PEBB modules in distributed generation applications

This paper examines how systems integrated to include multiple types of prime movers, such as fuel cells, microturbines, photovoltaic, and batteries, can benefit from a power electronic building block (PEBB). Fuel cell stacks, batteries, and solar cells produce DC output power. This power must be converted to the desired output voltage, which is usually 50/60 Hz AC. High-speed turbine generators that produce high-frequency AC outputs also require a rectifier and power converter to provide the desired output voltage. Previously it was sufficient to have only one source of power. Now multiple power sources like fuel cells, microturbines and batteries can be combined into one integrated power output while maintaining separate and decoupled control of the power provided by each independent source. The power drawn from each of the sources can be individually and independently controlled so that each voltage source capability with respect to energy and power availability is matched to the load requirements. These DG applications require semiconductor power topologies that can be arranged to provide 3 basis functions: (1) rectification (AC/DC), (2) conversion (DC/DC), and (3) inversion (DC/AC). The programmable feature of the PEBB module, coupled with slight rearrangement of the magnetic components, can provide all three of these functions. The PEBBs could be adapted to cover the 5 kW to 50 MW range.