Design Of Switching Mode Power Supply In Frequency Converter

The market competition of low voltage frequency converter become more and more cruel because of the homogenization problem.Cost down and reliability improvement of the frequency converter are two big problems for every manufacturers.Switching mode power supply(SMPS)is a kind of power supply that uses modern power electronic technology to control the on-off duty ratio of power semiconductor device and maintain the stable output voltage.on and off.SMPS design is one of the key point for frequency converter,Performance of SMPS will directly affect the overall performance of frequency converter system.The focus of this thesis is to develop a low cost and high reliability multioutput flyback switching power supply for low voltage frequency converter.The key point is to design the transformer and circuit parameters through theoretical calculation,and verify its performance,and finally meet the demand of the product.Firstly,this thesis briefly summarizes the development and current status of SMPS,and expounds that the core task of this thesis is to design a switching power supply system for 15kW frequency converter.Then,the hardware structure of frequency converter is analyzed,including internal internal hardware structure,load type and input power acquisition way of the SMPS.Next,five kinds of switching power supply topology are analyzed in depth,and the advantages of flyback switching power supply are summarized.Based on the above analysis,taking the SMPS system of 15kW frequency converter as the object,using UC2844 as the control chip,all parameters are designed and calculated,and finally the calculation results are applied to the actual circuit.Finally,the designed SMPS is tested,and the results are analyzed.The performance meets the requirements of the frequency converter,the developed SMPS is used in the actual products.