Optimization and Control for Solid Oxide Fuel Cell System Hybrid DC Microgrids From the Perspective of High Efficiency, Thermal Safety, and Transient Response

Abstract

Managing the power transients with both high efficiency and thermal management constraints is a difficult task in the solid oxide fuel cell (SOFC) hybrid direct-current (DC) microgrids. This article proposed a SOFC-based DC microgrid, which consists of the SOFC stand-alone system, DC microgrid network, and DC/DC boost converter, along with the associated DC/DC load. The control and optimization strategy of the SOFC-based DC microgrids has been designed, including the thermal and electrical characteristics analysis. First, the voltage and current regulator based on the proportional–integral (PI) is designed, which can maintain the voltage stability of the proposed SOFC system. In addition, the optimal regulator based on the optimal operating points (OOPs) is designed, which can realize high efficiency and steady-state thermal safety of the proposed SOFC system. Finally, the main performance, including the SOFC stack electrical characteristics verification, SOFC stand-alone system electrical and thermal response, load-tracking characteristics, and system efficiency is observed and discussed in the proposed control and optimization strategy. Experimental results verify the correctness of the theoretical analysis and the effectiveness of the proposed optimization and control strategy.

Optimization of energy management in hybrid SOFC-based DC microgrid considering high efficiency and operating safety when external load power goes up

“…6, and the optimization process has been discussed in our previous work. [38][39][40][41][42] From Fig. 6, it is seen that the system Sustainable Energy Fuels efficiency can be capable of reaching up to 44%.…”

“…Our early works have studied the structure of the SOFC system, simulation stratagem, parameter, and system-level optimization, and control strategies. [38][39][40][41][42] The battery of Li_ion is considered in our paper since it has been proven with good energy density and electrical efficiency compared to the other energy modes. The supercapacitor is oen known as the electric double-layer capacitor (EDLCs), which can charge and discharge more electrical energy because of its high capacitance.…”

“…For further analysis of the performance of the SOFC system, considering the high efficiency, model-based optimization can be performed to determine the optimal combination of the operating parameters (I s , BP, AR, FU). Our previous studies [38][39][40][41][42] have traversed the OOPs in the different external load powers for the steady-state operation, which can satisfy the efficiency optimization and thermal safety simultaneously. The OOPs and their related system efficiency and voltage outputs are shown in Fig.…”

A Novel Hybrid MPPT Controller for PEMFC Fed High Step-Up Single Switch DC-DC Converter

“…In EVs, the permanent magnet machine is utilized along with the battery for running the EV at constant speed. In [44], the solid oxide fuel stack network is merged with the quasisource DC-DC converter topology and it is applied to the fourwheeler electric vehicle system to improve the efciency of the system. In SOFS, the electricity supply process happens by utilizing the ceramic electrolyte [45].…”