{"title":"利用负反馈减少隔离变换器中的共模电磁干扰","authors":"L. Katzir, S. Singer","doi":"10.1109/EEEI.2006.321136","DOIUrl":null,"url":null,"abstract":"In the field of power electronics, there is a trend for pushing up switching frequencies of switched-mode power supplies to reduce volume and weight. This trend causes an increasing level of electromagnetic interference (EMI) emissions. It is well known that common-mode EMI is resulted in by the switching of a parasitic capacitance of transistors, diodes, and transformers the power circuit consists of, which implies current flow to ground (actually the shielding) of the circuit. In this paper a method of common-mode EMI reduction, based on a negative feedback which implies compensating current flow is presented. More specifically, desired EMI reduction in the family of isolated DC/DC converters is achieved by means of a compensating transformer winding and a capacitor. An isolated flyback converter was constructed and tested in the Power laboratory in Tel-Aviv University. Using a spectrum analyzer, it was found that the common-mode EMI created by the parasitic capacitance of the switching transistor decreased between 10 and 15 dB in the low frequency harmonics of the converter.","PeriodicalId":142814,"journal":{"name":"2006 IEEE 24th Convention of Electrical & Electronics Engineers in Israel","volume":"13 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Reduction of common-mode electromagnetic interference in isolated converters using Negative feedback\",\"authors\":\"L. Katzir, S. Singer\",\"doi\":\"10.1109/EEEI.2006.321136\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"In the field of power electronics, there is a trend for pushing up switching frequencies of switched-mode power supplies to reduce volume and weight. This trend causes an increasing level of electromagnetic interference (EMI) emissions. It is well known that common-mode EMI is resulted in by the switching of a parasitic capacitance of transistors, diodes, and transformers the power circuit consists of, which implies current flow to ground (actually the shielding) of the circuit. In this paper a method of common-mode EMI reduction, based on a negative feedback which implies compensating current flow is presented. More specifically, desired EMI reduction in the family of isolated DC/DC converters is achieved by means of a compensating transformer winding and a capacitor. An isolated flyback converter was constructed and tested in the Power laboratory in Tel-Aviv University. Using a spectrum analyzer, it was found that the common-mode EMI created by the parasitic capacitance of the switching transistor decreased between 10 and 15 dB in the low frequency harmonics of the converter.\",\"PeriodicalId\":142814,\"journal\":{\"name\":\"2006 IEEE 24th Convention of Electrical & Electronics Engineers in Israel\",\"volume\":\"13 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2006-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"2006 IEEE 24th Convention of Electrical & Electronics Engineers in Israel\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/EEEI.2006.321136\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"2006 IEEE 24th Convention of Electrical & Electronics Engineers in Israel","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/EEEI.2006.321136","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Reduction of common-mode electromagnetic interference in isolated converters using Negative feedback
In the field of power electronics, there is a trend for pushing up switching frequencies of switched-mode power supplies to reduce volume and weight. This trend causes an increasing level of electromagnetic interference (EMI) emissions. It is well known that common-mode EMI is resulted in by the switching of a parasitic capacitance of transistors, diodes, and transformers the power circuit consists of, which implies current flow to ground (actually the shielding) of the circuit. In this paper a method of common-mode EMI reduction, based on a negative feedback which implies compensating current flow is presented. More specifically, desired EMI reduction in the family of isolated DC/DC converters is achieved by means of a compensating transformer winding and a capacitor. An isolated flyback converter was constructed and tested in the Power laboratory in Tel-Aviv University. Using a spectrum analyzer, it was found that the common-mode EMI created by the parasitic capacitance of the switching transistor decreased between 10 and 15 dB in the low frequency harmonics of the converter.