Efficient power factor correction for zero voltage switching control in electromagnetic transmitters: A technique and experimental verification

Electromagnetic transmitters have been extensively applied in the exploration of geological structures and mineral resources. Their effectiveness and signal quality are directly governed by the performance of their power supply modules. To achieve high power density and high stability in electromagnetic transmitters, this study proposed a power factor correction (PFC) technique based on the critical conduction mode (CRM). This technique employs a composite control strategy that combines voltage loop feedback with inductor volt-second balance feedforward. By leveraging the resonance between the boost inductor and parasitic capacitance during the dead time, this technique enables zero voltage switching (ZVS) for all power switch tubes, thereby significantly reducing switching losses. Experimental results demonstrate that the designed PFC achieved the expected performance, yielding an efficiency of 95.4% and a power factor of 0.99. Overall, this technique can effectively enhance the performance of the power supply modules in electromagnetic transmitters, holding significant practical value.