Optimization of the Fuel Cell Renewable Hybrid Power System Using the Control Mode of the Required Load Power on the DC Bus

Abstract

In this paper, a systematic analysis of seven control topologies is performed, based on three possible control variables of the power generated by the Fuel Cell (FC) system: the reference input of the controller for the FC boost converter, and the two reference inputs used by the air regulator and the fuel regulator. The FC system will generate power based on the Required-Power-Following (RPF) control mode in order to ensure the load demand, operating as the main energy source in an FC hybrid power system. The FC system will operate as a backup energy source in an FC renewable Hybrid Power System (by ensuring the lack of power on the DC bus, which is given by the load power minus the renewable power). Thus, power requested from the batteries’ stack will be almost zero during operation of the FC hybrid power system based on RPF-control mode. If the FC hybrid power system operates with a variable load demand, then the lack or excess of power on the DC bus will be dynamically ensured by the hybrid battery/ultracapacitor energy storage system for a safe transition of the FC system under the RPF-control mode. The RPF-control mode will ensure a fair comparison of the seven control topologies based on the same optimization function to improve the fuel savings. The main objective of this paper is to compare the fuel economy obtained by using each strategy under different load cycles in order to identify which is the best strategy operating across entire loading or the best switching strategy using two strategies: one strategy for high load and the other on the rest of the load range. Based on the preliminary results, the fuel consumption using these best strategies can be reduced by more than 15%, compared to commercial strategies.

Better Fuel Economy by Optimizing Airflow of the Fuel Cell Hybrid Power Systems Using Fuel Flow-Based Load-Following Control

“…Experimental tests have been performed for the first strategies (such as [3,4]) proposed in the research grant mentioned in the Acknowledgments section, but these will continue for recently proposed advanced strategies [14,[45][46][47], including the strategy detailed in this paper. Acknowledgments: This work was supported by a grant of the Ministry of National Education and Scientific Research, Romania, CNCS/CCCDI-UEFISCDI, within PNCDI III, code PN-III P1-1.2-PCCDI2017-0332 and title "Increasing the institutional capacity of bioeconomic research for the innovative exploitation of the indigenous vegetal resources in order to obtain horticultural products with high added value", and within PNCDI III, code PN-III P2-2.1-PED-2016-1223, number #53PED and title "Experimental validation of a propulsion system with hydrogen fuel cell for a light vehicle -Mobility with Hydrogen Demonstrator".…”

Sustainable CO2-Derived Nanoscale Carbon Support to a Platinum Catalyst for Oxygen Reduction Reaction

“…As the most mature and widely used type of fuel cell, the low-temperature proton-exchange membrane fuel cell (PEMFC) is known for its clean and smooth operation and high energy density output . By using hydrogen as a fuel and oxygen (or air) as an oxidant to convert chemical energy to electrical energy, PEMFC can reach a competitive energy efficiency of up to 40–50% . However, the technology comes with a major limitation originating from the sluggish kinetics of the oxygen reduction reaction (ORR) occurring on the cathode side of the fuel cell.…”

A Simple and Safe Strategy for Improving the Fuel Economy of a Fuel Cell Vehicle

“…Another aim of this work was to compare the performance of the SW-LFW strategy with other strategies, such as the Air-LFW technique [111] and the Fuel-LFW approach [112], which use the load-following set for the hydrogen regulator or oxygen regulator, respectively, in the entire loading scale. The main benefit of the load-following regulator (employed for one of the fueling regulators [111,112] or for both regulators [110]) is the battery operation in a charge-sustained approach [113], which substantially improved the battery's lifespan [114]. The FC power source generates the required power on the DC grid, according to the load demand.…”