The efficiency of a multiphase wireless power transfer (WPT) system varies with the size and position of loads. Based on the traditional WPT system, the efficiency improvement of three-phase WPT system under load variation was studied. A three - phase shift control (PSC) strategy is proposed. Mathematical formula of optimal resistance is deduced and the optimal phase shift angles (PSA) for maximum efficiency are presented in the three-phase WPT system. Through the analysis of the electromagnetic model of the system, the optimal phase angle at which the load maintains optimum efficiency at different locations is deriving. A three-phase WPT phase experimental platform based on PSC is built. Verify the validity and correctness of PSC strategy. Simulation and experimental results show that the efficiency of the receiving coil can be increased by 10% -15% after the phase is adjusted at different positions. The proposed three-phase phase shift control strategy has a guiding and reference significance for subsequent related research.

多相无线电力传输（WPT）系统的效率随负载的大小和位置而变化。基于传统的WPT系统，研究了三相WPT系统在负载变化下的效率提高。提出了一种三相移相控制（PSC）策略。推导了最佳电阻的数学公式，并在三相WPT系统中给出了最大效率的最佳相移角（PSA）。通过对系统电磁模型的分析，得出了在不同位置负载保持最佳效率的最佳相位角。建立了基于PSC的三相WPT相实验平台。验证PSC策略的有效性和正确性。仿真和实验结果表明，在不同位置调整相位后，接收线圈的效率可以提高10％-15％。提出的三相相移控制策略对后续相关研究具有指导和参考意义。