The particle swarm optimization method for microgrids formulates a control problem as an optimization problem and PSO is used to search the solution space for optimal parameter settings in each mode. As the ability to access these markets is related to the rating of the assets, the model simulates rating movements over time and uses historical funding information of like assets to make estimates of future funding needs. A supply of crude fuel gas fed to the reformer 34 successively passes through the catalyst layers 81, 83, and 85 in this sequence to be subjected to reforming reactions and converted to a hydrogen-rich gaseous fuel. Furthermore, a method of driving such a security system is described. The nozzle body has protrusions to receive an end portion of the cover plate and press this cover plate from upward, and an urging member is provided to urge the cover plate in a direction that the end portion of the cover plate intrudes into the protrusions.