Application of solid-oxide fuel cell in distributed power generation

A dynamic model of a solid-oxide fuel cell (SOFC) of 100 KW capacity has been developed with a control action associated with it for application in distributed power generation. The SOFC system is chosen as a distributed energy resource (DER) because of its ability to tolerate relatively impure fuels. It also can be operated at a higher operating temperature. This dynamic model can be used to simulate and analyse the performance of such a system both in stand-alone and integrated mode with other DERs to predict its dynamic behaviour and load-following characteristics. With a control strategy developed to control the active power and inverter output ac voltage, it is highly efficient and capable of providing good dynamic behaviour and load-following characteristics while maintaining load parameters. The proposed model is used to simulate a step change in power demand from the inverter-side controller to the SOFC-inverter system. It uses two proportional-integral controllers separately with the SOFC system to control fuel flow in accordance with power demand and to maintain the bus voltage constant at the set point value.