The EMC Design And Assessment Of LED Switching Power Supply

In recent years, the semiconductor lighting industry develops rapidly in global.On theone hand, it provides substantial facilitation to our daily life, but it also brings increasinglyserious electromagnetic pollution problems. One of the major source of the electromagneticpollution is the core component of the semiconductor lighting-Light-emitting diode(LED)switching power supply.Of particular concern, is the Electromagnetic Compatibility(EMC) performance of LEDswitching power supply, which is the ability for electronic equipment or system functionproperly in its electromagnetic environment, and would not generate electromagneticdisturbance to any substance in the same electromagnetic environment that they can notaffording to.The characteristic of the Electromagnetic Compatibility(EMC) of LED switching powersupply is: it would cause voltage and current distortion in the semiconductor device switchingprocess, which generates electromagnetic interference and harmonic interference. This wouldnot only bring serious electromagnetic interference into its around electromagneticenvironment and its nearby electrical equipment, but also this may pose safety threats to thenearby operating persons. At the same time, the pilot circuit inside the power source, mustsustain the electromagnetic interference caused by the switching motion and also that comesfrom its circumstances surrounding. Because of these specific characteristics, and with theconcrete difficulties for the electromagnetic interference measuring, there are a lot ofinterdisciplinary and cutting-edge sciences need to be researched of LED switching powersupply in the electromagnetic compatibility field like assessment etc..Therefore, this thesis conducted some research of analysis, design, assessment andrectification on the problems of the LED switching power supply EMC design and assessmentfield.To be specific, the main related researching including below: Firstly, to research andanalysis the existing LED switching power supply, study the problems the EMC facing andclear the EMC testing directionSecondly, based on the LED switching power circuit principles, to analysis the majorsource of the EMC and its circumvention method, and then to accomplish the optimization ofthe EMC design.Thirdly, conduct detection assessment to the EMC of LED switching power supply in thespecified field according to the domestic and abroad standard. Meanwhile, it analyzes and makes improvement of the nonconforming items of electromagnetic interference on theconduction, radiation etc., to put forward one kind of comparably practical improvementscheme.In all, the project selective analyzed the common problems of radiation interference,conducted emission, harmonics of the LED switching power supply, to summarize a set ofEMC optimized design and a practical rectification method, laying the foundation for therelated detection task in lab.