Static var system with means for correcting for negative phase shift

Claim 1

Reactive current supply apparatus for an a-c electric power system including a critical voltage supply bus electrically separated by series impedance from load terminals which are adapted for connection to a load subject to rapid oscillatory variation of reactive current demand comprising: fixed capacitor means connected across said load terminals, fixed inductor means connected across said load terminals in series circuit relation with static switching means, said static switching means including gating means for phase controlling the conduction angle of said switching means thereby to control the magnitude of reactive current traversing said inductor means; means for developing a first electrical signal representative of the magnitude and polarity of the reactive load current coefficient at said load terminals, second means responsive to said first electrical signal for so controlling said gating means for determining the sum of the reactive current traversing said fixed capacitor means and said fixed inductor means, which further comprises: means for receiving said first electrical signal and developing a first intermediate electrical signal of substantially the same frequency as said first electrical signal but having a predetermined positive phase shift relation thereto, said second means being responsive to said first intermediate electrical signal.