一种最小电压跟踪的感应电能传输系统调频调谐方法

摘要

感应电能传输（IPT）系统在进行电能传输的过程中，系统负载受到外部环境以及系统不同工况的影响而发生变化，进而导致一次侧回路等效阻抗发生变化，并且一次侧回路等效阻抗的变化量难以用准确的数学表达式表示。这种情况导致IPT系统一次侧回路不谐振，逆变器工作在非软开关状态，增大了一次侧电源的容量。为解决这一问题，以基于串联-并联补偿的一次侧恒流的IPT系统为研究对象，分析系统一次侧谐振状态受二次侧整流性负载影响的原因，采用一种最小电压跟踪的调频调谐方法，以实时检测的当前降压直-直变换器输出电压值为反馈量，控制逆变器的输出电压频率，通过不断跟踪降压直-直变换器输出的电压的最小值，使系统一次侧回路恢复到谐振状态。实验结果表明，所采用的方法能够有效地恢复一次侧回路的谐振状态，降低了一次侧电源的容量需求，使逆变器工作在软开关状态。%In the process of inductive power transfer (IPT), the secondary impedance changes due to changing operation conditions or other environmental factors, which also causes the change of equivalent impedance in the primary side. This leads to the deviation of resonance and soft-switching condition and requires higher capacity of the power supplyin the primary side. To solve the problem, aminimum voltage tracking based receiver's resonant frequency tracking technique is employed in the IPT system. This approach adopts real-time detection of the DC-DC output voltage and the operating frequency of the inverter to restore resonance of the primary circuit by constantly tracking the minimum DC-DC output voltage. The experimental result shows the validity of the proposed approach. It has been shown that the proposed approach lowers system capacity and helps to achieve soft-switching conditionin the primary side.