Using LabVIEW to measure transformer residual flux for inrush current reduction

Power transformers can experience large inrush currents upon energization, the severity of which depends on the source strength, the angle of the applied voltage at energization, and the residual flux of the transformer. A novel inrush current reduction strategy has been investigated which involves setting the transformer´s residual flux. Testing of this strategy required a measurement system capable of measuring transformer residual flux. This paper details the construction of the flux measurement system, based on LabVIEW software, and presents test results which confirmed properly measured residual flux values.