An S-CLC Compensated Load-Independent Inductive Power Relay System with Constant Voltage Outputs

This article proposes an S-CLC compensation network to achieve a relay system to power multiple gate drivers of series modules. There are three major contributions. First, it achieves the constant voltage (CV) and load-independent property, meaning the induced voltage on each receiver is immune to load variations. Second, the S-CLC circuit topology is compact to be constructed, and an integrated coil structure is proposed to limit the system size. Third, the efficiency of the power relay system is analyzed, including parasitic resistances of resonant components and coils, which reveal the load regulation phenomenon in practical applications. In order to validate the proposed topology, the parameter design methodology to achieve the highest efficiency is proposed, and a single-input-four-output prototype is implemented. The coil size is 180 mm × 175 mm, the transfer distance between receivers is 50 mm, and the switching frequency is 200 kHz. When the input dc voltage is 18 V, the induced voltage of each receiver is around 15 V, and the voltage difference between receivers is within 2 V. When the load resistances vary in a wide range from 15 to 100 Ω, the output voltage regulation rate is within 17.01%. The maximum power of the receiver can reach 13.53 W, and the maximum efficiency can reach 89.79%, showing that the proposed system can be used in practical applications. Besides, the prototype is exploited to power gate drivers with a total power consumption of 2.75 W, further verifying the practical application value.