Solar PV Industrial Visit Presentation JUNE 15 2013 IEEE 1

8/12/2019 Solar PV Industrial Visit Presentation JUNE 15 2013 IEEE 1

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WELCOME

TO

MEMBERS OF IEEE


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Solar PhotovoltaicSystems


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INDEX

Evaluationofthesolarresource

Increasingtheplantprofitabilityfromthe

design

Choosingthecomponents

Photovoltaicfacilitiescalculations

Single-linediagram

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INDEX


Increasingtheplantprofitabilityfromthedesign



Single-linediagram


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System losses (PR)

Shadows

Disconnections &Breakdowns

Panel tolerance

Pollution, dispersion &

reflectance

Temperature

Inverter

Cables

Towardstheprofitabilityoftheplantfromthedesign

Resource evaluation

Latitude

Longitude

Altitude

Data from closest

meteorologicalstations

Data from satellites

OPTIMUM

PROFITABILITY


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INDEX





Single-linediagram


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The inverter can be considered as the heart of a solar facilityIts cost, in relation to the complete installation, is between 6% - 9%

Its performance is already between 95 %-97 %

It is important to know about their operation principles. We canfind 2 options:

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Inverters:Trends

Theelectricalcompaniescanaskforgalvanicisolationtransformerswhentheconnection isinlowvoltage


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Inverters:Features

Other important parameters are:

Inverterefficiency:

As it is shown in the graphic, the inverter has a different efficiencydepending on the load. Usually, the manufacturers give the maximumefficiency and the european efficiency, which is the weighting of thedifferent efficiencies when the load is: 5%, 10%, 30%...100%

Invertertemperaturerange:

This is really important, as in some places the temperature can reach

over 40, and extra cooling might be considered


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CrystallineorThin-filmPanels

Visualidentification:

Monocrystalline Policrystalline ThinfilmA-Si:H

They are cheaper, but they need larger surfaces & structures

The guaranteed output power is not as precise as in Mono/

Poly crystalline modules

There are no references from facilities producing an important

amount of years

Source: Atersa

Thin film panel observations:


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PV System Standards


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THINFILMPANEL

CGIS(Copper-Gallium-IndiumSelenide)

CIS(Copper-IndiumSelenide)

CdTe(Cadmiumtelluride)

A-Si:Htriple(Amorphoussilicon

tripleunion)A-Si:Htandem(Amorphoussilicon

doubleunion)

A-Si:Hsingle(Amorphoussilicon)

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CrystallineorThinf i lmmodules

CRYSTALLINEPANEL

Mono crystalline

Poly crystalline

EFFICIENCYREQUIREDSURFACE

This information can be altered depending on each manufacturer price policy


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PVModuleSpecs

The most important electrical spec is thepanel efficiency

Thehighesttheefficiencyis,wewill

requireasmaller surfacetoreachacertainoutputpower

Voltage and current parameters are notdeterminant, as we can connect the panels inseries or in parallels to fit the inverter input.

Source: Atersa


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STC Vs PTC Difference between STC and PTC

STCstands for Standard Test Conditions which are 1,000 watts per square meter solar irradiance, 1.5 Air Mass and 25 degrees C. cell temperature.

STC are indoor factory test conditions.

PTCstands for PV USA Test Conditions which were developed at thePV USA test site at Davis, California. PTC are 1,000 watts per square meter solar irradiance, 1.5 Air Mass, and

20 degrees C. ambient temperatureat 10 meters above ground level and wind speed of 1 meter per second.

PTC is more like "real-world" conditions but does not factor indust and dirt, module mismatch, DC and AC wire losses, actualinverter efficiency, and electric storage efficiency if you havebatteries.


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ConcentrationPanel

Concentration technology is still being developed

Fresnel Lens (and other kinds)

Refractive optical system

Concentration up to 500x

Potential cost savings

Improvement in cell efficiency: from actual 30% towards 40%

Increasing the concentration: from actual 500x towards 1000x

Hardest challenges

Extremely accurate suntracking(Accuracy


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Example: ABB S800PV (Specifications)S800PV-SHighPerformanceMCB

Versions: 2P, 3P & 4P

Current: Up to 80 A

Voltage: 800 Vdc with 2P & 1200Vcc with 3P & 4P

S800PV-MSwitch-Disconnector

Versions: 2P, 3P & 4P

Current: Up to 125 A

Voltage: 800Vcc with 2P & 1200Vcc with 3P & 4P

ACMCBACDifferential

DCFuses

Source: ABB

DCMCB

ACside

Protections

The protections to be installed are:

DCside


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Type 150 275 320 385

Accordingtostandard IEC616431

Maximumvoltage(AC/DC) Uc(L-N/N-PE) 150/200V 275/350V 320/420V 385/500V

Nominaldischargecurrent(8/20) In(L-N/N-PE) 20/20kA

Maximumdischargecurrent(8/20) Imax(L-N/N-PE) 40/40kA

ProtectionLevel Up(L-N)

Up(N-PE)


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Cables

Cable Requirements for PV facilities

The facility has a lifetime of over 25 years

From solar panel to inverter: weatherproof foroutdoor conditions and suitable for indoorconditions (in houses or industries)

From inverters to meters: direct burial or insidecable ducts

If medium-voltage is required, it might besuitable:

For underground installation (inside cableducts)

For aerial installationSource: TopCable


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Cables

It is recommended to use*:

Specific PV usage cable

Main features:

Conductor: electrolytic copperInsulation: halogen free

Cover: fireproof; low emissions (corrosive gas & toxic smokes)

In case of fire

Toavoidhealthdamagesanddevicedamages

Obligatoryinpubliclocations

Source: TopCable

*Basedinpreviousslideconsiderations


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Typical elements (used in every electricalinstallation):

Earth peg: different sizes depending on therequired depth

(from 1,5 to 2,5 meters)

Cable: copper without cover >35mm2.

Depending on the installation:

Low-power installations: It would be enoughto use several earth pegs connected by acopper cable (without cover)

High-power installations: a copper cable gridis usually used (without cover). Dependingon the physical measures, earth pegs can bealso used.

EarthingSystem


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Source: Circutor

MeteringDevice

The meter must be certified

Typical specifications to meet are:

Class 1.0 ( Class B)

Bidirectional

Optical & RS 485 outputs

DependingontheinstalledpowerthemetercanbedirectlyConnected orcoilinductorsaretobeused.

The most usual cases are:

The grid connected PV facility exports all the generated electricity towards

the grid, except the consumption of its own devices: Inverters, Monitoringcommunications devices, Auxiliary services, Suntracking devices

The grid connected PV facility uses the network as a battery. This type is

known as Netmetering


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INDEX





Single-linediagram


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Radiation(Wh/m2)

PR = 0,74 - 0.78

System Losses

Considerations:

The values considered in the following slides are estimated values andshould only be used as an approach. They may vary depending oneach location.

A detailed PerformanceRatiostudy is fundamental to evaluate theprofitability of each solar facility

TowardsthePR(PerformanceRatio)

definition

ElectricEnergy(Wh)


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1. Temperature. (9%)+10C 4% received energy

2. Inverter.We can consider about 6%. New inverters canreach 4%

3. Cable:AC, DC & other electric devices: < 2%

4. Pollution,dispersion&reflectance.

1. Fixed panel: aprox.3%2. Suntracking system: 2%.Inurbanareas,itshoulddeincreasedby2%

5. Shadowing. They should be below 4%. In case of usingsun tracking systems, a shadowing study might be necessary.

6. Otherlosses(incidences,etc).

1. Fixed panel: 2%2. Suntracking system: 4%.

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100%

91%

87,%

85,%

80%

78%

76%

SystemLossesevaluation


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Choose cool locations, as elevated areas

Select inverters with high efficiency and Maximum Power Point Tracking(MPPT)

Consider extra cable sizing avoiding long traces with voltage drops

Choose solar panels with tolerances between +/- 2-3%

Cleaning the modules in long periods without rain

Balance the separation between panel rows (to avoid shadowing) with the

optimization of the surface area

Minimize the impact of breakdowns, with a preventive maintenance.

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KeystooptimizethePR


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Shadowingevaluation

Depending on the type of installation, the shadowing study and the surface

optimization, the project profitability may vary.

The main aspect to study are:

Azimuthal deviation from the south (North hemisphere) or north

(South hemisphere)

Tilt of the solar panelShadows of extern elements

Shadows of own elements

FIX - GROUND SUNTRACKING-GROUND FIX - ROOF INTEGRATION


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Fix-Ground

1. Distance between panel rows

A basic rule would be to avoid shadows during the 4 central hoursof the day, in the day of the year with less radiation.

This implies calculating the angle of the sun (height regarding the line

of the horizon) to +/-2 hours regarding the solar midday.This angle will vary depending on the latitude

The objective is to avoid that the top of the front panel projects ashadow to the lowest part of the panel that is placed behind.

d=h/k

Latitudek

291,600

372,246

392,475

412,747

433,078

453,487


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The optimum tilt angle of the solar panel can be expressed by the following

simplified formula: Tilt = Latitude 10 for Latitude above 30deg

In India, tilt angles from 15 to 33 are considered as optimum, but tilt angles

between 30 40 dontmean considerable system losses

Tilt angles below 15 in urban areas may cause system losses due to pollution

and dirt accumulation on the panels.

Local land slope will be logically taken into account, which can help reducing

distance between the panel rows to improve the surface profit. (Obviously, the

opposite effect can happen)

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F ix-Ground

2. Tilt angles


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The most favorable orientation is 0 South (North hemisphere).An orientation deviation below 20 (East or West) cause negligible system losses.

The following graph (which is valid for a 40 latitude) shows how additional

Losses may appear depending on the combination of orientation and tilt angle.

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Fix-Ground

3. Orientation angle


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Environmental conditions

Urban conditions

Topography

External elements shadowing study (trees, electrical posts, etc)

Own elements shadowing study: direct & crossed (in suntracking

cases)

Definition of the distance between suntrackers (or panel rows)

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Suntracking-ground

Locationoptimization

Previous tasks:


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To adapt the solar panels to the roof shape

We should take into account:

Impact of angle orientation.

Impact of tilt angle.

Impact of shadows

Roof geometrical limits

Remarks: be careful with panels fromthe same rowin different planes

Fix-Roofs

As grid connected solar facilities are considered as an investment, we have

to choose between the following cases:To place the solar panels at the optimum tilt and orientation angle.

OPTIMUMANGLE&ORIENTATION

ROOFADDAPTED


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Twopossibilities:

To avoid visual impact, adapting the solar panels to the roof shape

To integrate the panel as a constructive element with a certain function:

Electricity generation

Sunshade effect: special panels which allow some sunlight to gothrough

Innovative design: usually special structures are required, and this

may increase the installation costs

In architectural integration, the solar facility is not considered as just

a profitable investment, but also as an image and design element

Architecturalintegration


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Hmed-day Average solar radiation per day

PR Performance ratio for the solar installation. Dimensionless

Finc Tilt coefficient: a ratio normally obtained from the optimum tilt for a

fixed panel(Which optimizes its performance).In

Hyderabad(Latitude=17.36) it is1.0

Pinst Installed solar power

ISTC Average irradiance in the horizontal plane

(5.6 kW-h/ m2 day x 0.74 x 1.0 x 365 day x 1 kW) / 1 kW/m2

Expected production for this horizontal radiation, with a PR = 0.74,would be: 1512.56kW-h

Hmed day PR finc days/ year Pinst

ISTCEannual/kWp

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Annualproduction

Production by kWp (installed with 5.6kwh/sq.m Irradiance)


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Maximum input voltage of the inverter

Maximum input current of the inverter

Voltage and current at Maximum Power Point

Whendesigningthesolarpanelconfigurationinseriesandparallels,wemusttakeinto accountthatthevoltageandcurrentofthebranchwillchangedependingonthe temperature.Thereforeitwillbenecessarytochooseextremevaluesoftheregionforthe calculation.

Systemconfiguration

Once the modules and inverters are selected, the configuration of the

system allows to maximize the produced energy

It is possible that in some cases we should consider the use of a differentmodule or inverter in order to improve the system performance.

The configuration of the systems takes into account:


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Systemconfiguration

Source: PVsyst

Aconfiguration example of a designing software for Solar Plants

(PVSYS screen shot )OR SOLAR PATHFINDER
http://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_6/Final%20Report%20on%20system.pdf


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ElectricalcalculationIt is very important to take into account:

Maximum current in the cables

Maximum allowed voltage drop.

If there is a long distance the main factor to determine the cable section

will be the voltage drop.

If there is a very short distance the current that flows along the cable will

determine the section of the cable

El t i l d i


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TypeofSoil Soilresistivity(Ohm)

Cultivable and fertile soils, compact and wet soils 50

Cultivable non fertile soil,or other soils 500

Naked rock soils, and dried and permeable soils 3.000

Electrode Soilresistivity(Ohm)

Buriedplate R=0,8/P

Verticalpeg R=/L

Buriedconductor R=2/L

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Electricaldesign

In order to do a simplified earthing calculation, we can start with the following formulas

depending on the soil resistivity and the electrode characteristics

,soil resistivity (Ohm x m)

P, Plate perimeter (m)

L, Peg or conductor length (m)

The average values of the resistivity, depending on the type of soil are:

El t i l l l ti


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Material 20 70 90

Copper 56 48 44

Aluminium 35 30 28

Temperature 20C 70C 90C

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Electricalcalculations

The cable sizing is based on the following formulas:

Three Phases

OnePhase

Considering:

P = Power

L = Cable length

= Cable conductivity

E = Allowed voltage drop

U= Line voltage

For example, for LV in Europe:

400V in Three-phase

230V in One-phase

TABLEOFCONDUCTIVITYDEPENDINGONTHETEMPERATURE


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DEVICE PROTECTIONLEVEL

INVERTER

METER

CC CABINET49

High Middle Low

OverVoltage

A lightning may produce a transitoryovervoltageof

short duration, with a huge amplitude.

The overvoltage produced due to network unbalances is

a permanentovervoltage, with a longer duration and a

lower amplitude.

Inordertoprotectourinstallationagainstovervoltage,

electricaldischargerscanbeconnectedattheinputand

outputofeachdevicetobeprotected.

There are three different protection levels:

Source: Cirprotect

TRANSITORYOVERVOLTAGE

PERMANENTOVERVOLTAGE


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Transformersconnectiontopology

In installations where more than one Medium Voltage transformer is required, it is

important to define the correct topology for the connection between all the MV

transformers and the main grid (Power line).

The possible connections options are:

STAR

RING

PRODUCTION

LOSSES

CABLEBREAKDOWN

NOPRODUCTION

LOSSES


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INDEX





Single-Linediagram

Single line diagram


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Single-linediagram

FUSE

DC

MCB

DIFERENTIAL

PROTECTION

AC

MCB

ELECTRICALCOMPANY

DEVICE


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Why Rooftop PV?

Reduced reliance on the grid

Offsetting the usage of diesel generators, leading to lower pollution

Max power generation at max load(for commercial segment)

Consumption at the point of generation

Significantly reduced transmission losses.

The Aggregated Technical and Commercial (ATC) losses in India are expected to be about 32%.

1 kWh of power lost for every 3 kWh generated, which means 2 kWh of power from rooftop = 3kWh of kWh from far-off thermal plant

Operation and MaintenanceEasy and inexpensive

Off-grid PV 48


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Off-grid or grid-tied PV?

Parameters Off-grid Grid-tied

Grid

connection

Operates independent of the utility

power grid

Connected to the utility power grid

Suitability Suitable when utility power is not

easily accessible or cannot be

installed

Used when selling power to utility or

the system smaller than the minimum

power load.

Storage

required

Yes No

Cost Costlierdue to battery bank Less expensive

Installation Easy to commission Complexrestricted by the utility grid

Monitoring Important, but not critical Requires grid related monitoring,

feedback and safety features

Off-grid PV 49


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Off Grid System


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Grid Connected System


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GRID INTERACTIVE


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POWER MW WITH SUNTRACKER WITHOUT SUNTRACKER

0,1

0,5 MW

1 PERSON.

INTERMITTENT

INFORMATION FROM THE

INVERTERS

0,51 MW 1 PERSON. HALFTIMEINFORMATION FROM THEINVERTERS

12 MW

1 PERSON. FULL TIME

WITH MONITORING

SYSTEM1 PERSON. HALFTIME

25 MW

2 PERSONS. FULL TIME

WITH MONITORING SYSTEM

1 PERSON. FULL TIME

WITH MONITORINGSYSTEM

FOR EACH 5 MW

ADDED.+ 2 PERSON. FULL TIME .+ 1 PERSON. FULL TIME

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Operation&MaintenanceOptions(IV)

Depending on the plant size and technology, we should answer the followinquestions:

Who? How? Withwhich tools?


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Componentstobemaintained:ThePVmodule(I)

It is the most massive element within the facilityIt has a guarantee for manufacturing defects during its first period of lif

Usually, from 3 to 5 years

It has a guarantee for producing with a minimal performance during

25 years

Duetothesereasons,thiselementshouldneverberepaired.Weanalyzethepanel,ifithasanydefect,itis

replacedbythemanufacturer

PanelAnalysis:Manufacturingdefects

They should be detected visuallyDefective frames

Yellowing (Thepanelbecomesyellow)

Defective connection boxes

Broken glass


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Componentstobemaintained:ThePVmodule(II)

PanelAnalysis:Productiondefects(I)They are harder to be detected, as other components may beinvolvedIt is important to isolate the defect, and confirm it has been

produced in the panels

Testingmechanisms

1. Todetectwhicharrayhastheissue

a. Within large facilities: The monitoringsystem could control each array separately

b. Within small facilities: we have to do amanual testing for each array


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2. Todetectthedefectivepanelswithinthearray:

a. Test both the voltage and the current for each panel:

Thevoltagemaybereducedifacellhasanydefects

Componentstobemaintained:ThePVmodule(III)

PanelAnalysis:Productiondefects(II)

b. The hot spots may produce a voltagereduction:

They can be detected visually, but a

thermographic camera can help to findthem out


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Componentstobemaintained:Theinverter(I)

TypeofinverterThe maintenance strategy may vary depending on the type of inverter

Small inverters: to be placed on the wall

Big inverters: to be placed on the ground

Smallinvertersmaintenance

We should have a number of inverters in stock, ready to replaceany defective one

When a malfunction is detected:

The inverter is replaced by one in stock

And it is sent to the factory for its reparation

NOTE:Thisoperationcanbedonereallyfast,sothatwecanavoid productionlosses,asifwehaveastockwedonotdependonthird parties


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Manufacturer maintenance Maintenanceby our own company

No need of qualifiedpersonnel in the plant The reparationmight be done faster

Thirdparty dependence when any incidence happens Need of qualifiedpersonnel in the plant,It mightbe profitable from a certain installed

power

Try to avoid sending the inverter to be repairedin the

factory

Itmay take more than a week to be repaired

In the contract, it is essentialto add a clause for indemnity

in case of production losses

Ifthe reparation takes more than a certain period, theindemnity may be executed

This period should be less than48 hours (weekends

included)

In thiscase, the spare parts stock

management is really important

For large inverters, the cost of the spare parts

can be important

Pros

Cons

O

bservaciones

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Componentstobemaintained:Theinverter(II)

Biginvertermaintenance

We can find two options:

NOTE:inanycase,ifwewanttoguaranteeafast

reparationwemusthavesparepartsintheplant


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Componentstomaintain:Thesuntracker

The suntracker has software, mechanical & electrical devicesMechanical:

Its preventive maintenance is very important:

Motor lubrication

Sensor state supervision

Any corrective measure will be more expensive

Control

The software must be always updated to the last version

The possibility to remotely update the software can reduce the

time to update it locally

NOTE:As in the inverters case, depending on the amount of units, it can be

interesting either to outsource the maintenance of the suntrackers, or to

employ qualified personnel to do it ourselves.


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Componentstomaintain:Controlcabinets,protections&cables(I)

Controlcabinets

Preventive:Visual inspection is very important to know

their state.

Punctual:if they are in the open air, if it is important to

check their state after bad weather conditions

For example, after a hard storm, water could have

gone inside the cabinet

If the control cabinet has lost its capabilities, it must bereplaced as soon as possible


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Componentstomaintain:Controlcabinets,protections&cables(II)

Protections

Preventive:

Periodical tests to the protections that allow them will be

done.

Periodical inspections will be done, specially in the

connections

If any defect is detected, the device will be immediately

replaced. Thesparepartstockisimportant

NOTE:Abadconnectioncanproduceanelectricalarc,thatmayraise

thetemperatureandcausethedevicebreakdown


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Componentstomaintain:Controlcabinets,protections&cables(III)

Cable

Preventive

To check the connections between the different

equipments

To check those parts where the cable cover can

be damaged

Facilities without suntracker: once the cable installation

has been verified, and its voltage and connection have

been checked, the cable shouldnthave any problems

Facilities with suntracker: it is important to periodically

check the cable route and test if there are any importantmechanical tensions at any point, which may cause a

serious problem in the future


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Componentstomaintain:Themeter

The meters are solid devicesThey have a critical function

Once they are installed and the plant has been commissioned,

the electric company seals them to avoid being operated

Anyway,apreventivemaintenanceshouldbedone:

To check if the data being sent by the meter is logical, and isthe same as the one

we can read at the display

When handling any incidence, we must contact the electric

company:

They can send their own personnel

They can allow us to operate the meter


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SOLAR SYSTEM AT SYNERGY infra

110 MODULES EACH OF 240W

POLY CRYSTALLINE MODULES

11MODULES IN EACH STRING WITH VOLTAGE OF 330V

MPPT RANGE OF INVERTER : 280-360V

10 STRINGS TOTALLY

ONE ARRAY JUNCTION BOX

25KW INVERTER GRID INTERACTIVE

BATERY OF 150AH CAPACITY


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MAKES OF COMPONENTS MODULES : PHOTON

INVERTER : NEOWATT

BATTERIES : EXIDE

ARRAY JUNCTION BOX : LOCAL

COST ANALYSIS INITIAL COST :

MODULES : RS 12LAKHS

INVERTER : RS 7LAKHS

BATTERY : RS 3 LAKHS

STRUCTURE : RS 6 LAKHS

OTHERS : RS 4 LAKHS

TOTAL : RS 32LAKHS


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PHOTOS
http://localhost/var/www/apps/conversion/tmp/scratch_6/PHOTOS/Photos-%20Terrace/DSC00265.JPGhttp://localhost/var/www/apps/conversion/tmp/scratch_6/PHOTOS/Photos-%20Terrace/DSC00265.JPG


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208KWp system at Bellary


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208KWp system at Bellary


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1000KWp system at Hyderabad


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Thankyou

Documents

Solar PV Industrial Visit Presentation JUNE 15 2013 IEEE 1