Virtual Inertia Controller Design Based on Mixed Sensitivity Constraint H∞ Approach for Load Frequency Regulation of Islanded AC Microgrid
Aatif Altaf, Mahendra Kumar, Deblina Biswas, Rajesh Mahadeva, Shashikant P. Patole
Abstract
This paper proposes the mixed sensitivity constraint H <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\infty $ </tex-math></inline-formula> based virtual inertia controller (VIC) design for load frequency control (LFC) of islanded AC microgrid (MG). Owing to the increasing integration of renewable energy sources (RESs) in the MG, the power electronic converters required to interface RESs into grid, does not support and maintain required inertia for MG reliable operation. So, system frequency deviates from its nominal value. Virtual synchronous generator (VSG) concept has been introduced to support system inertia in the inverter-based MG. This work introduces the robust control technique based on H <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\infty $ </tex-math></inline-formula> approach for design of VIC for the frequency regulation of MG. The mixed-sensitivity concept is utilized for H <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\infty $ </tex-math></inline-formula> control-based VIC design. The proposed design aims to strike a balance between achieving high performance in terms of control objectives, such as frequency regulation, while ensuring robust stability in the face of uncertainties and disturbances. The effectiveness and robustness of the suggested VIC for frequency control are assessed under communication time delay, step load demand, parametric uncertainty, and various generation scenarios. Further, the efficacy of the suggested control design is verified in comparison to the existing control approach.