Analysis and Diagnosis of Conducted EMI Generated by Automatic Voltage Regulator (AVR) System in Synchronous Generator

With the power integrated technology is adopted, the capacity of power system in ships became larger and larger. More and more equipments are connected in the same power mains, and the requirement of system EMC become stricter than before. In such power system, the generator output should not only satisfy the demand of power quality, but its high-frequency effect to environment should also be considered. Thus, the interference which spread from power frequency to several mega Hz should all be reduced. Since the power electronics technology is introduced, automatic voltage regulator (AVR) system becomes the main interference source in conducted radio-frequency span. Furthermore, the interference could conduct to the generator output by the exciter transformer. In this paper, the interference generated by AVR system is analyzed and the diagnosis method of generator output interference is illustrated.