Impact of the voltage and frequency of a pulse signal applied to a toroidal coil on near magnetic field measurements

Abstract

In power electronic systems, electromagnetic radiation of the near field is detrimental because it generates electromagnetic interference in static converters ultimately leading to the degradation of the EMC filter performance. This paper presents an experimental investigation into magnetic radiation generated by magnetic components, specifically toroidal inductors, in the time domain (TD) using an oscilloscope and in the frequency domain (FD) via a spectrum analyzer. The method employed to quantify the magnetic field is the near field scan (NFS) using magnetic probes. This approach enables us to identify the areas with the highest magnetic field emissions from the toroidal inductance across its three components (HX, HY, HZ). Initially, our investigation focused on two key parameters of the pulse signal. First, we examined the impact of varying the pulse signal’s frequency while keeping the voltage constant. Next, we analyzed the effect of variations in the amplitude of the pulse signal while keeping a constant frequency. Following these experiments, we generated magnetic field maps in the frequency domain (FD) above the surface of the inductor, specifically focusing on the HZ component. The scanning step is equal to 0,5 cm. The scanning area is equal to (x, y) = (4 cm, 4 cm).

Keywords

• toroidal inductor
• scanning near magnetic field
• time domain (td)
• pulse signal
• frequency domain (fd)