Fast Calculation Approach of the Radiated Magnetic Field Based on the Equivalent Model of a Flat Ground Plane

For the functionality of the modern electric and electronic devices, high current is needed. However, this can produce a very high magnetic field in cables especially for low frequency ranges to 400 kHz according to IEC TS 42764-1, which can infringe the legal limits and the thresholds for health protection. Generally, to evaluate the influence of the radiated magnetic field, measurements and comparison with the related standards are needed. To check the magnetic field, full wave simulation can be applied. However, such simulations can be extremely time-consuming. Therefore, alternative calculation methods, which can predict magnetic fields reliably in short time, are needed. This article presents a fast calculation approach based on the superposition of the magnetic field radiated by a conductor and the equivalent model of the ground plane. This equivalent model consists of different regions, where the return currents flow. These currents are calculated as a function depending on the total current, the material of the ground plane and the frequency. The results of the fast calculation approach are then validated by comparing them to the results of the full wave simulation and measurement.