MPPT stands for Maximum Power Point Tracking and it is a highly efficient technique used in the solar energy domain. Intuitively, what MPPT does is to literally draw as much power as possible from the solar panel. Power is, by definition in the electrical domain, the product of voltage and current. So, what MPPT or at least the tracking part of MPPT does is to vary the voltage using a converter (usually a buck converter) and look at the corresponding values of current. Then it (it being a microcontroller) calculates their product or power and decides the combination of voltage and current where the power obtained is maximum. Then it operates the circuit at that maximum power point for efficient functioning. MPPT, fundamentally, is an algorithm that runs as a program in a controller to achieve this maximum power state.
This is my implementation of a MPPT system. Even in MPPT, there are many algorithms like incremental conductance etc. However, I used the Perturb & Observe method. Quite simply put, the controller keeps slightly changing the voltage (perturb) and checks if the power increases or decreases (observe). If, power increases it continues to change the voltage in that way until it reaches a peak point which is the maximum power point. In theory, I haven’t changed anything with regard to MPPT, however I added an Xbee module to allow wireless data transfer.
So what this system does, is to get the electrical data about voltage & current and transmit them to any remote computer. This is exceptionally important for day long analysis that can be carried out efficiently only by a computer when it would be impractical to leave a computer under the sun for an entire day. In my implementation, I chose to do the analysis in Matlab but the applications can be diverse. Anyway, the main purpose is the same – transmit data wirelessly to any processor (in a more sheltered place) for analysis and by extension detailed calculations.