MJLorton Solar Power and Electronic Measurement Equipment Forum

Solar Power => Solar Power => Topic started by: kibi on May 24, 2012, 03:20:16 PM

Title: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on May 24, 2012, 03:20:16 PM
I have taken some interest in Tim Nolan's MPPT solar charge controller based on an Arduino.

Please refer to Tim's website below:

http://www.timnolan.com/index.php?page=arduino-ppt-solar-charger (http://www.timnolan.com/index.php?page=arduino-ppt-solar-charger)

The one problem I did have with his design was that it didn't support an LCD.
I have rectified this problem and modified his original code to support an LCD. Upon checking his circuit digram and I/O usage, I have determined that there are still enough I/O's on a standard UNO to drive a parallel LCD which saves a lot of cost. Serial or I2C displays are really cool, but come at a monetary cost.
I have got the code going utilising preset resistors to simulate the feedback from a live system to display certain parameters as below.

(http://www.wkirby.co.uk/Images/MPPT/IMG_2072.JPG)

Now, I ran out of space with a 16x2 LCD. My requirements are to display more information about the charger's status. I have a 20x4 LCD on order, so when it arrives and I figure out the code, I'll post an update.

Unfortunately, I'm reluctant to share the modified code without permission from Tim, so once I've got the code going how I think it should be, I'll request his permission to publicise it.

Also, I don't plan on sacrificing an Arduino board for the final project, so I am in the process of designing a PCB around the ATMAGA328 which can be programmed in the Arduino board an then the MCU can be simply transferred to a dedicated PCB.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: MJLorton on May 25, 2012, 04:40:22 AM
You are brilliant! Tim Nolan's site and MPPT project are great.

I'll certainly be following your progress with a keen eye as this is one of the Arduino projects I know I'm going to really enjoy.

Thanks for sharing good man.

P.S. the Arduino Nano can be used for putting Arduino projects into "production" without sacrificing your main project board:
http://arduino.cc/en/Main/ArduinoBoardNano

Martin.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on May 30, 2012, 03:53:27 PM
OK, so I have made some more progress with this project.
The 20x4 display arrived and I have got it to display more useful information in a more easy to read manner.

(http://www.wkirby.co.uk/Images/MPPT/IMG_2074.JPG)

I'm quite pleased with the way it works now.
I am now busy designing the PCB, well I have designed it, but looking at it, I've decided its crap. I'm going to have to start again, but that's just the way these things go.
Idea's of networking the charger have popped into my head, but I'm not sure if I have enough I/O's left on the MEGA328. It would be cool to have remote monitoring and data logging ability.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: MJLorton on May 31, 2012, 06:00:46 AM
OK, so I have made some more progress with this project.
The 20x4 display arrived and I have got it to display more useful information in a more easy to read manner.

I'm quite pleased with the way it works now.
I am now busy designing the PCB, well I have designed it, but looking at it, I've decided its crap. I'm going to have to start again, but that's just the way these things go.
Idea's of networking the charger have popped into my head, but I'm not sure if I have enough I/O's left on the MEGA328. It would be cool to have remote monitoring and data logging ability.

Great update, keep them coming good man!
Remote monitoring and data logging...yes, yes, yes...I'd purchase one!

Cheers,
Martin.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on June 03, 2012, 04:14:27 PM
I finished re-designing the PCB and I have fabricated a prototype. Considering that I last made a PCB back in the space year 1996, I am reasonably pleased with the result. I only went single sided because there is less to go wrong. It's not very neat, but it works.
I made a giant error, well two actually, but the first big mistake was that I forgot to include the ICSP header. I have soldered one on temporarily so that the code can be tweaked.
The second big mistake I discovered during testing. The AMPS readout was five times lower than the actual measured current. Like a klutz, I did not read the data sheet for the MAX4173. It turns out that there are three versions of this device. The part number is suffixed with T, F or H. I didn't pay too much attention to this fact when I ordered the chip from Mouser and just clicked on some random one which turned out to be the T version. The T version has a gain of 20, the F has a gain of 50 and the H has a gain of 100.
The design uses a H version with a gain of 100 and my project has ended up with a gain of 20, hence the reason why the readout was 5 times less.
With my bodged on ICSP lead I tweaked the code to get the readings correct.
I have not installed any of the power devices yet until I'm sure that the code is running properly.

Bottom side of the board with the ICSP lead soldered on temporarily.
(http://www.wkirby.co.uk/Images/MPPT/IMG_2076.JPG)

Top
(http://www.wkirby.co.uk/Images/MPPT/IMG_2077.JPG)

Top, including the display.
(http://www.wkirby.co.uk/Images/MPPT/IMG_2075.JPG)

Lessons learned: READ the data sheet! Don't forget to include facilities to alter the code, the code WILL need to be perfected or modified.



Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: MJLorton on June 04, 2012, 06:22:59 AM
This is brilliant, thanks so much for sharing the progress AND the mistakes. A great learning experience for all of us getting into this. I chuckled at the comment about making the PCB back in "space year 1996". I'm going to have to go through the same process myself for the multimeter reference check once I move from a prototyping board....I think it was back in 1989 / 1990 when I last did a PCB design on a PC and had the PCB made....

Cheers,
Martin.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on June 05, 2012, 11:40:24 AM
I have installed the MOSFETs and the MOSFET driver and powered it up.
Alas, no go. The MCU is trying to switch the MOSFETs on, but they won't turn on.

It turns out that the IR2104 MOSFET driver that I ordered is not an IR2104. It's some TI part that I can't even find any information on.
So now, unfortunately, the project is on hold until the correct parts arrive.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on June 07, 2012, 04:18:00 PM
The IR2104 arrived from America this morning, Mouser are really quick.
I have installed it and everything is running well.
In also got the MAX4137H. It is necessary to have this higher gain version because the lower voltage presented to the ADC is too low with the low gain version. This means that the resolution of the measurements is not very good. It not only provides low resolution readings on the display, but the calculations are made with poor quality data.
I'll replace the MAX4173 at the weekend perhaps.
The display updates too quickly to be able to make legible readings. I'll have to figure out how to send updates to the display less frequently.
Otherwise, I'm pleased that it's working.

The sub-assembly with heat sink. For the eagle eyed, the TI part is still on the board at this time.
(http://www.wkirby.co.uk/Images/MPPT/IMG_2078.JPG)

The fully assembled device.
(http://www.wkirby.co.uk/Images/MPPT/IMG_2079.JPG)

The unit in operation, charging an actual battery.
(http://www.wkirby.co.uk/Images/MPPT/IMG_2086.JPG)

After that, I'll start work on getting network or logging or even better, both working for "version 2".
I'd also like to get some more power transfer out of this thing. I'd have to look into higher power MOSFET's with otherwise similar characteristics to the IRFZ44. It'd need a more staunch inductor too. However, there is not point in upgrading the power if I don't even have one solar panel yet :)
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Tooms on July 02, 2012, 12:00:32 PM


Hi

Is this MPPT only supporting 12v system or can it be used at 60V or 48V system ?


Thomas
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on July 27, 2012, 05:19:28 AM


Hi

Is this MPPT only supporting 12v system or can it be used at 60V or 48V system ?


Thomas

Soory for the delayed response.
I don't see any huge problems with operating this at higher voltages. 24v systems will just require the voltage dividers for the voltage sense inputs to be adjusted appropriately and the code modified.
48v and 60v systems are slightly more tricky because the 7805 regulator can't cope. A 5v supply will have to be arranged to power the controller and then the voltage dividers and code can be modified to suit.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on August 14, 2012, 04:31:18 PM
It would seem that you need to read the code :)
At the top of Tim Nolan's code it says that his code is free to share as long as you give mention to him and link to his website.
Tim has been mentioned, so here is his website - www.timnolan.com (http://www.timnolan.com)

Attached is the code that I have modified.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: s3n on October 08, 2012, 12:47:00 PM
OK, so I have made some more progress with this project.
The 20x4 display arrived and I have got it to display more useful information in a more easy to read manner.

(http://www.kirbyw.pwp.blueyonder.co.uk/Images/MPPT/IMG_2074.JPG)

I'm quite pleased with the way it works now.
I am now busy designing the PCB, well I have designed it, but looking at it, I've decided its crap. I'm going to have to start again, but that's just the way these things go.
Idea's of networking the charger have popped into my head, but I'm not sure if I have enough I/O's left on the MEGA328. It would be cool to have remote monitoring and data logging ability.

can u share or give the schematics of the MPPT w/LCD using MEGA328?
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on November 05, 2012, 01:39:53 PM
(http://www.wkirby.co.uk/Images/MPPT/MPPTsch.jpg)
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on December 08, 2012, 10:13:18 AM
I have modified the code so that it runs a bit faster and there is less flicker on the display.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Neeraj3 on December 31, 2012, 02:23:16 AM
Hi, I am working on this project.I am facing problems.The mosfet is not getting turn ON when i connected the current sensing input to the A/D channel of arduino. It always shows current input as 0.00. I need the help to over come this problem.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: harimelath on January 02, 2013, 11:58:30 PM
Kibi
Please post a better schematic in PDF
Thanks
Hari
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on January 03, 2013, 06:19:02 PM
This is the best one that I have. I have not worked on this project for a long time, so I have no better versions. :)
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Earley8 on January 04, 2013, 05:56:08 PM
The 100 micro-F capacitor blew up when I connected a 21.84 V panel to the MPPT.
Would you happen to know why this happened? I am a student attempting to learn about Mr. Nolan's MPPT, so any help would be awesome!
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: SeanB on January 05, 2013, 12:28:30 AM
Either it was connected the wrong way round or it had too low a ripple current rating. If the wrong way round it normally does a confetti shower, overcurrent it normally will run hot then split the vent open. New one use a 63V low ESR unit, it will be bigger. A higher value will also work, anything from 470uF to 1000uF will work there as well, just needs to be low ESR and it will survive.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Earley8 on January 08, 2013, 07:20:56 PM
Thanks for the quick response.  It blew through the vent, so I will try a 100 micro/ 100 V just to be safe.
As far as the MOSFETs: the IRFIZ44 were unavailable on DigiKey, so I ordered the IRLIZ44 FETs.  They seem to have the same operating parameters; think I will have an issue??

Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Earley8 on January 13, 2013, 03:43:05 PM
The IRLIZ44 FETS seem to work fine..  The only difference I notice is the 5V drop instead of the 10V that turns on the switching MOSFET in the schematic (Q2). If anyone knows an easy way of draining a 12 V lead acid battery please let me know.  Thanks for all the posts Kibi!
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: SeanB on January 13, 2013, 11:46:25 PM
I use a 12V 50W downlighter and a socket. Draws 5A nearly and will discharge a common 7Ah unit in under 2 hours. A car headlamp also works.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: retiree on February 01, 2013, 01:09:26 AM
Hi - a great project. Would it be possible to post a zip file of the brd. file? I am battling to get my layout correct and woul appreciate it

Thanks in advance.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: SAFIX on February 12, 2013, 04:48:35 PM
Fantastic! how about some help with a 24v PV conversion or is this not on the cards?

Many thanks
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Blesk on March 07, 2013, 10:01:25 AM
hi could you give here in eagle pcb? THX

Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: hary on March 07, 2013, 06:05:18 PM
Just a question :

What happen when MOSFET Q3 is on ?

http://www.timnolan.com/uploads/Arduino%20Solar/ArduinoSolar.pdf

Isn't the battery shortened ? Woudn't we need a rectifying diode somewhere ?

Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: manfredong on June 17, 2013, 03:41:00 AM
Can you share with me how you program this device?
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on June 18, 2013, 11:40:40 AM
As this is Arduino based, ATMEGA328 MCU, I did all the programming on an Arduino Uno, then transferred the MCU to the final board.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mustapha_kazaure on July 06, 2013, 03:53:59 PM
Hi mr. Nolan's thank you for all your contribution in this project.
    but sir i dont know i am using i aduino uno R3, i.e am using ATMEGA328 but if i run the code u share it given me this error pls sir i need help out
 "MyMPPT.ino:16:105: error: TimerOne.h: No such file or directory
MyMPPT.ino: In function 'void setup()':
MyMPPT:83: error: 'Timer1' was not declared in this scope
MyMPPT.ino: In function 'void set_pwm_duty()':
MyMPPT:154: error: 'Timer1' was not declared in this scope
MyMPPT:158: error: 'Timer1' was not declared in this scope"
    this is my e-address mustaphamohammed01@gmail.com.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: willbr on August 17, 2013, 07:42:48 PM
I'm doing this project ... I'll put ethernet shield to send data from arduino!
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: smaBonham on August 31, 2013, 04:36:19 PM
This is exactly what I would like to build, but it currently exceeds my ability to do so. Are there any videos or tutorials that take you through a project like this, step by step, explaining the circuit, the principals and the code for the arduino?
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: studioeng on September 09, 2013, 10:04:05 AM
I read your initial posts and you mentioned about including networking capability, but would be short of I/O pins; have you looked into controlling the LCD via a shift register 74HC595 etc, which would only require 3 pins, possibly freeing up others for networking.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: bricofoy on September 18, 2013, 11:26:45 AM
Hi everyone.

I need to use 3 PV panels to power a small electric water heater. I know, this will give a very bad efficiency compared to regular solar water heater, but in that case I really need to do it this way.

So if I directly connect my PV panels output to the heating resistor, I will get a very bad efficiency most of the time. So I need to place some sort of mppt or impedance  converter between panels and resistor.

I think with this device I can get something working. But my problem is I have 3 120Wp panels in series, so I get nearly 45V/8A at mpp, and 60Voc. So this circuit need some adjustment to allow working with higher voltages, especially because I must power the mcu from the solar panels, as there is no battery.

So do you guys have some links to somewhere that can explain how to calculate the dc/dc converter elements to change the working voltage ? I have absolutely no idea how to calculate the inductance and capacitors for the converter.

Do you think I need another converter to produce the 5v ? or can I do it with some sort of linear regulation ?

thanks
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: SeanB on September 18, 2013, 01:51:01 PM
Best is not to use a MPPT unit, but just run the heater direct. Use a heater rated for about half the open circuit voltage ( or a little below the MPPT voltage) and rated to draw the nominal power of the panels. It will be a little overdriven during the peak part, but for a simple resistive heater this is fine. For you this will mean a heater of around 36V and rated at 360W. Simpler will be to use a series connected set of 12V 120W heaters if possible, or else you will have to contact a heater element supplier and get one made to fit as a custom unit.

Overdriving the heater is not going to be much of a problem so long as you do not do so while it is dry, as the water moderates the temperature. I have some heater elements in a machine which does a fast warm up by running them for 3 minutes at double the supply voltage ( so 4 times the power) and they generally last many years in this application.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: bricofoy on September 19, 2013, 03:40:24 AM
Hi

thanks for your answer.

This will work ok for the most sunny hours of the day. But what about the sunrise and sunset ? And what about cloudy days ? I gess the working point will be far from mpp point of the panels in such a situation.

The other problem I have is I can't change the resistor in the heater. I think I need to explain a bit what I need to do : in a house we build, there is a solar water heater with the storage tank located near bathrooms, and PV panels covering all the roof.
That's ok for bathrooms, because hot water will arrive quickly.
But not for the kitchen, wich is located quite far from the hot water tank. So we plan to place a small (30 liters) water heater just in the kitchen, feeded by the hot water line, to have a little storage of hot water inside the kitchen and get hot water quickly when demanding for it.
For legal reason here in france, it is complicated for individual people to connect more than 3kWp PV to the mains, so as we want all the roof surface covered with PV panels for esthetical reasons, we get 3 panels we can't connect to the inverter because we will override the 3kWp legal limit.

So the idea here is to use these 3 panels to power the kitchen's water heater when possible. But that implies when there is no sun I also need to connect this heater to mains, so for this reason I must keep the 600W 220V heating element. And there is no way to put 2 different resistors together in the device.
Connecting this 600W element to 360Wp panel will give me a working point quite far from mpp, and give me a very bad efficiency. That's why I think with some sort of mpp device between panels and resistor I can transfer my 300W available power to the resistor.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kaizer98 on October 15, 2013, 11:46:09 AM
Hi kibi,

Thanks a lot again, for this great project!

Cheers,
Yikai
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: MJLorton on October 21, 2013, 12:35:46 PM
For those interested this gent (Julian Ilett) has done an interesting project too:

Arduino MPPT Solar Charge Controller #17 - Buck Converter Efficiency
http://youtu.be/c0mE4nS0low
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kaizer98 on November 09, 2013, 11:18:46 AM
Thanks Mr Martin for introducing another project on MPPT.
I wish someone could help me out on this. This is quoted from: http://www.timnolan.com/index.php?page=arduino-ppt-solar-charger.

"On the graph (Fig. 5), the line labeled “PPT On” shows the watts generated by the solar panels when the PPT was running the hill climbing algorithm. Every 10 seconds the PPT set the DC/DC converter to a 1/1 ratio simulating a direct connection between the solar panel and the battery. The watts are measured and plotted on the graph as “PPT Off” showing the power that would be generated by the solar panel if it was directly connected to battery. The difference in watts between “PPT On” and “PPT Off” is the power gained by using the PPT. In this case the battery is being charged with about 20% more power when the PPT is on."

I want to do this, but I do not know how to edit his code to achieve this. I really wish someone could help me out on this, and really thank you to anyone who is willing to help!

Cheers,
Yikai
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: jam770 on January 11, 2014, 01:43:38 PM
OK, so I have made some more progress with this project.
The 20x4 display arrived and I have got it to display more useful information in a more easy to read manner.

(http://www.kirbyw.pwp.blueyonder.co.uk/Images/MPPT/IMG_2074.JPG)

I'm quite pleased with the way it works now.
I am now busy designing the PCB, well I have designed it, but looking at it, I've decided its crap. I'm going to have to start again, but that's just the way these things go.
Idea's of networking the charger have popped into my head, but I'm not sure if I have enough I/O's left on the MEGA328. It would be cool to have remote monitoring and data logging ability.

Hi

I am too working with tim nolan design, in order to use the least data lines i am using the shift reg library. this limits to 3 i/o lines and i can use the rest for other uses.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 13, 2014, 05:03:55 AM
Hi,

a week ago i  found Tim Nolans Website and build the MPPT for my 235W Solarpanel.
It works great, i put a RF24 Radio to send the Data to my Datalogger.
Works fine.
The idea with the LCD is great, that feature will be implementated soon.

But now something strange...:

Yesterday i had a look at Tim Nolans DC-AC Inverter..
Today all of Tims Website is down!
A week ago i send a mail to him but did get no reply...
I have a strange feeling something happend to Tim. :-[
Does anyone know something?

Regards,
Wolfram.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: SeanB on July 13, 2014, 11:42:06 AM
Do not know, but luckily Archive.org has a snapshot from 9 June that is still good.

http://web.archive.org/web/20140626064134/http://www.timnolan.com/index.php?page=arduino-ppt-solar-charger

Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 15, 2014, 02:48:41 AM
thank you, thats nice that they keep a copy of his site!

@jam770:
how is your project going?
I started a new pcb for this mppt charger, it includes Tim Nolans Arduino Code with your LCD-routines,
i removed the serial part and added a RF24 wireless data communication,
added Battery_amp and watts and added a voltage-controlled output switch wich turns off the load when battery goes under BAT_MIN (11V) and reactivate output at 12.5V.
The Output-switch is made of 10x BTS432 in paralell.
I also changed the voltage-divider for the solar-panel, so you can use bigger panels with higher voltage.
My panel make 44V and 38V without load.
Because the MAX4173 doesnt work with 50V i changed it to a AD8218 current-sensor which can handle up to 80V.
These Current sensors are not yet included in the eagle files..
here some files:
(http://www.mega-hz.de/solar_mppt_charger/solar_mppt_charger_brd0.png)
(http://www.mega-hz.de/solar_mppt_charger/solar_mppt_charger_sch0.png)

note, the current sensors are not yet includet!

here the eagle-files:
http://www.mega-hz.de/solar_mppt_charger/arduino_solarcharger.brd (http://www.mega-hz.de/solar_mppt_charger/arduino_solarcharger.brd)
http://www.mega-hz.de/solar_mppt_charger/arduino_solarcharger.sch (http://www.mega-hz.de/solar_mppt_charger/arduino_solarcharger.sch)

and the Arduino Code:
http://www.mega-hz.de/solar_mppt_charger/solar_regler_wf.ino (http://www.mega-hz.de/solar_mppt_charger/solar_regler_wf.ino)

Note the pin numbers for the lcd have changed!
Another change is the use for either IR2104 or IR2101 (those i have laying in the drwaer), thats why the 74HCT00 is there...
If you use the IR2104 dont use the 74HCT00 and close the jumpers!
Also ther is a place for either the DIP-8 or the SO8 SMD Version.


any suggestions?

going on with the tests on the breadboard..

EDIT:
removed 74HCT00 and the option for a IR2101... the signals for the pwm are not as they should. Just use the IR2104.

Found an error: the VCC of the IR2104 was on +5V, that doesnt work, it must be 10-20V.
Added a 330R and a 18V Zenerdiode for the supply of the IR2104. (Hope this won't get to hot when the Solar gives 40V...)

(http://www.mega-hz.de/solar_mppt_charger/solar_mppt_charger_brd.png)
(http://www.mega-hz.de/solar_mppt_charger/solar_mppt_charger_sch.png)




Wolfram

EDIT:
another error found!
The connection between ir2104-pin6 to the mosfet-outputs was missing..
also added 2x 1k resistors for quicker and safer turn-off of the mosfets.

(http://www.mega-hz.de/solar_mppt_charger/missing_connection.jpg)


Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 17, 2014, 04:33:12 PM
the schematics and the layout are updatet now, i think its ready for itead-studio...  :)

(http://www.mega-hz.de/solar_mppt_charger/22-29-52.jpg)

(http://www.mega-hz.de/solar_mppt_charger/22-29-47.jpg)

also 3 current sensor are includet now! (AD8217)

What do you say to this? (Or isn't anybody reading this threat??)
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 20, 2014, 03:51:39 AM
5 prototype pcbs are ordered now.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mjeanne on July 20, 2014, 04:28:41 AM
good job

I'm looking for documentation for building my own solar mpp tracker.
I've some questions:

- what is your power source for the nano ? I'm looking at a LM2596 which could convert from 4 - 40V to 5V @3A, so I can power all chip (µC+display) from the battery, and I got 5V for charging my phone. Do you think it can be ok to power from the battery ?
- why do you use AD827 which require a resistor, instead of something like acs712 which doesn't affect the circuit ?
- do you have a better resolution of your schematics and can I use it for my testing ?

(sorry if bad english, I'm french)
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 20, 2014, 05:44:23 AM
Hi,

the power for the nano is taken via Diode from +Batterie going to Nano-Vin, the Nano has a 7805 regulator...
i use the ad8217 with a small piece of thick wire to get 0.005Ohm, the showing resistors are those wires...
if you make a click on the eagle-files you can download them directly!

here the eagle-files:
http://www.mega-hz.de/solar_mppt_charger/arduino_solarcharger.brd
http://www.mega-hz.de/solar_mppt_charger/arduino_solarcharger.sch

and the Arduino Code:
http://www.mega-hz.de/solar_mppt_charger/solar_regler_wf.ino

looking forward to see your tests!
next week the pcbs should be here... can't wait...  :)

you are welcome to contact me with email too. I am in Germany...

regards,
Wolfram
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mjeanne on July 20, 2014, 08:03:04 AM
I think I will not use a regulator for the µC, as I'm looking for better efficiency. A 7805 will lost energy in heat from a 12-14V battery (because I want to have a 5V/3A output for my phone and some other devices).
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: SeanB on July 20, 2014, 11:39:02 AM
Cheap MC6403 based switchmodes will drop the voltage down with reasonable efficiency, but you will need a better step down regulator to get 5V at 3A for a cellphone charger. I would recommend having 2 so the micro is always powered by a device with good efficiency and low consumption, and the high power output is only turned on when needed. You probably will want the high power one to have an output of around 5V2 with no load so that you compensate somewhat for cable voltage drop during charging. Not more than 5V25 as this is the limit for a 5V nominal rail.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 20, 2014, 03:18:28 PM
it's no problem to use one of these step-down converter, i also thought about it,
but i only need the 5v for the nano+lcd.
of course it has more power to heat, maybe later i change that too.. but thats only a small nice feature...

note if you want to use the arduino-sketch:
the values for UBat,IBat and so on are not yet the right values!
i firstly have to get the pcb and assemble one, than i adjust those value.
i hope there is no bug in the schematics/layout...

wolfram.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mjeanne on July 21, 2014, 04:07:13 AM
Hi,

I don't understand the schematics for D1. Is it one schottky or two ? (and how to choose the model ? )

For information, this is my project:
For the output, I need 12V for 4 lights (12V/3W) and 2 USB port for charging phones (at 1A each).
Actually, I've a 12V/50W solar panel, a 20Ah battery and a cheap PWM regulator (cmp12).
I'm using the 4 lights every night for the outside of my home. It work great from may to october, but in winter battery is empty (<10.5V) after 5 days.
I've try a mppt controller from a friend, and I get about +30% efficiency during morning and evening or poor solar conditions.

My project will use a atmega328p (because I already have lot of them), and ACS712 for current sensor (because I already have them too). So your schematics is a very good starting point for me, very few modifications.
I won't use RF for the moment, I'll use the serial port of the arduino for debug.
LCD will be use during debug, but will be remove too.


Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 21, 2014, 12:11:48 PM
no no :)
D1 is a bipolar Overvoltage-protection diode!
Just in Case the Solar-Panel gets static charge or so.
D1 should be (in my case) a 47V Version. (P6KE47CA)
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kibi on July 24, 2014, 04:18:52 PM
Excellent work mega-hz.
It's nice to someone doing some work to improve this. I, unfortunately, don't have any time to spend on this project at this time, but you seem to be making some good improvements.
Thank you.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 24, 2014, 06:51:11 PM
Thanx,
yes, i want a complete system for my (or yours) solar-panels and windmills.
I have tried to contact Tim Nolan but after i wrote a mail his website went down.
It looks like the worst case (wich i don't hope!) that he has gone...
Can't explain that, but i have a bad feeling about Tim...
So whatever happend, keep in mind, the most of this project is not from me, it's Tims Devolepment!

Wolfram.

PS: Got a mail today, the PCBs are shiped!
They should be coming soon...
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mjeanne on July 28, 2014, 10:13:09 AM
Hi,

don't you need pull-down for the 'in' pin of BTS432 to secure at first start (so output is off while µC is not ready) ?
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on July 28, 2014, 11:11:23 AM
i don't think thats a problem, it normally happens only once, because the system will be running all the time.

but good idea!
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on August 01, 2014, 01:35:57 AM
Hi,
on Monday the pcb's have arrived, but i had to go to hospital for an operation on my right shoulder..
they look good and i am coming home on Saturday.
Will assemble one next week and see how it works.

Wolfram
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mjeanne on August 01, 2014, 06:22:16 AM
strange coincidence, I've break my left shoulder two week ago..
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on August 07, 2014, 07:06:04 AM
Hello Folks,
after i made one pcb assembled i try to set it up...
firstly my shunt-resistors (0.025OHM) between mosfet and battery burned...
When the PWM starts, the coil make some strange sounds, about 1Khz and the 5V of the arduino is pulsing.
LCD shows garbage than...
if the solar-volts are smaller as the battery-volts, the system (lcd) shows everything well.
I think there is a need for a seperate 5V, not of the battery.
And there must be an improvement with the mosfet to GND, i dont think this one is needed, it should run also if one takes a diode...
There must be some work on it to do.
At the end my 7805 on the arduino-nano burned too.
(http://www.mega-hz.de/solar_mppt_charger/DSC09908.JPG)
So sadly ... but i must stop here!
If anybody is interested in the hardware, i can sell it!
I have another 4 empty pcbs here and the one completely assembled with 4x20 white lcd.
the only thing i need and cant sell is the RF24 Module.
(http://www.mega-hz.de/solar_mppt_charger/DSC09909.JPG)
So, who is interested taking over this project?

Regards,
Wolfram.

(Meanwhile i have an Grid-Tie Inverter and have no use for Batteries)
[time... i have not so much time as i would like to have for this project.]

Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: jam770 on August 10, 2014, 04:25:24 PM
Hi everyone !

I am doing a similar project using tim nolan design. i designed my prototype pcb an all is well . now i am doing the second version with larger current sensors.

here is the pic in 3d of the first design.

the design will be available for sale as a kit also !!

Look here !! http://freesolarenergy.1colony.com/whats_new_2.html (http://freesolarenergy.1colony.com/whats_new_2.html)

regards
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mjeanne on August 21, 2014, 04:07:11 AM
I'm still working on my own version, but with only one arm working, I'm going very slow...   :P
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: andrewid on September 29, 2014, 06:53:25 AM
Anybody have a problem with low side mosfet? (M3)
I understand that it minimizes power loss on the schottky diode, but in my setup it remains open too long, and make a short circuit with the battery, and of course produces a lot of heat.
If i connect the gate to gnd (so only the schottky diode remians) everything is runing fine without any heat production. I know something is failing, but I dont't know what and why.

EDIT:
I just figured out that my AVR running only at 8Mhz instead of 16 or 20Mhz. Switching to 20Mhz solved the problem.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: Rusdy on October 13, 2014, 02:51:35 AM
Hi All,
I'm another one that got inspired by Tim Nolan's arduino MPPT, so here is my project:
http://epxhilon.blogspot.com.au/2014/06/bmppt-solar-charger-3.html (http://epxhilon.blogspot.com.au/2014/06/bmppt-solar-charger-3.html)

The difference is, I had to redesign from scratch, as mine is boost version, i.e. solar panel voltage is lower than my battery. This is because my panel is 80Watt 12V (21V open circuit), and need to charge my eBike battery (36V lithium NMC).

Efficiency is almost 90%, and been running happily since June 2014.

Rusdy
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: ybpvin on January 01, 2015, 02:43:27 PM
Hi friends!

I apologize for the English, I translate translator!
I picked up a similar device and was faced with the driver ir-2104. On the 3 contact existents 10-15 volts, and at the same time vihode 5 existents voltage, which leads to almost a short circuit. Do not know why?

https://yadi.sk/i/Ul8mWUP4djrot
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: 3roomlab on January 03, 2015, 11:45:53 PM
Hi All,
I'm another one that got inspired by Tim Nolan's arduino MPPT, so here is my project:
http://epxhilon.blogspot.com.au/2014/06/bmppt-solar-charger-3.html (http://epxhilon.blogspot.com.au/2014/06/bmppt-solar-charger-3.html)

The difference is, I had to redesign from scratch, as mine is boost version, i.e. solar panel voltage is lower than my battery. This is because my panel is 80Watt 12V (21V open circuit), and need to charge my eBike battery (36V lithium NMC).

Efficiency is almost 90%, and been running happily since June 2014.

Rusdy

nice ... any chance you could log the charge voltage vs panel voltage for a see look ?
i see you wind your own inductor, did you by any chance try to use "mini ring core" calculator program?
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on March 18, 2015, 03:03:56 PM
Hi, back to the topic...
has anyone build my schematics or found any errors?
Maybe i come back to this project....

Regards,
Wolfram
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on January 02, 2017, 06:03:24 PM
still any interests on this thing?

meanwhile i have some ideas to improve it, so feel happy to join again!
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: PoBoySolar on January 04, 2017, 11:02:57 AM
I have a totally different view on this. I run my system at a fixed power point voltage with an arduino. I live successfully totally off grid for a little over four months in the summer with only a car battery.  This system provides refrigeration, lights and all hot water.  My take on efficiency is different. 40 years ago I made a machine that was the fastest in the industry.  It didn't matter at all.  In a 12 hour work day it only ran for 4 hours.   The same problem exists in solar. A minimum number of panels is needed to operate through the worst days. On other days There is excess energy that could be used and it is just wasted.  My system was a test bed to show solar could be implemented very cheaply, basically only the expense of the panels.  If what I do seems a little odd, it is not because I don't know better.  As it turned out, I don't see much reason to change it.  It won't be long before solar equipment joins the other compost of our electronic society.  I'll certainly upgrade when this free stuff becomes available.

The power point of a panel is pretty much dependent on temperature.  During one season the temp doesn't change that much. It does during the day.  Mornings are colder, but there isn't much power there.  At peak sun times it is hard to put that extra energy someplace useful.  I have a chest fridge that I fill with a lot of liquid.  I store cold through the night.  Fridge operates in a very tight band just above freezing.  It only operates when the battery has a pretty good charge, about 13.4V if I remember.

The arduino is the charge controller, a simple buck converter off the 36V string with about a 51V power point.  Charging the battery has priority above all else.  The battery can be thought of as the fridge.  The converter is less than 180W on a 900W array. Don't laugh, PWM is at 120Hz using power transformer as the inductor.  The losses don't really matter, it is a part that anyone can find. All I need to do is power the fridge real time. The excess power is fed to two water heaters. I can generally dump 2.5KWH to heating water a day.  These heating elements are PWMed from a large capacitor bank, the same that feeds the converter.
The program decides where to send power based on the buss voltage.  This year my wife wants a dishwasher and I will be doing that in time slices.  Doesn't matter if it takes two hours to do.  The display for the entire system is just two blinking LED.

What I am trying to say is that it should be looked at as an entire system, not a bunch of black boxes slung together.  I see enormous energy waste in most RE systems.  Battery storage makes every system cost ineffective.
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: kikiloaw on January 07, 2017, 11:52:08 PM
can somebody tell what is the max:
input voltage:?
input current:?
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: mega-hz on January 08, 2017, 02:59:03 AM
i my new design it will handle voltages up to 200V and Currents up to 20A
Title: Re: Tim Nolan's Arduino MPPT - now with LCD
Post by: NealXu on December 01, 2017, 11:21:23 AM
Hi...I also think this is an interesting project and would like to know how you are getting on.Btw have you looked at how the commercial units do this? Or any reference designs.I know of 2 or 3 companies e.g. Microchip who have application notes on this sort of thing.

turnkey pcb (https://www.7pcb.com/)