Advanced EMI Simulation and Mitigation in Electromechanical Relays using MATLAB with Contact Material and Suppression Analysis

Electromechanical relays continue to play a vital role in modern control and protection systems, yet they are inherently prone to electromagnetic interference (EMI) and electromagnetic compatibility (EMC) issues caused by contact bounce and arcing phenomena. This paper presents a detailed simulation-based analysis of EMI and transient behavior for various relay contact materials, including Silver, Copper, Gold, Tungsten, and Silver Tin Oxide (AgSnO?). The proposed MATLAB model integrates both bounce and arc effects as a single overlapping event, providing a realistic representation of dynamic contact behavior during switching. Multiple suppression techniques, such as RC snubbers, metal oxide varistors (MOV), flyback diodes, and hybrid RC–MOV configurations, are evaluated across a broad frequency range to determine their effectiveness in reducing radiated and conducted emissions. The results demonstrate that AgSnO?, when paired with a combined RC–MOV suppression network, yields the lowest EMI energy and the most stable transient response. This study establishes a quantitative foundation for selecting optimal contact materials and suppression strategies to achieve improved EMC performance in electromechanical systems.