Week #5 Post

This week our group finalized our design. Our design allows the high school students to be interactive with the system at a safe level, i.e. no touching the hardware. Every aspect of control is centered with the GUI control center on the laptop. This way the students can examine the system without the fear of getting shocked or breaking anything.

The electronic schematic which shows all of the wires and connections. The type of wire is stranded wire due to its flexibility. The color of the wires are depicted on the electronic schematic.

DC

Red is active

Black is ground

Green is earth ground

AC

Black is active

Grey is ground

Purple wire indicated data transfer

We are continuing to work on the Google SketchUp model of our photovoltaic system. Also, we are working on calculations for different aspects of the system. These calculations allow us to simulate what we expect to happen. We are also working on finalizing our product list. This list includes all of the hardware used in our design.

Week #4 Post

Since week 1,  we've focused on revolving our design around providing the best user experience possible for the students. Each week we come into class, we tweak our idea with great care so that it will ultimately serve the students well in a learning environment. Our interface will be clear and simple and everything will load instantly with LabVIEW. It will be designed so well that no one will even consider how they might have designed it differently.

Also, some technical aspects of this project were debated and resolved. We asked ourselves, should we put our batteries in series or parallel? The group decided that perhaps we will do both so that the students can see both the voltage and current relationships of each. We also voted that the panel should be mobile on a cart of some sorts. For maximum efficency the group decided it would be best if the solar panels always faced due south at an angle of 33.5 degrees (if not properly mounted with a solar tracker). The computer keyboard will pull out from a cart drawer for convenience. The batteries and charge controller will be below the computer and the solar panels will be on top. The group also decided that it would be best if 6 and 22 gauge wires are used to make all the necessary connections throughout the system. An inverter will be used between the charge controller and the meterbus if the group decides to do both AC and DC current and voltage readings. To make sure that the solar panels and the DPDT relays don't fry, we will place fuses between them (not sure yet what Amp fuse). Also a 25 Amp fuse will be placed between the 12 Volt battery and the Charge Controller (again to prevent frying the charge controller or blowing up the battery).

As we approach Week 5 our hope is to bring our project to life in some kind of visual software (AutoCAD or Google Sketch Up). There is still a lot of unexplored areas that our group needs to cover and it should be exciting in uncovering the mysteries of our solar panel design.

Week #3 Post

Our group knows that the answer to all our questions lie in the (yet to be seen) hardware. Since it's already Week # 3 the group knows it's going to be a creative and fast-paced environment for the construction of our solar panel design! What's exciting the group the most this week is that everything is starting to come together. When we sit down we draw up diagrams and have ideas of how the PC is going to communicate with the microcontroller which will send a signal to the relay to turn on a fan.We are considering putting a fuse on the fan(AC load) line to  ensure that a voltage spike doesn't blow up the fan. The group is also considering adding  micro controller to see the effects of different AC loads. We can say with confidence that we have half of our communication already done. We know that we can communicate with the system via LabVIEW. The only thing that we need to know now is a little bit more information on the meterbus communicating with the PC. I (Mike) plan on handling that by contacting Morningstar and figuring out how it communicates exactly. Also we decided it might be a good idea to draw up the model in Auto CAD and or Microsoft Visio to give a more visual idea of what we are doing. Being in Group # 6 is awesome. Everyone is inspired by their work and are constantly thinking and executing on the next big idea.

Research on LabVIEW to simulate the system

Computer connected hardware:

1. Morningstar Charge Controller & Inverter
• RS-232
• 9600 Baud Rate
• 8 Data Bits
• 1 or 2 Stop Bits
• No Parity
• No Hardware Flow Control
2. B&K Programmable Electronic Loads
• RS-232 (USB)
• 9600 Baud Rate
• 8 Data Bits
• 1 Stop Bit
• No Parity

Programming Techniques for Hardware

1. Morningstar Charge Controller
• http://www.morningstarcorp.com/en/support/library/SSMPPT.APP.Modbus.EN.10.pdf
2. B&K Programmable Electronic Loads
• The DC Load is programmed using packets of bytes. A packet always contains 26 bytes, either going to or coming from the instrument.
• The basic programming rule is:
• You send a 26 byte packet to the instrument.
• You then read a 26 byte packet back from the DC Load to either
• Get the status of your submitted packet or
• Get the data you requested.
• Here is a link to the B&K Programmable Electronic Loads model 8500 site. 
• 8500 - 300W Programmable DC Electronic Load
• The LabVIEW driver is located under the "Software" tab.
• There are also other types of software. See below.
• You can download the files by clicking on the corresponding "File Link".

  	Note/Description	File Size	File Link
  V1.00	Python Library	184.97 KB	PyLib85xx.zip
  V1.00	Python Setup Package	15.52 MB	python.zip
  V1.0.2	NI Certified LabVIEW 8.0 Driver	1.79 MB	LV85xx.zip
  V1.3.0	IT-E132 USB Cable Adapter Driver	2.26 MB	ITE132_driver.zip
  V6.37	Operating Software (Supports Windows(R) XP/7)	8.82 MB	PV85xx.zip

Designed Lab view GUI's

  

Parts Cost Estimate

           

  

Part	Quantity	Cost per unit($)
Solar Panels	2	249.00
Arduino Microcontroler	1	21.00
Charge Controller	1	210.00
Inverter	1	215.00
Dc Load	1	1095.00
Power Strips(AC load)	1	11.00
24 AGM Batteries(80AH)	2	177.21
PC meter bus adapter(RS 232 )	2	37.95
Power Strip	1	11.00
5A circuit breaker	2	19.00
5A DPDT Relay (V23079)	2	3.20
2A SPST Relay	1	4.21
100 AMP CB (35C0101)	1	63.16
25 AMP CB  (98k5994)	2	13.45
3 AMP CB  (08WX5768)	1	14.15
16 AWG(black)	1	77.78
16 AWG(red)	1	77.78
12 AWG(black)	1	182.30
12 AWG(red)	1	182.30
6  AWG(black)	1	666.64
6  AWG(red)	1	666.64

Electrical Schematic

a. Basic Schematic:

b. Detailed Schematic:

           (i) Solar Panel, Charge Controller and Batteries connection

         (ii) Solar Panel, Charge Controller, Batteries connection,Micro Controller connected to    
                    the PC

               (iii) Solar Panel, Charge Controller, Batteries connection,Micro Controller, inverter    
                    connected to the PC

       
               (iv) Solar Panel, Charge Controller, Batteries connection,Micro Controller, Inverter,DC    
                     load connected to the PC

  

Mechanical Drawing of the System

2D View of the System

3D View of the System

Deliverables

     1. Solar Panels

a.       How the PV cells are connected in the solar panel?

                                                              i.      Each module consists of 72 solar cells connected in series providing sufficient voltage for battery charging under extreme high temperatures.

b.      How the PV cells are affected by “peak” sun hours, partial shade and nighttime?

                                                              i.      Max System Voltage 600Vdc

                                                            ii.      Series Fuse Rating 6 Amps

c.       How the efficiency of the solar cells would change according to high temperatures?

                                                              i.      Voltage Temperature coefficient (Voc) -0.35%/C

                                                            ii.      Current Temperature coefficient (Isc) 0.065%/C

                                                          iii.      Power Temperature coefficient (Pmax) -0.5%/C

                                                          iv.      Peak Power Tolerance +/-10%

d.      How the efficiency of the solar cells changes under different frequencies of light?

2  2.Batteries

a.       How the connection of the batteries would affect the DC load. The difference in having the batteries connected in series and parallel.

                                                              i.      1 battery in series to provide 12 V

                                                            ii.      4 batteries in parallel

b.      The most efficient connection vs the least effective connection.

                                                              i.      The most affective connection would be to have the batteries each in series and having both of those in parallel.

3  3. Labview and Micro Controller

a.       How a microcontroller along with lab view can be used to switch off the number of solar panels connected into the system. 

                                                              i.      Signal relays allow for on/off control

                                                            ii.      Connect/Disconnect panels to circuit for charging/discharging

b.      Demonstrate how different circuit breakers have been used within the system to protect it with overloads.

                                                              i.      Per datasheets, the appropriate fuses have been placed within the circuit.

                                                            ii.      Also, circuit breakers were added between the solar panels and relays to protect the relays.

c.       How different kinds of AWG wires were chosen to connect different components of the system.

                                                              i.      Per datasheets, the appropriate wires were used in the design.

                                                            ii.      To simplify and reduce costs, some gauge wires were decreased to accommodate for less variance of wire gauges. For example, using 4 AWG gauge wire instead of 6 AWG because 4  AWG was required for the earth ground but 6 or less was required for +/- of the inverter.

   4. Effects of Different AC and DC loads 

Parts Documentation

1. Mono Crystalline Solar Panel

   

 a. Product Summary

 b. Electric and Mechanical Parameters

c. Design Calculations and Parameters

2. Charge Controller

      a. Product Summary

 b. Electric and Mechanical Parameters

  c. Design Calculations and Parameters

3. Batteries

a. Product Summary

     

 b. Electric and Mechanical Parameters

  

   

c. Design Calculations and Parameters

    

4. Meter Bus Adapter

a. Product Summary

b. Wiring Diagram

5.  DC Load

a. Product Summary

b. Electrical Parameters

c. Front Panel Operation

s
d. Rear View Operation

6. Inverter

a. Product Summary

b. Key Features

c. Electrical and Mechanical Parameters

d. Design Calculations and Parameters