Alzola, Rafael Pena1; Liserre, Marco1; Blaabjerg, Frede3; Sebastián, Rafael4; Dannehl, Jörg5; Wilhelm Fuchs, Friedrich6
1 The Faculty of Engineering and Science, Aalborg University, VBN2 Department of Energy Technology, The Faculty of Engineering and Science, Aalborg University, VBN3 Power Electronic Systems, The Faculty of Engineering and Science, Aalborg University, VBN4 Department of Electrical, Electronic and Control Engineering, National University for Distance Learning, Madrid5 Danfoss Solar Inverters, Sønderborg6 Institute for Power Electronics and Electrical Drives, Christian-Albrechts-University of Kiel
Passive damping is the most adopted method to guarantee the stability of LCL-filter-based grid converters. The method is simple and, if the switching and sampling frequencies are sufficiently high, the damping losses are negligible. This letter proposes the tuning of different passive damping methods and an analytical estimation of the damping losses allowing the choice of the minimum resistor value resulting in a stable current control and not compromising the LCL-filter effectiveness. Stability, including variations in the grid inductance, is studied through root locus analysis in the z-plane. The analysis is validated both with simulation and with experiments.
I E E E Transactions on Power Electronics, 2013, Vol 28, Issue 6, p. 2642-2646