Moderní metody přenosu výkonu v soustavách s akumulací elektrické energie

Abstract

This Ph.D. thesis deals with the power devices for grid-connected systems with renewable resources and electrical energy accumulators. The thesis first presents available power devices with energy storage systems, converters for renewable resources, and different energy storage technologies. Thereafter, the proposed power configuration is introduced together with the location of a parallel-connected inverter (PCI) and a series-connected inverter (SCI) in this system. The main task of the SCI is to dynamically support the PCI and to keep the load voltage at required level. The focus is given to an investigation of modern control methods suitable for the SCI. A vector control strategy with a software phase-locked loop is selected and analyzed. The verification of the proposed control strategy is given by simulation in MATLAB/Simulink. Two prototypes of power converters are based on TMS320F28335 digital signal controllers, and are operated in grid mode or in island mode with different loads. In island mode, the PCI generates the basic voltage waveform and the SCI increases or decreases the injected voltage according to the reference load voltage. The experimental results demonstrate the correct system functionality.