Power Profile Measurement and System Design Analysis for a Wearable Photovoltaic Application

As wearable devices are gaining popularity for applications, like fitness trackers and health monitoring devices, an important aspect is how to most effectively power them. Solar photovoltaic (PV) power has great potential for powering wearable devices, but faces some challenges. The PV panels used in wearable applications will face different angles and capture different amounts of sunlight, which is challenging to model. To determine a realistic power profile for PV wearables, the power generated from each PV panel is measured for a variety of usage scenarios. A measurement device was developed that can simultaneously measure and log data of four identical PV panels used in a wearable bag application under realistic conditions. After data was collected, a modeling and fitting procedure was used to calculate the irradiance level on each PV panel. The resulting model was used to determine the PV profiles over time for the maximum power point (MPP) voltage, current, and power. These realistic profiles were then used to properly design, simulate, and compare three different converter architectures that transfer power from the wearable PV panels to the load.