## 1 Introduction
[36] combined this technique and equivalent consumption minimization strategy (ECMS) to design an EMS for the hybrid locomotive. Based on detailed evaluations of stochastic uncertainties in tramway operation, a suboptimal real-time power-sharing technique was proposed to deal with operation uncertainties, enhance fuel efficiency, and guarantee system durability. In this work, the FLC was conducted to coordinate the power flows of energy sources that could adapt to the requirement of load power. In [37], [PERSON] et al. established a fuzzy logic-based differential power compensation module to balance the performance deterioration of the PEMFC and BAT for a hybrid tramway system. In the aforementioned studies, the requirements of power distribution between the PEMFC and ESDs are effectively implemented by using fuzzy logic techniques. Nevertheless, the voltage control scheme of the DC bus was not considered to design, so the output voltage could not be maintained at the desired value. This thing can cause instability and decrease the working performance of the hybrid system. Based on the literature, although there are more challenges in the design procedure to achieve high efficiency, the fuzzy logic approach is still a good solution to construct an EMS for a hybrid PEMFC-BAT-SC system. This technique can handle most situations of operating behavior and mutual impacts of the charging and discharging process of ESDs to keep the high performance of all energy sources. Motivated from the above analyses and building on our previous work in [38], this paper proposes an EMS to improve the energy efficiency and fuel economy of a hybrid tramway system by using two levels of control. High-level control includes fuzzy logic rules and a bus voltage control loop to define the reference power of PEMFC and BAT. Then, low-level control is utilized to determine the appropriate control signal for converters of PEMFC and BAT. Accordingly, the main contributions of this research can be summarized as follows: Firstly, a new fuzzy logic strategy is designed to determine the sufficient power of the PEMFC based on the status of the BAT SOC and the required power of load under different working scenarios. Then, an adaptive proportional-integral-derivative (PID) control is employed to maintain the DC bus voltage at a steady state by using the BAT. Furthermore, the SOC regulator is constructed to maintain the SOC of BAT within the desired range to protect the BAT from the depth of charge or discharge and prolong the lifespan of the component. Finally, the proposed strategy is conducted and compared to the other completed strategies to verify the effectiveness. The rest of this paper is organized as follows. The configuration of the hybrid tramway is dedicatedly described in Section 2, and then Section 3 analyzes the proposed energy management strategy comprehensively with high- and low-level control to guarantee the system qualification. Based on the presented strategies, comparative simulations with other approaches are given in Section 4 to validate the effectiveness of the proposed strategy. Finally, Section 5 presents conclusions as well as merits for further developments.