Abstract
Diesel generator-based systems commonly provide uninterruptible power supplies for critical loads. However, their slow dynamic behavior, particularly during start-up, can cause delays in power supply. Supercapacitor storage offers fast response and high power density but low energy density. This paper uses a supercapacitor energy storage system to address power issues caused by the slow dynamic behavior of the diesel generator. The hybrid UPS energy management system uses adaptive droop control, which uses DC bus signaling and droop control. The approach dynamically adjusts power sharing between the diesel generator and supercapacitor, enabling optimal energy management by changing the droop factor of the supercapacitor converter. The supercapacitor shares most of the load power at grid failure by operating with a relatively small droop factor. Then, the supercapacitor droop factor increases to reduce power sharing. Simulation results from MATLAB and Simulink show that the hybrid UPS operates for short and long grid failures, with a seamless start-up for a hybrid UPS based on a diesel generator and supercapacitor energy storage, which can improve the reliability and efficiency of backup power systems. © 2024 Elsevier B.V., All rights reserved.