Exhaustive Classification and Quantification of Coupling Modes in Power Systems with Power Electronics

TL;DR

The paper addresses dynamic coupling between synchronous machines and inverter-based resources in modern power systems. It introduces an exhaustive EMT-based benchmark with an SM, an IBR, and an equivalent grid to capture interactions, and applies linearization and modal analysis to quantify small-signal stability, complemented by sensitivity analyses. It classifies coupling modes into structural and non-structural tendencies and demonstrates the methodology on the IEEE 39-bus system, revealing high-frequency, damped modes whose behavior depends on topology and controller settings. The results have practical implications for stability assessments and guide grid design and control tuning in systems with substantial IBR penetration.

Abstract

Due to the energy transition, today's electrical networks include synchronous machines and inverter-based resources interfacing renewable energies such as wind turbines, solar panels, and Battery Energy Storage Systems to the grid. In such systems, interactions known as coupling modes or dynamic interactions, between synchronous machines and inverter-based resources may arise. This paper conducts a clear and exhaustive study on a proposed benchmark, in order to analyze, quantify and classify these new types of modes. Detailed models representing electromagnetic transient phenomena are developed and linearized, then used for conducting modal analysis to fully characterize the small-signal stability of the system. Also, a sensitivity analysis is presented to evaluate the impact of key parameters on the detected modes of oscillation. Besides the exhaustive classification of the possible coupling modes, the proposed benchmark and methodology can be used to study any given power system in a minimal order modeling. The case of a fully detailed power grid based on the IEEE 39 bus system was studied as an illustrative example.

Figures (11)

• Figure 1: A benchmark representing a real power system.
• Figure 2: SM's AVR and frequency control.
• Figure 3: Grid-Following Control block diagram
• Figure 4: Participation factors
• Figure 5: Eigenvalues sensitivity to $l_{cc}$