Efficiency Improvement and Harmonic Suppression of Single-Wire Power Transmission System Through Compensation Network

In the single-wire power transmission (SWPT) system composed of Tesla's coils, only one loop resonates, which not only limits the further enhancement of efficiency, but also brings harmonic harm. Moreover, the adoption of accurate circuit model has increased the complexity of analysis and design. To address the above three issues, in this article, the LCL compensation network is added to the SWPT system to achieve simultaneous resonance of three loops to improve transmission efficiency, and high-order harmonics are greatly suppressed due to the effect of the compensation network. A simplified model of the SWPT system is obtained by establishing and solving nonlinear equations. Then, the detailed design process of the compensation network has been elaborated. A comprehensive comparison is conducted between the uncompensated SWPT system and systems with various compensation networks. Finally, in the experiment with a transmission distance of 70 m, the effectiveness of the simplified model is verified. The system with compensation transmits power of 720 W with an efficiency of 91.3%, which is 4% higher than the uncompensated system. The high-order harmonic voltage dropped by 87.5% compared with that before compensation.