LED switching power supply EMC design - YSD driver
In recent years, the semiconductor lighting industry has developed rapidly in the world. This has brought a lot of convenience to our lives, but it has also led to the increasingly prominent electromagnetic pollution problem. One of the important sources is the core component of semiconductor lighting. Diode (Light-emitting diode, LED) switching power supply.
The electromagnetic compatibility (EMC) performance of an LED switching power supply refers to the ability of an electronic device or system to function properly in its electromagnetic environment without posing an unacceptable electromagnetic disturbance to any other object in the environment. The characteristics of the LED switching power supply
EMC are as follows: the switching process of the semiconductor device generates voltage and current distortion, and the electromagnetic disturbance and harmonic disturbance generated by the semiconductor device cause serious electromagnetic disturbance to the surrounding electromagnetic environment and nearby electrical equipment. It may also endanger the safety of nearby operators. At the same time, the control circuit inside the power supply must also withstand the electromagnetic disturbance introduced by the switching action and the surrounding environment.
Due to the above characteristics, coupled with the specific difficulties in electromagnetic disturbance measurement, there are many cross-disciplinary issues in the field of EMC evaluation of LED switching power supply supplies, which need further research. Therefore, in view of some problems in the field of EMC design and evaluation of LED switching power supply, this topic has carried out some corresponding researches on analysis, design, evaluation and rectification. Specifically, the main related research work is as follows:
1) Investigate and analyze the existing LED switching power supply, explore its existing EMC problem, and clarify its EMC testing direction;
2) Circuit based on LED switching power supply Principle, analyzed the main source and avoidance method of EMC, and completed its EMC optimization design;
3) According to relevant domestic and international standards, the corresponding test sites were arranged, and the EMC of LED switching power supply was tested and evaluated. The unqualified items such as electromagnetic interference in conduction and radiation have also been analyzed and rectified, and a more practical rectification plan has been proposed. In short, this topic focuses on the common problems of radiated disturbance, conducted disturbance and harmonics of LED switching power supply, and has developed a set of EMC optimization design and rectification methods, which has laid a good foundation for the relevant laboratories to carry out testing work. basis.