Arabian Journal for Science and Engineering https://doi.org/10.1007/s13369-020-04941-5 RESEARCH ARTICLE-ELECTRICAL ENGINEERING A Study on Flight Time Enhancement of Unmanned Aerial Vehicles (UAVs) Using Supercapacitor-Based Hybrid Electric Propulsion System (HEPS) Muhammad Adil Khan 1 · Aqib Khan 1 · Mafaz Ahmad 1 · Shahryar Saleem 1 · Muhammad Shahbaz Aziz 1 · S. Hussain 2 · Fida Muhammad Khan 1 Received: 30 December 2019 / Accepted: 3 September 2020 © King Fahd University of Petroleum & Minerals 2020 Abstract This composition portrays the verification of applied research for increment in the flight time of an unmanned aerial vehicle (UAV) utilizing a hybrid electric propulsion system (HEPS) comprised of a solar cell, lithium-ion polymer battery, and supercapacitor bank. The implementation of a hybrid power supply comprised of both lithium polymer batteries having high specific energy (Wh/kg) and supercapacitors with high specific power (W/kg) with the additional option of solar charging was funded to be the optimal approach. High thrust requirements can be fulfilled by solar charging and a lithium polymer battery working in parallel with a proper conversion unit. The rapid charging potential of the supercapacitor helps to fulfill the power requirements of the UAV during flight time. Real-time experiments with special consideration were conducted to examine the increase in flight time of the UAV with the proposed HEPS. Very small and lightweight voltage regulation circuits were used to reduce the payload of the UAV and avoid unnecessary power consumption to achieve extra thrust. Simulations (MATLAB/Simulink) and experimental analysis were performed for a Phantom II DJI under different operating conditions. The effectiveness of the proposed HEPS was also validated. Keywords Unmanned aerial vehicle (UAV) · Supercapacitor · Li-Po · Hybrid electric propulsion system (HEPS) 1 Introduction Unmanned aerial vehicles (UAVs) are useful in a range of applications, including monitoring woodlands, data gath- ering for military surveillance, and media coverage. The long-term endurance of a UAV is important for achieving the desired tasks effectively. Several techniques to increase the flight time of UAVs have been proposed. One innovation with potential is the utilization of a hybrid electric propulsion system (HEPS) [1]. Hybrid innovation incorporates upsides of at least two sources of power to deliver a progressively proficient vehicle propulsion system. At the same time, numerous variations of hybrid frameworks are accessible now; mostly we derived it B Aqib Khan aqib.khan@mail.au.edu.pk 1 Department of Electrical and Computer Engineering, Air University, Islamabad, Pakistan 2 School of Electrical Engineering, Pusan National University, Busan, South Korea from three fundamental classifications: series, parallel, and power split. Even though the maximum system put to use an inward combustion or burning engine as the essential power source, others may utilize a turbine engine or fuel cell. Every framework has some uncommon favorable cir- cumstances and hindrances that can be versatile to the needs of the vehicle [2]. Series arrangement-based HEPS performs very well for high-torque and low-speed and application. However, because many energy conversions are performed, first mechanical energy from internal combustion engine (ICE) is changed over to electrical energy in a battery, at that point passed on to the electric machine, and ultimately changed over repeatedly into mechanical energy to control the propeller, expansive conversion of energy results in losses among the mechanical and electrical systems. Hence, it con- tributes a reduction in the performance of the system. Parallel HEPS is energy efficient because of the less number of energy conversion steps; anyway for researchers, it is always a dif- ficult task to control the flow of power among the various sources of energy. At the University of Colorado, a proto- 123