Investigating the Impact of Induction Motor Starting on Grid-Forming Inverter-Based Microgrid

Microgrids using inverter-based resources (IBR) are becoming increasingly popular due to the sharp rise in energy consumption. With well-defined frequency and voltage droop control algorithms, these microgrids use parallel linked inverters that exchange power according to their ratings. With increased penetration of IBRs, stable islanded operation of a microgrid is aspired irrespective of the connected load. The induction motor starting either draws a high inrush current or currents with harmonic content. This current nature can interfere with the grid-forming (GFM) inverter control loops and create complications in the islanded microgrid. This paper considers different starting methods of induction motors connected to a GFM, and a comparison concerning starting current, voltage drop, frequency drop, and total harmonic distortion (THD) is carried out. The analysis is supported through simulations using MATLAB/Simulink.