Numerical Investigation for Electromagnetic Interference Generated by Linear Motor of EMALS

摘要

In this paper, the electromagnetic interference (EMI) generated by the electromagnetic aircraft launch system (EMALS) linear motor is numerically investigated. The full-scale EM model of the linear motor is build up and simulated by two steps in a private computer. In the first step, the magnetic field intensity distribution inside the linear motor and along the air gap is calculated and recorded as functions of time. In the second step, the magnetic field intensity data in time domain is divided into its frequency components, and used as source to excite the electromagnetic field outside the linear motor. It is found that, because of the nonlinearity caused by the movement of loads along the linear motor, there is not only strong static magnetic field component, but also strong second harmonic component of the magnetic field distributed around the linear motor. The space distribution of the static and second harmonic magnetic field components outside the linear motor is calculated. Results show that, even at the distance of as far as 5 m away from the linear motor, the two magnetic field components have the intensity of 263.5 uT, which is about 5 times of Earth magnetic field and have significant effect on electronic devices.