Research On Conducted EMI Suppression Of The Power Eletronics

This paper mainly discusses the method of suppression for conducted interference to reduce the influence on electronic devices from power system, other electronic devices and themselves. It is of profound significance in the field of military and aviation to analyze the conducted interference of electronic devices, to take the method of harmonic suppression, to employ power filter to suppress the high-frequency interference and to improve the performance of electronic devices.The definition of degree of harmonic distortion and power factor is give firstly. Then the relationship between harmonic and power factor is analyzed. In non-linear loads, the suppression of harmonic is the method of increasing power factor and the circuit of power factor correction also has the function of harmonic suppression.The third chapter analyze harmonic and power factor of typical single-phase and three-phase rectification circuits. Harmonic and power factor also are analyzed when the load is undulant. The parameters of circuit which impacts the harmonic are got. After that the sort of harmonic source is determined.The fourth chapter researches the two technologies for harmonic suppression, including power factor correction and harmonic compensation. Power factor correction comprises of passive power factor correction and active factor correction. Harmonic compensation contains passive filtering and active filtering. Main circuit and operating principle of active power factor correction circuit and active filter circuit are analyzed in the paper. Through comparison of characteristics between power factor correction and harmonic compensation it is finding the method of solving problem about harmonic in electromagnetic compatibility.Power electronic correction and harmonic compensation are used to suppress low-frequency harmonic in power electronic circuits, which include lots of power devices. Because power thyristor will generate pulses of which front and back edge is sharp when they are in the fast conversion between on and off. The pulses will cause the transient voltage and current, which will lead severe electromagnetic interference through power lines, parasitic parameter and stray electromagnetic coupling. EMI power filter is the most effective method for suppression of electromagnetic interference. So the research and design of EMI power filter is in the fifth chapter. The operation principle of EMI power filter is give at first. Then the main factors which influence the performance of EMI power filter is analyzed. The design method of EMI power filter is...