Effects of Electronic Warfare Systems on Microprocessor-Based Relay Protection and Automation Devices Under Wartime Conditions

Introduction. The operation of modern power facilities under wartime conditions creates additional risks for microprocessor-based relay protection and automation devices due to the potential effects of electronic warfare systems and intentional electromagnetic interference. The aim of this study is to analyse these effects, identify the principal mechanisms leading to functional disturbances and destructive failures, assess the electromagnetic immunity of commercially available РС83 and РС830 devices, and determine technical measures for improving their resilience. Materials and Methods. The mechanisms through which high-intensity electromagnetic interference may affect measurement and information circuits of protection and automation devices, data communication channels, and GNSS-based time synchronisation systems were analysed. The assessment of electromagnetic immunity was based on verified test characteristics of the РС83 and РС830 devices and published experimental results on IEMI effects on digital protection relays. A calculation approach was proposed that takes into account the electromagnetic radiation source parameters, the distance to the affected equipment, and shielding effectiveness. Results. Electromagnetic exposure may cause interference in measurement and information circuits, disruption of communication channels, degradation of GNSS-based time synchronisation, functional disturbances and, at sufficiently high exposure levels, damage to electronic components. For the РС83 and РС830 devices, electromagnetic immunity was verified within standardised test levels, including 10 V/m over the frequency range of 80–1000 MHz according to EN IEC 61000-4-3. This value does not represent a device failure threshold and should not be regarded as a universal criterion for immunity to HPEM/IEMI. Analysis of published experimental data confirmed that the response of a digital protection relay depends on the frequency and spatial configuration of electromagnetic exposure. The proposed calculation approach enables preliminary estimation of the required shielding effectiveness or permissible distance from a radiation source, provided that the far-field model is applicable. Conclusions. Improving the resilience of protection and automation systems to high-intensity electromagnetic exposure requires an integrated combination of shielding, appropriate grounding, protection and filtering of electrical circuits, fibre-optic communication links, and redundant time synchronisation with holdover capability. Reliable assessment of the immunity of specific devices to HPEM/IEMI requires specialised testing that accounts for the frequency, polarisation, magnitude, and spatial configuration of electromagnetic exposure.