基于二极管钳位五电平技术的rLCL型感应电能传输系统谐波分析

摘要

感应电能传输(IPT)系统通常采用单相全桥逆变器作为交流电源,受功率半导体器件容量和成本限制,输出功率受限.为实现IPT系统的大功率输出,将二极管钳位五电平逆变技术应用到IPT系统中,并详细分析二极管钳位五电平逆变技术在IPT系统中的工作原理.利用逆变器输出电压的傅里叶级数表达式及电路拓扑,建立基于谐波与移相角、脉宽的关系表达式,得到五电平逆变器的最优工作点.与全桥逆变拓扑相比,所提控制策略能消除逆变器输出电压的3次、5次谐波,降低电压谐波总畸变率,同时增加IPT系统的输出功率.最后,构建一个五电平IPT的实验系统,实验结果验证了该方法的正确性与有效性.%The single-phase H-bridge inverter is usually used in inductive power transfer (IPT) system. With the constraints of the power electronic device capacity and the cost, the output power of single-phase H-bridge inverter is limited. To achieve higher power output, this paper applies diode-clamped five-level inverter to IPT system. The working principle of clamped diode multilevel technology in the IPT system is analyzed. The relationships of harmonic with phase-shift angle and pulse width are constructed using Fourier series expressions of the primary side output voltage to find the optimal operation point. Compared with single-phase H-bridge inverter, the controlling strategy proposed can eliminate the 3rd and 5th harmonics of output voltage, reduce the total harmonic distortion (THD) and increase the output power of IPT system. Finally, a prototype of proposed algorithm is built and the analysis is verified by experiments.