{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34449"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34449","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Passive Cancellation of Common-Mode Electromagnetic Interference in Switching Power Converters","abstract":"It is well known that common-mode (CM) conducted electromagnetic interference (EMI) is caused by the common-mode current flowing through the parasitic capacitance of transistors, diodes, and transformers to ground in the power circuit. Because of the potential for interference with other systems as well as governmental regulations, it is necessary to attenuate this noise. Ordinarily this must be accomplished by using a magnetic choke on the input power lines, which can result in large penalties to the overall size, weight, and cost of the completed system. In order to lessen the requirement for this magnetic choke, there has been in recent years a desire to introduce noise cancellation techniques to the area of EMI. This text introduces a method of canceling the common-mode EMI by using a compensating transformer winding and a capacitor. Compared with active cancellation techniques, it is much simpler and requires no additional transistors and gate-drive circuitry since it merely adds a small copper winding and a small capacitor. By using this technique the size of the EMI filter can be reduced, especially for applications requiring high currents. In this thesis a survey of CM noise reduction techniques is presented, encompassing conventional and active cancellation techniques. The new method for passive noise cancellation is presented, which is then applied to families of isolated DC/DC converters, non-isolated DC/DC converters, and DC/AC inverters and motor drives. The method, results, and ramifications of this technique are presented in order of appearance.","abstract_html":"It is well known that common-mode (CM) conducted electromagnetic interference (EMI) is caused by the common-mode current flowing through the parasitic capacitance of transistors, diodes, and transformers to ground in the power circuit. Because of the potential for interference with other systems as well as governmental regulations, it is necessary to attenuate this noise. Ordinarily this must be accomplished by using a magnetic choke on the input power lines, which can result in large penalties to the overall size, weight, and cost of the completed system. In order to lessen the requirement for this magnetic choke, there has been in recent years a desire to introduce noise cancellation techniques to the area of EMI. This text introduces a method of canceling the common-mode EMI by using a compensating transformer winding and a capacitor. Compared with active cancellation techniques, it is much simpler and requires no additional transistors and gate-drive circuitry since it merely adds a small copper winding and a small capacitor. By using this technique the size of the EMI filter can be reduced, especially for applications requiring high currents. In this thesis a survey of CM noise reduction techniques is presented, encompassing conventional and active cancellation techniques. The new method for passive noise cancellation is presented, which is then applied to families of isolated DC/DC converters, non-isolated DC/DC converters, and DC/AC inverters and motor drives. The method, results, and ramifications of this technique are presented in order of appearance.","abstract_has_math":false,"creators":["Cochrane, Daniel"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical and Computer Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Chen, Dan Y."],"committee_members":["Boroyevich, Dushan","Lai, Jih-Sheng"],"year":2002,"date_issued":"2002-08-10","date_published":"2002-08-10","updated_at":"2026-07-22T22:20:17Z","subjects":["Switching Power Supplies","Noise Reduction","Noise Cancellation","EMI"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08102001-123915"],"render_values":[{"text":"etd-08102001-123915","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34449","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Chen, Dan Y."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Boroyevich, Dushan","Lai, Jih-Sheng"]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Cochrane, Daniel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:43:06Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:43:06Z","2002-08-10"]},{"key":"dc:date.issued","label":"Date","values":["2002-08-10"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Switching Power Supplies","Noise Reduction","Noise Cancellation","EMI"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08102001-123915"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/34449"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["It is well known that common-mode (CM) conducted electromagnetic interference (EMI) is caused by the common-mode current flowing through the parasitic capacitance of transistors, diodes, and transformers to ground in the power circuit. Because of the potential for interference with other systems as well as governmental regulations, it is necessary to attenuate this noise. Ordinarily this must be accomplished by using a magnetic choke on the input power lines, which can result in large penalties to the overall size, weight, and cost of the completed system. In order to lessen the requirement for this magnetic choke, there has been in recent years a desire to introduce noise cancellation techniques to the area of EMI. This text introduces a method of canceling the common-mode EMI by using a compensating transformer winding and a capacitor. Compared with active cancellation techniques, it is much simpler and requires no additional transistors and gate-drive circuitry since it merely adds a small copper winding and a small capacitor. By using this technique the size of the EMI filter can be reduced, especially for applications requiring high currents. In this thesis a survey of CM noise reduction techniques is presented, encompassing conventional and active cancellation techniques. The new method for passive noise cancellation is presented, which is then applied to families of isolated DC/DC converters, non-isolated DC/DC converters, and DC/AC inverters and motor drives. The method, results, and ramifications of this technique are presented in order of appearance."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Passive Cancellation of Common-Mode Electromagnetic Interference in Switching Power Converters"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Chen, Dan Y."],"dc:contributor.committeemember":["Boroyevich, Dushan","Lai, Jih-Sheng"],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["Cochrane, Daniel"],"dc:date.accessioned":["2014-03-14T20:43:06Z"],"dc:date.available":["2014-03-14T20:43:06Z","2002-08-10"],"dc:date.issued":["2002-08-10"],"dc:description.abstract":["It is well known that common-mode (CM) conducted electromagnetic interference (EMI) is caused by the common-mode current flowing through the parasitic capacitance of transistors, diodes, and transformers to ground in the power circuit. Because of the potential for interference with other systems as well as governmental regulations, it is necessary to attenuate this noise. Ordinarily this must be accomplished by using a magnetic choke on the input power lines, which can result in large penalties to the overall size, weight, and cost of the completed system. In order to lessen the requirement for this magnetic choke, there has been in recent years a desire to introduce noise cancellation techniques to the area of EMI. This text introduces a method of canceling the common-mode EMI by using a compensating transformer winding and a capacitor. Compared with active cancellation techniques, it is much simpler and requires no additional transistors and gate-drive circuitry since it merely adds a small copper winding and a small capacitor. By using this technique the size of the EMI filter can be reduced, especially for applications requiring high currents. In this thesis a survey of CM noise reduction techniques is presented, encompassing conventional and active cancellation techniques. The new method for passive noise cancellation is presented, which is then applied to families of isolated DC/DC converters, non-isolated DC/DC converters, and DC/AC inverters and motor drives. The method, results, and ramifications of this technique are presented in order of appearance."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-08102001-123915"],"dc:identifier.uri":["http://hdl.handle.net/10919/34449"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Switching Power Supplies","Noise Reduction","Noise Cancellation","EMI"],"dc:title":["Passive Cancellation of Common-Mode Electromagnetic Interference in Switching Power Converters"],"dc:type":["Thesis"],"thesis:degree_discipline":["Electrical and Computer Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:17Z"}