Remote Management and Performance Tuning of Photovoltaic

Solar Panels Group Members:

Abeer Alsenani 200524466

Haleema Alazizi 200503369

United Arab Emirates UniversityCollege of Engineering

Department of Electrical EngineeringGraduation Projects Unit

Advisor: Dr. Atef Abdrabou

Introduction. Objectives. Project objective. General Overview. Project specs.

Summary of Achievements in GP I. Photovoltaic panel selection. Motor selection. Motor driver selection. Communication part selection.

Detailed Design. Selection changes in GP2 Measuring PV parameters. Acquisition of PV parameters. Controlling PV inclination. The management software. Graphical user interface. Photovoltaic test. Xbee test.

Ethics, healh and saftey. References.

Outline

2

Introduction:

This project aims at designing and implementing a remote management system for solar panels using wireless communications.

The management system can be used to control the PV panel and to tune its performance.

The system shall state the parameters of PV panels at different inclination.

3

Project Objectives:

Design and implement a remote management system of

photovoltaic solar panels using wireless communications.

Measure the PV panel parameters at the remote part

such as: power, current and voltage.

Do performance tuning by changing the inclination of PV.

Compare the different values of each PV inclination to

determine the best inclination of the PV panel at

different times of the year.

4

General Overview:

5

Project Specs:

Reduced power consumption

Reduce the size of the Photovoltaic panel, therefore,

reduce its weight.

Motor sizing (which is based on the size and weight of PV

panels).

Motor speed must be slow to get the accurate tilt and

inclination of PV panel.

Transmission range for the communication system has to

be reasonable but not too big

6

Project Specs: Reliability of the PV panel cells. More efficiency means more reduction in

size.

Cost: A limited budget was assigned to this project so cost estimation is one of the most important constrains.

The communication system must be able to collect the required data and send it to the software in management part.

Analog to digital conversion should be done before sending the data over wireless communication.

The PV panels stand has to be able to move, not fixed.

The motor has to be able to move back and forward (with precise angles, for that high speed is not required).

The system must be environment friendly and safe. 7

8

Summary of Achievements in GP I:

Photovoltaic panelDesign Specification

Monocrystalline

Power (W) 30

Voltage (V) 17

Current (A) 1.7

Size (mm) 730*325*25

Weight (Kg) 3.2

9

Summary of Achievements in GP I:

Stepper MotorSpecifications Design

Stepper motor

Motor type BIPOLAR

Rated voltage (v)

4.6

Rated current (A)

0.4A

Step Angle (Degree)

1.8 DEGREE

HOLDING TORQUE

30 MN.M

10

Summary of Achievements in GP I:

Stepper motor controller and driver

• We selected an Atmel microcontroller (Atmega324).

• We selected a stepper motor driver from pololu.

11

Summary of Achievements in GP I:Communication part

Specifications Design

XBee 1mW Chip Antenna

Power consumed Approximately

0.165 W

Transmission range

Indoor range: 30m-40m Outdoor range: 90m -100m

Output power 1 mW

Data rate 250 kbps

Input signals Digital and Analog

Interface with the computers

Yes

Environmentally and Safety

Yes

12

Thin film photovoltaic panel was chosen as our PV in GP2 because:

• Its has very light weight, only 1.5 kg.• It has no frame.

• Under different perturbation conditions ( such as temperature) thin film has best efficiency.

• Its is not made of class.

• Its flexible and easier to carry from place to place.

Selection changes in GP2:

13

Easy driver stepper motor from spark fun, was selected for GP2 because:

• The pololu stepper motor had a very small potentiometer, which used to affect the motor dramatically; it was inefficient and very badly made.

Selection changes in GP2:

14

• Two analog inputs capture the voltages.• Voltage divider will be done to reduce the amount of voltage coming from the PV as Xbee work on 3.3V only.

The following equation was used to determine the values of the resistors used: Vout = 3.3 (Xbee rated voltage) Vin = 20 (from PV panel) Vout/Vin = R2/R1+R2 = 3.3/20 = 33/200

R2 = 33 ohm , R1 = 167 ohm.

Measuring PV parameters:

15

• From the UART output of the Xbee transceiver at the management unit the amount of voltage of the PV panel will be known.

• As the data in UART will be in API format , so if the output came out to be: 7E 00 0C 83 56 78 2E 00 02 00 18 00 18 00 18 36, the UART API data stream can be broken down.

• From the bits lined up in AX and DX, we can know the value of the voltage coming from the PV panel.

Acquisition of PV Parameters: 7E start delimiter 00 0C Length Bytes 83 API Identifier Byte for 16bit DIO data. 56 78 Source Address Bytes 2E RSSI Value Bytes 00 Option Byte 02 Sample Quantity Byte 00 18 00000000 00011000 channel indicator* 00 18 Sample data DIO 3 & 4 00 sample data 1 18 sample data 2 36 Check sum .

Controlling PV inclination

When an angle input is entered by the user in the management part, the microcontroller will change this value to steps and send it to the motor driver to drive the motor depending on different angle values.

Each pulse from the microcontroller moves the motor one microstep.

If the driver is adjusted to full step mode, this means the motor will do 200 microsteps per revolution. Each microstep is 1.8 degrees.

For example, in the quarter step mode, the motor will do 800 microsteps to complete one revolution, which means it will do 1.8/4 degree per microstep.

Suppose we configured our driver for quarter step and we want the motor to run 3.6 degrees, then the microcontroller will generate 8 pulses only. This will turn the motor 8 microsteps = 1.8/4*8= 3.6 degrees and stop.

16

17

• The remote part Xbee will send the management part Xbee the values of the PV voltage, these values will be saved on text file.

• The visual basic software will open text file, take the value of voltage and resistor to calculate the current and power values for several hours a day at different positions of PV.

• The values will be compared and displayed to the user as graphs.

The management software

Graphical user interface:

18

Graphical user interface:

19

20

Photovoltaic test

The steps of the Xbee test range were :• Connect one xbee with its USB interface and then to the personal computer (PC1) • The other xbee is connected to a USB cable after cutting one terminal of the cable and the other terminal is connected to the second personal computer (PC2). • Then we need to connect as we see in figure.

21

Xbee test:

Xbee test:

After the second xbee is connected to another PC via USB cable the following procedure were done:

1. Open XCTU software in both computers. 2. Fix the transmitter in one location and move the receiver away from

it. 47 3. Use the XCTU chat between two computers and check that the

receiver receives whatever we transmit in the transmitter. 4. When we stop receiving record this distance and this is the range of

xbee. The results that got from this test if the two xbee face to each other

were : Indoor = 12 meter, outdoor approximattely = 19 meter On other hand results that got if the one of xbee up the other were Result indoor= 6 meter, outdoor approximately = 18 meter.

22

Ethics, Health and environment:

23

Some years ago, sociologist Raymond Baumhart asked business people, "What does ethic mean to you?" [18] Among their replies were the following:

"Ethics has to do with what my feelings tell me is right or wrong." "Ethics has to do with my religious beliefs." These replies might be as our own, in the other hand it might be different, as the

definition of “ethics” is hard to define, and the beliefs and vision people have about ethics are wobbly.

But for us ethics is to: accept and take responsibility for our mistakes. to be willing to do this in the face of harshest critics. not to cheat from other projects, not to copy and paste to work as hard as we can to provide a safe prototype for the user to use without

being scared to get harmed or injured. We treat the user as a family of our own and his safety is important. We are required to be honest in the budget that we are using and give critical

measurements without increasing or decreasing any amount. We must be honest in our prototype measurements and testing, even if it’s not

working correctly. We are trusted engineers and we are working to keep this trust gained.

Ethics, Health and environment:

24

Advantages: Our project helps to improve the performance of one of the most widely used

renewable energy resources, which are photovoltaic panels. PV installations can operate for many years with little maintenance or intervention

after their initial set-up, so after the initial capital cost of building any solar power plant, operating costs are extremely low compared to existing power technologies.

When grid-connected, solar electric generation replaces some or all of the highest-cost electricity used during times of peak demand (in most climatic regions). This can reduce grid loading, and can eliminate the need for local battery power to provide for use in times of darkness. Grid-connected solar electricity can be used locally thus reducing transmission/distribution losses.

Disadvantages: solar electricity is it is more expensive than most other forms of small-scale

alternative energy production and it is not produced at night and is much reduced in cloudy conditions. Therefore, a storage or complementary power system is required.

It depends on the limited power density of the location's insulation. Solar cells produce DC which must be converted to AC (using a grid tie inverter) when used in existing distribution grids. This incurs an energy loss of 4–12%.

References:

[1]” Wikipedia (2011, 7 jan). [Online]. Available at: http://en.wikipedia.org/wiki/Electric_motor”

[2] ” Shawn Glover. (2010,Feb 15).[Online]. Available at :http://www.ehow.com/facts_5991381_definition-transceiver.html”

[3] SunEdison LLC and Beltsville, MD, “Quality Assurance, Quality Control Plan”, MIST 1A Photovoltaic Rooftop, Abu-Dhabi, February 01, 2010.

[4]Erika Weliczko, “Crystalline vs thin film”, October and November 2008. “Wikipedia. (2011, Jan 5).[Online]. Available at: http://en.wikipedia.org/wiki/Specification_(technical_standard)”

[5]“Wikipedia. (2011, Jan 7).[Online]. Available at: http://en.wikipedia.org/wiki/Photovoltaics”

[6] “Pauline Gill. (Undated). [Online]. Available at: http://www.ehow.com/about_5077120_definition-stepper-motor.html”

[7] “ Wikipedia. (2011, Jan 7).[Online]. Available at: http://en.wikipedia.org/wiki/Visual_Basic”

[8] “ Lavape. (undated).[Online]. Available at: http://lavape.sourceforge.net/doc/html/AdvantVB.htm”

25

Any Question ??