Recently, I have undertaken a Solar sun tracker project with the soul purpose of learning in mind. The basic operation of the project is to implement a dual axis solar sun tracker, this is done by using an Arrduino Uno board to operate a mechanical structure, the movement is based on readings from 4 LDR's. This part of the project has been successful.
The part where I'm a bit lost is at the output of the solar cell. The solar cell is rated at 5.5V, 320mA - I am looking to somehow boost the 5.5v to around 14v. I have looked into DC-DC Boost Converters and I have realised that there are various ways to implement them. I first took the route of using the raw components of the circuit with no IC chip, this ultimately failed and I came to the conclusion that I needed to take a different approach. I started to look into the various other methods and came across using a MC34063 chip, this seems quite appealing as I'd be able to calculate the components using the data sheet. The problem I'm facing is that as the DC input is a solar cell, the voltage input of the DC-DC Boost Converter will vary a fair bit. Could I get away with having a Vin of around 3v (+/- 50%) or is this just plain stupid?
Alternatively, I have been looking into creating a boost converter using a microcontroller, this is something I haven't looked into as much but seems promising. In time, I'd like to also attempt to implement the MPPT algorithm and have an inverter circuit on the output, in order to create a 'smart inverter'. But for now I'd like to take things one step at a time. Can anybody offer some guidance on the matter? which route would be the best to go down considering my goals?
MPPT Control Algorithm;
What I can work on from here is to have my readings from the solar panel input into my Arduino UNO - then I can start to have a look at the different readings and how a MPP can be found from these readings. Based on the findings I'll be able to alter the duty cycle of the square wave input and hence, increase Vout of the boost converter. I started to have a look at the various implementation methods of the MPPT algorithm and I've come across the 'Peturb-and-Observe' method. Is this a good place to start?
DC - DC Converter;
I'm still struggling to get my head around the application of the converter types, I understand how both Buck and Boost Converters work but I'm still unsure as to which circuit would be more fitting for my project. Currently, the vision I have is that I would build a Boost Converter circuit with a Vin of approximately 3v and a Vout of 14v. I'm aware that as my application uses a solar panel the input voltage will constantly change, but based on the readings from my solar panel I'll be able to alter the duty cycle so no matter what the input voltage is (within reason) I'll always be able to produce a figure reaching 14v at the output. Is this a viable solution? and how would I begin to calculate my component values, based on the fact that I don't have a definitive Vin.