NMOSFET based Analysis of Radiated Electromagnetic Interference in Indian Railways

摘要

Background/Objectives: The relevance of this study is prescribed by the rapid congestion of residential complexes around railway tracks especially in metropolitan cities of India. Railway network ejects unwanted electromagnetic emissions and have adverse effect on human nervous system. Hence this study aims to measure and analyze the safety level of electromagnetic interference produced by Indian railway infrastructure. Methods/Statistical Analysis: The method involves detection of EMI using drift current of NMOSFET bed which is modulated from the antenna inputs. The output detecting signal can tell the EMI safety of an area after processing the drift current. EMI at different frequencies were recorded as change in drift current in accordance with standard EN:50121. The test simulation of NMOSFET drift current with increasing electromagnetic frequency resulted in abnormality in reverse recovery time of MOSFET verifying that EMI affects the drain current, therefore using NMOSFET bed various antennas reading where measured and plotted with respect to radiation value leading to conclusion that some values of radiated emission are exceeding the safety values. Findings: The comparison of radiated emission with the European safety standard proves radiated emission is exceeding the safety value. Majority of the radiated voltage which is exceeding the safety lies in Radio frequency region (120-200MHz) are crossing the safety value while minority fluctuations above in IF region is also observed. Application/Improvements: These finding can lead to development of economical yet effective device of indicating EMI safety of a particular area helping them implement various techniques mitigation against harmful EMI showers. It can also helpful in setting Indian EMI standard for railway infrastructure.