The integration of Distributed Generation (DG) units, especially from renewable sources, is transforming low-voltage grids from passive to active systems. Accurate grid impedance information is vital for the reliable operation of grid-connected inverters, enabling stability analysis, fault detection, short-circuit current calculation, and islanding detection. This paper proposes a passive grid impedance estimation method leveraging on the harmonics introduced by variations in the operating conditions. The method records voltages and currents and uses these data when a current variation is detected. Moreover, it performs the parametric estimation using two approaches in parallel to achieve redundancy and it validates the impedance estimates to ensure a Desired Reliability Rate (DRR). Simulation parameters and validation results show a very small error in estimating resistive and inductive components. Hardware-In-the-Loop (HIL) emulation using a real-time FPGA-based platform confirms the algorithm's effectiveness in a controlled environment.
Di Nezio, G., Marini, G., D'Arco, S., Tedeschi, E., Lidozzi, A. (2024). A Passive Grid Impedance Estimation Method in Exploiting Variable Operating Conditions. In 2024 IEEE Energy Conversion Congress and Exposition, ECCE 2024 - Proceedings (pp.1198-1203). Institute of Electrical and Electronics Engineers Inc. [10.1109/ecce55643.2024.10861770].
A Passive Grid Impedance Estimation Method in Exploiting Variable Operating Conditions
Di Nezio, Giulia;Marini, Giovanni;Lidozzi, Alessandro
2024-01-01
Abstract
The integration of Distributed Generation (DG) units, especially from renewable sources, is transforming low-voltage grids from passive to active systems. Accurate grid impedance information is vital for the reliable operation of grid-connected inverters, enabling stability analysis, fault detection, short-circuit current calculation, and islanding detection. This paper proposes a passive grid impedance estimation method leveraging on the harmonics introduced by variations in the operating conditions. The method records voltages and currents and uses these data when a current variation is detected. Moreover, it performs the parametric estimation using two approaches in parallel to achieve redundancy and it validates the impedance estimates to ensure a Desired Reliability Rate (DRR). Simulation parameters and validation results show a very small error in estimating resistive and inductive components. Hardware-In-the-Loop (HIL) emulation using a real-time FPGA-based platform confirms the algorithm's effectiveness in a controlled environment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
