Static VAR generator having reduced harmonics

摘要

There is provided a static VAR generator employing a bank of series-connected inductors, each inductor being supplied by different secondary taps of a step-down transformer. The voltage rating of each inductor is appropriately decreased so as to make their sum correspond to the supply voltage. All but one of the inductors are controlled by thyristors in an on-off fashion to supply reactive power to the network in incremental steps. One of the thyristors is continuously phase-angle fired in combination with the incremental insertion of the other inductors to vary the VAR output over the full range, but generating harmonics that are proportional only to the continuously controlled inductor.