Control Challenges of Fuel Cell-Driven Distributed Generation

This paper discusses the load following capability of fuel cell-driven power plants. A linear model of a Solid Oxide Fuel Cell power plant is obtained and utilized for the design of robust controllers which enhance tracking response of the plant and reject disturbances originating from the distribution grid. Two robust controllers are synthesized applying the H∞ mixed-sensitivity optimization and their performance is validated by means of nonlinear time-domain simulations. The obtained results indicate that the disturbances can be successfully attenuated; however, the tracking response cannot be significantly improved without a modification of the design of the fuel cell power plant. The paper is concluded by a brief discussion on the physical limitations on the fuel cell output power ramp and possible solutions are outlined.