracing control method based on β parameter improved, it is characterised in that comprise the following steps:
S01: sample photovoltaic module output voltage, electric current, obtains sample voltage value V (k) and sampled current value I (k), then calculates instantaneous value β of βa；
S02: define the span of β according to the scope of temperature and illumination, minima is βmin, maximum is βmaxIf, βmin≤βa≤βmax, then following the trail of step-length is fixed step size；
S03: if βa>βmax, adjusting step-length, use less scalefactor value N1, scope is [Isosorbide-5-Nitrae], step delta D=N1 × (βa–βg), wherein, βgFor reference value, take βmaxWith βminIntermediate value；
S04: if βa<βmin, adjusting step-length, use bigger scalefactor value N2, scope is [5,7], step delta D=N2 × (βa–βg)。
The variable step maximum power point-tracing control method based on β parameter of improvement the most according to claim 1, it is characterised in that β in described step S01aComputing formula be:
βa=ln(I(k)/V(k))–c×V(k)
Wherein c=q/ (NsAKT) it is photovoltaic property parameter.
The variable step maximum power point-tracing control method based on β parameter of improvement the most according to claim 1, it is characterised in that the span of described scalefactor value is relevant to actual environment temperature and illumination.
4. the variable step MPPT maximum power point tracking control system based on β parameter improved, it is characterised in that include photovoltaic module, dcdc converter and MPPT control module；Described dcdc converter is as the power interface between photovoltaic module and load, for providing the conversion of voltage or electric current, described MPPT control module uses the variable step maximum power point-tracing control method based on β parameter of the improvement described in any one of claim 1-3 to carry out MPPT maximum power point tracking.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106951023A (en) * | 2017-03-22 | 2017-07-14 | 西交利物浦大学 | A kind of multi-peak maximum electric power tracking and controlling method based on β parameters |
| CN107589776A (en) * | 2017-10-20 | 2018-01-16 | 南方电网科学研究院有限责任公司 | Maximum power point tracing method, MPPT controller and photovoltaic generating system |
| CN109388174A (en) * | 2017-08-11 | 2019-02-26 | 华南师范大学 | Variable step disturbance observation MPPT algorithm based on dichotomy |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104866002A (en) * | 2015-05-15 | 2015-08-26 | 西交利物浦大学 | Mixed type maximum power point tracing control method based on Beta parameter |
-
2016
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104866002A (en) * | 2015-05-15 | 2015-08-26 | 西交利物浦大学 | Mixed type maximum power point tracing control method based on Beta parameter |
Non-Patent Citations (1)
| Title |
|---|
| XINGSHUO LI ET: "Photovoltaic Modified β-Parameter-based MPPT Method with Fast Tracking", 《JOURNAL OF POWER ELECTRONICS》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106951023A (en) * | 2017-03-22 | 2017-07-14 | 西交利物浦大学 | A kind of multi-peak maximum electric power tracking and controlling method based on β parameters |
| CN109388174A (en) * | 2017-08-11 | 2019-02-26 | 华南师范大学 | Variable step disturbance observation MPPT algorithm based on dichotomy |
| CN107589776A (en) * | 2017-10-20 | 2018-01-16 | 南方电网科学研究院有限责任公司 | Maximum power point tracing method, MPPT controller and photovoltaic generating system |
| CN107589776B (en) * | 2017-10-20 | 2019-06-28 | 南方电网科学研究院有限责任公司 | Maximum power point tracing method, MPPT controller and photovoltaic generating system |
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Application publication date: 20160803 |