Interleaved SPWM of Parallel CSC System with Low Common-mode Voltage

Parallel current source converter (CSC) with multilevel modulation has the advantages to increase the system power range, reliability and improve output quality. In this paper, an interleaved sinusoidal pulse-width modulation (SPWM) for paralleled CSC system is proposed. The gating signals for each CSC are produced by comparing two triangular carriers and three-phase current references directly. Multilevel output can be achieved by simply interleaving the carriers. Comparing to the multilevel space vector modulation (SVM), the proposed method is more straightforward and easier to extend to N-CSC parallel system due to its inherent scalability and modularity. Moreover, lower common-mode voltage (CMV) and circulating current can also be achieved by the proposed SPWM strategy compared to multilevel SVM. The validity and effectiveness of the proposed method are verified on a paralleled CSC system with both simulation and experimental results.