Technical University of Sofia, Bulgaria,. Faculty of Electronic Engineering and Technology. Jubilee 40th International Spring. Seminar on Electronics Technology.
Jubilee 40th International Spring Seminar on Electronics Technology 10-14 May 2017, Sofia, BULGARIA
Extraction of Solar Cell Parameters using Source Measure Unit Georgi Nikolov, Boyanka Nikolova, Elitsa Gieva and Ivelina Ruskova Technical University of Sofia, Bulgaria, Faculty of Electronic Engineering and Technology
Jubilee 40th International Spring Seminar on Electronics Technology 10-14 May 2017, Sofia, BULGARIA
INTRODUCTION The modeling of equivalent schemes of solar cells is of great importance in order to be included in electric circuits for wireless sensor networks power supply. The parameters extraction of these devices requires experimental data, computing and modeling. In the present investigation a model parameter extraction of a single solar cell is implemented by measuring the I-V characteristics of a low power solar module. The accurate measurement of current-voltage characteristics is achieved by using a modular source-measure unit (SMU) U2722A from Keysight Technologies SMU gives the ability to evaluate the I-V characteristics of solar module across all four measurement quadrants and supports four-wire measurements to eliminate the voltage error caused by residual resistance of wires.
Jubilee 40th International Spring Seminar on Electronics Technology 10-14 May 2017, Sofia, BULGARIA
SPICE MODEL OF SOLAR CELL shunt resistor RSH, serial resistor RS, dark current I0, ideality factor N, light-generated current IPH.
I I PH
V I .RS I 0 exp N .VT
V I .RS 1 RSH
One of the most commonly used circuits for solar cell simulations is Five-parameter model
Jubilee 40th International Spring Seminar on Electronics Technology 10-14 May 2017, Sofia, BULGARIA
SYSTEM FOR MODEL PARAMETERS EXTRACTION
Architecture of a system for solar cell parameters extraction.
The LabVIEW block diagram of developed virtual system.
SMU has three channels and a 4-quadrant operation. Two ranges for voltage source and measure ± 2 V and ± 20 V - 0.1 mV resolution. Six ranges for current source and measure – from ± 1 µA to 120 mA - 100 pA resolution.
The front panel of developed measurement system.
Jubilee 40th International Spring Seminar on Electronics Technology 10-14 May 2017, Sofia, BULGARIA
SOFTWARE FOR PARAMETERS EXTRACTION I I SC1 0 I1 V1
R1
R2
V2 V1 I SC1 I SC 2 V3 V2 I SC 2 I SC 3
R3
V3 V1 I SC1 I SC 3
RS
R1 R2 R3 3
Method of calculation of serial resistance
RSH
Vdark I dark
I0
Solar cell I-V characteristics obtained at a different irradiance - 4,5 W/m2, 9,3 W/m2 18,8 W/m2
The dark current I0 and RSH are obtained from measured solar cell I-V characteristic in a lack of light in third quadrant.
Jubilee 40th International Spring Seminar on Electronics Technology 10-14 May 2017, Sofia, BULGARIA
RESULTS AND CONCLUSION
Comparison between measured and simulated values
An approach for automated model parameters extraction of single solar cell, based on SMU and virtual techniques is suggested. The architecture of the system is presented and some important aspects of graphical programming code are described in details.
The efficiency of the approach is demonstrated by extraction of model parameters of two low-power solar panels. The difference between measured and simulated characteristics does not exceed ten percent.
Thanks for your attention
