This paper presents a simple energy harvesting system using unpowered freewheeling propellers mounted on the quadcopter without changing its actual design. Different layout configurations have been analysed and its thrust variation also tested to place the harvesting system in a suitable place in the quadcopter. The same and different size freewheeling propellers running coordination and its speed ratio are examined at various speed. To know the flow performance the freewheeling propellers Reynolds number is calculated. The freewheeling propellers rotational energy which creates an electrical power by means of micro BLDC generator. The harvested energy from the BLDC generator is maximized using three-phase MOSFET enabled controlled rectifier with hysteresis comparator. To meet the requirement of powering the quadcopter the output voltage from the generator is boosted and regulated using single DC-DC SEPIC boost converter with high voltage and current range. This energy can be directly charge secondary battery or power the other electronic payloads. The freewheeling propeller energy harvesting system has been implemented and tested in the laboratory at static condition which gives 51 per cent of harvested current.

Brushless DC drives are extensively used in many automotive applications as motor or generator because of its more efficiency, more power density, simplicity of control, and lesser maintenance. This paper deals the power maximization and control of Brushless DC Generator (BLDC) using PI and Fuzzy logic controller (FLC) with hysteresis comparator. Sensorless control of position estimation is employed instead of Hall Effect position sensor where heat effective and costly. The BLDC generator power conversion, when using the conventional uncontrolled rectification methods using diodes, have their own limitations which may not maximize the possible power due to non-optimal current and low power per ampere ratio. This problem is cured using controlled rectifier and suggested to maximize the power generated from the BLDC generator. Traditional PI controller and Fuzzy Logic Controller are applied to control and maintain the DC link output voltage via Hysteresis comparator. Both controller performance is analysed using MATLAB simulation and experimental test verify the results.