The Research Of Electromagnetic Environment Of High Voltage Pulse Discharge And The Test Method

High voltage pulse discharge will cause transient high voltage, large current, and great electromagnetic radiation. This strong interference may lead to the breakdown of other electrical equipments, electronic devices and systems that depend on them or at least disturb their normal performance.According to compulsory certification implementation regulations in China, the products must be in conformance with related Chinese EMC standards.Considering the cost and the convenience more and more companies today are using a new kind of instrumentation system that records and isolates EUT signals of interest without the need for pricey anechoic chambers. This system is able to use EMI precompliance measurement systems to perform conducted and radiated EMI emissions tests prior to sending the product to a test facility for full compliance testing. The paper is mainly about the research of the design of this effective system of EMC test.Ambient signals create a significant problem for EMC test. The signal produced by the EUT could be modulated by the ambient noise, and this would make the identification of the EUT's signal very difficult. In the second part of this article, an effective adaptive filter is introduced to set up an ambient cancellation system, which is the basic theory of the new method of EMI test.