HVAC instrument system for gas-insulated coaxial lines. Final report

This program was conducted for the development of metering quality, 0.3% accuracy class, current, and voltage instrumentation for an advanced 1200 kV, as gas-insulated power transmission system. This instrumentation is designed and uniquely adapted to the geometry of the coaxial line. The physical objective of the program is a test section of 1200 kV coaxial gas bus containing prototype instruments for measuring line current (1 per unit = 3000 A, 60 Hz), line voltage (1 per unit = 693 kV, 60 Hz line-to-ground) and for injecting and receiving carrier power (about 10W) at frequencies typically in the 100 kHz to 500 kHz range. In addition to a metering specification, current and voltage instrumentation must respond to transient conditions with sufficient bandwidth (about 5 kHz) for use in protective relaying or measuring fault transients. The design fabrication and testing of the measuring instruments and associated electronic equipment for signal amplification are described. Test results indicate the system will meet the requirements of both revenue metering, 0.3% class, and protective relaying. Outputs of the signal amplifier channels are typically 3 to 5 V rms at normal line power and are suitable for metering or driving static relays and other low-load-burden (2000 ..capmore » omega..) devices. Initial field tests are planned at the EPRI Waltz Mill Cable Testing Facility, near Pittsburgh, PA.« less