基于线性状态空间模型的WPT系统频率分析

Frequency Analysis of a Wireless Power Transfer System Based on the Linear State Space Model

以电压源型磁感应式电能传输(MIPT)系统为分析对象,基于线性状态空间模型,讨论电路谐振频率与其影响因素,以及它们对系统工作性能的影响。通过列出电路稳定工作时初、次级电压和电流状态方程,分析各变量的通解特性,得到初、次级两个固有谐振频率,并重点讨论两个谐振频率的内在联系。通过分析电路参数取值,对两个固有谐振频率表达式进行化简。经分析,在某些参数条件下,初、次级谐振频率分别只与该侧电路参数有关,电路工作频率范围只与初级参数相关。仿真与理论相吻合,并通过实验验证了分析结果的正确性。

Taking voltage source magnetic inductive power transfer（MIPT） system as an object based on the linear state space model, the resonant frequency of the circuit and their influence on the performance of the system are discussed.Two natural resonant frequencies are suggested by listing voltage and current state equations of the primary and secondary side when the circuit works stably and by analyzing the characteristics of each variable＇s general solution which help to study the internal relations of the two resonant frequencies.Simplified forms of the natural resonant frequency expressions are obtained according to the analysis of the circuit parameter.It is found that under certain circumstance, the resonant frequencies of primary and secondary side depend only on parameters of their respective side. Besides, the range of operating frequency is associated with the parameters of the primary side.The simulation results are consistent with the theoretical analysis, which is verified by experimental results.