Electrical engg

1. Wireless Data Acquisition for Photovoltaic
Power System
Makbul Anwari', Arief Hidayat', M. Imran Hamid', and Taufik'
'Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia
Electrical Engineering Department, Cal Poly State University, San Luis Obispo, USA
E-mail: makbul@ieee.org
Abstract - This paper presents a wireless system for
monitoring the input and output of the array in a photovoltaic
generation plant. The system comprises of sensors, data
acquisition system, wireless access point and user computer that
enable the users to access the array parameter wirelessly.
Description and function of set up equipment are presented as
well as the application program that supports the system.
1. INTRODUCTION
Recently, the number ofenergy in the world is reaching to
concern state. This is caused by the need of energy is growing
very fast. Due to concerns regarding global warming and air
pollution, there has been an international movement in the
promotion of renewable energy technologies for electricity
generation, green energy is one among proposed solutions for
these issues [I].
Solar energy is converted to electricity in a photovoltaic
generation plant that contains photovoltaic array as solar­
electricity conversion equipment, electrical power converter,
power storage and other supporting equipment. According to
operation mode, photovoltaic generation plants are met in
isolation mode, grid interconnected mode and plant that can
operate in both modes. For all of these modes, there are needs
to acquire the input and output parameter of the photovoltaic
array as the generation equipment. The acquired parameters
are used for control action information, generation planning,
energy forecasting, and performance observation or
documentation need. Some of the parameters are irradiance,
temperature and array's electrical output. A satisfied data
acquisition system is required for this need.
Related to acquisition system for photovoltaic performance,
Benghanem et aI. have accomplished a research in which,
several instruments are used to detect, integrate, and record
solar energy measurement using both conventional electronics
as well as microprocessor data acquisition system [2]. Further,
Machacek et aI., developed a system for measuring, collecting,
analyzing, and displaying data for 100 W solar energy
converter, data acquisition is formed by NI-6023E plug-in
card and feed the rough data to the control program built in a
MATLAB script [3].
Data from acquisition system module are needed to produce
useful information. The speed of the process is the important
parameter. To accommodate this requirement, during the past
decade, digital control has been widely used. Digital control,
which is determined by application of microprocessors, makes
the sampling and computing process are faster than before.
Implementation of such a system has been done on a dc
voltage monitoring and control system for a wind turbine
inverter [4].
sp User
Vo ltag e Divider
FIg 1. Simplifieddiagramof the Wireless data acqutsitron for photovoltaic system.
-----
I -I
~urre~ ~ensoJ
I
Solar Cell
IModule
~ I
Inverter
I I
I
V,ltage Oi
-s en so J
I Solar Cell
I fcurren
@Module
h
In verter
I I I
I + ltagoO .
~"I GRID
I Solar Cell I ~urren se ns a
~
In verter
Module
II I
L ..J I
I II
Temperature and Irradiance
Data Acquisiti on Sy stem
~n ---r:I--sens o r
Access
Point Lapto
. ..
Wireless Data Acquisition for Photovoltaic
Power System
Makbul AnwariI, AriefHidayatI, M. Itnran HamidI, and Taufik2
IFaculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia
Electrical Engineering Department, Cal Poly State University, San Luis Obispo, USA
E-mail: makbul@ieee.org
Abstract - This paper presents a wireless system for
monitoring the input and output of the array in a photovoltaic
generation plant. The system comprises of sensors, data
acquisition system, wireless access point and user computer that
enable the users to access the array parameter wirelessly.
Description and function of set up equipment are presented as
well as the application program that supports the system.
l. INTRODUCTION
Recently, the number ofenergy in the world is reaching to
concern state. This is caused by the need of energy is growing
very fast. Due to concerns regarding global warming and air
pollution, there has been an international movement in the
promotion of renewable energy technologies for electricity
generation, green energy is one among proposed solutions for
these issues [l].
Solar energy is converted to electricity in a photovoltaic
generation plant that contains photovoltaic array as solar­
electricity conversion equipment, electrical power converter,
power storage and other supporting equipment. According to
operation mode, photovoltaic generation plants are met in
isolation mode, grid interconnected mode and plant that can
operate in both modes. For all of these modes, there are needs
to acquire the input and output parameter of the photovoltaic
array as the generation equipment. The acquired parameters
are used for control action information, generation planning,
energy forecasting, and performance observation or
documentation need. Some of the parameters are irradiance,
temperature and array's electrical output. A satisfied data
acquisition system is required for this need.
Related to acquisition system for photovoltaic performance,
Benghanem et ai. have accomplished a research in which,
several instruments are used to detect, integrate, and record
solar energy measurement using both conventional electronics
as well as microprocessor data acquisition system [2]. Further,
Machacek et aI., developed a system for measuring, collecting,
analyzing, and displaying data for 100 W solar energy
converter, data acquisition is formed by NI-6023E plug-in
card and feed the rough data to the control program built in a
MATLAB script [3].
Data from acquisition system module are needed to produce
useful information. The speed of the process is the important
parameter. To accommodate this requirement, during the past
decade, digital control has been widely used. Digital control,
which is determined by application of microprocessors, makes
the sampling and computing process are faster than before.
Implementation of such a system has been done on a dc
voltage monitoring and control system for a wind turbine
inverter [4].
SpUser
Voltage Divider
FIg l. SImplIfied dIagram ofthe Wireless data acquIsitIOn for photovoltalc system.
- - - - -
I -I
~urre: ~ensoJ
I Solar eel!
IModule
~ I
Inverter
I I
I
Vfltaga Di .
-sensoJ
I Solar eel!
I rcurren
~Module
h
Inverter
I I I
I 'fltago 0 .
~""I GRID
I Solar Cell I ~urren sensa
~
Inverter
Module
II I
L ..J I
I II
nTemperature and Irradiance
Cata Acquisition System
f..-.. --r:z--sensor
Access
Point Lapto
.. .

2. Regarding with data transmission, Chen,et.al, have studied
carrying the acquired signal from data acquisition module
using internet [1]. Java language is used for designing a
dynamic webpage to graphically display various real time
waveforms of the controlled system for multi-user at the same
time. The system is implemented on a small scale wind power
generation system equipped with an EZDSP 2812 controller.
An FPGA ECIO is implemented as a bidirectional
communication interface for coordinating the asynchronous
data transmission modes.
In this paper, we present a photovoltaic generation
monitoring system for a 5 kWp laboratory scale photovoltaic
generation. Temperature, irradiance, voltage, and current of
the array are acquired, processed and then transmitted such
that can be used for reviewing the performance of the
generation plant. Acquired data is transmitted by wireless
method using Wi-Fi signal (IEEE 802.11 standard), while
microcontroller of PIC 16F877A is used to control the
acquisition system process and a Delphi application program
is built to graphically display the acquired data. Figure 1
show the simplified diagram of such system.
As shown in Figure 2, photovoltaic array characteristic (V-I
curve) shows the dependency of cell current and voltage to
irradiance and temperature. Irradiance contributes to the cell
current, the higher irradiance the higher current draw by array
photovoltaic, while the temperature effects to the cell voltage,
the higher temperature the lower voltage appears on the cell
terminal. In Figure 2a, it is shown a set ofphotovoltaic cell 1-V
curve under varying irradiance at a constant temperature,
meanwhile figure 2(b) shows the one at the same irradiance
values, but under varying temperature. Both figures are also
show the point where the multiplication of PV array voltage
and current reaches the maximum value: maximum power
point (MPP), at which condition that the array operates with
maximum efficiency and produces maximum output power.
Variation of irradiance and temperature in photovoltaic
module is characterized as short time fluctuation; follows the
behavior of atmospheric condition around plant during time.
The effect of this variation is the unpredictable variation of
power output, current and voltage of the plant. An acquisition
system for this condition should consider the phenomenon.
III. PV GENERATIONMONITORING SYSTEM
The PV generation and monitoring system shown in Figure
1, is a diagram of a laboratory scale system that contains three
units photovoltaic array produces three de voltages of 0 - 150
range. These de voltages is then fed to three single phase PV
inverter respectively to be inverted to ac power before sending
to the utility. Maximum current for each array are lOA de.
Array power input in form of temperature and irradiance and
the de output of array are picked up as data acquired for the
monitoring system.
Three ACS754 current sensors with maximum current 50A
and sensitivity of 37.8 mV/A are connected to de output of
each solar array, while irradiance and temperature sensor
placed around the array. For voltage acquisition, 1k.o.-1M.o.
voltage divider was used, which means 10mV for every one
volt de solar panel output. LM35 temperature sensor which
sensitivity of 10mV/oC is used for measure the ambient
temperature of solar panel. The irradiance is sensed using
LDR.
Data acquisition diagram is shown in Figure 3. In order to
determine the analog signal from the sensor to be passed to
ADC, which contains eight analog signal from sensors (3 for
de current, 3 for de voltage, one for irradiance and the
remaining for temperature) dual eight-channels analog
multiplexer DG407B are used. The analog multiplexer was
controlled using microcontroller and passing the multiplexing
signal with their own voltage references.
In the ADC block, each analog signal from multiplexer is
digitalized to eight bits digital signal. Eight-bit signal is used
caused by the condition that communication between
microcontroller and serial to Ethernet module uses eight bit
data. Thus, voltage reference Vrej for ADC is
Vrej = resolution x 28
, where the resolution is equal to
sensitivity ofeach sensor. ADC operation is also controlled by
the microcontroller.
In this system, the microcontroller is employed to run the
eo co
Vol tage (Volt)
I I I I
- - T - - 1 - - - I - - - 1-
__ 1 __ J 1 I _
I I
- I­
I
1-
- - r - - "'T - - --, - - -1-
* = MPP , I I
- - T - - , - ---,- - -I-
I I I I
- - T - - "1 - - - - - ,-
I I I
--T--l- I
I I I I
~ ' 00 - - T - -
80 -_ !­
I
60 __ 1
I
(b)
(a)
Voi laga(VoIl)
I I I I
I r ra dianc e in c re a c e I
5 - - ... - -;. - - -1- - - I-
I
f----'--+-..L..--.!.' I
4 __ L __ ...1 __ ~ _I_
I , ?' :
I _ I _~ :_
I I ~ I
I I ;::--,; _
: : :', -- +-- -t-- .... --
I I I
I I I
I
I I I I
5 - - T - - 1- - , - - - I-
I I
I I I
- - T - - -t - - - I-
I I I
!: I I I
S 3 - - ~ - - ~ - - I-
I I
'2 -- +--- 4--
I I
II. PV GENERATIONCHARACTERISTIC FORMONITORING
SYSTEM
The acquisition system is aimed to detect and collect the
parameters that indicate the electrical characteristic of the
array and the factors influencing them.
Fig.2. V- I characteristic ofPV module, (a) characteristics on various
irradianceat a constanttemperature, (b) Characteristic on various
temperature at a constantirradiance
Regarding with data transmission, Chen,et.al, have studied
carrying the acquired signal from data acquisition module
using internet [1]. Java language is used for designing a
dynamic webpage to graphically display various real time
waveforms of the controlled system for multi-user at the same
time. The system is implemented on a small scale wind power
generation system equipped with an EZDSP 2812 controller.
An FPGA ECIO is implemented as a bidirectional
communication interface for coordinating the asynchronous
data transmission modes.
In this paper, we present a photovoltaic generation
monitoring system for a 5 kWp laboratory scale photovoltaic
generation. Temperature, irradiance, voltage, and current of
the array are acquired, processed and then transmitted such
that can be used for reviewing the performance of the
generation plant. Acquired data is transmitted by wireless
method using Wi-Fi signal (IEEE 802.11 standard), while
microcontroller of PIC 16F877A is used to control the
acquisition system process and a Delphi application program
is built to graphically display the acquired data. Figure 1
show the simplified diagram ofsuch system.
As shown in Figure 2, photovoltaic array characteristic (V-I
curve) shows the dependency of cell current and voltage to
irradiance and temperature. Irradiance contributes to the cell
current, the higher irradiance the higher current draw by array
photovoltaic, while the temperature effects to the cell voltage,
the higher temperature the lower voltage appears on the cell
terminal. In Figure 2a, it is shown a set ofphotovoltaic cell I- V
curve under varying irradiance at a constant temperature,
meanwhile figure 2(b) shows the one at the same irradiance
values, but under varying temperature. Both figures are also
show the point where the multiplication of PV array voltage
and current reaches the maximum value: maximum power
point (MPP), at which condition that the array operates with
maximum efficiency and produces maximum output power.
Variation of irradiance and temperature in photovoltaic
module is characterized as short time fluctuation; follows the
behavior of atmospheric condition around plant during time.
The effect of this variation is the unpredictable variation of
power output, current and voltage of the plant. An acquisition
system for this condition should consider the phenomenon.
III. PV GENERATION MONITORING SYSTEM
II. PV GENERATION CHARACTERISTIC FOR MONITORING
SYSTEM
The PV generation and monitoring system shown in Figure
1, is a diagram of a laboratory scale system that contains three
units photovoltaic array produces three dc voltages of 0 - 150
range. These dc voltages is then fed to three single phase PV
inverter respectively to be inverted to ac power before sending
to the utility. Maximum current for each array are lOA dc.
Array power input in form of temperature and irradiance and
the dc output of array are picked up as data acquired for the
monitoring system.
Three ACS754 current sensors with maximum current 50A
and sensitivity of 37.8 mVfA are connected to dc output of
each solar array, while irradiance and temperature sensor
placed around the array. For voltage acquisition, lkQ-IMQ
voltage divider was used, which means 10mV for every one
volt dc solar panel output. LM35 temperature sensor which
sensitivity of 10mVfOC is used for measure the ambient
temperature of solar panel. The irradiance is sensed using
LDR.
Data acquisition diagram is shown in Figure 3. In order to
determine the analog signal from the sensor to be passed to
ADC, which contains eight analog signal from sensors (3 for
dc current, 3 for dc voltage, one for irradiance and the
remaining for temperature) dual eight-channels analog
multiplexer DG407B are used. The analog multiplexer was
controlled using microcontroller and passing the multiplexing
signal with their own voltage references.
In the ADC block, each analog signal from multiplexer is
digitalized to eight bits digital signal. Eight-bit signal is used
caused by the condition that communication between
microcontroller and serial to Ethernet module uses eight bit
data. Thus, voltage reference Vrej for ADC is
Vrej = resolution x 28
, where the resolution is equal to
sensitivity of each sensor. ADC operation is also controlled by
the microcontroller.
In this system, the microcontroller is employed to run the
20 30
Voltage (Volt)
I I I I
- - T - - '1 - - -I - - -1-
__ 1 __ J 1 I_
I I
- I­
I
1-
- - T - -.,. - - - , - - -1-
* = MPP , I I
- - T - -.,. - - -,- - -I-
I I I I
- - T - - I - - - - -,-
I I I
--T--l- I
I I t I
~ '00 - - T - -
eo -_.!.­
I
60 __ 1
I
(b)
(a)
I
I rradiance increace I
5 - - +- -...;. - ~ -!~ - -I-
I
f----'--+-..L.--.!.' I
__ L __ ...1 __ ~ _I_
I I ?':
f3 I I -~:
f------7--+--7-~~ I
~
I : : '
1 --+---f--....,--
I I I
I I I
I
1 I t I
5 - - T - -.., - - ...,- - -I-
I I
I I I
- - T - - ""1 - ~ -I-
I I I
!: ! I I
~ 3 - - 7--~ -- I-
I I
:<' --+---4--
I I
1 ~::;:~:~:ture_-+t-+-I8
°o:'---CO-~~.----c;30;,-~-'
Voltage (Volt)
Fig. 2. V- I characteristic ofPV module, (a) characteristics on various
irradiance at a constant temperature, (b) Characteristic on various
temperature at a constant irradiance
The acquisition system is aimed to detect and collect the
parameters that indicate the electrical characteristic of the
array and the factors influencing them.

3. function: controlling the multiplexer for
determining the analog signal from the sensor to be passed;
controlling the operation of ADC, and as communication
protocol between Ethernet and the acquisition system. To
accommodate these functions, the low-power consumption
PIC 16F877A microcontroller is used. This unit is built within
eight channels 10 bit ADC and an UART connection for serial
communication.
Microcontroller serial connection is connected to Wiznet
EGSR7150 in order to convert format data from serial to
Ethernet data, conversion process is reversal. Further, the
acquainted data is sent to the access point to be sent in form of
Wi-Fi signal to connected user computer.
To accommodate communication between computer and
acquisition system and to display the result, a computer
application program is required.
There are 5 charts that show the measured and calculated
parameters. Voltage, current, and calculated PV array power
of whole channel is displayed in one chart respectively. Each
PV array power output is obtained by multiplying the voltage
and current of respective array. The array temperature and
irradiance are displayed separately in others charts. Nominal
values of these parameters are also displayed. To start data
acquisition, user must connect the application to acquisition
module by pressing the "Connect to network" button. Timer
setting button is provided to determine measurement interval
ofthe acquisition data.
Prototype ofthe photovoltaic acquisition system is shown in
Figure 6. The left side picture shows layer for power supply,
voltage divider and current sensor, this layer is placed in the
bottom of acquisition compartment. The right side pictures
shows layer for the microcontroller, multiplexer, Vref board
and data converter.
For this need, an application program, written in Delphi
language is developed. This program is built to allow the user
can interact and control the process steps in these two sub­
systems (microcontroller in acquisition system and displaying
process in computer). Communication between computer and
acquisition system is done wirelessly.
Communication process involves two application programs,
one is in the computer side and the other is in microcontroller
side. Flowchart of communication between these two
application programs is shown in Figure 4, which shows two
main blocks, indicates the process flow in each side.
First of all, the programs will self-initialize when they are
activated. User can decide whether to acquire data or not. If
acquisition data will be done, program will send a query
command to the acquisition program on microcontroller
contains which data to be acquired. Microcontroller in
acquisition system -based on the command query- orders the
multiplexer to by-pass the intended analog signal from the
sensors and digitalized them.
Analog signal from the sensors contains high noise, which
can degrade the measurement accuracy. To avoid this, analog
signal is picked up and converted three times; their average is
computed and become data to be sent back as acquisition data
to user computer. In user computer, acquisition data is
received by Ethernet port. Application program then processes
the data to be displayed and to be saved in the virtual memory.
The displaying application program is shown in Figure 5.
No
Receivequery? :>----......
Receivequeryfrom PCI
notebook trough
wlrelessaccesspoint?No
Fig. 4. PC and microcontroller software flowchart
SerialtoEthernet
Converter
Serial
PIC16F877A Connection Serial Microcontroller Ethernet
Microcontroller
~~~
Fig. 3. Data acquisition system diagram
Vref
Sensor
System
following function: controlling the multiplexer for
determining the analog signal from the sensor to be passed;
controlling the operation of ADC, and as communication
protocol between Ethernet and the acquisition system. To
accommodate these functions, the low-power consumption
PIC 16F877A microcontroller is used. This unit is built within
eight channels 10 bit ADC and an UART connection for serial
communication.
Microcontroller serial connection is connected to Wiznet
EGSR7150 in order to convert format data from serial to
Ethernet data, conversion process is reversal. Further, the
acquainted data is sent to the access point to be sent in form of
Wi-Fi signal to connected user computer.
To accommodate communication between computer and
acquisition system and to display the result, a computer
application program is required.
There are 5 charts that show the measured and calculated
parameters. Voltage, current, and calculated PV array power
of whole channel is displayed in one chart respectively. Each
PV array power output is obtained by multiplying the voltage
and current of respective array. The array temperature and
irradiance are displayed separately in others charts. Nominal
values of these parameters are also displayed. To start data
acquisition, user must connect the application to acquisition
module by pressing the "Connect to network" button. Timer
setting button is provided to determine measurement interval
ofthe acquisition data.
Prototype ofthe photovoltaic acquisition system is shown in
Figure 6. The left side picture shows layer for power supply,
voltage divider and current sensor, this layer is placed in the
bottom of acquisition compartment. The right side pictures
shows layer for the microcontroller, multiplexer, Vref board
and data converter.
For this need, an application program, written in Delphi
language is developed. This program is built to allow the user
can interact and control the process steps in these two sub­
systems (microcontroller in acquisition system and displaying
process in computer). Communication between computer and
acquisition system is done wirelessly.
Communication process involves two application programs,
one is in the computer side and the other is in microcontroller
side. Flowchart of communication between these two
application programs is shown in Figure 4, which shows two
main blocks, indicates the process flow in each side.
First of all, the programs will self-initialize when they are
activated. User can decide whether to acquire data or not. If
acquisition data will be done, program will send a query
command to the acquisition program on microcontroller
contains which data to be acquired. Microcontroller in
acquisition system -based on the command query- orders the
multiplexer to by-pass the intended analog signal from the
sensors and digitalized them.
Analog signal from the sensors contains high noise, which
can degrade the measurement accuracy. To avoid this, analog
signal is picked up and converted three times; their average is
computed and become data to be sent back as acquisition data
to user computer. In user computer, acquisition data is
received by Ethernet port. Application program then processes
the data to be displayed and to be saved in the virtual memory.
The displaying application program is shown in Figure 5.
Receive query? >---No-......
Receive query from PCI
notebook trough
wlrelessaccess point ?No
Fig. 4. PC and microcontroller software flowchart
SerialtoEthernet
Converter
Serial
PIC16F877A Connection Serial Microcontroller Ethernet
Microcontroller
~~~
Fig. 3. Data acquisition system diagram
Vref
Sensor
System

4. ~~!c~
'0,,,,,-. 1 .....,....-. 1T_,... 1~ ~ ~
V .ACKNOWLEDGMENT
The authors thank the Malaysian Government, Ministry of
Science, Technology and Innovation (MOST!) for the Science
Fund Grant, Project No. 01-01-06-SF0205.
O»Y.~.S1JllOOl l... :I~:Z2:S. 'adteIs:I92.l68.l,1I0.llI<a'r«tei
VI. REFERENCES
[I] Po-Yen Chen; Se-Kang Ho; Wei-Jen Lee; Chia-Chi Chu; Ching-Tsa
Pan, "An Internet Based Embedded Network Monitoring System for
Renewable Energy Systems", Proc. The 7th International Conference on
Power Electronics, pp.225-228 , October 22-26,2007.
[2] M.Benghanem; A. Maafi, "Data Acquisition System for Photovoltaic
Systems Performance Monitoring", IEEE Trans. on Instrumentation and
Measurement, Vo1.47, No.1, pp.30-33, February 2008.
[3] J. Machacek; z. Prochazka; 1. Drapela, "System for Measuring and
Collecting Data from Solar-cell Systems", Proc.9th International
Conference Electrical Power Quality and Utilization, Barcelona, 9-11
October 2007.
[4] Z. Wang; L. Chang, "A DC voltage Monitoring and Control Method for
Three Phase Grid-Connected Wind Turbine Inverters", IEEE Trans. On
Power Electronics, Vol. 23, No.3, pp. 1118-1125, May 2008.
[5] T. Yuki; H. Yoshikiro; K. Kosuke, "Temperature and Irradiance
Dependence of the I-V Curves of Various Kinds of Solar Cells"
International Photovoltaic Science & Engineering Conference,
Shanghai, China 2005
[6] A. Moein, M. Pouladian, "WIH-Based IEEE 802.11 ECG Monitoring
Implementation", Proceedings of the 29th Annual International
Conference of the IEEE EMBS Cite Internationale, Lyon, France August
23-26,2007.
[7] H. Zhao, X. Chen, K.H. Chon, "A Portable, Low-cost, Battery-powered
Wireless Monitoring System for Obtaining Varying Physiologic
Parameters from Multiple Subjects" , Proceedings of the 28th IEEE
EMBS Annual International Conference, New York City, USA, Aug 30­
Sept 3, 2006
[8] A. Perujo; R. Kaiser; D.U Sauer; H. Wenzl; I. Baring-Gould; N.Wilmot;
F. Mattera; S. Tselepis; F
[9] H. Zhiqiang; Z. Wenxian; L. Jianke, "Research on High-Speed Data
Acquisition and Processing Technique", The Eighth International
Conference on Electronic Measurement and Instruments, ICEMI'2007
Tw
Tw
Tw
Tw
Clrrerll Clrrffl1 ~l
jii1 jii5 jii5
Tw
Fig.5. Application program appearance
Fig. 6. Prototype of the photovoltaic acquisition system, (a) upper layer, (b)
lower layer
IV. CONCLUSION
A wireless data acquisition system for photovoltaic
generation system that uses PICI6F877A microcontroller as
the main control has been presented. Implementation of the
EGSR7150 Ethernet to serial module and the access point as
Wi-Fi communication tool between acquisition equipments
and user computer for graphically displaying the acquired
parameter has work properly as intended. Implementation of
such a system on a laboratory scale photovoltaic generation
shows the practical simplicity, efficient and low cost.
$PM.ltlltllitolillt: yl.l = ~ C
[fe~~
,...."..... 1................ 1T_... I~~~
V.ACKNOWLEDGMENT
'ld
H .. -CU'IInl
~J~.'.' '_•.. _.-:.~
i1S .-.• '-,.-.--.-:
!i1 '
0"
o~ r-w - ..•
.5 1~ 15 J1:!S XllS lOIS 50
"EJ "0
_YttIgoI ~ IS
XQ _._, -::; i: .. ,
1,"" ~;" ..•.••...•..
t ~ :!S-'- '" -, .
'100 . ' i~
50 . ~ 10 '
,
o 5 1015 J1:!S XllSlOlS 50 0 5 I~ 15 JI 25 11 lS lO IS 50
The authors thank the Malaysian Government, Ministry of
Science, Technology and Innovation (MOST!) for the Science
Fund Grant, Project No. 01-01-06-SF0205.
'''' EJ" 1t;]"'" 'all .~. ..' .:' .•. ron 1
/Ill " ;. ,. . ., . 'P(),lJ ~.
{JI[CJ,:,.'::"j' ~: : .....• ,'••
.::;::: ,:", ,• !XQ ...__ .... ,- ..• . . . . . '.. - -••
~l
1 • 6' lOlll.616;ll21:!l2li2IJ1I1l31J6ll1lO11"II5~50SlSl$ 5 1015 JI 25 11 lS III IS 50 55
VI. REFERENCES
[I] Po-Yen Chen; Se-Kang Ho; Wei-Jen Lee; Chia-ehi Chu; Ching-Tsa
Pan, "An Internet Based Embedded Network Monitoring System for
Renewable Energy Systems", Proc. The 7th IntenuJtional Conference on
Power Electronics, pp.225-228, October 22-26,2007.
[2] M.Benghanem; A. Maafi, "Data Acquisition System for Photovoltaic
Systems Performance Monitoring", IEEE Trans. on Instrumentation and
Measurement, Vo1.47, No.1, pp.30-33, February 2008.
[3] J. Machacek; z. Prochazka; 1. Drapela, "System for Measuring and
Collecting Data from Solar-cell Systems", Proc.9th International
Conference Electrical Power Quality and Utilization, Barcelona, 9-11
October 2007.
[4] Z. Wang; L. Chang, "A DC voltage Monitoring and Control Method for
Three Phase Grid-Connected Wind Turbine Inverters", IEEE Trans. On
Power Electronics, Vol. 23, No.3, pp. 1118-1125, May 2008.
[5] T. Yuki; H. Yoshikiro; K. Kosuke, "Temperature and Irradiance
Dependence of the I-V Curves of Various Kinds of Solar Cells"
International Photovoltaic Science & Engineering Conference,
Shanghai, China 2005
[6] A. Moein, M. Pouladian, "WIH-Based IEEE 802.1 1 ECG Monitoring
Implementation", Proceedings of the 29th Annual International
Conference ofthe IEEE EMBS Cite Internationale, Lyon, France August
23-26, 2007.
[7] H. Zhao, X. Chen, K.H. Chon, "A Portable, Low-cost, Battery-powered
Wireless Monitoring System for Obtaining Varying Physiologic
Parameters from Multiple Subjects" , Proceedings of the 28th IEEE
EMBS Annual International Conference, New York City, USA, Aug 30-
Sept3,2006
[8] A. Perujo; R. Kaiser; D.U Sauer; H. Wenzl; I. Baring-Gould; NWilmot;
F. Mattera; S. Tselepis; F
[9] H. Zhiqiang; Z. Wenxian; L. Jianke, "Research on High-Speed Data
Acquisition and Processing Technique", The Eighth International
Conference on Electronic Measurement and Instruments, ICEMI'2007
T~
T~T~
Fig.5. Application program appearance
T~
T~
Clrrettl Clrrett, ~l
Ii" Ii"" Ii""
o:Ior.!Inlof,S1ll'2llIlr... :I~:22:54 J'.... :lt2.16l1.110"~
Fig. 6. Prototype ofthe photovoltaic acquisition system, (a) upper layer, (b)
lower layer
IV. CONCLUSION
A wireless data acquisition system for photovoltaic
generation system that uses PICI6F877A microcontroller as
the main control has been presented. Implementation of the
EGSR7150 Ethernet to serial module and the access point as
Wi-Fi communication tool between acquisition equipments
and user computer for graphically displaying the acquired
parameter has work properly as intended. Implementation of
such a system on a laboratory scale photovoltaic generation
shows the practical simplicity, efficient and low cost.