LCL型双向感应电能传输系统建模及控制

Modeling and control of An LCL bi-directional inductive power transfer system

由于双向感应电能传输(IPT)系统存在高频开关网络以及较多的工作模态,易引入高次谐波和EMI干扰,LCL滤波网络的加入,可以有效滤除导轨电流中的有害谐波并减小EMI干扰,通过对电路交流变量进行复数分析,建立了系统关于传输功率的数学模型,并由此得出,在最大传输效率条件下,原边输入电压Upi与副边输出电压Uso的相角差δ为±90°,系统能量分别正、反向传输;传输功率的大小则可通过调节Upi或Uso的模来实现。在此基础上,为保证导轨电流恒定,在原副边设计了相互独立的移相控制策略。仿真和实验结果表明,该控制策略在调节原边导轨电流恒定的同时,能根据负载的工作状态和实际需求,动态地改变能量传输的方向和大小,有利于提高系统的运行效率。

Since there exist high-frequency switching networks and complicated operating modes in bi-directional inductive power transfer （IPT） system, it is easy to result in high harmonics and EMI interference. An LCL filter network is introduced to effectively filter out the unwanted harmonics in track current and reduce EMI interference. Based on a mathematical model of the power transmission established by complex analysis of the AC variables, under the condition of maximum transmission efficiency, the phase angle differences between the primary input voltage and secondary output voltage Uso are ±90° and the energy is respectively transferred in forward or backward direction. Moreover, the power magnitude can be controlled by adjusting the modulus of Upi and Uso. In addition, to keep the track current constant, different phase-shifting control strategies are designed in the primary and secondary parts. Simulation and experimental results show that these strategies can not only adjust track current to keep constant but also dynamically change the direction and magnitude of power transmission according to the working conditions and actual needs of the system load to improve the system operating efficiency.