TSFLC based DC link voltage regulation of grid connected DC micro grid

Abstract

Integration of micro grid with utility power network has major concerns such as active power control and maintaining desired power quality (PQ) standards. Among several power quality issues, voltage dip and harmonics are critical concerns impacting the overall performance and stability of system. In this paper, a grid connected DC micro grid (DCMG) is designed and controlled to ensure requisite power allocation between the micro-grid and utility grid system vis-a-vis DC link voltage regulation, load balancing and harmonic elimination. The utility grid and DCMG system are interfaced via voltage source converter (VSC). The DC link voltage of VSC is regulated using Takagi-Sugeno fuzzy logic controller (TSFLC) based synchronous reference frame technique to compensate for the reactive power demanded by the load. In the proposed architecture, DCMG consists of 8 kW photovoltaic (PV) energy system with maximum power point tracking (MPPT), 6 kW wind energy generation system with MPPT, 3 kW fuel cell (FC) energy systems and a VSC interfaced to three phase utility grid. Further, the TSFLC is compared with conventional PI controller under different operating conditions. It has advantages over classical controller such as better performance under dynamics and can be expressed in the form of the exact linear function. The effectiveness of proposed control method is validated under MALAB/SIMULINK software under different loading conditions.