Tri-window compensator for loads with non-periodic current.

• Impacts of non-periodic are similar to harmonic current but more difficult to mitigate. • Time-frequency distortion index is most suitable for non-periodic loads. • Hybrid time-frequency method provides temporally distributed current reference. • Temporal distribution of compensation increases efficiency and reduces overall cost. • Fuzzy algorithm based on non-periodic characteristics decreases bandwidth requirements. This paper presents a new technique for the compensation of non-periodic load current. The method provides control references for three co-located devices, each corresponding to one moving calculation window and one decomposed part of the compensated current. They are slow compensator with high power rating, large calculation window, and low switching frequency; fast compensator with lower power rating, shorter calculation window, and higher switching frequency; and the reactive compensator which is an ordinary static VAR compensator (SVC). A fuzzy based adaptive window is proposed for the slow compensator to find the optimum window for different load characteristics. The technique is evaluated using real-world data and controller hardware-in-the-loop (HIL) implementation. [ABSTRACT FROM AUTHOR]