新型耦合电感阻抗源逆变器应力简化分析方法*
A Simplified Stress Analysis Method for Coupled-inductor Impedance-source Inverters
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摘要: 耦合电感型阻抗源逆变器含有多个电感和电容,器件应力分析时通常采用安秒和伏秒平衡计算变换器的状态变量,计算过程冗长且容易出错。因此,为了简化电路分析,提出一种适用于耦合电感型阻抗源逆变器拓扑的无源器件消除方法。通过消除电路中的电容支路或电感支路,然后在一个开关周期内对电路进行平均化,根据所获得的等效平均化电路求解电路中电流、电压状态变量,使得电路的各个状态量之间耦合关系得到简化。为了阐述所提方法的分析过程,以高升压比Y源逆变器为例计算关键元件的电流和电压应力,并与传统分析方法进行比较。最后,通过试验验证所提方法的正确性。Abstract: The coupled-inductor impedance-source inverter contains multiple inductors and capacitors. The ampere-second and volt-second balance have been commonly adopted for calculating state variables in the stress analysis. But the calculation process is tedious and error-prone. Therefore, to simplify the circuit analysis, a reactive component elimination method is proposed to be applied for coupled-inductor impedance-source inverters. By eliminating the capacitor branches or inductor branches, the circuit can be averaged in one switching period. Then, the voltage and current variables can be calculated in the obtained equivalent average circuits, consequently simplifying the coupling relations among state variables. To illustrate the analysis procedure of the proposed method, current and voltage stresses of a coupled-inductor impedance-source inverter are determined using both the traditional and the proposed methods. Finally, their subsequent comparison and experimental results confirm the effectiveness of the proposed method.