FIELD OF THE INVENTION
The invention relates to an optimized supporting arrangement used in high saline
environment for solar photovoltaic modules. More particularly the invention
relates to an optimized aluminium supporting structures used in high saline
environment for solar photovoltaic modules, which has improved load carrying
capacity and is non-corrosive.
BACKGROUND OF THE INVENTION
The photovoltaic module is a non-conventional method of generating electricity.
For erecting such modules, a highly efficient and cost effective supporting
structure is required.
Prior art patent publications US 5125608, US 4371139 and US 7481211 disclose
different types of structural pattern, which can be mounted on ground or on flat
roof top or inclined roof top. The main disadvantages of these prior art are the
complicated structure and connection pattern, which is time consuming during
erection. The structures also show plurality of components for assembly.
The prior art discloses various methods and structures for solar panel support
including tilting system, wiring cases and use of recycled rubber material to make
it environment friendly etc. Though it serves the purpose of withstanding
extreme wind loads, the plurality of components used makes it difficult to erect.
Hence, the present invention proposes a simple supporting structure, which can
be used to support the photovoltaic modules under extreme wind load and high
saline conditions.
The present invention is based on support structures made of aluminum alloy
with stainless steel hardware for mounting of solar photovoltaic modules for
specific locations of highly saline nature.
Apart from conceptualizing the details of the array size and the sections, which
are required to build each photovoltaic module mounting structures, it has to be
designed to withstand severe climatic conditions like sudden wind loads and
storms.
The supporting structures per se constitute photovoltaic modules, supporting
struts, connecting beams, bracings and purlins in longitudinal direction. The
major drawbacks of the structure are the failure at the supporting location due to
the cantilever action. Accordingly, there is a need to propose a suitable support
structure to withstand the high stresses.
OBJECTS OF THE INVENTION:
It is therefore the object of the invention to propose an optimized supporting
structure used in high saline environment for solar photovoltaic modules, which
eliminates the disadvantages of the prior art.
Another object of the invention is to propose an optimized supporting structure
used in high saline environment for solar photovoltaic modules by replacing the
existing prior-art materials with a suitable material, which prevents corrosion in
the high saline environment.
A further object of the invention is to propose an optimized supporting structure
used in high saline environment for solar photovoltaic modules, which renders
stability to the structure while making it light.
A still further object of the invention is to propose an optimized supporting
structure used in high saline environment for solar photovoltaic modules, which
prevents excessive deflection of the structure and limits the stresses up to
acceptable safe limits under severe wind load conditions.
A still another object of the invention is to propose an optimized supporting
structure used in high saline environment for solar photovoltaic modules, which
facilities easy assembling and dismantling of the structure.
SUMMARY OF THE INVENTION
Accordingly, it is proposed a supporting structure for solar photovoltaic module
adopted in solar power plant comprising three frames, which are non-
symmetrically placed in longitudinal direction. Each frame constitutes one
elevated rear strut and another small front strut in the transverse direction
bolted by inclined beam and horizontal beam at the bottom, all made of
aluminium sections. Each frame is connected through bracing in the longitudinal
direction along the rear elevated strut side. At the top, the inclined beams are
connected through purlins in longitudinal direction to support the PV modules
placed on top.
The system of the invention constitutes an assembly of beams of various section
sizes. The system has improved load stability and this structure is suitable for
use in high saline environment, where the problem of corrosion is immense. The
structural features facilitate easy fabrication and erection of these structures at
site. From manufacturing point of view, it will reduce the amount of inventory
and the total engineering hours. The system will also help in easy dismantling of
the structure in the future, if required.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1:- shows the system along with photovoltaic modules.
Figure 2:- shows the isometric view of the system (structure only) without the
photovoltaic module.
Figure 3:- shows the isometric view without the purlins.
Figure 4:- shows the Side view of one of the frames.
Figure 5:- shows the backside view of the structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
OF THE INVENTION
The system developed through this invention is capable of supporting the solar
photovoltaic module (A) shown in Figure 1, withstanding its entire weight and
the wind load that acts on it.
The system is basically a trapezoidal shaped three frame structure comprising
aluminium channel sections of various sizes. The system comprises elevated rear
struts (1, 2, 3), as shown in Figure 2, at the head of the solar photovoltaic panel,
fabricated from channel sections of similar sizes. It also consists of short front
struts (4, 5, 6) at the tail end of photovoltaic panel. These struts are
interconnected by an inclined members (10, 11, 12) respectively at the top in the
transverse direction. At the bottom, the elevated rear struts (1,2,3) and short
front struts (4,5,6) are connected by the bottom horizontal beams (7,8,9) in
transverse direction of similar sizes, which is supported by the ground. Three
such single frames are connected at definite intervals through side horizontal
members (15, 16), as shown in Figure 3, and cross-bracings (13,14) of similar
section in the longitudinal directions. On top of the inclined beams (10,11,12),
the frames are connected through purlins (20,21,22,23) in the longitudinal
direction. On top of the purlins (20, 21, 22, 23) the solar photovoltaic panel (A)
will be placed (Fig. 1).
According to the invention, the short struts (4,5,6) is provided to take the high
level of stress acting on that region. It is assumed that the wind pressure acts 0°
and 45° inclined in horizontal direction. The analysis results show that the
stresses were high due to the cantilever action in structure. So, it was decided to
increase the distance between the elevated rear strut and short front strut in the
transverse direction from 1700 mm to 1900mm through various iterations. The
distance between the frames was also modified from 2210 mm to 2425 mm
through iterations. Selection of the struts (1,2,3,4,5,6) as well as the bottom
horizontal beams (7,8,9), inclined beams (10,11,12), cross-bracings (13,14) and
side horizontal beams (15,16) are optimized in order to determine acceptable
limits of deflection and stresses.
Selection of the struts (1,2,3,4,5,6) and the beams (7,8,9,10,11,12,13,14,15,16)
are always of an iterative nature. A rigorous finite element analysis was carried
out to study the stresses and deflection pattern. The next step is an iteration of
the analysis, wherein size and location of the struts (1,2,3,4,5,6) and the
distances between the frames are accurately selected. Such analyses are
repeated with the selected members till an acceptable stress and deflection is
arrived.
A plurality of iterations performed during selection of optimized and economical
support members and the beams is presented in a Table-1 below.
According to the members selected as tabulated hereinabove, the summarized
results of the finite element analysis for deflection and stress of the system along
with the solar photovoltaic module. Consolidated results are tabulated in Table-
II, which shows that the stresses and deflections are maintained within the
allowable limit.
The inventive system as shown in figure 3, comprises:
- an elevated strut (1,2,3);
- a short strut (4,5,6);
- bottom horizontal beam (7,8,9);
- inclined beam (10,11,12);
- cross bracing (13,14);
- side horizontal beam (15,16) and
- frame (17,18,19) which consist of both the struts, inclined beam and
bottom horizontal beam
The present invention is illustrated along with the photovoltaic module (A) in
figure 1. Figure 2 depicts the supporting structure, which is an assembly of
different beam sections of different sizes. A detailed, description of the system is
given below.
The complete system comprises three frames, which are arranged in non-
symmetrical way. Each member in the frame substantially consists of aluminium
channel section as cross-section of various sizes and orientation. In each frame
the bottom horizontal beam (7,8,9) are connected to the inclined beam
(10,11,12) through elevated strut (1,2,3) in figure 3 respectively near the head
end of the solar photovoltaic module. The height of the elevated strut is decided
by the requirement of photovoltaic module to the installed.
The bottom horizontal beam (7,8,9) are connected to the inclined beam
(10,11,12) through short strut (4,5,6) in figure 3 respectively near the tail end of
the solar photovoltaic module. The final optimized height of the short strut was
obtained through iterative process by doing finite element analysis.
Likewise the interval between the three frames was optimized through various
iterative process carried on through finite element analysis. These members
comprises of plurality of aluminium channel cross section with varying section
sizes.
The individual frames are connected through side horizontal beam (15, 16) and
cross bracing (13, 14) in the longitudinal direction. These consist of aluminium
channel section of various sizes and orientation. The three frames are connected
through purlins (20,21,22,23) in figure 2 on top in the longitudinal direction
through bolted joints.
The supporting structure of the system of the invention is designed such a way
that the structure as a whole will withstand the extreme wind load conditions. In
order to achieve this critical location of high stress value was located and a short
strut was introduced to avoid the cantilever action that takes place. Similarly, to
reduce the overall stress acting on the structure the distance between frames
was optimized through iterative process.
We claim
1. An optimized supporting structure used in high saline environment for
solar photovoltaic modules comprising;
- a plurality of frames (17,18,19) placed vertically in upright position; the
frames (17,18,19) are kept at certain interval and fixed with longitudinal
beams (15,16) at the rear end and cross bracings (13,14) wherein the
transverse beams ( 7,8,9 ) connect the frames (17,18,19) at the base
and inclined members
(10, 11, 12) at the top that hold the solar photovoltaic panel at the top
characterized in that;
- the elevated strut (1,2,3) at the head end and the short strut (4,5,6) at
the tail end are connected with the bottom horizontal beam (7,8 and 9) and
inclined member (10,11 & 12) renders stability to withstand high level of
stress created by the wind pressure and self load.
2. The supporting structure as claimed in claim 1, wherein the short strut
provided at the tail eliminates the high level of stress caused due to
cantilever action
3. The supporting structure as claimed in claim 1, wherein the elevated strut
(1,2,3) and the short strut (4,5,6) are supported at the ground by grouting
to foundation pedestal by means of foundation bolts.
4. The supporting structure as claimed in claim 1, wherein the material used is
aluminium, which is light and anti-corrosive.
5. The supporting structure as claimed in claim 1, wherein the individual members are
fixed with nuts and bolts to make it easy to assemble and disassemble.

ABSTRACT

The proposed supporting structure to the particular solar photovoltaic module
supporting structure adopted in solar power plant comprises of three frames at a
particular interval which are non-symmetrical arranged in longitudinal direction.
Each frame constitute of one elevated rear strut and another small front strut in
the transverse direction bolted by inclined beam and horizontal beam at the
bottom, all made up of aluminium sections. These elevated rear strut and short
front strut will be placed over the concrete pedestal, which will on the ground
level. Each frame is connected through bracing in the longitudinal direction along
the elevated strut side. At the top, the inclined beams are connected through
purlins in longitudinal direction to support the PV modules placed on top. It is
arranged is such a way to withstand the high wind load conditions in high saline
environment.