With the acquisition of Promethean Devices in the summer of 2014, Genscape gains a powerful new tool to enhance the accuracy and coverage of the Power Real-time (RT) and Transmission Real-time (RT) services. Over the past 12 years, Genscape has deployed thousands of monitors worldwide, providing energy market participants with the only source for accurate real-time and historical output of power plants and flows on transmission lines. With Promethean’s technology, Genscape can now improve accuracy on plants and lines currently monitored, and expand coverage to facilities which, until now, could not be accurately monitored.
In April 2014, the Department of Energy published a topical report on Dynamic Line Rating (DLR) Systems for Transmission Lines, which provides useful detail about the Promethean DLR technology:
The fifth type of DLR device, which measures conductor clearance, is unique among conductor temperature-measuring devices in that it has no contact with the transmission line itself. Promethean Devices’ Real-Time Transmission Line Monitoring System (RT-TLMS is an example of this technology. Rather than measuring conductor temperature directly, the RT-TLMS utilizes three ground-based sensors to measure the magnetic field around the conductor. The magnetic field strength is proportional to the amount of current flowing through the line. By monitoring the phase currents of a transmission line and performing calculations of the installation geometry, the conductor height (i.e., clearance) and the conductor temperature may be calculated and therefore monitored. (DOE Report, p. 11)
The goal (of DLR devices) is to measure specific parameters to calculate the dynamic rating and capacity margin. This goal is accomplished by measuring key operating conditions that affect the line’s capacity in real time: (1) weather conditions—such as ambient temperature, solar radiation, wind speed, wind direction, and rainfall—and (2) the characteristics of the line itself, such as conductor temperature, clearance, sag, and tension. Effective wind speed is the biggest driver of capacity, but it can be difficult to determine unless it is measured directly. (DOE Report, p. 9)