根据在高频脉冲交流环节逆变器(HFPALI)中实现稳定直流供电的这一需求,分析了HFPALI的特性和LCL-T导抗网络的具体特征,提出了一种与HFPALI公用高频方波逆变器的DC/DC变换器。分析了该DC/DC变换器的工作模态,给出了主要工作波形,推导出了该DC/DC变换器的输出电压表达式。在控制方面,HFPALI的并网电流控制采用周波变换器实现,DC/DC变换器的直流输出电压通过相移高频逆变器的驱动信号来实现,因此并网电流控制与直流电压控制相互独立,据此特性,提出一种基于数字信号处理器(DSP)的相位移动方法。仿真和实验结果表明,所提出的带DC/DC变换器的HFPALI系统能稳定运行。
A stable DC power supply may be required in the high frequency pulse AC link inverter(HFPALI).To meet this demand,this paper proposes a DC/DC converter that shares the high-frequency square-wave inverter with HFPALI after analyzing the characteristics of the HFPALI and LCL-T immittance network.Each working mode of this DC/DC converter is analyzed and the key waveforms are presented.The expression for the DC output voltage is then deduced.With respect to control,the grid-connected current of HFPALI can be adjusted with a cycloconverter and the DC output voltage can be controlled by shifting the phases of driving signals of the high-frequency inverter.So the grid-connected current control is independent of the DC voltage control.A simple phase shifting method is hereby proposed based on the digital signal processor (DSP).Finally,the simulation and experimental results show that the proposed HFPALI system with DC/DC converter is stable in operation. This work is supported by National Natural Science Foundation of China (No.51107108,No.51077070),Qing Lan Project and Jiangsu Key Laboratory of New Energy Generation and Power Conversion.