摘要
在电动汽车无线充电系统工作过程中,锂离子电池负载参数会随着电池荷电状态(SOC)的改变不断变化,从而导致系统频率处于失谐状态。其主要原因在于系统的输入阻抗发生了改变,偏离了谐振点使系统的传输效率降低。针对这一问题,提出了一种基于负载实时变化的阻抗跟踪补偿方法,用矩阵电容代替接收端谐振电容的大小,以补偿负载阻抗的虚部;采用DC-DC型阻抗匹配电路,以补偿负载阻抗的实部。以锂电池负载为研究对象,分析了SS型谐振网络参数与传输效率的关系,推导了系统最大效率传输的条件,使用Matlab/Simulink软件进行仿真。仿真结果表明,使用该阻抗补偿方法,系统传输效率约为82.55%;相较于无阻抗匹配电路的无线充电系统,传输效率约提高3.25%,验证了该方案的可行性。
During the working process of the electric vehicle wireless charging system,the load parameters of the lithium-ion battery will continuously change with the change of the battery SOC.This situation will cause the system frequency to be detuned.Because the input impedance of the system has changed,it deviates from the resonance operating point,resulting in a decrease in the transmission efficiency of the system.To solve this problem,an impedance tracking compensation method based on real-time load changes is proposed.The matrix capacitor is used to replace the size of the receiving end resonant capacitor to compensate for the imaginary part of the load impedance;a DC-DC impedance matching circuit is used to compensate for the real part of the load impedance.Taking the lithium battery load as the research object,the relationship between the parameters of the SS resonant network and the transmission efficiency is analyzed,the conditions for the maximum efficiency transmission of the system is deduced.Matlab/Simulink software is used for simulation.Simulation results show the transmission efficiency is about 82.55%by using this impedance compensation method.Compared with the wireless charging system without impedance matching circuit,the transmission efficiency is about 3.25%higher,which verifies the feasibility of the scheme.
作者
廖力
刘坤
吴铁洲
LIAO Li;LIU Kun;WU Tiezhou(Key Laboratory of Solar Energy Efficient Utilization and Energy Storage Operation Control in Hubei Province,Hubei University of Technology,Wuhan Hubei 430068,China)
出处
《电源技术》
CAS
北大核心
2021年第3期374-377,共4页
Chinese Journal of Power Sources
基金
湖北省教育厅科学研究计划重点项目(D20191402)。
