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

This paper 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 implemented, 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 clearly reveals the load regulation phenomenon in practical applications. A single-input-four-output prototype is implemented. The coil size is 180mm×175mm, the transfer distance between receivers is 50mm, and the switching frequency is 200kHz. When the input dc voltage is 18V, the induced voltage of each receiver is around 15V, and the voltage difference between receivers is within 2 V. When the load resistances vary in a wide range from 15ω to 100ω, the output voltage regulation rate is within 17.01%. Besides, the maximum power of the receiver can reach 13.53W, and the maximum efficiency can reach 89.79%, showing that the proposed power relay system can be used in practical applications.