Ensuring Electromagnetic Compatibility of Microprocessor Relay Protection Devices

The article discusses the problems, relevance and methods of solving the problem of electromagnetic compatibility (EMC) of microprocessor devices in relay protection and automation systems. Theoretical information is provided on methods for calculating electromagnetic fields from holes in metal surfaces. Electromagnetic fields penetrate into electrical cabinets through technological openings such as ventilation, power and information cable entries, door slits, viewing windows, etc. The electric field distributions in an electric cabinet are given for three frequencies in the microwave range, the wavelengths of which are commensurate with the sizes of ventilation holes and holes for supply lines based on the High Frequency System Simulator (HFSS) software product. The current test requirements are set out in the International Electrotechnical Commission (IEC) 61000-4-3 standard, which regulates the requirements for the stability of electrical and electronic equipment to radiated electromagnetic energy.