*4.4.1 Experimental analysis of the impact of shielding system*

In order to verify the theoretical assumptions, an experimental prototype of a previously designed shielding was created. The photograph of the experimental workplace is evident from **Figure 31**.

The aim was to significantly reduce the switching frequency of the supply voltage and to suppress the emission of the EM field to meet the hygienic limits according to "ICNIRP 2010" [38, 39]. The operating parameters of the newly implemented prototype are quantified in **Table 4**. The values are valid for a working distance of 20 cm.

Full-scale maps measured at reduced power (maximum efficiency) can be seen in **Figure 32**. The resonance is around 121 kHz, with the high efficiency range more

*Optimization to U***<sup>1</sup> [V]** *P***<sup>1</sup> [W]** *P***<sup>2</sup> [W]** *η* **[%]** *fr* **[kHz]** *f* **[kHz]** *Rz* **[Ω]** Power 312 5116 4865 95.1 121.1 121 35 Efficiency 312 4056 3886 95.8 121.1 125 29

> *R*1/*R*<sup>2</sup> [Ω] *L*1/*L*<sup>2</sup> [μH] *C*1*/*C2 [nF] 0.21/0.21 172/167 10.444

The results confirm the ability of the systems to deliver 4 kW to the load at an efficiency of>95%, which, apart from the higher supply frequency, places it in the

than 10 kHz wide.

**Figure 30.**

**Figure 31.**

**Table 4.**

**69**

*Magnetic induction around shielded system.*

*Theoretical and Practical Design Approach of Wireless Power Systems*

*DOI: http://dx.doi.org/10.5772/intechopen.95749*

*Laboratory set-up for evaluation of the EM shielding impact.*

*Operational parameters of the system after application of the shielding.*

**Figure 29.** *Proposed electromagnetic shielding (left) and EM field distribution (right).*
