INRUSH CURRENT ALLEVIATING DEVICE AND INRUSH CURRENT ALLEVIATING METHOD

摘要

Disclosed is an inrush current alleviating device provided with: a residual magnetic flux calculation unit (51) that obtains the residual magnetic flux of a reference phase of a three phase transformer (30), on the basis of the result of measurement by a transformer voltage measurement unit (60) before and after opening the contacts of a three phase breaker (1), assuming the maximum magnetic flux to be generated upon application of the rated voltage is 1 PU; a steady state magnetic flux calculation unit (52) that responds to a command to close the contacts of the three phase breaker (1), and obtains the steady state magnetic flux of the reference phase of the three phase transformer (30), on the basis of the result of measurement by a power supply voltage measurement section (61), using the maximum magnetic flux level obtained as 1 PU as a reference level; and a control unit (53) that switches on a switch corresponding to the reference phase of the three phase breaker (1), at a timing whereupon the steady state magnetic flux and the residual magnetic flux of the reference phase match.