Design and implementation of an MPPT technique based on synchronous demodulation

Abstract

Artificial satellites use solar panels to produce their electric energy. Solar panels possess an operating voltage for which the power they deliver is maximal. This voltage is called the Maximum Power Point (MPP). The MPP of a given solar panel changes with respect to external conditions such as the sun irradiance or the temperature. In addition, the operating voltage of a solar array is fixed by the loads it is connected to. Techniques that put a solar array at its MPP are called Maximum Power Point Tracking (MPPT) techniques. Those techniques control a power converter that connects the solar array to the loads in order to track the MPP. Classical MPPT techniques require at least two measurements (current and voltage) per solar panel in order to work. This thesis described the design and the implementation of a disruptive MPPT technique applied to a system composed of solar arrays connected to a battery through buck converters. The technique relies on synchronous demodulation of orthogonal signals and requires a single measurement of current to control an undetermined number of solar panels. The technique proved to work with state of the art performances, therefore paving the way for a new generation of MPPT technique that are less demanding in hardware components.