Analysis of Knee Point Temperature (KPT) Determination on High Capacity Low Sag (HCLS) Conductors for Optimizing the Ampacity Load and Sag on the Overhead Transmission Lines System
Hery Prasetyo, Budi Sudiarto, Rudy Setiabudy

Department of Electrical Engineering, Faculty of Engineering, University of Indonesia
Depok, Indonesia

Abstract

The modern overhead lines with High Capacity Low Sag (HCLS) conductors can operate with an increased current carrying capacity. The main advantage of HCLS conductors is the specially designed operating conditions which cause the transformation of the mechanical pull load from the conductors to the reinforcing core. This transformation is called knee point temperature. This study aims to determine the knee point temperature and determine this effect on sag HCLS conductors. In this study a simulation will be conducted on the HCLS conductors, namely ACCC LISBON (310) which stretches between a span of 100meters. Initial tension applied about 25% of rated tensile strength (RTS) of conductors. The ampacity loading is carried out in gradually until the maximum permissible operating temperature reached, the value is 180oC with an ampacity of around 1200A. From the simulation results we can determine the knee point temperature of the ACCC LISBON (310) conductor is around 55-60oC. From the graphic shows, the value of the sag after the knee point temperature tends to be stable even though the ampacity loading is increased. From this study results can be utilized to predict the optimized ampacity loading on the overhead lines system to get a stable sag.

Keywords: ampacity, high capacity low sag (HCLS) conductors, sag tension, knee point temperature, overhead line

Topic: Electrical Engineering