TPWJ, 2014, #1, 25-29 pages
IMPROVEMENT OF POWER EFFICIENCY OF MACHINES FOR RESISTANCE SPOT WELDING BY LONGITUDINAL COMPENSATION OF REACTIVE POWER
Journal The Paton Welding Journal
Publisher International Association «Welding»
ISSN 0957-798X (print)
Issue № 1, 2014 (January)
E.O. Paton Electric Welding Institute, NASU. 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: firstname.lastname@example.org
Considered is the operation of supply system of a single-phase machine for resistance spot welding (RSW) with introducing of scheme of longitudinal compensation of reactive power into the primary circuit of welding transformer. Machines for RSW are characterized by a high consumed power, the significant part of which is a reactive component. This leads to increase in general installed power of working regions and asymmetry of loading phases of supply distribution three-phase mains. It is shown in the work that system with a longitudinal compensator is well interacted with a standard thyristor controller of power of machine and allows keeping a high value of power factor within the range of phase control up to 60°. The application of longitudinal compensation gives technological advantages of spot welding, as the power factor of machine with a compensator depends little on the resistance of welding contact. Therefore the welding of metals in the wide range of specific resistances is possible: from low-carbon steels up to some light alloys and metals with protective coatings. Low cost of additional equipping of existing machines with longitudinal compensator with a simultaneous improvement of their technological properties makes the method of longitudinal compensation challenging for industrial application. 7 Ref., 1 Table, 4 Figures.
resistance spot welding, power system, compensation of reactive power, power factor
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