具有稳流输出的无线电能传输电路

Wireless power transmission circuit with constant current output

针对LC串联谐振和并联谐振在工作频率发生漂移时,电路整体功率传输能力及效率都会明显下降的问题,提出一种一次侧带有LCC(电感-电容-电容)复合谐振网络的无线电能传输电路。依据互感模型,在基波条件下,分别建立了耦合线圈一次侧与二次侧的等效电路,得到了谐振频率和输出电流表达式,并进一步导出了复合谐振网络中电感与电容的计算公式。实验结果表明,谐振频率与负载电阻无关,在谐振频率下,当耦合线圈的距离保持不变(即互感恒定)时,输出电流的有效值恒定,具有电流源特性。通过实验与仿真结果的比较,验证了对该电路分析与设计结果的正确性和有效性。因此该电路适合于需要电流源供电的负载,经改进后还可用于电场耦合式无线电能传输。

In order to eliminate the decrease of transmission power and efficiency when the working frequency drifts in LC series resonance and parallel resonance,a wireless power transmission circuit with LCC （inductor-capacitor-capacitor） composite resonant network in primary side was proposed.Based on mutual inductance coupling model of the two coils,the equivalent circuit models of primary-side and secondary-side were derived under the condition of the fundamental wave,respectively.With these equivalent circuits,the closed-form expressions for resonant frequency and output current were obtained.Furthermore,the expressions of inductor and capacitors in composite resonant network were deduced.It is demonstrated that the resonant frequency is irrespective of the load changing.Under the condition of resonant frequency,the RMS value of output current is constant when the distance between the two coupling coils remains unchanging,that is,the mutual inductance keeps constant.The circuit has the characteristics of current source.At last,the experimental and simulation results demonstrate that the circuit design and analysis are valid.Therefore,the circuit is suitable for the load supplied by current source.Besides,it can be adapted to electric field coupling wireless power transmission.