Research on electromagnetic interference characteristics and electromagnetic compatibility standard of intelligent equipment

With the rapid development of intelligent coal mine, higher requirements are put forward for EMC reliability of equipment.The problem of interference in the application of the new mining safety monitoring system still occurs occasionally.In order to make the communication and control equipment of intelligent mine work reliably without the influence of electromagnetic interference, several coal mines were investigated, studies the causes of interference,and the interference of main equipment was tested on site,analyzes the field test data, and summarizes the characteristics of electromagnetic environment in coal mine, and puts forward the types and parameters of electromagnetic environment interference of mine equipment, low-frequency interference, conducted interference of radio-frequency radiation coupling, voltage drop and interruption, radiated interference, etc.The interference low frequency component of the converter is more than 90 dBμV , which exceeds the standard limit.At the position close to the output of the converter, the high-frequency radiation is even close to 30 V/m, reaching the level of immunity level 4; the 50 Hz power frequency magnetic field intensity reaches 0.19 μT, which is close to the dangerous value.Voltage drop and changes occur frequently in coal mine power grid, which impact the working stability of intelligent equipment through power line.Based on the test results of electromagnetic environment,combined with the existing test standards of intelligent equipment, this paper suggested that the EMC problem should be considered comprehensively, and the conducted immunity test, magnetic field immunity test and voltage drop test of RF field induction should be added as the test supplement of intelligent control equipment.According to the characteristics of electromagnetic compatibility level of intelligent equipment in coal mine, the EMC standard system of equipment is proposed, including steady-state and transient interference parameters and items.The whole frequency band is covered by using different standard parameter combinations.At the same time, it is suggested that the test level should be determined by considering the practical application area, interference form and equipment sensitivity.