Year: 2026
Type: article
Abstract: Power quality is a growing concern in modern electrical power systems due to the increasing penetration of power electronic interfaced nonlinear loads and generation, which introduce voltage and current distortions. Active filter techniques have been developed to mitigate these distortions. Among these techniques, virtual harmonic impedance is the most desired for harmonic power sharing or general power quality improvements. However, existing methods often lack explicit passivity considerations, which can lead to adverse interactions with the grid resonances. This paper presents a control design for a grid-forming Modular Multilevel Converter (MMC)-based STATCOM with virtual harmonic impedance. The proposed method enables the selection of a harmonic impedance that improves power quality while ensuring a positive passivity index around the converter harmonic admittance, thus guaranteeing stable interactions with the grid. This control approach is based on a dq-frame feed-forward harmonic compensator. The paper outlines the tuning methodology to achieve a harmonic virtual impedance, operational boundaries, and robustness of the proposed approach. Simulation results in a harmonic benchmark system demonstrate that the proposed control achieves the desired harmonic impedance while maintaining a passive response, ensuring stable system performance.
Authors: Eros Avdiaj, Marco Lindner, Jef Beerten
Institution: KU Leuven
Language: English
Topic: Power Quality and Harmonics
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7129738136