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Research And Design Of Switching Power Supply Based On Soft Switch Technology

Posted on:2019-03-22Degree:MasterType:Thesis
Country:ChinaCandidate:J J HeFull Text:PDF
GTID:2322330548461468Subject:Control engineering
Abstract/Summary:PDF Full Text Request
With the gradual progress of the energy crisis,zero-loss has gradually become a new benchmark for the development of new energy industries,and switching power supply is one of the most important parts of most power electronic devices.Its performance is not only related to the The use of electricity equipment has an impact,and it also imposes a certain burden on the power grid.Therefore,in this paper,how to reduce the loss of switching power supply is taken as the starting point.The switching power supply with Boost APFC(active power factor correction)and DC/DC phase-shifted full-bridge two-stage circuit structure is studied.The soft-switching technology is applied to the front and back two stages.The structures are individually optimized to improve the performance of the power supply.Firstly,the research status and development direction of the switching power supply are introduced,and the power factor correction and soft switching technologies that affect the power supply performance are described in detail.Secondly,the structure improvement,working principle analysis and parameter design of the main circuit of the front and rear stage are separately performed.For the pre-stage circuit,analyze the reasons for choosing the Boost circuit and its working principle.Through the discussion of the traditional soft-switch circuit,design a new minimal stress passive lossless soft-switching circuit suitable for the Boost APFC circuit.The implementation uses the inductor and capacitor.The passive features,detailed analysis of the working principle of the designed circuit,giving the theoretical working waveforms of the key components of each working phase,discussing the implementation conditions of the soft-switching circuit,and expounding the control method of the APFC,selecting and introducing TI's Based on the average current type control chip UC3854 as the controller of the preceding stage circuit,the design process of the preceding stage parameters is then given.By comprehensively comparing and analyzing the characteristics of the mainstream DC/DC phase-shifted full-bridge topology,an improved ZVS(zero-voltage)phase-shifted full-bridge soft-switching topology with a primary side additional clamping diode and a blocking capacitor is selected as the later stage.Based on the detailed analysis of the improved ZVS phase-shifted full-bridge soft-switch topology,the main circuit proposes and analyzes the key issues affecting its performance.At the same time,it discusses the corresponding processing procedures and analyzes the control mode while selecting TI's The UC3875 is used as the controller of thepost-stage circuit,and then carries out the parameter design of the post-stage circuit and the selection of the key components of the overall circuit.Finally,in the simulation software saber to build a circuit for simulation,through the analysis of simulation waveforms to verify the design of the circuit and the rationality of the theoretical analysis.
Keywords/Search Tags:Switching power supply, Power factor, Soft switching, Phase-shifted full-bridge
PDF Full Text Request
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