Dynamic VAR compensation system and method for AC furnace

摘要

#$%^&*AU2010291895B820150917.pdf#####ABSTRACT A furnace power supply system 10 comprises at least one furnace power supply voltage step-down transformer 12 for stepping down a first voltage V1 to a second voltage V2. A secondary winding 12.2 of the voltage step-down transformer is connectable to at least one electrode 14 of the furnace 16. The power supply system comprises a compensation system 18 connected to the secondary winding 12.2 of the step-down transformer. The compensation system 18 comprises a plurality of capacitors 20.1 to 20.n in respective parallel branches 22.1 to 22.n. At least some of the branches comprise a respective switch element 24.1 to 24.n. A controller 28 for operating the switch elements comprises an input 29 for a signal representative of a power factor to be controlled and the controller being configured to open and close the switch elements in response to the signal, thereby to control the power factor in real time.