This workshop was conducted for participants of Hackathon event PV-COM organized by B.H.Gardi College of Engineering & Technology, Rajkot. The main objective was to show importance of the software approach to understand analytical part for effect of parametric effect on PV output.

1. Department of Electrical Engineering Date-07-03-2018

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3. Understanding PhotoVoltaic System
Name Plate
Material
Efficiency
Characteristics
Working
Concept
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4. • Depending on Brand Specification Detail
changes.
• Generally PV Name Plate includes:
 Maximum Power
 Maximum Voltage (for Max Power)
 Maximum Current (for Max Power)
 Open Circuit Voltage (VOC)
 Short Circuit Current (ISC)
 System Voltage
• All measurements given under STC
 Standard Test Condition (STC)
 T=25°C
 G=1000 W/m2
 Air Mass= 1.5
Name Plate H
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5. • Monocrystalline
• Multicrystalline
How To Identify Panel
Material?
→Check for the shape of cell.
Pseudo Square → Monocrystalline
Rectangle →
Multicrystalline
Polycrytalline
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6. Layers of PV Module H
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9. • 𝜼 =
𝐏 𝐨/𝐩
𝐏𝐢/𝐩×𝐀
Here Po/p = Vm*Im
Pi/p = Measured Power by device
A = Module Area.
Usually PV efficiency ranges from 15-20%.
• FF(Fill Factor) =
𝐕 𝐦×𝐈 𝐦
𝐕 𝐨𝐜×𝐈 𝐬𝐜
.
• FF represents squareness of a curve.
Efficiency & Fill Factor H
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10. Solar Cell
Sunlight
1
0.5
0
t→
G→
• A solar cell is a 2 terminal power generating device, in which one is
anode and other is cathode.
I→
V→
I→
V→
Diode Characteristics
Dark
Light
I→
V→
PV Characteristics
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11. Rs
V
IIL
PV Mathematical Model
ID
• IL is photo generated current
• ID is PV module Saturation
current
• Rs is series resistance of PV
module
• I is PV current
• V is PV voltage
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12. Terminology
Parameter Nomenclature Value
k Boltzmann Constant 1.38×10-23 J / K
A Diode Ideality Factor 1~2
q Charge of Electron 1.6×10-19 C
Ki Temperature Co-efficient of Isc
Eg Band-Gap Energy 1.1eV
Tref Reference Temperature 298 K
Gref Reference Irradiance 1000 W/m2
VT Thermal Voltage
𝐤 ∗ 𝐀 ∗ 𝐓
𝐪
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13. Research on PV Models H
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14. Rs
VPV
IIL
G
T
IPV
RLoad
CPV
Mathematical Approach Electrical Quantity
PV Electrical Model H
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15. PV Electrical Characteristics
Under No-Load Condition.
Rload=0
Under Short Circuit.
Rload=∞
V
I Increasing Load
Rload=R1
Increasing Load
Rload=R2
Increasing Load
Rload=R3
VOC
ISC
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16. PV Electrical Characteristics
V
I
VOC
ISC
dI3
dV3
dI1
dV1dV2
dI2
𝑅1 =
∆𝑉1
∆𝐼1
We can observe that ∆ 𝐼1 changes more so R1 is small
𝑅3 =
∆𝑉3
∆𝐼3
We can observe that ∆ 𝑉3 changes more so R3 is large
𝑅2 =
∆𝑉2
∆𝐼2
We can observe that ∆ 𝑉3 changes same as ∆ 𝐼3
∴ R2 is optimal point for getting maximum power transfer.
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17. MPP Tracker H
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18. • Set of instruction written to achieve desired output.
• Uses various functional codes to relate quantities with each other.
• To write a code open a new m-file and write necessary equations.
• Steps to write a code for any programming platform remains same, they are :
 Initialization
 Programme
 Output
Coding Approach to MATLAB
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19. Coding Approach to MATLAB
Define Constants
Write Relative Equations
Desired Outputs
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20. Coding Approach to MATLAB
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21. • It involves arrangement of blocks to get desired result.
• Uses Simulink Library to connect various blocks to get desired output.
Modelling Approach to MATLAB
Following is a part of PV Model Approach
Temperature
25
Photon Current
G
T_ref
Iph
Irradiance
1
Iph
3.8
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22. Isc_T2-Isc_Tref
Isc_Tref
T2-T_ref
K0
T-Tref
K0*(T-T_ref) 1+K0*(T-T_ref)
G*Isc_Tref
Modelling for Iph
Iph
1
Temperature Coefficient
0.0006316
T_ref1
T_ref
T_ref
25+273
T2
T2
Isc_Tref
-C-
Isc_T2
Isc_T2
Isc1
3.8
G*Isc_Tref
Divide2
Divide1
Divide
Constant
1
T_user
2
G
1
Modelling Approach to MATLAB H
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23. • Ns = No. of series connected cells/module;
• Np = No. of parallel connected cells/module.
• Ns is used to increase voltage capacity of PV arrangement.
• Np is used to increase current capacity of PV arrangement.
• Ns & Np must be calculated so as to meet Power demand.
• In any case it must not increase System Voltage capability.
Significance of Ns and Np
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24. • Q. You are given a Module having 60W, Voc=21.1V, Isc=3.58A, and it is given that,
Ns=36. Find the voltage and current capability of each cell?
Vcell(oc)=Voc/Ns
= 21.1/36
= 0.58 V (0.5V-0.6V).
Icell(oc) =Isc/Np
= 3.58/1
= 3.58 A (~3.5 A).
• Q. PV module is rated for above condition. Find the value of Ns & Np required to meet
230V for 1kW load.
Significance of Ns and Np
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25. Effect of G & T on I-V & P-V Curves
0 100 200 300 400 500 600 700 800 900 1000
0
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10
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35
40
VPV (V)
IPV(A)
G=1000 W/m2
G=800 W/m2
G=500 W/m2
0 100 200 300 400 500 600 700 800 900 1000
0
5
10
15
20
25
30
VPV (V)
PPV(kW)
G=500 W/m2
G=800 W/m2
G=1000 W/m2
0 200 400 600 800 1000 1200
0
5
10
15
20
25
30
35
40
VPV (V)
IPV(A)
T=15°C
T=25°C
T=35°C
0 100 200 300 400 500 600 700 800 900 1000 1100
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5
10
15
20
25
30
VPV (V)
PPV(kW)
T=15°C
T=25°C
T=35°C
Effect of G &T on I-V, P-V curves.
Change in Insolation
Change in Temperature
T↑ Eg↓ Isc↑
T↑ Io↑ Voc↓
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26. Partial Shading
• A common MPPT tracker would get
confused and would result in wrong
detection of Peak point.
• The magnitude of peak point depends on
PV array configuration & shading
pattern besides G & T.
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27. • We got an insight on Solar Cell.
• We got to know about different type of parameter that a
cell is dependent.
• We learn about types of PV model and its characteristics.
• An introduction to Coding and Modelling approach to PV.
• Effect of Solar Parameters.
• Partial Shading and its effects.
Conclusions H
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