Comparison of winding configurations of a 3-phase system for generating a rotating magnetic field powered by rectangular signals

The article compares two versions of 3-phase system for generating a rotating high-frequency magnetic field f = 100 kHz powered by rectangular signals with appropriately shifted phases. Obtaining sinusoidal signals from square waveforms was obtained using passive filters consisting of capacitors and inductors. The magnetic system was housed in a ferrite torus. In one version the filter branches were connected in a delta-system (Δ) and in the other version they were connected in a (Y)-system. The delta-system delivered a 72% higher magnetic field strength than the (Y)-system at the same supply voltage. Similarly, it turned out that the delta-system gives more than 3.5 times the temperature increase rate dT/dt compared to the (Y)-system. The advantage of the delta-system is its high efficiency, which can be used in magnetic hyperthermia as a treatment supporting radio- or chemo-therapy.