1200W 25A mppt charger with synchronous source

Hello guys welcome to my blog, my name is Maria Ramirez, today I bring a great project for those fans of clean energy, in this case I bring an MPPT solar charge controller based on arduino.

This charger has an efficiency close to 98% since it has a synchronous source controlled by means of the arduino, this charger is ideal for applications where it is required to feed large powers and it could even be implemented to charge the batteries of electric cars.

I designed this charger since in many parts of the world, unfortunately they do not have electricity in their homes, so I thought that this charger could be of great help since it could be used to power lights, computers and even refrigerators, if you have enough batteries, but nevertheless design this charger since today the world demands a change towards that the energies we use must be clean energies to help the planet, and of course, to learn from them since they are the future.

Initially this charger is designed to operate solar panels with a power of 300 watts each for a total of 1200 watts Although something that I must highlight is that the charger has a maximum input voltage of 80 volts and a maximum output current of 25 A, This charger is designed to work with various battery voltages, it can work with 12 V - 24 V - 36 V - 48 V batteries, in addition, if the charging algorithm for each type of battery is taken into account, this charger can charge batteries of all.

I decided to design a synchronous BUCK type converter since they offer us a very high efficiency Therefore we will waste less energy and at the same time our charger will be more efficient and smaller, this Source will have a switching speed of 60 khz and will be controlled by means of Our arduino which by means of a resistive divider at the output of the Source and a current sensor, will analyze the power delivered to our batteries and modify the PWM always in order to find the highest possible power.

This design is very versatile since it is possible to increase the power in a very easy way, we will only have to change mosfet for much more powerful ones depending on the power we want to obtain, in the same way we must take into account the LC output filter of the Source since we do modify the input voltages We will have to recalculate the filter, speaking of the filter I want to highlight the importance of quality What must these components have to obtain the calculated power, since the inductor must be able to withstand the maximum current of the source without get to saturate, since if it saturates this it will modify its value also modifying the cutoff frequencies of the filter and directly affecting our quality of energy that we obtain from the charger, in the same way the capacitor must be of very good quality to ensure the least possible ripple at the source outlet.

Thinking about the future, it would be a very good idea to design a system to analyze the monthly energy production, and in this way have more control in our system, a charge controller could also be implemented for the batteries that need it. How is the case of lithium batteries, and in this way always keep the batteries balanced and be aware of the entire system in general, the efficiency of this charger will depend directly on the quality of the mosfet and the coil used.

This charger implements several protection systems, for over temperature, for short circuit and for overload, in all cases, turning off the DC - DC converter directly, in this type of sources it is of utmost importance to have a good system on and off the mosfets Jackie this way we will avoid the accidental on or off of any of the mosfets causing a short circuit in this case, we must also take into account the dead time of the mosfets in the Source to guarantee the correct operation of the source and avoid heating in vacuum of the mosfet.

When we talk about high-power converters, it is essential to take into account the correct design of the PCB since a bad design of this could cause significant losses in the source and its malfunction, therefore it is important to take into account the correct dimensions of the tracks depending on the intensity of current that circulates through them, that is why in my PCB design I left some tracks without antisolder to reinforce with tin, since a significant amount of current will circulate, it is also of utmost importance to ensure correct cooling for the mosfets, since depending on the temperatures of these, we will have more or less limitation regarding the amount of current that they can switch, in addition to the impact that this has on the useful life of semiconductors.

Without more to say I say goodbye and I hope you enjoy this project as much as I do, any questions or suggestions in the comments, thank you very much for your attention guys.:)