Utility Application of Static Var-Compensation

The Marcy South Project, 200 miles of 345KV (kilovolts) transmission lines, is being constructed to permit the cost-effective north-south transfer of low cost hydro-produced power from Canada, downstate to New York City by 1988. This project has involved new and interesting technology in its design and construction. One such technology, soon to be implemented at New York State Electric Gas (NYSEG), on a scale unprecedented in North America, is the Static Var Compensator (SVC). This paper describes NYSEG's SVC, a multi-million dollar power electronics technology not only new to NYSEG, but relatively new to the entire electric power industry. The various component parts of the SVC are discussed: thyristor valves, high voltage shunt capacitors, shunt reactors, harmonic filters, and the microcomputer controller. Basically, a gigantic parallel tuned circuit at 345KV, the SVC will regulate the voltage and enhance damping of power system oscillations, by controlling reactive power flow on the Bulk Power Transmission System in the area of Fraser, New York, in NYSEG's Oneonta District. This regulation and damping ability is critical to the stability and operability of the New York State Bulk Power System at the high levels of power transfer anticipated.