Power conditioning in fuel cell systems

The power conditioning module (PCM) in a residential fuel cell system manages the electrical interfaces between the fuel cell stack DC electrical output and the AC electrical outlet of the residential customer. The power-conditioning module can be ideally considered a power amplifier with an intermediate storage element. The role of this module is to provide sinusoidal voltage to loads when operated independent of the grid, and a sinusoidal current (power) source when operated in parallel with the grid. The output of the fuel cell stack is unregulated DC voltage with the added constraint that its output power cannot be rapidly varied to follow the instantaneous power requirements of the AC loads. Therefore, an electrical energy storage module (EESM) is used along with the fuel cell stack to form a DC bus for the DC to AC power conversion that can provide the instantaneous power requirements of the AC residential load. With the integration of a fully digital implemented control algorithm that provides flexibility for any of the control tasks.