Utilizing high-order passive filters for the voltage-source converters is becoming attractive in industrial applications due to the excellent attenuation performance, smaller size, and lower cost. The LCL, the multituned traps, and recently the combined LCL with multituned traps (LCL-mT) are the most popular high-order filters. However, the increased number of elements and the inherent resonances complicate both filter parameter design and current control loop stabilization, especially, in the presence of parameter uncertainties and wide variations of the grid inductance. Hence, in this paper a straightforward and robust design procedure for the LCL-mT filter is proposed. Compared to the existing methods, the proposed technique is not iterative and satisfies the traditional practical limits on filter parameters, while ensures stability even in the presence of wide grid inductance variations and filter parameter uncertainties. The validity and effectiveness of the proposed method are proved by simulation and experimental results.

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