Two parallel converters with small interconverter inductor for elevator drive system

This paper presents a two parallel converters hardware configuration for elevator drive system with individual DC-Links to reach more modular design. And a new circulating current suppressing strategy is proposed to reduce the Inter-Converter inductor as low as possible. With the new hardware configuration, first, the zero-sequence circulating current and the cross current paths are analyzed. Then, based on the analysis, the control algorithms consisting of two main loops in d, q, and zero axes are proposed. The hardware design and circulating current suppressing strategy are verified by the experimental. Therefore, the Inter-Converter inductor can be reduced very low.