FIELD OF THE INVENTION
[001] The present invention relates to the field of the system for producing
maximum power by the photovoltaic PV arrays. More particularly, the present
disclosure relates to the system and method for multiple power peak detection with
regular tracking of solar panel voltage and based on load & power balance to
enhance the performance.
BACKGROUND OF THE INVENTION
[002] Photovoltaic (PV) energy has gained great .popularity in electricity
generation, due to its clean and sustainable nature. A number of achievements have
been made in academia and industry where many researchers put their efforts on
maximization of power extracted from solar panel, which is commonly referred to as
Maximum Power Point Tracking (MPPT). Conventional MPPT methods, like
Perturbation and Observation (P&O) method, Incremental Conductance, and Ripple
Correlation Control, are very useful when the Photovoltaic PV receives uniform solar
irradiation. However, solar irradiance applied on entire Photovoltaic PV array cannot
guarantee uniform density continuously. That's because part of Photovoltaic PV
panel may be shielded by trees, clouds or buHdings. In this case, the nonttnearity of
the Photovoltaic PV characteristic curve has been changed from a unique maximum
to multiple local maxima, which make the traditional MPPT methods without
considering Partial shading conditions PSCs cannot be applied directly. Therefore, a
lot of researchers are interested in finding effective MPPT techniques with stronger
adaptability under Partial shading conditions PSCs.
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[003] Accordingly, there remains a need in the prior art for a technical
convergence to make a system and method based on multiple power peak detection
with regular tracking of solar panel voltage despite the inevitable changes in the
environment and a charge controller, which is implemented with the MPPT that can
track maxima under Partial shading conditions PSCs. Therefore, it would be useful
and desirable to have a system to meet the above-mentioned needs.
OBJECTS OF THE INVENTION
[004] Some of the objects of the present invention satisfied by at least one
embodiment of the present invention are as follows:
[005] An object of the present invention is to provide a razor Maximum
Power Point Tracking rMPPT system, which adjusts the solar operating voltage close
to Maximum Power Point MPP under changing environmental conditions.
[006] Yet another object of the present invention is to provide a controller,
which regularly tracks panel voltage at Maximum Power Point MPP within a
particular range, in a regular time interval, tracking done in both direction of available
Maximum Power Point MPP point.
[007] Another object of the present invention is to provide a processing unit
to process the multiple power peak detection in which tracking solve the of partially
or fully shaded panel issue for efficient power point tracking, in this controller
continuously search the absolute Maximum Power Point MPP beyond the trapped
maxima in a long range.
[008] Still another object of the present invention is to provide a solution by
the razor Maximum Power Point Tracking rMPPT of the controller, which provide
better accuracy to track maximum power during sudden change in load.
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[009] These and other objects and advantages of the present invention will
become more apparent from the following description, when read with the
accompanying figures of drawing, which are however not intended to limit the scope
of the present invention in any way.
SUMMARY OF THE INVENTION
[010] In the view of the foregoing disadvantages inherent in the known types
of systems, which use normal MPPT methods and may fail when shading conditions
occur and the power loss can over as much as 70% due to the multiple maxima in l-P
curve in shading conditions vs. single maximum point in uniformly solar irradiance,
now present in the prior art, the present invention provides a system and method for
producing maximum power generation by the photovoltaic PV arrays. As such, the
general purpose of the present invention to provide a method and system, which is
having a razor Maximum Power Point Tracking (rMPPT) based charge controller
under Partially Shaded Conditions PSCs is introduced to deal with the abovementioned
problems which is advanced, fastest & much accurate method to track
Maximum Power Point MPP with conversion efficiency, which will be described
subsequently in greater detail, is to provide a new and improved, which has all the
advantages of the prior art and none of the disadvantages.
[011] According to an embodiment of the present invention, the razor
Maximum Power Point Tracking rMPPT unit is used to adjust the solar operating
voltage close to Maximum Power Point MPP under changing environmental
conditions. In order to continuously gather the maximum power from the photovoltaic
PV array, they have to operate at their Maximum Power Point Tracking MPPT despite
of the inhomogeneous change in environmental conditions.
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[012] According to an embodiment of the present invention, the razor
Maximum Power Point Tracking rMPPT unit, which is implemented with advanced
Perturb and Observe (P & 0) and the working is based on Hill Climbing Principle, in
which operating point of the PV module moves in the increasing direction of power.
[013] According to an embodiment of the present invention, a new method
with adaptive capacity in finding the global maxima under the Partial shading
conditions PSCs is introduced to overcome the environment uncertainties.
[014] According to an embodiment of the present invention, the rMPPT unit is
the advanced, fastest & much accurate technology to reach the Maximum Power
Point MPP & track the maximum available power from PV arrays and to charge the
battery, further, the present invention is verified by different simulations &
experimental conditions..
[015] According to an embodiment of the present invention, the rMPPT
optimization problem with constraints is also defined, where the change rate of duty
cycle is also considered to prevent power switches damages and reduce unnecessary
energy losses.
[016] According to an embodiment of the present invention, the method and
the system incorporates with the conventional systems with a slight modification in the
charge controller unit and no additional circuit is required to measure operating
voltage.
[017] In this respect, before explaining at least one embodiment of the
invention in-detail, it is to be understood that the invention is not limited in its
application to the details of construction and to the arrangements of the components
set forth in the following description or illustrated in the drawings. The invention is
capable of other embodiments and of being practiced and carried out in various ways.
Also, it is to be understood that the phraseology and terminology employed herein are
for the purpose of description and should not be regarded as limiting.
[018] These together with other objects of the invention, along with the
various features of novelty which characterize the invention, are pointed out with
particularity in the disclosure. For a better understanding of the invention, its
operating advantages and the specific objects attained by its uses, reference should
be had to the accompanying drawings and descriptive matter in which there are
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illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[019] The invention will be better understood and objects other than those set
forth above will become apparent when consideration is given to the following detailed
description thereof. Such description makes reference to the annexed drawings
wherein:
[020] FIG. 1 is a block diagram illustrating the working of a system for multiple
power peak detection with regular tracking and power balancing in accordance with an
embodiment of the present invention;
[021] FIG. 2 is a simplified flow diagram of one embodiment of a method for
multiple power peak detection with regular tracking and power balancing in
accordance with another embodiment of the present invention;
[022] FIG. 3 Shows various graphs of the MPP points Varies as solar
Irradiance change in accordance with another embodiment of the present invention[
023] FIG. 4 depicts V-P curves under different partial shading conditions of
various PV Arrays in accordance with another embodiment of the present invention;
[024] FIG. 5 Shows a detailed view of a razor maximum power point tracking
rMPPT unit performance in accordance with another embodiment of the present
invention;
[025] FIG. 6 depicts a graphical comparison of the rMPPT unit performance
of proposed system and conventional system in accordance with another
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[026] In the following detailed description, reference is made to the
accompanying drawings which form a part hereof, and in which is shown by way of
illustration specific embodiments in which the invention may be practiced. These
embodiments are described in sufficient detail to enable those skilled in the art to
practice the invention, and it is to be understood that the embodiments may be
combined, or that other embodiments may be utilized and that structural and logical
changes may be made without departing from the spirit and scope of the present
invention. The following detailed description is, therefore, not to be taken in a limiting
sense, and the scope of the present invention is defined by the appended claims and
their equivalents.
[027] FIG. 1 shows a block diagram, generally represented the working of a
system 100 for multiple power peak detection with regular tracking and power
balancing in accordance with an embodiment of the present invention. In a preferred
embodiment the system comprises a charge controller 15, a processing unit 20, a
memory unit 25 and a plurality of photovoltaic PV arrays (10A, 10B, 10C, 10D, 10n).
[028] m accordance with an embodiment of the present invention, the
Plurality of photovoltaic PV arrays (10A, 10B, 10C, 10D, 10n) have a nonlinear
voltage-current characteristic, with a distinct maximum power point (MPP), which
depends on the environmental factors, such as temperature and irradiation.
[029] The plurality of photovoltaic PV arrays (10A, 10B, 10C, 10D, 10n) is
having a distinct maximum power point MPP, i.e. there is a point on l-V. P-V
characteristic curve of PV array called as Maximum Power Point (MPP), where the
PV system produces its maximum output power, location of MPP changes with
change in environmental condition.
[030] In accordance with an embodiment of the present invention, the charge
controller 15 is used for regular tracking of the plurality of photovoltaic PV arrays
(10A, 10B, 10C, 10D, 10n) in search of multiple power peak detection point with a
regular tracking unit 15A. The charge controller is further comprised of a razor
maximum power point tracking unit rMPPT unit under Partially Shaded Conditions on
search of an absolute maximum power point MPP on the plurality of photovoltaic PV
arrays (10A, 10B, 10C, 10D, 10n) beyond the trapped maxima in a long range.
[031] In accordance with an embodiment of the present invention, the razor
maximum power point tracking rMPPT unit 15B is configured to provide a global
maxima of the maximum power point MPP point to the charge controller for
generating maximum power available from the plurality of photovoltaic PV arrays
{10A, 10B, 10C, 10D, 10n). The razor maximum power point tracking rMPPT unit
15B is having a load power balancing unit 15C to track maximum power during
sudden change in load.
[032] in accordance with an embodiment of the present invention, the
processing unit 20 is configured to receive input from the charge controller 15 and
provide same to a battery 35 of the photovoltaic cell. Further, the memory unit 25 is
connected to the processing unit for storing a plurality of values. The memory unit 25
stores required information of operating voltage and the corresponding generation
current in a database 30.
[033] Referring now to FIG. 2, in one illustrative embodiment, a method 200
for multiple power peak detection with regular tracking and power balancing in a
photovoltaic cell, comprising of the following steps.
[034] At step 15A regular tracking, by a charge controller, take a short track
of a panel voltage in a pre-determined available tracking range and move in direction
in which more power is available.
[035] At step 15B long tracking for detecting multiple power peak, by a
charge controller, on strings of panels connected in then if any or some panel
partially or fully shaded then multiple Maximum Power Point MPP points generated.
In addition to the long tracking, the next step of storing in a memory unit, required
information of operating voltage and the corresponding generation current.
[036] At step 15C load balancing tracking for controlling maximum power
during sudden change in load. This step is based on load & power balance to
enhance rMPPT unit performance which provide better accuracy to track maximum
power during sudden change in load. Further, the rMPPT unit can be tracked
maxima under the Partial shading conditions PSCs without any additional circuits.
[037] For example, as shown in FIG. 3, various graphs of the MPP points
Varies as solar Irradiance change in accordance with another embodiment of the
present invention.
[038] In accordance with an embodiment of the present invention, the charge
controller take a short track of panel voltage Up to, but not limited to, 6 Percent of
available tracking range and Move in direction in which more Power is available. This
tracking time is very fast and occurs, but not limited to, every 1 to 5 sec of time
period. This Fast tracking helps controller to find Maximum Power point MPP of
panel regularly because irradiance of solar vary every time and thus every time there
is shift in Maximum Power Point of panel and this shift in Maximum Power point MPP
is captured by regular tracking unit. As the Image 3A Shows MPP points Varies as
solar Irradiance change so regular tracking keep always controller at MPP.
[039] In accordance with an embodiment of the present invention, the
Multiple Power Peak Detection: In case when Strings of panels connected in then if
any or some panel partially or fully Shaded then multiple MPP points generated as
illustrated in Image 3B and Image 3C. So the system to check a TRUE MPPT
besides of being STUCK in Auxiliary/Local MPPT. And thus the rMPPT unit of Long
tracking recognize all available Peaks of Power and select the maximum Peak as
MPPT point.
[040] In accordance with an embodiment of the present invention, the Load
and Power balance: In case if system has sufficient power to deliver load and
running on currently selected MPP point, But if a sudden load is applied on system
then system need to extract more power from Panel so we need to check to check
and verify the maximum available power of the panel for this controller perform a
long track to determine the maximum available power point for fast and better
accuracy.
[041] FIG. 4 depicts V-P curves under different partial shading conditions of
various PV Arrays in accordance with another embodiment of the present invention,
these partial shading conditions, the V-P curve emerges multiple peaks and the PV
array should work on the global optimal curve to get maximum power instead of
theoretical optima! curve for a larger power output, see dotted lines in Image 43.
Image 4A shows a 100% shading case and the corresponding MPP returns to the
theoretical optimal curve in the image 4A.
[042] By this example, it is easy to see that the traditional MPPT methods
without considering PSCs will follow the theoretical curve instead of the global
optimal curve, which will miss the real global maxima. Hence, a new method with
adaptive capacity in finding the global maxima under PSCs is introduced.
[043] The present invention illustrates the positive effect of the rMPPT
technique on the PV system to overcome the environment uncertainties. In addition,
it illustrates the theory of operation of advanced Perturb and Observe P&O.
[044] Referring to Fig. 5, a detailed view of the rMPPT unit performance can
be observed. When the shading appears, the working point follows the global
optimum curve to jumping out of local optimum and the corresponding working
voltage changes. When the shading disappears, photovoltaic arrays receive uniform
solar intensity again and the operating point move back to the theoretical optimal
curve. These results show the feasibility of re-positioning and tracking the rMPPT
among multiple local maxima exhibited. This tracking method of MPPT under PSCs
is solve the uncertainty of solar irradiations & temperature. Moreover the
comparison of rMPPT unit performance between conventional P&O method is shown
.in Fig.6. The conventional method miss tracking the MPP during the partial shading
period. The peak value of output power & efficiency is less as compared to our
proposed system. To demonstrate effectiveness and fast response of the proposed
system in a deeper perspective, the trajectory of operating points is compared with
voltage-power and voltage-current curves to test whether the PV system is working
at the true MPP.
[045] The above-mentioned system and method maximize the utilization and
efficiency of any Photovoltaic (PV) system by the Maximum Power Point Tracking
technique (MPPT). MPPT is specifically used to extract the maximum available power
from the PV array, maximum power can be achieved by tracking the Maximum Power
Point (MPP) using specialized charge controllers, which working based on Perturb
and Observe (P&O) and Incremental Conductance (INC). These charge controllers
are the most common used due to its simplicity in implementation compared to other
systems and methods, eventually, which makes the present invention economical in
use.
[046] It is to be understood that the above description is intended to be
illustrative, and not restrictive. For example, the above-discussed embodiments may
be used in combination with each other. Many other embodiments will be apparent to
those of skill in the art upon reviewing the above description.
[047] The benefits and advantages which may be provided by the present
invention have been described above with regard to specific embodiments. These
benefits and advantages, and any elements or limitations that may cause them to
occur or to become more pronounced are not to be construed as critical, required, or
essential features of any or all of the embodiments.
[048] While the present invention has been described with reference to
particular embodiments, it should be understood that the embodiments are illustrative
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and that the scope of the invention is not limited to these embodiments. Many
variations, modifications, additions and improvements to the embodiments described
above are possible. It is contemplated that these variations, modifications, additions
and improvements fall within the scope of the invention.

We claim:
1. A system 100 for multiple power peak detection with regular tracking and
power balancing in a photovoltaic cell, comprising:
a plurality of photovoltaic PV arrays (10A, 10B, 10C, 10D, 10n) having a
distinct maximum power point MPP;
a charge controller 15 for regular tracking of the plurality of photovoltaic PV
arrays (10A, 10B, 10C, 10Df 10n) in search of multiple power peak detection
point;
a processing unit 20 for receiving input from the charge controller 15 and
provide same to a battery 35 of the photovoltaic cell; and
a memory unit 25 connected to the processing unit for storing a plurality of
values.
2. The system as claimed in claim 1, wherein the charge controller 15 is
comprised of a razor maximum power point tracking rMPPT unit 15B under
Partially Shaded Conditions on search of an absolute maximum power point
MPP on the plurality of photovoltaic PV arrays (10A, 10B, 10C, 10D, 10n)
beyond the trapped maxima in a long range.
3. The system as claimed in claim 1, wherein the memory unit 25 stores required
information of operating voltage and the corresponding generation current in
a database 30.
13
4. The system as claimed in claim 1, wherein the razor maximum power point
tracking unit rMPPT unit 15B is configured to provide a global maxima of the
maximum power point MPP' point to the charge controller for generating
maximum power available from the plurality of photovoltaic PV arrays (10A,
10B, 10C, 10D, 10n).
5. The system as claimed in claim 2, wherein the razor maximum power point
tracking rMPPT unit 15B is having a load power balancing unit 15C to track
maximum power during sudden change in load.
6. A method 200 for multiple power peak detection with regular tracking and
power balancing in a photovoltaic cell, comprising the steps of:
regular tracking 15A, by a charge controller, take a short track of a panel
voltage in a pre-determined available tracking range and move in direction in
which more power is available;
long tracking 15B for detecting multiple power peak, by a charge controller,
on strings of panels connected in then if any or some panel partially or fully
shaded then multiple Maximum Power Point MPP points generated.
storing in a memory unit, required information of operating voltage and the
corresponding generation current; and