Modeling and Harmonic Impact Analysis of a Squirrel Cage Induction Generator Interconnected to the Power Network and Driven by an Electromagnetic Frequency Regulator
Electromagnetic frequency regulator (EFR); Power quality; harmonics and interharmonics; Squirrel Cage Induction Generator (SCIG); weak networks.
The analysis of electricity quality is an essential issue in the integration of distributed energy sources. Due to the increased penetration of such sources connected to the electricity grid, using power converters, new harmonic disturbance limits are regulated by technical standards. . This system is based on a Squirrel Cage Induction Generator (SCIG), and driven by an Electromagnetic Frequency Regulator (EFR). The steady state harmonic model of the REF is developed from the stationary frame, according to the conventional induction machine modeling. Thus, it is possible to analyze the harmonic disturbances occurring in electrical and mechanical quantities due to the EFR armature voltage inverter. The electrical connection between the EFR and the SCIG is non-existent, and the results demonstrate that the system's inherent inertia contributes to the mitigation of the harmonic content on the network side, arising from the converter switching. In addition to steady state results, Total Nominal Distortion (TND), which includes harmonic and interharmonic components, was calculated and performed better compared to the IEEE 1547-2018 standard and real data extracted from a single Generator Powered Induction System (SCIG). Finally, the harmonic performance of the proposed system was evaluated taking into account the impact of the Thevenin equivalent impedance of the electrical network on the Point of Common Coupling (PCC).