The Effect of Temperature on the Performance and Lifetime of Communication Switching Power Supplies
The main component of communication switching power supply is high-frequency switching rectifier, which has gradually developed and matured with the development of power electronics theory and technology as well as power electronic devices. The rectifier using soft switching technology has reduced power consumption, lowered temperature, significantly reduced volume and weight, and continuously improved overall quality and reliability. However, whenever the ambient temperature increases by 10 ℃, the lifespan of the main power components decreases by 50%. The reason for such a rapid decline in lifespan is all due to temperature changes. Fatigue failure caused by various micro and macro mechanical stress concentrations, ferromagnetic materials and other components will initiate various types of micro internal defects under the continuous action of alternating stress during operation. Therefore, ensuring effective heat dissipation of equipment is a necessary condition for ensuring its reliability and lifespan.
The relationship between operating temperature and the reliability and lifespan of power electronic components
A power supply is an electrical energy conversion device that consumes some electrical energy during the conversion process, which is then converted into heat and released. The stability and aging rate of electronic components are closely related to environmental temperature. Power electronic components are composed of various semiconductor materials. Due to the fact that the loss of power components during operation is dissipated by their own heating, the thermal cycling of various materials with different expansion coefficients, which are interconnected, can cause significant stress and may even lead to instantaneous fracture, leading to component failure. If the power component operates under abnormal temperature conditions for a long time, it will cause fatigue that will lead to fracture. Due to the thermal fatigue life of semiconductors, it is required that they should operate within a relatively stable and low temperature range.
At the same time, rapid cold and hot changes will temporarily generate a temperature difference in semiconductors, resulting in thermal stress and thermal shock. Make the component withstand thermal mechanical stress, and when the temperature difference is too large, it can cause stress cracks to occur in different material parts of the component. Premature failure of components. This also requires power components to operate within a relatively stable operating temperature range, reducing sharp temperature changes to eliminate the impact of thermal stress shock and ensure long-term reliable operation of the components.
The influence of working temperature on the insulation capacity of transformers
After the primary winding of the transformer is energized, the magnetic flux generated by the coil flows through the iron core. Due to the fact that the iron core itself is a conductor, an induced electromotive force is generated in a plane perpendicular to the magnetic field line, forming a closed circuit on the cross-section of the iron core and generating current, known as "eddy current". This' eddy current 'increases the loss of the transformer and increases the temperature rise of the transformer due to the heating of the iron core. The loss caused by "eddy current" is called "iron loss". In addition, the copper wires used in transformers need to be wound. These copper wires have resistance, which consumes a certain amount of power when current flows through them. This loss becomes heat and is consumed, which is called "copper loss". So iron and copper losses are the main reasons for temperature rise during transformer operation.
