采用同轴相位检测线圈的感应无线电能传输系统谐振调节技术

Coaxial Phase Detection Coil and Its Application for Dynamic Resonance Tuning in Inductive Wireless Power Transfer Systems

在感应无线电能传输系统(inductive wireless powertransfer,IWPT)中,常采用谐振电路保证系统以最大功率和最大效率传输电能。受到系统参数变化的影响,IWPT系统容易发生谐振频率偏移,需借助有效的谐振点检测技术和谐振调节装置实现电路谐振调节。针对副边线圈感应电压难以检测,无法通过副边感应电压电流相位判定副边电路谐振的问题,该文首先设计了基于同轴相位检测线圈的副边电路谐振点检测方法,并对该方法的原理进行了详细分析。然后构建了一种基于同轴相位检测线圈和相控电容器的副边电路谐振调节控制方法,并根据该方法搭建了实验平台。实验结果表明应用该文的调谐方法后,系统传输功率和传输效率均有提升。特别是在原边线圈恒流有效值11A条件下,系统负载输出功率从508.92W增大至577.41W,原边直流电源至负载的总体效率从85.24%提升至88.98%,验证了同轴相位检测线圈用于副边电路谐振调节的可行性。

Inductive wireless power transfer （IWPT） systems generally operate at their resonant condition for maximum otttput power and maximum transfer efficiency. IWPT systems sometimes deviate their resonant states due to unavoidable parameter changes, thus it is essential to explore resonance detection methods for effective tuning. However, since it is difficult to detect the induced voltage in the secondary circuit, detecting resonance by comparing the phases of induced voltage and current would be impractical. Therefore, a coaxial coil wound along the secondary coil was first introduced for tuning point detection in the secondary circuit with its basic principle discussed in detail. This paper then proposed a tuning method based on phase-controlled capacitor and the aforementioned coaxial phase detection coil for controlling the resonance of the secondary circuit dynamically. A constant current-fed IWPT system was set up for experimental verification. When the primary coil was fed with 11A rms current, the result shows an output power rise from 508.92W to 577.41W, and a transfer efficiency boost from 85.24% to 88.98% after applying the proposed aming method. This verifies the feasibility of coaxial phase detection coil for dynamic resonance tuning in IWPT systems.