Dynamic thermal ratings realize circuit load limits

• Published in: IEEE computer applications in power Vol. 13; no. 1; pp. 38 - 44
• Main Authors: Douglass, D.A., Lawry, D.C., Edris, A.-A., Bascom, E.C.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Application software; Circuits; Energy exchange; Graphical user interfaces; Investments; Java; Power generation economics; Power system economics; Power system reliability; Ratings & rankings; Thermal loading
• ISSN: 0895-0156; 1558-4151
• DOI: 10.1109/67.814665

As economic pressure builds to fully utilize the capacity of existing power equipment, dynamic rating systems allow for informed decisions about circuit load limits. Dynamic thermal ratings offer a way to increase capacity under most weather- and load conditions while reducing the risk of failure under unfavorable conditions. EPRl's Dynamic Thermal Circuit Rating (DTCR) system makes thermal information readily available and provides a solid basis for higher equipment utilization. DTCR calculates dynamic thermal ratings (real-time ampacities) of power equipment based on actual load and weather conditions that are generally accessed through the utility's SCADA/EMS system. Given series or parallel combinations of equipment, the software determines dynamic circuit ratings by evaluating all equipment ratings on a circuit and finding the most limiting ampacity for each rating scenario. Dynamic ratings offer two key benefits over traditional static ratings: (1) higher loading of equipment is usually possible using actual measured load and weather parameters; traditional static ratings are overly conservative, since they are based on worst-case weather and load assumptions; and (2) a better understanding of equipment thermal response is achieved. This results in increased reliability.