WO2023097354A1

WO2023097354A1 - Fluid dynamics based solar tracking system

Info

Publication number: WO2023097354A1
Application number: PCT/AU2021/051564
Authority: WO
Inventors: Thanh Tri Lam
Original assignee: Thanh Tri Lam
Priority date: 2021-12-03
Filing date: 2021-12-25
Publication date: 2023-06-08
Also published as: AU2021290398B1

Abstract

The Fluid Dynamics Based Solar Tracking System is developed for floating solar. As it incorporates dynamic fluid-structure interactions, its model for structural analysis is closer to the real working conditions of the structures on the body of water. As a result, the structures are designed to be simpler and lighter, leading to saving cost of materials and installation while maintaining structural stability. This invention mainly focuses on structural components and related methods of the proposed Fluid Dynamics Based Solar Tracking System. These are defined, described, specified and demonstrated with respect to the concept of dynamic fluid-structure interaction. In addition to a number of methods added such as damping systems, the destructive limit of the geometrical variable structure is also established and presented for structural designs.

Description

1. TITLE: FLUID DYNAMICS BASED SOLAR TRACKING SYSTEM

2. FIELD

[0001] The Fluid Dynamics Based Solar Tracking System is related to the fields of:

1. Solar tracking systems for harvesting solar energy.

2. Structural mechanics and fluid mechanics and Finite Element Method for

Dynamic Fluid-Structure Interaction analysis.

3. SUMMARY

[0002] A typical solar tracking system is usually modelled for structural analysis with fixed ground connections as illustrated in (FIGURE 2). In this case, the ground, which is the base of the structure, is assumed to be completely hard. Similarly, a typical floating solar tracking system is designed with a hard floating structure as shown in (FIGURE 3). In this case, for structural analysis of the tracking system structure, the floating structure is also assumed to be completely hard (FIGURE 4). In other words, the interaction between the floating structure and the dynamic current of water underneath is disregarded.

[0003] The invention being presented is a different floating solar tracking system based on dynamic interactions between the Upper Structure (FIGURE 6), the Flexible Interlocked

Float Compound Structure, which is a soft floating structure (FIGURE 7), and the body of water. The system is then further enhanced with the Total Distributed Damping Systems.

In order to carry out structural analysis for this floating solar tracking system, a finite element model of dynamic fluid-structure interaction is required.

[0004] The difference of this system in comparison with other typical floating tracking systems is: the structure of this system takes into account the interaction of its geometrical variation and dynamic fluid. This model is working beyond the limit of geometrically stable (non-variable) structures of other typical floating tracking systems.

Please refer to (FIGURE 5), which demonstrates the concept of this system in comparison with (FIGURE 4) of typical systems. The proposed name of this floating solar tracking system is "Fluid Dynamics Based Solar Tracking System" (FIGURE 19 and FIGURE 1). 4. (SPECIAL) DEFINITIONS

4.1 Convention of coordinate system

[0005] The cartesian coordinate system used here has the vertical OZ axis and the two horizontal OX and OY axes.

4.2 Floating structure (FIGURE 6)

[0006] It is the structure that can work as a float and also as a structure bearing loads.

4.3 Rotating Structure (FIGURE 6)

[0007] It is the structure that rotates and bears loads.

4.4 Support Structure (FIGURE 6)

[0008] It is the structure that supports and bears weights of the Rotating Structure and solar panels. It transfers these loads to floats or floating structure. There are two types of Support Structures defined and used for the Fluid Dynamics Based Solar

Tracking System: Post and Cone-frame Structures.

4.5 Upper Structure (FIGURE 6)

[0009] It is the structure above ground or above floating structure. The Upper

Structure composes of Support Structure and Rotating Structure.

4.6 The Flexible Mechanical Power Transmission

[0010] This mechanical power transmission rotates the array of solar panels.

4.7 Moored/ Anchored Geometrically Variable Structure

[0011] It is a type of structure specially created and configured for the Fluid Dynamics

Based Solar Tracking System.

4.8 Base Connection (FIGURE 6)

[0012] Base Connection is the connection of the Support Structure to the base which is either ground or floating structure or floats. 4.9 Float's Joint (FIGURE 8)

[0013] A direct connection or a connection via a joint mechanism between two floats is called "Float's Joint". There are two types of Float's Joint: Vertical Rotatable Axis

Joint and Horizontal Rotatable Axis Joint.

4.10 Horizontal Rotatable Axis Joints (FIGURE 8)

[0014] Beside the Vertical Rotatable Axis Joints of typical floats which are popular in the market, the Horizontal Rotatable Axis Joints are developed for this Fluid Dynamics

Based Solar Tracking System. Some types of these joints are illustrated in (FIGURE 8).

4.11 Flexible Interlocked Float Compound (FIGURE 7)

[0015] The word "Interlocked" indicates that the floats are interlocked together via

Float's Joints as displayed in (FIGURE 8). The word "flexible" implies that the vertical degree of freedoms of the Float's Joints is free. The structure of The Flexible

Interlocked Float Compound is a type of floating structure.

4.12 Modified Flexible Interlocked Float Compound (FIGURE 17)

[0016] It is a Flexible Interlocked Float Compound that is further modified for enhancements while maintaining all its prior functions: "floating" and "interlocked" and "flexible".

4.13 Flexible Solar Tracking Array (FIGURE 9)

[0017] A Flexible Solar Tracking Array is a multi-span array of solar panels, consisting of three main parts working on the body of water: 1) the Upper Structure (FIGURE 6), including drive shafts, and solar panels, 2) the (Modified) Flexible Interlocked Float

Compound (FIGURE 7) and 3) Mooring/ anchoring and/or damping devices. The combination of the Upper Structure, the Flexible Interlocked Float Structure and the structures of mooring/ anchoring and damping systems is called the Flexible Solar

Tracking Array Structure as described in (FIGURE 1).

4.14 Span of Flexible Solar Tracking Array SPAN _{(N →N+1)} [0018] Span is a section of the Flexible Solar Tracking Array within two consecutive supports (Cone-Frame or Post) N and (N + 1). It is written as SPAN _{(N →N+1)}. Please refer to "SPAN" in (FIGURE 9).

4.15 Span Structure

[0019] It is the structure within a span of the Flexible Solar Tracking Array.

4.16 Vertical Displacement D_OZ(N) (FIGURE 9)

[0020] D_OZ(N) is the vertical displacement along the axis OZ of the Base Connection of the support N.

4.17 Relative Vertical Displacement Of Span Δ_{OZ(N →N+1)} (FIGURE 9)

[0021] It is the difference of the absolute vertical displacements of two consecutive

Base Connections: Δ_{OZ(N →N+1)} = D_OZ(N+1) - D_OZ(N) .

4.18 Maximum Relative Vertical Displacement of Span Δ_{OZ max}

[0022] It is the maximum value of the Relative Vertical Displacement of all spans with respect to all cases of loads, including dynamic loads. This value is obtained from the output of the dynamic fluid-structure interaction analysis.

4.19 Bending angle displacement between two floats β (FIGURE 10)

[0023] The value β represents the relative angle of two connected floats when bending.

4.20 MaximumBendingAngleDisplacementoftwofloatsβ_max(FIGURE 10)

[0024] β_max is the maximum bending angle between two floats. The value of β_max can be obtained by carrying out tests or structural analyses using Finite Element Method on the two floats.

4.21 Condition of Destructive Limit of Two Floats β ≤ β_max

[0025] β_max is the maximum value of β that the two joined floats are still not destructive when bending. 4.22 Length of a float L _float (FIGURE 11)

[0026] L _float is the length of a float along the Span of the Flexible Solar Tracking Array.

4.23 Angle Displacement of Span α _{(N →N+1)} (FIGURE 11)

[0027] Given a SPAN _{(N →N+1)} of a Flexible Solar Tracking Array. The SPAN has n floats.

The Relative Vertical Displacement of Span along OZ axis is: Δ_{OZ(N →N+1)} = Δ_OZ(1) + Δ_OZ(2) + Δ_OZ(3) +...+ Δ_OZ(n) = [sin (β) + sin(2β)+ ...+ sin(nβ)] L _float

The length of the span projected onto OX axis is:

Δ_{OX (N →N+1)}— Δ_OX(1) + Δ_OX(2) + Δ_OX(3) +...+ Δ_OX(n) = [cos (β) + cos(2β)+ ...+ cos(nβ)] L _float

Tan(α _{(N →N+1)})= Δ_{OZ(N →N+1)} / Δ_{OX(N →N+1)}

Thus, the Angle Displacement of Span: α _{(N →N+1)} = arctan(Δ_{OZ(N →N+1)} /Δ_{OX(N →N+1)})

4.24 Maximum Angle Displacement of Span α_max = Max { α _{(N →N+1)} }

[0028] The maximum value of α _{(N →N+1)} of all Spans with respect to all cases of loads is called α_max.

4.25 Limit of Relative Vertical Displacements of Span Δ_{OZ limit} versus Limit of Angle

Displacement of Span α_limit

[0029] The value Δ_{OZ limit} reflects the limit of Relative Vertical Displacements of Span and the value α_limit reflects the limit of Angle Displacement of Span. They are explained below:

Given a SPAN _{(N →N+1)} of a Flexible Solar Tracking Array. The SPAN has n floats. The limit of Δ_{OZ(N →N+1)}, which is called Δ_{OZ limit} : Δ_{OZ limit} — [sin(β_max ) + sin(2β _max )+ ...+ sin(nβ _max )] L_float

Δ_{OX limit} = [cos(β _max ) + cos(2β _max )+ ...+ cos(nβ _max )] L _float tan( α_limit)— Δ_{OZ limit}/ Δ_{OX limit} α_limit= arCtan(Δ_{OZ limit}/ Δ_{OX limit})

[0030] The value Δ_{OZ max} for all cases of loads, obtained from the dynamic fluid- structure interaction analysis, must be smaller than or equal to Δ_{OZ limit}. By contrast, if the current of water causes the value Δ_{OZ max} to be greater than Δ_{OZ limit}, the structure of the Flexible Interlocked Float Compound might be destroyed because of bending between floats.

The above condition of destructive limit β ≤ β_max can be demonstrated for a Span in the formula: Δ_{OZ max} ≤ Δ_{OZ limit} or alternatively, α_max ≤α_limit

The above condition represents the stability condition of structure subjected to dynamic loads caused by the body of water.

4.26 Damping Float (FIGURE 12)

[0031] A float partially filled with water is not only a float but also a damper. When a waves of the current of water outside shakes the float, the water inside the float responds and absorbs the energy of the waves. Thus, it helps to reduce the amplitudes of oscillations caused by waves of water outside the float.

4.27 Damping System of Interlocked Floats (FIGURE 12)

[0032] If all floats of the Fluid Dynamics Based Solar Tracking System are partially filled up with water, the whole Flexible Interlocked Float Compound can work as a distributed damping system, of which every float is a damper. This system is called

"the Damping System of Interlocked Floats"

4.28 Hanging Liquid Damping Tank (FIGURE 13)

[0033] It is a tank, partially filled up with water and hung at a torsional beam where is close to a pivot axis. It works as a damper to reduce the displacements of the top of the Support Structure. The tank also contributes to reducing torsional moment caused by the weight of solar panels by generating a torsional moment in the opposite direction due to the weight of the tank.

4.29 Damping System of Hanging Liquid Tanks (FIGURE 13)

[0034] This Damping System consists of damping tanks hung along all the torsional beams of the Fluid Dynamics Based Solar Tracking System.

4.30 Damping Net (FIGURE 14)

[0035] It is a net of elements that are capable of creating tensional forces, which help to reduce the amplitudes of oscillations caused by the current (including waves) of water underneath. The elements can be ropes, cables, bars, beams, frames or a combination of these types of elements. The elements are made of steel or any other materials. In addition to tensional forces, beam and frame elements of the damping system are able to create bending resistances which improve damping efficiency.

4.31 Damping System of Nets (FIGURE 14)

[0036] It is the combination of the Damping Nets and the Flexible Interlocked Float

Compounds, secured together at the nodes of the Damping Nets. Due to the inertial tensional forces created and transferred along elements of the Damping Nets, the

Damping System of Nets resists oscillations caused by the body of water within the area of the Nets. The inertial forces are created by the weight of the structures, the weight of the solar panels, the weight of the floats and by the water inside as well as outside of the floats.

4.32 Total Distributed Damping System

[0037] Depending on different circumstances, including the results from dynamic fluid-structure interaction analysis, up to three systems of the Damping System of

Nets, the Damping System of Interlocked Floats and the Damping System of Hanging

Liquid Tanks are selected to create a system that is called the 'Total Distributed

Damping System". The Damping System of Vertical Nets, which is a special case of the

Damping System of Nets, is included in the Total Distributed Damping System as well. [0038] The Total Distributed Damping System helps to reduce the oscillations of the

Fluid Dynamics Based Solar Tracking System Structure on the body of water. It also helps to reduce the amplitudes of waves of water outside the floats because of absorbing the waves' energy. Thus, the Total Distributed Damping System is a significant tool for the Fluid Dynamics Based Solar Tracking System: making the solar tracking system capable of working on larger waves of water while its simpler (and lighter & cheaper) structure is indestructible.

4.33 Floating Motor Base (FIGURE 15)

[0039] It is a floating base which floats the electric motors and is a base to moor/ anchor the following components: the Flexible Solar Tracking Arrays, the (Modified)

Flexible Interlocked Float Compounds, the Damping System of Nets and drive shafts.

It is also a base for other floating components to moor/ anchor to.

4.34 Floating Enclosure Base

[0040] The Floating Enclosure Base is not only used to enclose the floating Flexible

Solar Tracking Arrays but also is the place where the Damping Nets, the (Modified)

Flexible Interlocked Float Compound, the Floating Motor Bases and other components are Moored/ Anchored to. It can also be used as a damping system, if necessary, to reduce amplitudes of waves in the area that it is enclosing. The Floating Enclosure

Base and the Floating Motor Base can be combined to be dual functional where necessary.

4.35 Special Corrugated Floats (FIGURE 16)

[0041] This Fluid Dynamic Based Solar Tracking System is designed to work with any kind of floats, including the popular plastic floats in the market. However, some kinds of specific floats are specially developed for the enhancement of the system.

4.36 Fluid Dynamics Based Solar Tracking System (FIGURE 19 & FIGURE 1)

[0042] It is a floating solar tracking system composing of: 1. Flexible Solar Tracking Arrays, including the (Modified) Flexible Interlocked

Float Compounds. Structures of these components are Moored/ Anchored

Geometrically Variable Structures.

2. Total Distributed Damping Systems

3. Floating Motor Bases.

4. Floating Enclosure Bases.

5. Mooring/ Anchoring Systems.

6. Others that are not required to be claimed and presented in this document.

4.37 Dual Grounding & Floating Fluid Dynamics Based Solar Tracking System (FIGURE 20)

[0043] It is a version of the Fluid Dynamics Based Solar Tracking System that has a number of Spans floating and the rest of the Spans grounding.

4.38 Vertical Damping Net (FIGURE 23)

[0044] This Vertical Damping Net is a special case of the Damping Net defined at 4.30 and illustrated in (FIGURE 14). As a result, its features remain the same except the plane containing the Net is vertical.

4.39 Damping System of Vertical Nets (FIGURE 23)

[0045] This Damping System is the combination of the Vertical Damping Nets in both directions of OX and OY. It is a special case of the Damping System of Nets.

5. DESCRIPTION OF EMBODIMENTS

[0046] This Fluid Dynamics Based Solar Tracking System uses every single electric motor to rotate multiple Flexible Solar Tracking Arrays, which have multiple Spans.

Each Span may carry multiple solar panels. Thus, each electric motor rotates multiple

Spans of which the displacements vary differently subjected to waves of water. In order to rotate the arrays in such conditions related to dynamic loads and large displacements, which may lead to geometrical variation of the system's structure, the system is based on the characteristics of "flexible" which are applied to all its components' structures described below.

5.1 Descriptions of the Moored/ Anchored Geometrical Variable Structure developed for Fluid Dynamics Based Solar Tracking System.

[0047] Floating structures of typical solar tracking systems are usually assumed to be completely hard for modelling in structural analysis. Thus, dynamic loads of waves are disregarded. The floating structures, in this case, are also assumed to be geometrical non-variable.

[0048] In contrast, the structure of the Fluid Dynamics Based Solar Tracking System is created based on a different concept:

1. It is a geometrically variable structure.

2. The structure interacts with the fluid of water dynamically.

[0049] The above concept, which is the spirit of the Fluid Dynamics Based Solar

Tracking System, is developed as a new method for floating solar tracking systems.

The method is called: "An Approach of Structure for Floating Solar Tracking System:

The Moored/ Anchored Geometrically Variable Structure". A model which reflects the basic concept of this type of structure on the body of water is demonstrated in

(FIGURE 21).

[0050] The required specifications of the Moored/ Anchored Geometrical Variable

Structure are described below: 1. It is a geometrically variable structure. The structure must comply with the

"Mooring/ Anchoring Requirements", which are the conditions of boundary connections, as specified below: a) The vertical degree of freedom along OZ axis is not fixed, allowing the structure to be free vertically on the body of water. b) The horizontal degree of freedom along OX axis must be fixed via mooring/ anchoring systems. c) The horizontal degree of freedom along OY axis is an option, depending on different circumstances, to be fixed via mooring/ anchoring systems for further enhancement of stability.

2. It is a structure that is Moored/ Anchored, with respect to the horizontal directions of OX and OY axes, in such a way that makes the geometrically variable structure stable on the body of dynamic water. Mooring/

Anchoring devices are a part of the structure and contribute a role of stability to the geometrically variable model for dynamic fluid-structure interaction analysis. The Damping Net can be used as a part of the mooring/ anchoring system for this structure.

3. Every support (Post or Cone-Frame) connects, either directly or indirectly, to a float or a float compound.

[0051] The following structures of the Fluid Dynamics Based Solar Tracking System, as presented in (FIGURE 1), are designed to comply with the specifications of the

Moored/ Anchored Geometrical Variable Structure as listed below:

1. The Fluid Dynamics Based Solar Tracking System Structure.

2. The Flexible Solar Tracking Array Structure.

3. The Span Structure.

4. The Flexible Interlocked Float Compound Structure.

5. The Upper Structure. 6. The Rotating Structure.

All structures of the Fluid Dynamics Based Solar Tracking System can be made from any type of appropriate materials.

A simple version of the Flexible Solar Tracking Array Structure, which is a Moored/

Anchored Geometrical Variable Structure, is illustrated in (FIGURE 5).

5.2 Descriptions of the Float's Joint

[0052] It is defined as any type of connection between floats that can be modelled as a joint in structural mechanics. The vertical degree of freedom of this connection is free. Thus, the joint can displace vertically while the floats are not destroyed.

[0053] Plastic floats with the Vertical Rotatable Axis Joint demonstrated in the first figure of (FIGURE 8) are being used widely in floating solar power plants. Due to the nature of plastic material and assembly tolerance, this type of plastic connection can be modelled as a joint in structural mechanics, allowing the floats (and the joint) to displace vertically. No matter how much the floats displace, if the bending angle of the two joined floats is still within limit, that is β ≤ β_max, the floats will not be destructive.

In this case, these connections of plastic floats can be modelled as joints.

[0054] Another type of connection, the Horizontal Rotatable Axis Joint, as illustrated in (FIGURE 8), is also modelled as a joint in structural mechanics. No matter from which material the floats are made, these Horizontal Rotatable Axis Joints are the most suitable to geometrical variation of structure on the body of water.

5.3 Descriptions of the Horizontal Rotatable Axis Joint (FIGURE 8)

[0055] The Horizontal Rotatable Axis Joint is specially developed for the Flexible

Interlocked Float Compound. In comparison with the Vertical Rotatable Axis Joint, the

Horizontal Rotatable Axis Joint is more suitable for working in extreme conditions: It decreases the risk of destroying plastic floats and increases the lifespan of floats by reducing stress and strain occurring in the floats' bodies as a result of oscillations caused by the waves of water.

5.4 Descriptions of the Flexible Interlocked Float Compound (FIGURE 7) [0056] The Flexible Interlocked Float Compound consists of floats interlocking together. Its required specifications are:

1. All floats must be interlocked.

2. Joints between floats must be Float's Joints or normal structural joints, capable to be flexible.

3. It must meet the required specifications of the Moored/ Anchored

Geometrically Variable Structure.

4. The floats are usually made of plastics. It may also be made of any other materials such as steel or concrete.

5.5 Descriptions of the Flexible Solar Tracking Array Structure (FIGURE 6)

[0057] As illustrated in FIGURE 6 and FIGURE 1, the Flexible Solar Tracking Array

Structure is composed of the Flexible Interlocked Float Compound Structure and the

Upper Structure. The Upper Structure is composed of the Support Structure and the

Rotating Structure.

[0058] This structure must meet the required specifications of the Moored/ Anchored

Geometrically Variable Structure. In other words, it is also designed and configured to be a Moored/ Anchored Geometrically Variable Structure.

[0059] It implies that the supports (Post or Cone Frame) are not always vertical and may oscillate when subjected to dynamic waves of water.

[0060] The Flexible Solar Tracking Array Structure can be made from any type of appropriate materials.

[0061] Dynamic structural analysis must be carried out for designing of the structure of the Flexible Solar Tracking Array. It requires that the Flexible Interlocked Float

Compound is not destructive: β ≤ β_max (defined in 4.21). The value of β_max (defined in

4.20) must be obtained by testing or computing the simulated model of Float's Joints.

[0062] For example, obtaining β_max= 3° and given a Span of 3 floats with L _float= 1m, according to 4.23, we have: Δ_{OZ limit} = [sin(4°) + sin(8°) + sin(12⁰)] × 1m = 0.3133m (approximated) and α_limit= arctan(0.3133/2.9808) = arctan(0.105) = 6° (approximated)

[0063] The example above demonstrates that, with a Maximum Bending Angle

Displacement of two floats β _max = 3°, the allowable (limit) Relative Vertical

Displacement of Span is 0.3133m, which is quite large and ideal for the model of Fluid

Dynamics Based Solar Tracking System. If the joint of the floats is the Horizontal

Rotatable Axis Joint, the allowable β_max must be much greater than 3°. That is why this type of Float's Joint is ideal for the Flexible Solar Tracking Array.

5.6 Descriptions of the Flexible Solar Tracking Array (FIGURE 9)

[0064] The Flexible Solar Tracking Array is an array of continuous solar trackers or

Spans. The structure of this array is flexible as explained in 5.5. It is composed of:

1. The Flexible Interlocked Float Compounds or the Modified Flexible Interlocked

Float Compounds.

2. The Upper Structure, including the Support Structure, the Rotating Structure

(flexible drive shaft, Pivot axis, Tilting Beam) and solar panels.

3. The Total Distributed Damping System.

4. The Flexible Mechanical Power Transmission such as flexible drive shafts with or without cardans.

5. Related devices for mooring/ anchoring.

5.7 Descriptions of the Damping Float and the Damping System of Interlocked Floats

(FIGURE 12)

[0065] The Damping System of Interlocked Floats composes of the Flexible Interlocked

Float Compounds, of which every float is partially filled up with water.

[0066] Designs of this damping system also require computations of damping and structural analysis of floats in order to prevent destructions of the joints between floats in response to inertial forces. In order to prevent this kind of destruction, a further enhancement to the Damping System of Interlocked Floats is to incorporate it with Damping Nets. Nodes of the Damping Nets are secured to a number of Float's

Joints of the Flexible Interlocked Float Compounds. In this case, elements of the

Damping Nets, which is explained in 4.30 and 5.9, bear most of the inertial forces instead of the joints of the floats

5.8 Descriptions of the Hanging Liquid Damping Tank and the Damping System of

Hanging Liquid Tanks (FIGURE 12)

[0067] The Damping System of Hanging Liquid Tanks is briefly demonstrated in FIGURE

12. It has the dual functions of:

1. Reducing oscillations of the tops of the Support Structures (Post or Cone

Frame) thanks to the liquid stored inside the hanging tanks. The oscillations are caused by the waves of the water underneath.

2. Reducing torsional moments caused by the weights of solar panels by generating an opposite torsional moment. The opposite torsional moment is created by the weight of the tank. It does not relate to the characteristics of liquid.

[0068] The Damping System of Hanging Liquid Tanks with the function 1 above is claimed below whereas the function 2 above is not claimed.

5.9 Descriptions of the Damping Net and the Damping System of Nets (FIGURE 14)

[0069] A Damping Net can be combined from one to all types of rope, cable, bar, beam or frame elements with respect to multiple directions of elements. It is mentioned that a damping 'net' of one direction is also applicable and the one of two right angle directions is the most appropriate. Elements of the Damping Net can be made from any type of appropriate materials.

[0070] The Damping Net may also be combined with other structures or modified to different versions. However, its core function is unit: The Damping Net is used for damping of floating solar systems thanks to tensional forces appearing along its elements.

[0071] Designing of the Damping Net, which takes into account the properties of the

Damping Net such as properties of elements (ropes, cables, bars, beams, frames), properties of materials, the length of step (FIGURE 14) and so on, depend on circumstances and are also based on fluid-structure dynamic analysis. From the results of this analysis, the required Damping Net is decided for individual cases.

[0072] The Damping Net must be Moored/ Anchored to either the Floating Motor Base or the Floating Enclosure Base or any other types of mooring/ anchoring systems.

[0073] There are two special types of Damping Net: Bottom Damping Net and Top

Damping Net. The plane containing these Top or Bottom Damping Net is horizontal.

Nodes of the Bottom Damping Net are secured to the Flexible Interlocked Float

Compounds or floats in a variety of ways while Nodes of the Top Damping Net are secured to tops or close to tops of the Support Structures (Posts or Cone-Frames). The

Damping Net is not only a damping device but also a mooring/ anchoring device.

[0074] The Base Connections of Support Structures (Post or Cone-Frame) need to be secured, either directly or indirectly, to the Damping Net as well.

5.10 Descriptions of the Floating Motor Base (FIGURE 15)

[0075] The Floating Motor Base is specially developed for the Fluid Dynamic Based

Solar Tracking System. Its specifications are described below:

1. It is a base for other components below to moor/ anchor to:

A. The (Modified) Flexible Interlocked Float Compounds: Connected via

Float's Joints, ropes, cables, bars, beams, frames (Interlinkages) as described in 5.13

B. The Damping System of Nets: connected via elements of the Damping

Nets. The Bottom Damping Nets connect to the bottom of the Floating

Motor Base. The Top Damping Nets connect to the top of the Floating

Motor Base.

C. Drive Shafts: connected via drive shafts and cardans.

D. Flexible Solar Tracking Arrays: connected as explained above. E. Any other floatable compounds necessary for floating solar power plant such as walkways, maintenance floors, floating invertors, floating buildings....

F. Depending on different circumstances, locations of the connections mentioned above can be from the top to the bottom of the Floating

Motor Base.

2. Its mooring/ anchoring requirements are described as follows:

A. How it is Moored/ Anchored: It is Moored/ Anchored securely, either directly or indirectly to the ground, preventing movements along horizontal directions of OX and OY. Its vertical degree of freedom is free. It must also be Moored/ Anchored to prevent it from capsizing. It can be Moored/ Anchored using ropes, cables, bars, beams, concrete piles or any other forms. In order to prevent capsizing, there are two solutions or the combination of these two solutions: 1) Both top and bottom of the Floating Motor Base are Moored/ Anchored. 2) The structure and floats/ float compounds of the Floating Motor Base are extended further in its two sides in order to improve the capacity of anti-capsizing.

B. How other components are Moored/ Anchored to it: It must be qualified to be a place for the Moored/ Anchored Geometrically

Variable Structures and for other components to secure to its top and bottom. For these requirements, in the models for structural analysis, it is modelled as a slidable joint as presented in (FIGURE 21).

[0076] All mooring/ anchoring devices and ropes, cables, bars or beams

(Interlinkages)can be made from any type of appropriate materials.

[0077] The basic structure of the Floating Motor Base consists of three structural continuous beams or frames securing on floats or Flexible Interlocked Float

Compound Structure as illustrated in FIGURE 15. Its structure is secured to concrete piles or concrete anchors or any other kinds of mooring/ anchoring systems. It might also be made of floating concrete.

5.11 Descriptions of the Floating Enclosure Base

[0078] The Floating Enclosure Base is identical with the Floating Motor Base, except the following:

1. It does not have electric motors installed.

2. It is used to enclose a part or the whole floating solar power plant.

[0079] The Floating Enclosure Base and the Floating Motor Base can be combined together where necessary and appropriate.

5.12 Descriptions of the Special Corrugated Floats (FIGURE 16)

[0080] The Special Corrugated Floats are developed with the following specifications outlined below:

1. Contributing to the damping efficiency: the floats absorb energy of the current of water thanks to the corrugated surface of the body. The corrugated surface also increases the efficiency of the damping liquid (water) inside the floats. In addition, the corrugated surface makes the body of the float harder.

2. Saving materials for making floats while meeting requirements of floating and damping. Saving costs for installation and maintenance.

3. The floats are also designed for better float's connection between floats and

Base Connection of floats with Support Structure, for better connection with the Damping System of Nets and more appropriate for Modified Flexible

Interlocked Float Compounds.

4. Both the Vertical and Horizontal Rotatable Axis Joints can be used with these corrugated floats.

5. Depending on the requirements of capsizing resistance or bearing more loads, the cross section of floats can be closer to round or to rectangular. [0081] The Special Corrugated Floats can be made from any type of appropriate materials.

5.13 Descriptions of the Modified Flexible Interlocked Float Compound (FIGURE 17)

[0082] It is specially developed for the Fluid Dynamics Based Solar Tracking System.

One of its versions is demonstrated in FIGURE 17.

[0083] In addition to the characteristics of the Flexible Interlocked Float Compound, the Modified Flexible Interlocked Float Compound has its own extra specifications as follows:

[0084] It is a combination of the Flexible Interlocked Float Compound and beams, bars, ropes or cables. These beams, bars, ropes or cables are used in lieu of a part of floats in the Flexible Interlocked Float Compound where the functions of "Flexible" and

"Interlocked" are still required but the function of "Floating" is not necessary. The beams, bars, ropes or cables are capable of withstanding tensional forces, linking floats or compounds of floats together. These beams, bars, ropes or cables are called

"Interlinkages" of the Modified Flexible Interlocked Float Compound. These

Interlinkages can be made from any type of appropriate materials.

1. Unlike Damping Net, Interlinkages are not required to be continuous.

2. All its Interlinkages connect to floats or float compounds via Float's Joints. This type of connection is modelled as joints for structural analysis.

3. The Modified Flexible Interlocked Float Compound must meet all requirements of the Moored/ Anchored Geometrically Variable Structure. It is a special case of the Flexible Interlocked Float Compound.

5.14 Descriptions of the Specially Developed Support Structure (FIGURE 18)

[0085] Functions of the Support Structure:

1. Working as a part of the Moored/ Anchored Geometrically Variable Structures.

2. Bearing loads of Rotating Structure and Solar Panels.

3. Being used as points to secure drive shafts. [0086] It is specially developed to be a part of the Moored/ Anchored Geometrically

Variable Structure. Its specifications are described below:

1. It must connect, either directly or indirectly, to a float or to a float compound.

The connection must be modelled to be fixed for structural analysis. If the base connection of the Support Structure is not fixed in any degree of freedom, mooring or anchoring must be established respectively in order to maintain the stability of the structure. The Support Structure, connected with its base of floats or float compounds, must be able to adapt to oscillations of the geometrically variable structures of the Flexible Solar Tracking Array. The

Support Structure contributes an important role, ensuring the solar panels do not capsize.

2. It can connect to Damping Nets via either fix or joint connections.

3. It can connect to Rotating Structure via joint connections such as cardan.

[0087] There are two types of Support Structure: Post and Cone frame. The Support

Structure can be made from any materials such as steel or plastics.

[0088] There are 11 types of Specially Developed Support Structure for the Fluid

Dynamics Based Solar Tracking System as illustrated in FIGURE 18 and suitable to circumstances below:

1. In case the floats are made of plastics, forces caused by loads might need to be distributed to more numbers of Base Connections, the Cone-Frame Support

Structure with multiple legs, types from 6 to 10, is preferable.

2. In case of light loads or the Base Connection is hard enough, the Post Support, types from 1 to 5, is preferable for the reason of costs.

3. In case of light loads or the base connection is hard enough and anti-corrosion is considered, the plastic version of Post Support, type 11 as presented in

FIGURE 18, might be selected.

5.15 Descriptions of the Combination of the Bottom Damping Nets and the Modified

Flexible Interlocked Float Compounds (FIGURE 22) [0089] This combination is a simple floating structure which helps to save the costs of materials and installation of the floating solar tracking systems. It is not only functional as a Modified Flexible Interlocked Float Compound but also capable to work as a damping system.

[0090] Depending on different circumstances, Interlinkages may or may not be used in this combination. The condition for this combination is that all individual float compounds must be Moored/ Anchored in both horizontal directions of OX and OY axes.

5.16 Descriptions of the Flexible Mechanical Power Transmission

[0091] The Flexible Mechanical Power Transmission must be "flexible" in order to work on the body of dynamic current of water. It must meet the required specifications of the Moored/ Anchored Geometrically Variable Structure. It can be drive shafts using cardans or any appropriate type of flexible drive shafts.

5.17 Descriptions of the Fluid Dynamics Based Solar Tracking System (FIGURE 19)

[0092] The Fluid Dynamics Based Solar Tracking System mainly consists of:

1. The Flexible Solar Tracking Arrays

2. The Floating Motor Bases and the Floating Enclosure Bases

3. The Total Distributed Damping Systems.

4. Mooring/Anchoring systems.

5. The Flexible Mechanical Power Transmissions.

[0093] Both single axis and dual axes of mechanical power transmission for solar tracking systems can be applied in the Fluid Dynamics Based Solar Tracking System.

5.18 Descriptions of the Dual Grounding & Floating Fluid Dynamics Based Solar Tracking

System (FIGURE 20)

[0094] Due to the characteristics of geometrical variation, The Fluid Dynamics Based

Solar Tracking System is also capable of working in areas that are flooded and dried repeatedly. If the water level changes too much and other solutions is not prefered, the Dual Ground & Floating Fluid Dynamics Based Solar Tracking System might be an option.

[0095] This dual system is simple. In the area of land that might be flooded, the floating version of Fluid Dynamics Based Solar Tracking System is applied. Otherwise, the support structures (Post or Cone frame) are simply grounded instead of connecting to floats.

[0096] Due to the changes of water level, the moor/ anchor ropes or cables need to be able to expand or shorten accordingly.

5.19 Descriptions of the Vertical Damping Net and the Damping System of Vertical Nets

(FIGURE 23)

[0097] The Damping System of Vertical Nets is the combination of the Vertical

Damping Nets that are secured to tops and bottoms of all the Support Structures (Post or Cone-Frame).

[0098] The Damping System of Vertical Nets, whether incorporated with the Top

Damping Net or not, is not only used in reducing oscillations of both bottoms and tops of the Support Structures, but also required as a part of mooring/ anchoring systems for the mechanism of the second axis of the Dual Axis Fluid Dynamics Based Solar

Tracking System which is presented in another invention.

[0099] The Damping System of Vertical Nets is also a part of the Total Distributed

Damping System.

Claims

The Damping Net and the Damping System of Nets, as defined under 4.30 & 4.31 and described under 5.9, are applied for any kind of floating solar, either with or without solar tracking systems, especially for the Fluid Dynamics Based Solar

Tracking System.

2. The Damping Float and the Damping System of Interlocked Floats, as defined under

4.26 & 4.27 and described under 5.7, are applied for any kind of floating solar, either with or without solar tracking systems, especially for the Fluid Dynamics

Based Solar Tracking System.

3. The Hanging Liquid Damping Tank and the Damping System of Hanging Liquid

Tanks, as defined under 4.28 & 4.29 and described under 5.8, are applied for any kind of floating solar, either with or without solar tracking systems, especially for the Fluid Dynamics Based Solar Tracking System.

4. The Total Distributed Damping System, as defined under 4.32, is applied for any kind of floating solar, either with or without solar tracking systems, especially for the Fluid Dynamics Based Solar Tracking System.

5. The Modified Flexible Interlocked Float Compound, as defined under 4.12 and described under 5.13, is applied for the Fluid Dynamics Based Solar Tracking

System.

6. The Moored/ Anchored Geometrically Variable Structure, which is specially developed and configured, is applied for any floating solar tracking systems, especially for the Fluid Dynamics Based Solar Tracking System as defined under 4.7 and described under 5.1.

7. The type of Horizontal Rotatable Axis Joint, which is used for enhancing the function of flexibility as well as the lifespan of the Flexible Interlocked Float Compound, is applied for any floating solar tracking systems, especially for the Fluid Dynamics

Based Solar Tracking System. It is defined under 4.10 and described under 5.2.

8. The Combination of the Bottom Damping Nets and the Modified Flexible

Interlocked Float Compounds, as demonstrated in (FIGURE 22) and described under

5.15, is applied for any floating solar tracking system, especially for the Fluid

Dynamics Based Solar Tracking System.

9. The Special Corrugated Floats, which are developed at least for damping efficiency, as defined under 4.35 and described under 5.12, are applied for any floating solar tracking system, especially for the Fluid Dynamics Based Solar Tracking System.

10. The Specially Developed Support Structures, which are created to accompany with the Moored/ Anchored Geometrically Variable Structures of the Flexible Solar

Tracking Array, together with their required Base Connections to floats, float compounds or to the (Modified) Flexible Interlocked Float Compounds, especially to the Special Corrugated Floats, as defined under 4.4 and described under 5.14, are applied for the Fluid Dynamics Based Solar Tracking System.

11. The Vertical Damping Net, which is a special case of the Damping Net, and the

Damping System of Vertical Nets, which is a special case of the Damping System of

Nets, as defined under 4.38 & 4.39 and described under 5.19, are applied for any kind of floating solar, either with or without solar tracking systems, especially for the Fluid Dynamics Based Solar Tracking System

12. The Fluid Dynamics Based Solar Tracking System, as defined under 4.36 and described under 5.17, comprises of one or more claims of the above claims from 1 to ll.

13. The Dual Grounding & Floating Fluid Dynamics Based Solar Tracking System, as defined under 4.37 and described under 5.18, comprises of one or more claims of the above claims from 1 to 12.