Transmission Loss Allocation of Integrated Nepal Power System Using Z-Bus Method

Authors: Suraj Gurung, Basanta Kumar Gautam

Abstract— This paper presents the implementation of Z-Bus method in the Integrated Nepal Power System Network (INPS). As of 2022, the loss allocation is determined at all 132 and 220 kV substations of INPS. The study of transmission loss allocation for INPS is carried out for six different loading cases, considering the variation in patterns of energy generation and demand, i.e., system full generation, summer peak, winter peak, average peak, dry peak, and contingency condition. The result shows the load, like Kathmandu Valley, which is in the region of generation, and the generator, like in the eastern region, which is in the region of demand, are mostly compensated with negative losses. Loads in the western region and generators like the Upper Tamakhoshi, which are far from the generator or load, are assigned the highest positive loss. Loss allocation to load and generator can vary depending on the loading conditions that INPS is operating under. The generation is comparably evenly distributed in the cases of full generation, and contingency instances; as a result, the loss allocation to both loads and generators is significantly evenly distributed. However, the bulk of losses are only attributed to the generator side in the four other scenarios with uneven distribution of generation, where the majority of the generation is only aggregated in a specific location. This is a result of the remote generator’s long-distance power flow, which raises system loss. As a result, the Z-Bus method assigned the generator side the majority of the losses. Additionally, the majority of INPS’s generation is determined to be remotely located, which increases the risk of transmission loss. Because of this, INPS is best served by the Z-Bus approach, which takes into account the locations of buses within the network. In order to minimize system loss, this also encourages big demand or generation to be positioned close to the center of generation or demand.

Keywords—Transmission loss allocation (TLA), Z-bus method, INPS

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Published In: International Conference on Role of Energy for Sustainable Social Development (RESSD-2023)
Date of Conference: 14th-15th May 2023                                
Conference Location: Kathmandu, Nepal
Publisher: IEEE Power and Energy Society Nepal Chapter

 Cite the paper as:

S. Gurung, B. K. Gautam, “Transmission Loss Allocation of Integrated Nepal Power System Using Z-Bus Method”, International Conference on Role of Energy for Sustainable Social Development, 14th-15th May 2023, Kathmandu, Nepal