降低反激式开关电源损耗的技术研究

发布时间：2018-08-31 16:39

【摘要】：反激式变换器最初应用在汽车点火线圈中。今天，反激式开关电源在消费电子等领域广泛应用。然而，反激式开关电源具有效率低的特点，如何降低它的工作损耗以提升工作效率，吸引了许多研究人员的注意。本文详细介绍了国内外降低反激式开关电源损耗技术的研究现状，深入分析了开关管占空比和输出整流器占空比对反激式开关电源中所存在的6种损耗（包括开关管的开关损耗与导通损耗、输入滤波电容器的损耗、变压器绕组的损耗、输出整流器的导通损耗、输出滤波电容器的损耗）的影响。理论分析得出：（1）当开关管占空比增大时，它的关断损耗呈现先减小后增大的规律，而输入端的各部分损耗则越来越小，但减小的速度随开关管占空比的增大而减小；（2）当输出整流器占空比增大时，输出端各部分的损耗和开关管的关断损耗将变小，但它们减小的速度也随着输出整流器占空比的增大而减小。本文设计了3组实验进行验证：（1）输出整流器的导通占空比保持不变，只改变开关管占空比；（2）开关管的占空比保持不变，只改变输出整流器的导通占空比；（3）同时以固定步长改变开关管占空比和输出整流器占空比，该组实验还通过搭建电路的方式进行了验证。仿真实验得出结论：当开关管占空比设定在0.45左右，输出整流器占空比设定在0.55左右时，，反激式开关电源的效率最高。实验结果验证了理论分析。
[Abstract]:Flyback converters were initially used in automobile ignition coils. Today, flyback switching power supply is widely used in consumer electronics and other fields. However, flyback switching power supply has the characteristics of low efficiency. How to reduce its working loss to improve its efficiency has attracted the attention of many researchers. In this paper, the research status of reducing the loss of flyback switching power supply at home and abroad is introduced in detail. Six kinds of losses (including switching loss and conduction loss of switch tube, loss of input filter capacitor, loss of transformer winding) existing in switch duty cycle and duty ratio of output rectifier in flyback switching power supply are analyzed in depth. The effect of on loss of output rectifier and loss of output filter capacitor. The theoretical analysis shows that: (1) when the duty cycle of the switch tube increases, the turn-off loss decreases first and then increases, while the loss of each part of the input becomes smaller and smaller, but the decreasing speed decreases with the increase of duty cycle of the switch tube; (2) when the duty cycle ratio of the output rectifier increases, the loss of each part of the output end and the turn-off loss of the switching tube will become smaller, but their decreasing speed will also decrease with the increase of the duty cycle of the output rectifier. In this paper, three groups of experiments are designed to verify: (1) the duty cycle of the output rectifier remains unchanged, only the duty cycle of the switch tube is changed, (2) the duty cycle of the switch tube remains unchanged, only the on-duty ratio of the output rectifier is changed. (3) at the same time, the duty cycle of the switch and the duty cycle of the output rectifier are changed with the fixed step. The simulation results show that when the duty cycle of switch is about 0.45 and the duty ratio of output rectifier is about 0.55, the efficiency of flyback switching power supply is the highest. The experimental results verify the theoretical analysis.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM461

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