Transilvania University of Brasov [302629]

Transilvania University of Brasov

Product Design and Environment Faculty

Diploma Project

Graduate:

Șerban Ioana Andreea

Programme:

Industrial Design

Scientific Coordinator:

Prof. Dr. Eng. Alexandru Catalin

Brașov

2017

Șerban Ioana Andreea

Simulation and modeling of an adaptive tracking system of the photovoltaic panels

Diploma Project

Programme:

Industrial Design

Brașov

2017

CHAPTER 1

1.1 Introduction

Energy consumption is a [anonimizat],[anonimizat],but where does all of this energy came from?

[anonimizat],nuclear and renewables fossil(fig 1.1).Fuels consist of extracted decomposed organisms and plants that existed millions of years ago.Biomass converts plants into bio metric material to produce energy.Nuclear energy is released during nuclear fusion.Leasly renewable energy comes from source that’s not depleted when used such as wind or solar power.

What’s the profound difference between them?How they affect our planet?

Fossil fuel cost more that we pay at the pump and impacts their environments in many ways.These impacts include global warmin air and quality deterioration oil spills and acid rain.It’s also projected that fossil fuel resources will be depleted within the next 50 to 100 years.Biomass and nuclear energy also have similar issues.We need a [anonimizat],renewable energy.

[anonimizat] a one-time use resource in the human timescale.Resources for renewable energy includes:sunlight,wind,rain,tides,waves and geothermal heat.

-Solar,which harnesses the Sun for energy.

-Wind,which utilizes the motion ofwind to create electricity.

-Hidropower,which uses moving water to generate power.

-Biomass,which refers to a [anonimizat].

-Tidal,[anonimizat].

-Geothermal,which uses the internal heat from the earth for energy.

We have to rely another nations for these resources which history a shun to be a contributor to:war,famine and political instability.So,how do get fosil fues to renewable energy? The truth is our infrastructure is build around our fossil depedency.If we could convert to what’s known as a [anonimizat]’s it going to be?

[anonimizat],high capital cost and intermittency.

Figure 1.1 Renwable energy

CHAPTER 2

IDENTIFICATION OF EXISTING PRODUCT

2.1[anonimizat] a [anonimizat] a single motor;the solution contains a [anonimizat](slew drive), bevel gears with stright teeth and three or two brake couplings respectively;

[anonimizat](solar radiation),structural and constructive systemazition of used/usable solutions,structural synthesis of the orientation of mechanism,multicriteria analysis,modeling of orientation mechanism at a multicorp systems and identifying the function dynamical and kinematical of the orientation systems..

Virtual refining of prototypes by modeling complex phenomena(friction,deformability)and studying their influence on the behavior of the orientation systems,evaluating the vibrational characteristics of the system

The specific energy and economic efficeiency developing studies,of the orientation systems photovoltaic panels,based on energy needs assessment,energy consumer modeling,energy system evaluation and cost orientation

2.2 Identification of existing products

Solar power remains,after hydro and wind,the 3nd most important renewable energy source in terms of globally intalled capacity.

Solar panels are electricity-generating structures that work throught the photoelectric effect.This was discovered by Bequerel(1839) when he observed that certain materials would produce a tiny electrical current when exposed to a light source.This started the production of Photovoltaic Solar Panels,where sunlight was converted straight into energy.First poineered on spacecraft in the 1960’s,today they can be found across the globe a top of hauses,offies and even boats.In some places,where irradiance is hiht,they can produce huge amountsof electricity and act as an alternative fossil fuels,producing clean,renewable energy.

In order to maximize the amount of solar radiation captured by the conversion systems,mainly uses tracker systems depending of the number of axes

movement, tracking systems are divided into two main categories: monoaxial systems and dual axial tracker systems.One of the disadvantage aspect of the biaxial tracker system is the economic aspect of the realization and implementation,but the energy gain is considerable.in relation with the energy gain of monoaxial systems.The energy advantage of dual axial systems increased interest in research and innovation of these types of tracking systems respectively implementation and their optimization.

Depending on the number of oriented modules and their layout, orientation can be classified as follows (Figure 2.1):

A. Orientation systems for individual modules – the modules are individually mounted on supporting frames and driven by their own engine sources;

B. Routing systems – the modules are mounted individually but oriented simultaneously,either using a single motor source (mono-axial orientation systems) or two Motor sources (dual axis tracking systems);

C. Platform orientation systems – the modules are mounted on the same support frame (platform type), and the source /sources navigate the entire platform;

D. Rail platform tracking systems – the modules are mounted in rows individual,which in turn are arranged on a common platform frame work.

Depending on the mode of operation, guidance systems can be classified as follows:

– passive orientation systems where the orientation movement is achieved by expansion thermal freon,fluid-fluid (due to heat sensitivity) in a mounted tube Parallel to the photovoltaic module

– active guidance systems – are mechatronic systems based on actuated devices, electric (for large systems, platform-string type, drive may be hydraulic), which may include gears with gears, articulated bars, chain transmissions, wire or belt.

Figure 2.1 a.Single axis tracker

Figure 2.1b.Routing systems

Figure 2.1 c.Platform orientation systems

2.1 d.Rail Tracking systems

The orientation of the photovoltaic modules should take into account the two movements in the photovoltaic modules the Sun-Earth astronomical system: the daily movement and the seasonal movement. That's how they were systematized two fundamental types of orientation mechanisms(fig2.2)

One axis (mono-axial), respectively two axes (bi-axial).

In the case of bi-axial systems, the literature has four main types, depending on how the rotation axes are located:equatorial, pseudo-equatorial,Azimuths and pseudo-azimuths(fig2.3)

Figure 2.2 a

Figure 2.2 b Dual axis systems orientation

As has been pointed out, active guidance systems are mechatronic systems, which

Integrates mechanical components (mechanical device), electronic & computer

(Device / control system).

2.3 General aspects regarding solar radiation

Solar radiation is the principal parameter that influences the efficiency of systems photovoltaics. After interaction of solar radiation with the atmosphere and the Earth surface they have many series of transformations according to the diagram figure 2.3

Figure 2.3 The solar radiation component

The solar radiation is influenced by the geographical location,shape of the relief,season,time of day,climatic conditions(clouds,rain,air clarity)and polutation lever from the area.To implement a photovoltaic system,estimed the amound of solar radiation,either using metrological databases or by empirical methods(mathematical)to asses the energy gain the system can bring.
Solar radiation can be measured using traditional instruments, or it can be Digitally recorded with a data acquisition system. In addition, different models have been developed To estimate solar radiation.

The orientation principle of the solar panels is based on the data on the solace's position on the celestial vault.To ensure the greatest possible efficiency of conversion of solar energy into electricity, the sun's rays must fall normally on the surface of the receiver,so the system must periodically modify its position in such a way as to maintain the relationship between the sun's rays and the panel.The earth describes an elliptical rotation around the sun for a year,and on the other, over a day, it performs a complete rotation around its own axis (motion that generates sunrise and sunset).The variation of the altitude of the sun over the celestial sphere over a year is determined by the precession movement,responsible for the inclination of the earth's axis in relation to the elliptical annual plane(the value of the angle is 23.5 °- v. Therefore,when designing guidance systems, it is necessary to consider the two rotation movements: the daily movement (diurnal) and the annual (seasonal) precessional movement. In order to determine a geometric algorithm for the orientation of the conversion systems,angular parameters that relate the position of the Sun to the position of the observer are illustrated in Figure 2.4, as follows:

– hourly angle ω – is the angle measured in the equatorial plane between the projection on the equatorial plane of the line joining the center of the Earth with the center of the Sun and the right joining the center of the Earth with the center of the Sun when the sun is at noon sun; Solar noon is the time when real solar time is 12:00; The hourly varistory angle is 15 ° per hour, by convention, the value being measured as follows: ω <0 – before the afternoon sun, respectively ω> 0 – in the afternoon;

– Sun's altitude or altitude angle α – is the angle that is formed between the direction of the sun's rays and the horizontal plane of the place;

-the zenith solar angle θz is the angle that is measured between the normal plane of the place and the direction of the sun's rays determined by the direction of the straight line between the point where the observer and the center of the Sun are located; The altitude and zenith angle are complementary: + Z = 90;

– azimuthal solar angle γs – is the angle to be measured between the projection of the N-S direction in the place plan and the horizontal component of the solar radiation (projection of the solar radiation in the horizontal plane of the place);

-Sunset or angle δ – is the angle that is formed between the right determined by the center of the Sun and Earth and its projection on the equatorial plane or, otherwise expressed, is the dihedral angle between the equatorial plane and the plane of the elliptic that the Earth rotates around the Sun ; For any day of the year, the declination value can be approximated by the expression:

Where n is the number of the day in the year,and 80 is the number of the day of the year in which the spring solstice takes place;Declination changes its value throughout the year from – 23.45ș to winter solstice to + 23.5ș at the summer solstice; The value of declination to equinoxes is δ = 0ș.

The global(equatorial)reference system OXYZ(fig2.4)had:

The angles of the equatorial orientation of the solar ray:

ω orar angle and declination angle δ

The azimuthal orientation of the solar beam

ψ – azimut angle and altitude elevation angle α

The pseudo-equatorial orientation angles:

β -diurnal angle and γ-elevation angle

Respectively pseudo-azimuthal orientation angles

ε diurnl angle and ρ-elevation angle

Fig 2.4The global reference systems

Using this mathematical modeling apparatus for solar radiation modeling, numerical simulations were performed for various geographical areas and days of the year. For example, considering the geographical area of ​​Brașov and the specific summer solstice input data (φ = 45.5 °, δ = 23.45 °, n = 172)we obtain the follow diagram(2.5 a,b)

2.5 a. Weather data 2011

2.5 b.Weather data 1/06/2017(source RETscreen.ro)

CHAPTER3

CAD MODELING

3.1 Engineering calculus

GEAR DIMENSIONING CALCULUS

As input data we have the power of the electric motor which is P=0.1KW,

The lifetime of the gears is Lh=50000hours.The number of rotation of the electric motor is n1=0.00069rpm.The gear ration u=1.

The distance between axis,aw it is measured in 3D model with the value of is 1000mm .

The speed of the tracking system assemble is determined by:

;

After calculus,the resultis v=0.00055 m/s,meaning 0.05cm/s, so the necessary time for tracking system is t=12h;

The torque moment,T1,Nmm;

T1=9.55106

T1=9.55106=1383956.268Nmm

The gear calculus were made by using “Sistem Interactiv de invatare a teoriei si de insruire pentru proiectarea Organelor de Masini”software and the interface of it represented below in fig (3.1)

Figure3.1

Gears are very important machine elements today and they are common used in different kinds of gearbox and transmissions.

Especially cylindrical gears are most applicable because of their very high efficiency and not complicated production.Modeling of cylindrical gears is very important process in machine design,asfor making rel model of gearbox,such dor gear and transmission structure analysis and optimization.

In fig (3.2) there are shown how the input data were introduced in software.

Figure3.2

In figure (3.3) there are represented the call contact

Figure3.3

In figure(3.4a,b) there are the input and output geometrical parameters of wheels

Figure 3.4 a

Figure 3.4 b

The calculus of the predimensionig of wheel shafts diameter is Represented in figureb bellow fig(3.5)

Figure 3.5

The speed of the tracking system assemble is determined by:

Figure 3.6

3.2 3D MODELING OF THE LAYOUT

For a development model of the PV tracking system, it is necessary, amongst others other, maso-inertial characteristics (mass, mass center location, moments and inertia products)of the bodies that make up the system. These data can be Established /determined on two paths: by calculating the analysis (based on mechanical relations General), respectively by analyzing solid-state models (3D) made using an environment Specialized CAD – Computer Assisted Design / Design (eg CATIA, ProENGINEER,SolidWorks, AutoCAD).

For the present paper, the solid model of the orientation mechanism (corresponding

The basic solution in figure(4.1) was achieved by using the licensed software package CATIA V5R19.

Stages of 3D modeling:

-Sketches

-3D parts

-Assambling 3D pieces

Catia Version 5 uses Sketcher workbench as its principal method to crate profiles.These profiles can be constrained using many different types of constraints.Sketches are the first step in creating 3D objects.These are usually like shadowns of object you woul create.

The CATIA V5 Part Design application makes it possible to design precise 3D models,from skething in an assembly context to iterative detailed design.After the 3D models,creaing the desired ensemble.

Considering that the main objective for this project represent designing of an adaptive traking system of a photovoltaic panel,focusing on development of the PV dual-axis tracker system fig (3.7).

Fig 3.7 The PV solar tracking system

In a figure 3.8 is shown the whole syste,also in the followingpage will be represented the component of the PV dual-axis tracker system.

Fig 3.8 The bevel-gear,Slew-drive,DCmotor and Cam mechanism

The first component created was a U-shaped iron,the role of this piece is to fix the whole ensamble,There are the 18 pieces.

Fig 3.9 The “U” Profile

To extrude the sketch the used command is Pad.This is the most used command .

The screws and nuts were used from Catia catalogue.

4.2 The panel

The panel was measured had the dimensions 1:1.The material applied is PV(fig3.10)

Fig 3.10 Solar panel,monocrystalin

The panel support

The material applied is aluminium.His mass are 2315.25kg and the density aren’t uniform.The measure of inertia is represented in (fig4.6)

Fig 3.11 Support and 10 panels assembly

Fig 3.12 Material applied and measure inertia

The pillar of the panel

The dimensions of the pillar is mm with thickness mm,with height mm,at the end of the column was made ahole with diameter of 400mm to attach the rotational coupler.At the base

Fig 3.13 The fixed pillar and drafting dimensions

The rotated pillar

Fig 3.14 The rotated pillar and drafting dimensions

Fig 3.15 Bevel gear

Fig3.16 Bevel gear with inertia

Fig 3.17Cam mechanism with measure inertia

The bearings (fig4.11)were taken from the Schaeffler catalogue.

Fig 3.18 Bearing

3.19 Bearing dimensions

Slew drive

3.20 Slew drive

3.21 Slew drive sections

CHAPTER 4

MBS SYSTEMS MODELING

4.1 Mechanical transmission proposed

Figure 4.1

The mechanical transmission proposed,make the azimuthal movement- around the Vertical axis I,and the altitude movement,around the horizontal axis II – using a single electric motor which rotate the worm screw 1.From the worm screw 1 the movement is trasmitted to the worm wheel 2 find as the shaft of the vertical axis I,then is reaching to pillar 3,how is fixed with the whell shaft.The pillar no3,engages with the conical gear 4 and cam&follower 6,connected to the horizontal shaft.

4.2 Optimizing the mechanical device

A virtual prototyping platform includes following types of softare products:

Computer Aided Design (CAD) (e.g., CATIA, PROENGINEER, SOLIDWORKS),multi-body systems(MBS) (e.g., ADAMS, PLEXUS, SD-EXACT),finite element analysis(FEA)(e.g., NASTRAN/PATRAN,

COSMOS, ANSYS),and design for control (DFC) (e.g., EASY5, MATLAB/SIMULINK, MATRIXX).The MBS software is the main component of the virtual prototyping platform, and it allows analyzing,optimizing,and simulating the mechanical system under “real” operating.conditions.

In CAD softer,Catia is used for creating the geometrical model on the mechanical system(solid model).This model contains the information about the mass and the inertia properties of rigid parts.

To solid model can be transferred from CAD to MBS from standard format files,sughas IGS,STEP,PARASOLID.

To import the CAD model into MBS model,are selected the elements that are joined by a joint.The steps to follow are the following:

I selected the item part by right clicking on the part,properties and mechanical File saved in “igs”.In ADAMS it was imported with the file type command,selecting the item saved as “igs”,the element named in command part name.Has been selected the first part,was used the modify comm. And where the folloing were insereted.Fig(4.2)

Figure 4.2

These are the commands for each element that have been used to import Catia softwere items into Adams.

4.3 Setting the MBS model

The tracker systems mechanism for a PV panel,contains 11parts.The whole mobile structure had 11.803kg.

The MAS virtual model of the mecanical device of the dual-axis tracker systems developed in Adams view in shown figure 4.3.

Figure 4.3The MBS model of tracking mechanism

To simplify the optimization process of the mechanical device,we reduce the number of design variables.The coordinates of the points/joints are presentate in figure bellow()

Body connection

The revolute joint,which makes the first motion is beween the rotated pillar(3),figure 4.3 and the DC Slew drive which is trains by the DC motor,true screw worm(1) and worm wheel(2),the revolute joint is represented below by figure 4.4

Figure 4.4

The fixed joint between Fixed pillar and ground is presented in figure 4.5

Figure 4.5

The revolute joint_3(figure 4.6)is between shaft(3)and the pillar which is find in rotated pillar(3) bearing

Figure 4.6

Figure 4.7 Fixed joint

Figure 4.8 Fixed joint

Figure 4.9 Fixed joint

Figure 4.10 Revolute joint

Figure 4.11 Fixed joint

4.12 Fixed joint

Figure 4.13 Fixed joint

Figure 4.14 Fixed joint

Figure 4.15 Fixed joint

Motion_1 is find in Joint_1.Motion_1 makes the first motion is beween the rotated pillar(3),figure 4.3 and the DC Slew drive which is trains by the DC motor,true screw worm(1) and worm wheel(2),the revolute joint is represented below by figure 4.16

Figure 4.16

Figure 4.17 Motion_2

References

[1]http://webbut.unitbv.ro/teze/rezumate/2011/rom/ButucBiancaRaluca.pdf

[2] https://www.nrcan.gc.ca/energy/software-tools/7465

[3] http://www.kinematicsmfg.com/products/sde-dual-axis-positioner/

[4]

[5] Alexandru, C., Pozna, C. Dinamica sistemelor mecanice pe baza prototiparii virtuale. Ed. Universitatii Transilvania din Brasov, 2003, ISBN 973-635-225-0.

[6] Alexandru, C. Analiza si optimizarea in mediu virtual, pe platforme de prototipare digitala, a sistemelor mecatronice utilizate pentru eficientizarea conversiei radiatiei solare in energie electrica. Raport de cercetare la grantul CNCSIS 892/2007-2008. Revista de Politica Stiintei si Scientometrie.
[7] Casolo, F. Motion Control. Ed. In-Tech, 2010, cap. 29 (The analysis and optimization in virtual environment of the mechatronic tracking systems used for improving the photovoltaic conversion), p. 553-580, ISBN 978-953-7619-55-8, DOI 10.5772/6985.
[8]Ionita, M., Alexandru, C. Dynamic optimization of the tracking system for a pseudo-azimuthal photovoltaic platform. Journal of Renewable and Sustainable Energy, vol. 4, nr. 5, 2012, p. 053117(1-15), ISSN 1941-7012, DOI 10.1063/1.4757630