Solar Powered Unmanned Aerial Vehicle With Active Output Filter Under Non-Linear Load Conditions

In this project, a new solar-powered unmanned aerial vehicle's electric powertrain (UAV) is proposed. The proposed system structure is based on the creation of a power supply system for both the Solong and Zyphyr aircraft models. The proposed UAV model incorporates the Zyphry UAV's use of an AC line feeder to power the propellers rather than DC power lines. Solar panels, an energy management system based on a lithium sulphide battery, an inverter, an AC bus-line, and an active output filter are all part of the proposed powertrain (AOF). The AOF topology is made up of a high switching frequency H-bridge inverter and a small LC filter. By incorporating an emulated series resistance with the H-bridge stage to ensure high quality pure sinusoidal waveform of the line voltage, the AOF system reduces the size and weight of the power transmission system while significantly improving its conversion efficiency. 

This emulated series resistance produces an injected voltage across it to diminish unwanted harmonics created from the non-linear load. A simulation model setup is created to simulate the proposed system and the system is tested under non-linear load condition with closed-loop feed-back control strategy. The obtained simulation and experimental results demonstrate that high-quality sinusoidal line voltage waveforms can be obtained using the active resistance compensation technique with total harmonic distortion factor less than 3%.

Keywords: Active output filter, active resistance compensation, loss analysis, non-linear load, solar powered, unmanned aerial vehicle.