I3E Technologies, #23/A, 2nd Floor SKS Complex, Opp. Bus Stand, Karur-639 001. IEEE PROJECTS AVAILABLE, NON-IEEE PROJECTS AVAILABLE, APPLICATION BASED PROJECTS AVAILABLE, MINI-PROJECTS AVAILABLE. Mobile : 99436 99916, 99436 99926, 99436 99936 Mail ID: i3eprojectskarur@gmail.com Web: www.i3etechnologies.com, www.i3eprojects.com

1. AN LCL-LC FILTER FOR GRID-CONNECTED CONVERTER: TOPOLOGY,
PARAMETER, AND ANALYSIS
ABSTRACT
In order to further cut down the cost of filter for grid-connected pulse width modulation
(PWM) converter under the more and more stringent grid code, a new kind of high-order filter,
named LCL-LC filter, is presented in this paper. The resonant frequency characteristics of the
filter are analyzed, and a parameter design method on the base of the characteristics is also
proposed in the paper. The proposed parameter design method can easily make full use of the
existing research results about the traditional LCL filter parameter design. And then a parameter
robustness analysis method based on four-dimensional graphics is proposed to analyze parameter
robustness of the presented filter. Compared with the traditional one, the proposed analysis
method can analyze the filter performance under variations of several parameters at a time
without any iteration. The comparative analysis and discussion considering the LCL filter, the
trap filter, and the LCL-LC filter, are presented and verified through the experiment son a 5 kW
grid-connected converter prototype. Experiment results demonstrate the accuracy of theoretical
analysis and prove that the presented filter has a better performance than two others.