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Research On Pulse Power Supply For Sintering Of Composite Conductive Materials

Posted on:2020-10-18Degree:MasterType:Thesis
Country:ChinaCandidate:Z Y HeFull Text:PDF
GTID:2392330578954920Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
In recent years,lightweight,high-strength,high-conductivity and high-carrying Cu/CNTs composite conductors have become the hotspot of new high-conductivity materials.In the preparation of composite materials,pulse current sintering can be achieved at lower temperatures than conventional processes.The rapid sintering of the composite material,and the sintered sample has the advantages of uniform grain size,good electrical conductivity,high hardness and good compactness.However,at present,there are few studies on the influence of different pulse current parameters on material sintering.This paper aims to develop a sintering power source with adjustable pulse current direction,amplitude,frequency and duty cycle.Used to explore the effects of sintering on composite materials under different pulse currents.On the basis of a large number of references,combined with the needs of this topic,the main topology of the power supply adopts a phase-shifted full-bridge conversion circuit,that is,two phase-shifted full-bridge DC/DC converter circuits are used as currents in both positive and negative directions.The output is then passed through a pulse output current chopper circuit to finally achieve bidirectional pulse current output.In the design of the main circuit,it mainly includes three-phase uncontrolled rectifier circuit and a phase-shifted full-bridge ZVS converter as the topology DC/DC conversion circuit.Among them,IGBT is selected as the main switching device of DC/DC converter circuit,and EE110 is selected.As the core structure of the transformer and the ratio is calculated.The DC/DC converter circuit uses a fall-wave rectification method as an output.In the control circuit,the small-signal model of the phase-shifted full-bridge conversion circuit is established,and the current closed-loop PI compensation design is adopted.UCC3895 is used as the phase-shift control chip of the full-bridge converter,and the PIC18F4520 single-chip microcomputer is used as the main control chip.The corresponding drive circuit,data sampling circuit and complete fault protection circuit are designed.Finally,the software part of the system was designed.Finally,based on the above analysis,the circuit was systematically simulated to verify the rationality of the circuit structure and parameter design.Waveform acquisition and testing were then performed on the power prototype.A simple sintering platform was built,and the microstructure and characterization of the sintered Cu/CNTs samples were carried out.The practicability of the pulsed power supply was further verified.
Keywords/Search Tags:pulse current sintering, phase-shifted full-bridge converter, soft switching, UCC3895
PDF Full Text Request
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