EXPERIMENTAL EVALUATION OF SOLAR CHARGE CONTROLLER INSTALLED IN A SOLAR-POWERED UNMANNED AERIAL VEHICLE (UAV)

Abstract

Electrically powered unmanned aerial vehicle (UAV) flight duration is limited by its capacity to carry the on-board battery. One of the methods to extend flight duration is by installing a string of solar cells into the UAV. Researchers have found that a good electrical connection between solar panels and the on-board electrical networks affects the output efficiency. Poor wiring connectivity and minor damages of solar panels contribute to loss of power and reduce the solar cells’ power output. On top of the electrical physical connectivity factor, the type of solar charging system also contributes to the efficiency of the power output. Therefore, this research aims to evaluate two different types of solar charge controllers; maximum power point tracking (MPPT) and pulse width modulation (PWM). Within the on-board solar charging system, a solar charge controller is installed to track the maximum power output of the solar cells and maintain a constant output voltage from the photovoltaic (PV) cell to charge the battery using the battery charging system. From the result of this investigation, by adding the solar charge controller into the system, the voltage output from all terminals (solar panel, battery, and load) were held constant even though the solar intensity varies. These findings conclude that both MPPT and PWM solar charge controllers are able to maintain constant output voltage with varying solar intensity. The results also show that the MPPT charge controller has marginally higher efficiency as compared to the PWM charge controller when used in our UAV platform.
Keywords: Unmanned aerial vehicle (UAV); solar cell; solar charge controller; maximum power point tracking (MPPT); pulse width modulation (PWM).

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