Assessment of Exposure to Magnetic Field from Pulse Width Modulated Currents

Abstract

This paper describes how it can be investigated whether fields caused by pulse width modulated (PWM) currents comply with exposure safety guidelines such as the ICNIRP (International Commission on Non-Ionizing Radiation Protection) guidelines, using weighting filters and coupling factors in such a way that the time and geometrical dependencies can be treated separately. With that separation, results can be obtained for different currents without the need to repeat computationally demanding field computations for each current and it can be investigated how for example the rise time of the current affects the field exposure. Such investigations can help determine how PWM currents can be modified to ensure that the ICNIRP exposure safety guidelines are complied with.