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

Posted on:2011-01-25Degree:MasterType:Thesis
Country:ChinaCandidate:J Y ZhangFull Text:PDF
GTID:2212330338967144Subject:Materials Processing Engineering
Abstract/Summary:PDF Full Text Request
The rail welding is an important part of building seamless line, which directly determines the quality of the rail joints. The rail flash butt welding machine is high-power spcial welding equipment, the function of which has an immediate impact on the performance of rail welding quality and productivity efficiency.AC rail flash butt welding machine has several advantages such as small dimension, low energy consumption, and high efficiency welding that it has being used more and more common in field application of seamless welding of rail. However, the traditional exchange of flash butt welding power source exsits in the course of the following disadvantages:one is the three-phase load imbalance which will cause to increase the capacity of power or engine, the other is that poor stability of the lack of flash produces welding defects such as gray leaf spot, due to short duration of the flash phase voltage and its zero-crossing rate slow in the process of rail flash welding, thereby affecting the joint quality, which for the present the accelerating construction of high-speed railway has a very negative impact.After studied the previous AC power source for steel rail flash welding, to solve the above problems in the flash welding process, this paper presents a new design idea of power supply:three-phase power supply with the frequency 50Hz is translated into DC through the ordinary controlled full-wave thyristor rectifier, and then DC is again turned into AC square wave with frequency 50Hz by the IGBT inverter. It is hoped that the above stated problems will be resolved completely.The design of AC square wave power for the rail flash welding has been completed in this paper through the integrated application of power electronic technology combined with the requirements of rail flash butt welding. In accordance with the design, the prototype production has been made by Chengdu JCL Science and Technology Co, Ltd., commissioned by Chengdu Aigre Mechano-Electronic Equipment Co, Ltd. The designer has conducted tests of unload and a little load, besides the circuit debugging of the prototype. Experimental results indicate that the system designed has hit the targets of a balanced three-phase power supply, reducing the power grid capacity requirements; meanwhile, power Experimental results indicate that the system designed has hit the targets of a balanced three-phase power supply, reducing the power grid capacity requirements; meanwhile, power output is symmetrical square wave, which has a positive meaning for the improvement of the stability of the flash in the process of welding.
Keywords/Search Tags:Hyristor full-bridge rectifier, IGBT inverter, AC flash butt welding
PDF Full Text Request
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