Comprehensive Multiple Indicators Optimizations for Two-Parallel Interleaved Three-Phase Two-Level Power Converters Using Optimal Vector Sequences

The comprehensive multi-indicator optimization aims for an optimal trade-off among various critical indicators. This approach can effectively handle diverse scenarios and ensures stable performance by optimizing each indicator without significantly sacrificing the others. This paper aims to comprehensively optimize the common mode voltage, zero-sequence-circulating current, and line current ripples, which existing methods have not addressed. The presented interplay analysis of the three indicators reveals that the comprehensive optimization lies in selecting the most suitable common mode voltage, and the common mode voltage of ± V DC /6 is the optimal balanced value for the comprehensive optimization, which avoids large common mode voltages but retains the essential condition for the comprehensive optimization. Then, we further investigate the factors that hinder the comprehensive optimization of the three indicators. Based on it, we selectively eliminate vector combinations that hinder comprehensive optimization. Then, with the selected vector combinations, six optimal vector sequences are proposed and assigned to specific subsectors in each 60° sector. Additionally, we streamlined the implementation of the proposed vector sequences using six general switching action pairs and two simple chart flows, eliminating the need for complex online calculations. Finally, the comparative analysis and experimental results prove our proposed method's successful performance in comprehensively optimizing line current ripples, common mode voltage, and zero-sequence circulating current.