A power-speed hierarchical optimization framework of diesel/battery/supercapacitor vehicular hybrid propulsion systems

Abstract

Ships' fuel consumption has emerged as the primary contributor to energy use and pollution in maritime transportation. This paper presents a novel marine vehicular hybrid propulsion system (VHPS) comprising a diesel generator and a hybrid energy storage device (HESD) that integrates batteries and supercapacitors (SCs). However, variations in the power and energy characteristics of the three sources result in heightened intricacies in energy management and system control. Therefore, a power-speed hierarchical optimization framework is proposed to optimize the fuel consumption and stability of the system. Within this framework, an AECMS-GRNN energy management strategy (EMS) is proposed to reduce the fuel consumption of VHPS. Based on the AECMS-GRNN strategy's power distribution results, a multi-zone target speed power hysteresis control strategy is proposed to ensure that the speed of the diesel generator is stable, so as to improve the stability of the system. Finally, an experimental hardware-in-the-loop (HIL) platform is employed to validate the proposed framework's performance. From experimental results, the AECMS-GRNN strategy demonstrates precise load prediction with a minimal predictive ARMSE value of 1.5886 kW. Compared with a conventional rule-based (RB) strategy, AECMS-GRNN strategy can reduce the fuel consumption by 0.077 kg, about 7.7%. Additionally, the proposed speed control strategy ensures a stable speed for the DG, contributing to the system's consistent power supply.