Dynamic thermal rating of critical lines-a study of real-time interface requirements

Power system operators need the ability to assess network performance from a thermal capacity standpoint. However, static ratings do not provide the level of information needed and, in fact, can mislead operators. To address this problem, a study that resulted in the instrumentation of a 138000 V line with the necessary equipment to rate the line dynamically was initiated by Wisconsin Power and Light. The line chosen for the project was the X20 line, a 6 mile transmission line that runs from the Columbia Power Plant substation to the Portage substation. The discussion covers the conductor temperature measurement systems; the real-time interface: monitoring and handling of raw data; the rating process; the thermal transient conductor response; suppressed rating during the transient period; thermal transient response display; and alarm processing.<>