DESC:FIELD OF INVENTION :

A photovoltaic module mounting system (MMS) wherein the structure shall support the PV modules at a given orientation, absorb and transfer the mechanical load to the structure uniformly.

OBJECTIVE OF THE INVENTION :

The Module mounting structure should be so designed that there should be no requirement of welding or complex heavy machinery at site. The structure shall be such that it shall occupy less space providing firm support to the modules. The structure should be able to withstand the heavy winds.

BACKGROUND OF INVENTION :

In Solar power plants, the Module Mounting Structure (MMS) is used to mount the solar modules which generate the electric power from the sunlight. The MMS provides stability and protects the solar modules from adverse wind & seismic conditions.

Due to the increase in the competition in solar market of various methods of mounting the solar modules on structure are available in the market. Cost related to the mounting structure of solar modules has gone down drastically due to higher wattage of modules and usage of higher yield strength of steel.

In this scenario different methods of mounting the solar panels are adopted. To stay competitive in the market we must introduce a structure which is having easiness in erection, having less weight and not compromising on the structural integrity.

PRIOR ART :

Few prior art documents are discussed herein.

D1-US 2012O061337A1: PHOTOVOLTAIC MODULE MOUNTING SYSTEM

This publication discloses a photovoltaic module mounting system using clamps to attach the modules to a mounting structure, thereby providing a universal mounting structure for use with laminate or framed modules of differing shapes and sizes, from different manufacturers.

S. No Feature Article Proposed System
1 Column post Multiple supports Single column post is used
2 Purlin Purlin is tube section.
No tension member is provided in lateral direction to arrest the force. No purlin is used. Tension member
(Tie rod) is provided in lateral direction to arrest the lateral force.
3 Structure Weight Structure weight/MWp shall be very high. Structure is for roof mounted scenarios. 1) 4 modules are placed in landscape, hence number of structures and weight/MWp will be comparatively less
2) Structure is applicable for ground mounted scenarios.
4 Erection Erection is possible only on a flat roof. In case of undulation & water flow structure cannot be used. In case of variation in ground level also structure can be erected.
5 Fixing Multiple bolt types are used which increases the time for erection. Fixing of purlins is done by clamps which requires separate arrangement. Single type of HDG Bolt’ is sufficient for all structural connections thereby simplifying the assembly at site and for faster construction.

D2- USOO866.1747B2: SOLARPANEL RACKING SYSTEM

This invention concerns solar collection systems, and particularly a racking or mounting system especially for photo Voltaic Solar panels, typically roof-mounted but also ground mounted, in a tilted-up array.

S. No Feature Article Proposed System
1 Column post Multiple columns posts used in MMS. The structure is roof mounted. Single column post is used.
Structure is ground mounted.
2 Purlin Purlin is C-section, however multiple extruded aluminum components are used which shall increase the cost. No purlin is used. Tension member (Tie rod) is provided in lateral direction to arrest the lateral force.
3 Structure Weight Structure weight/MWp is higher. 4 modules are placed in landscape, hence number of structures and weight/MWp will be comparatively less
4 Erection Multiple profiles and large number of parts which causes increase in erection time.
In case of variation in ground level also structure can be erected.
5 Foundation concrete Volume Volume of concrete is very high since number of foundations are more. Volume of concrete is less as pile foundation is adopted.

D3- US 2013 0146554A1: SOLAR MODULE MOUNTINGAPPARATUS

The present invention is directed towards a universal Solar module mounting system which can be used to secure. Solar modules have different sizes to mounting brackets. The mounting brackets can include a plurality of parallel beams that are horizontal or angled so that the modules are positioned for maximum Solar exposure.

S. No Feature Article Proposed System
1 Column post Single post MMS with circular tube Single column post with channel section
2 Purlin Purlin is “Z” steel section, which has more torsional loads. No purlin is used. Tension member (Tie rod) is provided in lateral direction to arrest the lateral force.
3 Module Orientation Landscape direction Landscape direction

SUMMARY OF INVENTION

S. No Salient Feature Parameter Remarks
1 Purpose To reduce the weight of the structure without impacting the structural integrity.
2 Module All commercially available monofacial and bifacial modules
3 Module Orientation Landscape direction
4 Purlin No purlin is used. Purlin members are replaced by tie rods for reduction in weight. Tension member is provided in lateral direction to arrest the lateral force.
5 Structure Weight Structures/MWp will be comparatively less. 4 modules are placed in landscape, hence number of structures and weight/MWp will be comparatively less
5 Erection In case of variation in ground level
(up to 2%) also structure can be erected. Purlinless MMS allows the flexibility of structure modification at any given undulated ground erection also.
6 Foundation concrete Volume Volume of concrete used is less. As pile foundation is adopted the volume of concrete used is less.
7 Connections Single type bolts is used in the design thereby reducing the erection time and avoiding confusion with multiple bolt types.
8 Adjustment to suit to multiple modules Adjustment can be provided in modules so that multiple modules can be fit into on the same structure.

DESCRIPTION OF INVENTION :

To run a solar power plant efficiently, good quality of mounting structure plays a vital and crucial role. A good and efficient structure design can significantly reduce structure weight per MW and accommodate thermal expansion so that sagging in structure does not occur. This has been attempted effectively in this invention. As per invention, Along the lateral direction there is no purlin member to arrest the wind force, tension resisting member is provided so that the deflection of structure in lateral direction is reduced/arrested within the permissible limits.

PURPOSE :

The increase in the price of steel is impacting the solar industry due to which less weight of structure shall help in taking care of increase in steel prices.

In module mounting structure the major weight component is due to the Purlin member, which supports the module. Refer to Fig 2(a) for the traditional structure.

Approximately the percentage of contribution of purlin member in the structure weight ranges from 35% to 60% of total MMS weight.

Hence if the purlin component is replaced with some other member there shall be a reduction in the weight of the MMS.

UNIQUENESS :

In the present invention, Purlin members which hold the module is not used only the tie rod is used so that the structure is also safe in higher wind speeds.
Distinguishing features with prior art (fig. 4) is illustrated in and compared in the table below:

S. No Typical Prior Art Designs disclose Invention Design discloses
1 Structure placed for only 4 modules Design can have 60 modules in a series
2 Lateral tension member is not provided Tension member (Tie rod) is provided in lateral direction to resist the lateral force
3 Concrete Block foundation needs to be adopted Pile foundation can be adopted
4 Two-legged structure is mandatory Single column structure is sufficient

Also, all MMS in prior art demand framed modules, whereas in this invention, the module with or without frame can be used. Both sets of modules can be fitted using clamps.

Also in prior art, in case of bifacial module, since the module is supported below the module, there shall be effect of shadow and this is the suffering in prior art. In the present invention, the design is suitable advantageously for bifacial module since the module is supported at the ends only (refer fig. 5).

Part nos. Part name
A As shown in applicant picture the module is supported at ends only in the present invention Purliness

Also prior art prefer usage of sections such Tube, C or Z but in this invention, section types used such as:-

1. Channel with lips.
2. Channel without lips and
3. Tension Resisting Members (Rods)

The invention essentially uses “channels” for reasons that “channels” with lips and without lips for the reasons which are:-

a. Member is an open section which allows easy access for bolting.
b. Channel with lip section allows using smaller length of bolts instead of through bolts.
c. Reduced stagnation of water in channel members and thereby reduced corrosion.

The preferred material is cold form steel sections for usage in the invention.

As disclosed in Purlinless design of this invention, a ‘single type of Bolt’ is sufficient, used for all structural connections and thereby simplifying the assembly at site.

The Purlinless design needs fastening at 6 points:

1. Post of Bracing cleat – 1 point.
2. Bracing to Rafter - 2 points.
3. Post to Rafter – 1 point.
4. Bracing cleat to Bracing – 2 points.

These are ‘standard’ and shall not be vary for any wind zone. Hence ‘Bolting’ process has been wholly and largely simplified as per this design. There is no complication/confusion in selecting ‘Bolts’ as only one type of bolt is used as per invention and the “Bolt” is a simple threaded bolt and since section is also ‘open type section’, it is very easy to fix the bolt.

Typically, in prior art the possible tilt angle is predetermined by the structure. But in this purlinless design, Rafter to post connection can be fixed based on the required tilt angle.

Rafter to post connection will be provided with a hole so that the angle required for the structure is maintained. The structure tilt is only based on structural support and none other factor as per this invention. The V-shape design is not limited by any other external parameter and V-shape shall remain same for any and all tilts. Further as per invention, more number of modules can be supported with less member of foundations in comparison to prior art.

The prior art do not utilize ‘Bracing’ whereas invention uses ‘Bracing’ advantageously. A bracing allows smooth transfer of force from rafter to the post. In prior art, the post is typically directly connected to the rail/purlin which supports the member and transfer of fore is not so smooth.

The prior art does not teach simple method for feasibility of adjustment for different wind speeds. The invention discloses various arrangements of the tie rod for different wind speeds in the range of 33m/s to 50m/s. Even at higher wind speeds, the only modification is limited to arrangement of tension members. The invention avoids inclusion of wind deflectors, additional link brackets, additional load bearing support, heavier gauge of steel, etc all of which is suffered in prior art. The modification required in tension member is also specific and simple.

In prior art, in case of variation in ground level, there is a need to redesign the MMS as a whole whereas in this invention, the “column post” needs to be merely adjusted and structure can be erected. In prior art, the pre-designed structure cannot be installed on the undulated ground since the module support is typically “straight”. Hence the invention allows the flexibility of structure modification at any given undulated ground erection also.

The invention has been described as detailed above but various embodiments and variations are possible beyond the preferred embodiments disclosed in this document. All such variations and modifications as obvious to the skilled person is within the scope of this invention.

SYSTEM

In typical known arrangement column post, vertical rafter and bracing form the support for the structure at the required tilt angle. Bracings have multiple holes, each hole typically corresponding to a specific tilt angle. Horizontal rafters run in west direction if the required module orientation is landscape. Purlins run over the Vertical rafter/Horizontal rafter on which solar modules are installed. Brackets are used to connect the purlin to the Vertical rafter or to Horizontal rafters and also Tie-Rods are provided to give additional support and avoid buckling. Refer to Fig 2(a).

ARRANGEMENTS

Typically, Module Mount structure Fig 2(a) comprises of following component:

1. Vertical Posts.
2. Vertical Rail (Rafter)
3. Horizontal Rail (Purlin)
4. Bracings
5. Tile Bracket
6. Mounting Clips
7. Cable Tray

These are all known in prior art and exhibit many sufferings as detailed previously.

Unlike the prior art where purlinless MMS contains the following parts (Refer fig: 2(b), 2(c))

Part no. Part name
1 Post
2 Bracing connecting cleat
3,4 Bracing
5 Rafter
6 Module connecting cleat
7 Tie rod
8 Clamp
9 Module

The module of this invention can be mounted on a cold-form channel rafter member, which is not possible in prior art, as module is typically supported by rail/purlin member which is tube/C/Z section etc.

Fig. 1a discloses Perspective view of Purlinless MMS
Fig. 1b discloses Module supported on rafter Middle clamping.
Fig. 1c illustrates the Module supported on rafter with end clamping.

As per the invention, based on the wind analysis the position of the tension resisting member and numbers can be decided and designed.

The tension member is a hot dip galvanized rod.

The tension member is threaded up to a certain length so that the bolting can be done.

The diameter of the tension member and its fixing position in structure is decided based on the design requirement.

The length of the tension member shall depend on the module size.

? For different wind zones one can adopt different arrangements of tension member i.e., the novel lateral sag member arrangement. This shall help in adopting a similar kind of structure without many trials on structure and thereby saving time.
? As per the invention, for different wind zones the number and position of tension member is given in the below table.

Option Suitability Remarks
1 Suitable for projects with lower wind speeds 33m/s to 39m/s (Wind zone-1 and 2) Since all the purlins are removed the lateral sway is the most critical parameter.
To arrest the lateral sway horizontal tension sa member connecting the two column posts has been provided.
In this option since wind pressure is less single horizontal tension member or tie rod is sufficient.
2,3,4 Suitable for projects with wind speeds of 44m/s (Wind zone 3) Since there is increase in the wind pressure, two horizontal tension member or sag member provided.
5,6 Suitable for projects with wind speeds of 47 m/s and above (Wind zone-4 and above) Since the sway is highest in the first and last bays additional diagonal bracing member provided in the first and last bay further to the two horizontal tension members or tie rod in all bays.

It is to be noted that in traditional MMS irrespective of wind zone there will be four purlins below modules to support the modules. As per invention which is PURLIN-LESS design, these purlins are eliminated and substituted using TIE ROD based on project wind zones.

As shown in fig.3(b), purlin member is removed in the Purlin less MMS and the members associated with the purlin are also reduced. This will help in faster erection due to a smaller number of parts to be assembled.

The options 1 to 6 mentioned in the table is illustrated in fig. 3(a) to 3(f), wherein
Option 1 has single tie rod – 3(a)
Option 2 has two tie rods– 3(b)
Option 3 has three tie rods – 3(c)
Option 4 has four tie rods – 3(d)
Option 5 has five tie rods – 3(e)
Option 6 has six tie rods – 3(f)

Hence it is easy to select tie rods, and which is merely based on wind zones.

The invention has been described as detailed above but various embodiments and variations are possible beyond the preferred embodiments disclosed in this document. All such variations and modifications as obvious to the skilled person is within the scope of this invention. The applicant intends to rely upon provisional specification and the drawings submitted along with provisional specification.
,CLAIMS:WE CLAIM :

1. A mounting system for mounting solar panels modules on mounting module structure without purlin the system comprising of :

a. a plurality of solar panels,
b. a plurality of series of vertical posts (1),
c. a plurality of series of horizontal rafters (5) mounted on posts (1) combinedly forming a plurality of bays,
d. a plurality of bracings with each pair of bracing (3,4) connected with bracing connect cleat (2) to a corresponding post at its one end, and terminating on a corresponding rafter (2) at its other end thereby forming a ‘V’ bracing of each rafter with its corresponding post,
e. a plurality of module mounting cleats (6) arranged on each of the rafter to support the plurality of solar panels modules mounted on plurality of rafters and secured with clamps (8),
f. atleast one tie rod (7) connected between and across every pair of rafters to arrest the lateral sway.

the said arrangement characterized in the combination of bracings and tie rod arranged between posts and rafters and thereby eliminating purlin.

2. The mounting system for mounting solar panels as claimed in claim 1, wherein the rafter is a cold-form channel member.

3. The mounting system for mounting solar panels as claimed in claim 1, wherein the V bracing can be predetermined V shape based on desired tilt angle which inturn is based on predetermined structural support.

4. The mounting system for mounting solar panels as claimed in claim 1, wherein tie rods can be connected in any of the many known fastening methods based on the wind speed.

5. The mounting system for mounting solar panels as claimed in claim 1, wherein each bracing has a plurality of holes and each hole corresponding to a predetermined tilt angle.

6. The mounting system for mounting solar panels as claimed in claim 1, wherein the tie rod (7) is threaded and bolted at its two ends onto rafters.

7. The mounting system for mounting solar panels as claimed in claim 1, wherein the diameter and the length of tie rod (7) is predetermined based on wind speed and sway management.

8. The mounting system for mounting solar panels as claimed in claim 1, wherein tie rod (7) be one or more in each bay.

9. The mounting system for mounting solar panels as claimed in claim 1, wherein each of solar panel module is supported with end clamps.

10. The mounting system for mounting solar panels as claimed in claim 1, wherein each of solar panel module is supported with middle clamps.