Study Of Radiated Disturbance On-site Test Technology About Large Electromechanical Equipment

Since implementation of the China compulsory product certification system “CCC”on May1,2002, electromagnetic disturbance of household electric products have been under effective control. In recent years，the trend of the import of large electrical equipmentsis rising, while most of those equipments are hardly moved tothe standard test site to take the measurement. Thus, the test of electromagneticdisturbance characteristics, especially the radiated disturbance of large electricalequipments is still a problem in the industry.Radiated disturbance is the common test item in the field of electromagnetic, andcarried out in semi-anechoic chamber usually. However, it is hard to take the measurementof the test because of the characteristics of the large mechanical and electricalequipments including big volume, heavy weight,the complex installation and difficultmovement.With the improvement of electrification, more and more larger mechanical andelectrical equipments are using integrated circuits, and the risk of excessiveelectromagnetic radiation is increasing. The EMC standard for such equipments is only GB4824.But in this standard, the limits and requirements of the site radiated disturbancemeasurements are given.The topic regards the project of the test of on-site radiation about Large mechanicaland electrical equipment as the study object. Firstly, it summarizes the typicalelectromagnetic noise in the environment. Secondly, it develops the near-field detectionsystem by using spectrum analyzer in order to distinguish harassment signaland environmental electromagnetic noise effectively. Thirdly, using the measuring receiver and other equipments build the system of radiated disturbance. Fourthly, on the basis of thefully study of the basic standards of the basic standards of electromagnetic compatibility, itproposes the test methods of the on-site radiated disturbance which has operability. Lastly,the article illustrates the use of methods of measurement through actual cases. The finalresearch results of this project will be submitted to the National Standards Committee inthe form of standard modification suggestion.