基于最小电流比值的IPT系统频率跟踪的动态调谐方法

Dynamic Tuning Method of Frequency Tracking Based on the Minimum Current Ratio for IPT System

在感应电能传输(IPT)系统中,含有磁心的电磁耦合机构的气隙间距变化会导致系统发送端与接收端自感及互感参数漂移,进而使得IPT系统处于失谐状态,增加了电源所需容量,降低了系统传输效率。针对该问题,提出一种基于最小电流比值的发送端频率跟踪的动态调谐方法。该方法通过实时测量发送线圈电流有效值与直流源输出电流平均值,在控制器中计算电流比值并根据最小电流比值原则,实时调节系统工作频率,使IPT系统恢复谐振状态,提高系统性能。最后,在不同气隙间距的情况下进行动态调谐实验验证。结果表明,当气隙间距变化时,所提方法有效实现了动态调谐,恢复了IPT系统谐振状态,达到减少电源所需容量、提高系统传输效率的目的,且最大效率提升幅度为1.64%。

In the inductive power transfer(IPT)system,either the mutual inductance or the self-inductance will drift as the airgap variation of the electromagnetic coupling mechanism with magnetic core between the primary coil and secondary coil.Then,the required capacity of the source will increase and the efficiency of the overall system will decrease because of the detuning state of IPT system.In order to overcome this detuning problem,a dynamic tuning method is proposed in this paper to track the resonance of IPT system.Through tracking the minimum current ratio of primary coil and DC source as well as adjusting the frequency of IPT system dynamically by the controller,the system performance can be improved accordingly.Finally,various experiments are conducted against different airgaps between the primary side and the secondary side by a prototype setup.The test results show that IPT system can return back to resonance with different airgaps by the proposed method.Moreover,the required capacity of the DC source is limited,and the efficiency of the overall system increases up to 1.64%.