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LCL Filter Design Method for Grid-Connected PWM-VSC
Majic, Goran,Despalatovic, Marin,Terzic, Bozo The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.5
In recent years, several LCL filter design methods for different converter topologies have been published, many of which use analytical expressions to calculate the ideal converter AC voltage harmonic spectrum. This paper presents the LCL filter design methodology but the focus is on presentation and validation of the non-iterative filter design method for a grid-connected three-phase two-level PWM-VSC. The developed method can be adapted for different converter topologies and PWM algorithms. Furthermore, as a starting point for the design procedure, only the range of PWM carrier frequencies is required instead of an exact value. System nonlinearities, usually omitted from analysis have a significant influence on VSC AC voltage harmonic spectrum. In order to achieve better accuracy of the proposed procedure, the system nonlinear model is incorporated into the method. Optimal filter parameters are determined using the novel cost function based on higher frequency losses of the filter. An example of LCL filter design for a 40 kVA grid-connected PWM-VSC has been presented. Obtained results have been used to construct the corresponding laboratory setup and measurements have been performed to verify the proposed method.
LCL Filter Design Method for Grid-Connected PWM-VSC
Goran Majic,Marin Despalatovic,Bozo Terzic 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.5
In recent years, several LCL filter design methods for different converter topologies have been published, many of which use analytical expressions to calculate the ideal converter AC voltage harmonic spectrum. This paper presents the LCL filter design methodology but the focus is on presentation and validation of the non-iterative filter design method for a grid-connected three-phase two-level PWM-VSC. The developed method can be adapted for different converter topologies and PWM algorithms. Furthermore, as a starting point for the design procedure, only the range of PWM carrier frequencies is required instead of an exact value. System nonlinearities, usually omitted from analysis have a significant influence on VSC AC voltage harmonic spectrum. In order to achieve better accuracy of the proposed procedure, the system nonlinear model is incorporated into the method. Optimal filter parameters are determined using the novel cost function based on higher frequency losses of the filter. An example of LCL filter design for a 40 kVA grid-connected PWM-VSC has been presented. Obtained results have been used to construct the corresponding laboratory setup and measurements have been performed to verify the proposed method.
Souri, M.,Kim, B. H.,Gruenewald, J. H.,Connell, J. G.,Thompson, J.,Nichols, J.,Terzic, J.,Min, B. I.,Cao, G.,Brill, J. W.,Seo, A. American Physical Society 2017 Physical review. B Vol.95 No.23
<P>We have investigated the electronic and optical properties of (Sr1-xCax)(2)IrO4 (x = 0-0.375) and (Sr1-yBay)(2)IrO4 (y = 0-0.375) epitaxial thin films, in which the bandwidth is systematically tuned via chemical substitutions of Sr ions by Ca and Ba. Transport measurements indicate that the thin-film series exhibits insulating behavior, similar to the J(eff) = 1/2 spin-orbit Mott insulator Sr2IrO4. As the average A-site ionic radius increases from (Sr1-xCax)(2)IrO4 to (Sr1-yBay)(2)IrO4, optical conductivity spectra in the near-infrared region shift to lower energies, which cannot be explained by the simple picture of well-separated J(eff) = 1/2 and J(eff) = 3/2 bands. We suggest that the two-peak-like optical conductivity spectra of the layered iridates originates from the overlap between the optically forbidden spin-orbit exciton and the intersite optical transitions within the J(eff) = 1/2 band. Our experimental results are consistent with this interpretation as implemented by a multiorbital Hubbard model calculation: namely, incorporating a strong Fano-like coupling between the spin-orbit exciton and intersite d-d transitions within the J(eff) = 1/2 band.</P>
Sr2Ir1−xRhxO4(x<0.5): An inhomogeneousjeff=12Hubbard system
Chikara, Shalinee,Haskel, Daniel,Sim, Jae-Hoon,Kim, Heung-Sik,Chen, Cheng-Chien,Fabbris, G.,Veiga, L. S. I.,Souza-Neto, N. M.,Terzic, J.,Butrouna, K.,Cao, G.,Han, Myung Joon,van Veenendaal, Michel American Physical Society 2015 Physical review. B, Condensed matter and materials Vol.92 No.8