Modal Characterization of Power-Line Filter Capacitors

• Published in: IEEE transactions on power delivery Vol. 25; no. 1; pp. 289 - 297
• Main Authors: Sanchez, A.M., Perez, A., Regue, J.R., Ribo, M., Rodriguez-Cepeda, P., Pajares, F.J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.01.2010; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Capacitance; Capacitors; Capacitors. Resistors. Filters; Common mode; conducted emissions; Delta modulation; differential mode; Electric filters; Electrical engineering. Electrical power engineering; Electrical power engineering; Electromagnetic compatibility; electromagnetic compatibility (EMC); equivalent modal model; Exact sciences and technology; Filtering; Filters; Impedance; Inductors; Information, signal and communications theory; Interference; Mathematical models; Methodology; Miscellaneous; modal conversion; Networks; Optimization; Power electronics, power supplies; Power networks and lines; power-line filter; Telecommunications and information theory; Testing; Various equipment and components; Y-class capacitor; Yttrium; Electric energy transportation; differential mode; Optimal filter; Electromagnetic compatibility; Power capacitor; Power electronics; electromagnetic compatibility (EMC); equivalent modal model; Common mode; Implementation; Y-class capacitor; Common mode rejection rate; Power filters; modal conversion; Equivalent circuit; power-line filter; Capacitance; conducted emissions; Electric device; Power transmission line
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2009.2028780

A typical power-line filter is composed, essentially, by common-mode chokes, X-class and Y-class capacitors. A good characterization of these components is needed to develop a technique to design the optimal power-line filter for an electric or electronic device by finding their best values. In this paper, a new methodology to characterize the behavior of power-line filter capacitors is presented. This methodology is based on a model where common-mode and differential-mode interference are separated into different ports in order to facilitate the study of the propagation phenomena. The methodology is used to explain modal conversion inside impedance networks with X-class and Y-class capacitors, to predict the common-mode and differential-mode emissions when these capacitors are connected to electric or electronic devices, and to improve the classical methodology of power-line filter implementation finding the optimal capacitances of the impedance networks. This new methodology has been successfully tested by using real measurements from capacitors and electric devices.