Interline fuel cell (I-FC) system with dual-functional control capability

Abstract

In this paper, a new system concept is presented for the grid connection of fuel cells. In conventional grid-connected systems, fuel cells ensure the generated power into a single electrical feeder and control the electrical-line through interfacing elements. In the proposed system, interline fuel cell (I-FC) system shares a common dc-dc converter tied fuel cell at the base of inverters and eliminates the additional fuel cell & dc-dc converter in a multi-feeder system. For this purpose, a fuel cell system is connected to multi-feeders through separate inverters, thereby sharing electrical power into the feeders and attenuating the harmonics at grid-side currents. In this direction, the proposed system presents an economical way for the mitigation of electrical problems for multi-feeders. In order to achieve the functional capabilities of I-FC system, dual-functional control is separately applied in the grid inverters. In the testing stage of I-FC, nonlinear loads in feeder I & feeder II create 31.29% and 27.61% total harmonic distortion (THD) at grid-side currents, respectively. With I-FC, the THD values are reduced to approximately 3% values in both feeders after the harmonic elimination capability. Also, I-FC allocates the active power to both feeders, and reduces the electrical power demand from the utility-grids. The evaluation results verify that I-FC system accomplishes the good performance to control power-sharing and attenuate the current harmonics at grid-side. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.