Wide-frequency-band high-attenuation common-mode conductive electromagnetic interference shunt mixed type wave filter

A technology for conducting electromagnetic interference and common-mode filtering, applied in waveguide-type devices, circuits, electrical components, etc., can solve the problems of insufficient high-frequency noise attenuation, small size, and heavy weight, and achieve strong noise attenuation capability and light weight. , the effect of convenient design

CN1851973BActive Publication Date: 2010-05-12XI AN JIAOTONG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2010-05-12

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Abstract

This invention discloses a broad band high attenuation common mode conductive electromagnetic interference parallel mixed filter including a passive common mode filter inductor LCM, the input end of which is serial to the output of the HF current inductor LCT to make up of an active filter and a passive filter, the passive common mode filter inductor is serial to a noise source device to filter the HF electromagnetic noise effectively and correct the source impedance property of the device, in which, the output of the operational amplifier is parallel to the resistor by two high voltage ceramic condensers to be connected to the input of a small passive common mode inductor and works at the open loop state, the input of which is serial to the network side of the device by a HF current mutual inductor.
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Description

technical field

[0001] The invention belongs to the field of production and application of electromagnetic interference filters, and relates to a parallel hybrid active electromagnetic interference filter with wide frequency band and high attenuation multiple. Background technique

[0002] While power electronic devices are widely used and developed rapidly, the problem of electromagnetic interference (EMI) is becoming more and more serious. Especially in recent years, power converters are constantly moving towards high-frequency, high-efficiency, and high-power-density technologies. This is a huge challenge for how to effectively suppress the electromagnetic noise generated by switching devices. The passive EMI filter composed of passive components such as inductors and capacitors that is widely used at present is bulky in the low frequency band, and the filtering effect is not good, but it shows good filtering performance in the relatively high frequency part. The active ...

Examples

Embodiment Construction

[0014] refer to figure 1 and figure 2 , the broadband high-attenuation common-mode conducted electromagnetic interference parallel hybrid filter of the present invention includes a passive common-mode filter inductor L CM , the passive common-mode filter inductor L CM The input end of the high frequency current transformer L CT The output ends of the filters are connected in series to form a hybrid filter of passive filter and active filter;

[0015] Passive common mode filter inductor L CM The winding directions of the primary and secondary windings are the same, and the primary and secondary windings are respectively connected in phase with the incoming line terminals of the noise source equipment;

[0016] High frequency current transformer L CT There are 3 windings respectively, and the 3 windings are all wound in the same phase. Two of the windings are connected in series to the output end of the impedance stabilization network LISN, and one end of the other winding...