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The Design And Debugging Of AC Square Wave Power For Rail Flash Butt Welding

Posted on:2012-01-29Degree:MasterType:Thesis
Country:ChinaCandidate:W QinFull Text:PDF
GTID:2212330338966362Subject:Materials Processing Engineering
Abstract/Summary:PDF Full Text Request
Laying of CWR is widely used in modern railway for the heavy completion and high-speed transport to improve the track structure. UN5-150 mobile rail welding machine has been widely used in the railway construction, the power system with voltage regulator function is simple and easy to be controlled. However, two-phase of three-phase alternating votage is used in the main circuit of UN5-150 rail flash butt welding machine,it is not good for generators;at the same time,the votage is not an integral sinusoidal AC voltage through the thyristor, during the rail welding process, flash is focused on the higher AC voltage,when the voltage is lower,flash is week,it may lead to generate weld defects and affect the quality of welded joints.Because there are some disadvantages in the original power system,an improved idea is proposed in this thesis,that is using square wave power to replace the original power system.The three-phase alternating votage is changed to a fluctuant direct current through the three-phase full controlled bridge rectifier, In the rectifier circuit, the KP2400-16 thyristor is used as rectifier and a common air-cooled radiator SF17 is used as radiator, KL-HYHL thyristor phase-shift trigger circuit is used in this thesis, An LC filter is used in filter, and then it is changed to a AC square wave through the full-bridge inverter circuit. In the inverter circuit, IGBT module CM1600HC-34H with fast switching speed,small drive power and low saturation pressure is used as as an inverter device. In the control circuit, a frequency pulse is generated by TL494,it is changed to be a 50Hz control signal by the frequency division and dead-adjustment circuit which composes of the chip 4015 and 4098.Square-wave power has been designed and producted,peripheral interface circuit has been designed and producted, The square wave power is assembled to UN5-150 welder,and then no-load tests and rail welded tests are done. Results show that the votage can be controlled remotely.All welding stages are normal in no-load tests,AC square wave is symmetrical, voltage is controlled by PLC. Rail welding has been carried out successfully.
Keywords/Search Tags:flash butt welding, full-bridge thyristor rectifier, IGBT inverter, interface circuit
PDF Full Text Request
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