Load-dependent reactive-current compensation

摘要

The invention relates to a load-dependent reactive-current compensation with compensation capacitance for transformers whose secondary operating voltage is considerably smaller than the no-load voltage, as they are for example applied in arc welding with so-called small transformer welders. It is the object to reduce the outlay in terms of material and to enlarge the application range of the transformers with predetermined primary connection parameters. In addition, there is the object of developing a reactive-current compensation which acts load-proportionally across a wide range without switching devices and additional windings, which does not over-compensate in no-load and in which the primary short-circuit currents are not larger than the primary nominal currents. According to the invention, the object is achieved by arranging a compensation capacitance in series with the secondary winding of the transformer and of the load. The capacitive reactance of the compensation capacitance is approximately the same in terms of magnitude as the inductive equivalent reactance acting on the connecting points of the compensation capacitance, or is between this inductive equivalent reactance and twice the inductive reactance of the leakage inductance for larger output currents.