APPLICATION OF HIGH CAPACITY CONDUCTORS FOR UPRATING OF EXISTING TRANSMISSION LINES IN NEPAL

Abstract

Due to high power losses and relieve transmission line from overload operation, Nepal has to upgrade its transmission system. The main objective of this research paper is to investigate technical and financial aspects of uprating existing 132 kV line of Nepal by re-conductoring it with High Temperature Low Sag conductor. For this purpose, electrical, mechanical and financial aspectsare evaluated using Institute of Electrical and Electronics Engineers (IEEE)-738-SA model for conductor capacity derating, Hybrid numerical method for sag calculation and Monte Carlo simulation for sensitivity analysis respectively. The derated capacity of existing conductor and proposed High Temperature Low Sag (HTLS) conductors are calculated which are less than manufacturer’s rating. The sag of Aluminium Core Steel Supported (ACSS)-Dove, Thermal-Resistant-Aluminium Conductor Steel Reinforced (TACSR)-Dove and Super Thermal Resistant Aluminium Conductor Invar Reinforced (STACIR) is found to be greater than maximum permissible sag, while Aluminium Conductor Composite Core (ACCC)-Amsterdam, Gap Type-Super thermal Resistant ACSR (GZTACSR)-Hen and Aluminium Conductor Composite Reinforced (ACCR)-Oswego with permissible limit. ACCC is evaluated to be the most profitable conductor for re-conductoring. The result shows that capacity of existing line can be increased upto 290% with additional profit.