Quantifying Cyber-Vulnerability in Power Electronics Systems via an Impedance-Based Attack Reachable Domain

TL;DR

This paper introduces an impedance-based framework to quantify cyber-vulnerability in power electronics systems by mapping feasible attacks to stability margin migration, enabling better vulnerability assessment.

Contribution

It proposes a novel Attack Reachable Domain framework and Attack Penetration Index to evaluate node-level cyber-vulnerability considering privilege constraints and impedance reshaping.

Findings

Coordinated cross-layer attacks are more damaging than isolated attacks.

The proposed metric reveals vulnerability patterns not evident from grid-strength indicators.

The gray-box workflow enables assessment without inverter models.

Abstract

Power electronics systems are increasingly exposed to cyber threats due to their integration with digital controllers and communication networks. However, an attacker-oriented metric is still lacking to quantify the extent to which a node can be pushed toward instability within a privilege-constrained action space. This letter proposes an impedance-based Attack Reachable Domain (ARD) framework that maps feasible adversarial actions to critical-eigenvalue migration through impedance reshaping. Based on the ARD, an Attack Penetration Index is defined to quantify node-level cyber-vulnerability by jointly characterizing the penetration of the nominal stability margin and the accessibility of successful destabilizing attacks within a privilege-constrained action space. To make the proposed assessment computable when inverter models are unavailable, a practical gray-box workflow is further established by integrating existing impedance identification and differentiable surrogate tools. Case studies on a 4-bus system and a modified IEEE 39-bus system show that coordinated cross-layer manipulations are markedly more damaging than isolated single-layer attacks, and that the proposed metric reveals vulnerability patterns that cannot be inferred from grid-strength indicators.