Interleaving Impact on AC Passive Components of Paralleled Three-Phase Voltage-Source Converters

This paper presents a comprehensive analysis studying the impact of interleaving on harmonic currents and voltages on AC side of parallel three-phase voltage source converters (VSCs). The analysis performed considers the effects of modulation index and the interleaving angle. Based on the analysis, the impact of interleaving on the design of AC passive components such as AC line inductor and EMI filter are discussed. The results show that interleaving has the potential benefit to reduce AC passive components. To maximize such benefit, the interleaving angle should be optimized according to the system requirements including THD limit, ripple limit or EMI standards in different operation conditions such as modulation index and PWM strategy. All the analysis is based on an example system containing two two-level VSCs. However the proposed analysis method in frequency domain can be easily extended to multiple VSCs systems with other topologies. Experimental results have verified the analysis results.