In the actual application process, the high temperature rise often occurs in the MOS tube of the power transformer and the transformer design itself. Today we will start from these two aspects and see how to effectively solve the temperature rise of the switching power supply transformer. high problem.
In the actual application process, the high temperature rise often occurs in the MOS tube of the power transformer and the transformer design itself. Today we will start from these two aspects and see how to effectively solve the temperature rise of the switching power supply transformer. high problem.
First of all, from the perspective of the transformer itself, once the temperature rise is too high, it is mainly caused by four problems, namely copper loss, winding process problems, transformer iron loss and transformer design power is too small. No-load heating means the transformer insulation is damaged or the input voltage of the transformer is too high. If the insulation is damaged, the coil needs to be rewound. If the input voltage is high, the input voltage should be reduced or the number of coil turns should be increased. If the voltage is normal and it is hot and hot when the load is on, it means that the load of the power transformer is too large, and its load design needs to be changed.
In the design process of the switching power supply transformer, the heating of the MOS tube is the most serious, and the problem of its own high temperature rise is caused by the loss. The loss of the MOS tube consists of two parts: the switching process loss and the on-state loss. To reduce the on-state loss, the on-state loss can be reduced by selecting a low on-state resistance switch tube. The switching process loss is caused by the size of the gate charge and the switching time. Yes, reducing switching losses can be reduced by selecting devices with faster switching speeds and shorter recovery times. But what is more important is to reduce the loss by designing a better control method and buffering technology, such as the use of soft switching technology, which can greatly reduce this loss.
In addition, there is also a possibility that the temperature rise of the power transformer itself is too high, that is, the transformer itself is aging. When the engineer checks the transformer itself and the MOS tube and finds no abnormality, it is necessary to make a comprehensive judgment based on the working time and working life of the transformer.
