Study On The Influence Of Dynamometer System On The Performance Of Loaded EMC Chamber

New energy vehicles are listed as a key development industry in the "14th Five-Year Plan",but due to the addition of electronic devices with high power,high voltage,high current and high switching frequency,the phenomenon of electromagnetic interference is serious.The development of energy vehicles is seriously unfavorable,so new energy vehicles need to be tested for Electromagnetic Compatibility(EMC)in an anechoic chamber.Foreign loading anechoic chamber and bench design manufacturers are relatively mature in EMC on-load testing equipment and related technologies,while domestic EMC testing institutions lack a testing environment that can simulate actual working conditions.In addition,after the dynamometer system is loaded into the anechoic chamber,the The performance impact of the anechoic chamber is unknown.Because the dynamometer system needs to pass through the wall of the semi-anechoic chamber through the connecting shaft,the integrity of the internal shielding of the anechoic chamber is destroyed,and at the same time,the resonance characteristics of the anechoic chamber cavity and the performance of the anechoic chamber are affected to varying degrees;The results measured in an anechoic chamber environment are not accurate.Therefore,this paper mainly studies the influence and optimization analysis on the performance of the loaded anechoic chamber after the dynamometer system is loaded into the anechoic chamber.The contents of this study mainly include:1)Loaded anechoic chamber is a test environment based on the dynamometer system loaded into the anechoic chamber.This paper briefly introduces the types and structures of anechoic chambers,as well as the principle and significance of performance testing of anechoic chambers,and makes a detailed analysis of the impact of the dynamometer system on the performance of anechoic chambers after being loaded into the anechoic chamber.The performance of the loaded anechoic chamber is optimized from two aspects of the inherent characteristics of the wave material,and the effectiveness of the optimization measures is judged by the normalized field attenuation,field uniformity and background noise of the anechoic chamber;2)Based on the structure of the loaded anechoic chamber,the important geometric parameters and layout of the anechoic chamber and the dynamometer system were extracted and a three-dimensional model of the loaded anechoic chamber was established.By geometrically simplifying the structure of the three-dimensional model,it was imported into the electromagnetic simulation software FEKO.A performance electromagnetic simulation model of an anechoic chamber.3)Based on the anechoic chamber test standards CISPR 25,CISPR16-1-4,GB/T-12190,IEC61000-4-3,the electromagnetic simulation of the resonance characteristics of the anechoic chamber cavity and the performance of the anechoic chamber are carried out respectively.By simulating the resonance characteristics of the loaded anechoic chamber cavity,it is found that the loading of the dynamometer system at the low point has a great influence on the resonance of the horizontal polarization of the anechoic chamber cavity;by changing the geometric parameters and layout of the dynamometer system to study the measurement The influence of the power system on the performance of the anechoic chamber has been studied.It has been shown that the geometric parameters of the dynamometer system loaded with the anechoic chamber with better performance are1800 mm long,1485 mm wide,and 1653.3mm high.4)The basic principle of normalized field attenuation and field uniformity(80MHz?1GHz)changes after the dynamometer system is loaded into the anechoic chamber is cited,and the dynamometer system is optimized based on the electromagnetic simulation software.The research shows that,Adding ferrite absorbing material to the base of the dynamometer system can greatly improve the normalized field attenuation and field uniformity.Grounding can improve the shielding effectiveness and background noise of the loaded anechoic chamber,which verifies the effectiveness of the optimization process.