Grid interaction operation of a telecommunications power system with a novel topology for multiple-input buck-boost converter

Typically, telecom power systems are connected to the grid and diesel generator. This paper represents a new telecom power system using local microsources (fuel cell and microturbine). Some benefits of this system are effectively eliminating batteries, diesel generator, and automatic transfer switch. In this study, a new multiple input buck-boost converter is utilized as an interface between the microsources and the dc bus. The peak current-mode control is used to control the current of fuel cell while the voltage-mode control is used to regulate the output voltage. A model for the proton-exchange membrane fuel cell (PEM FC) and microturbine (MT) along with their subcomponents and internal controls are presented. Furthermore, the parallel operation of FC and MT by using the proposed multiple-input dc/dc converter is investigated. In addition, the dynamic response of the system to the dynamic behavior of the load is analyzed. Using an inverter, the common bus of the system also connected to the distribution network in order to supply the excess power to the grid. For grid interconnection, an LC filter, double-tuned filters, and a C-type high-pass filter are developed for eliminating high-frequency switching oscillations, selected harmonics, and high-order harmonics, respectively.