Deployment of Lifetime Cost Analysis to Reassess Economic Current Density in the Presence of Vietnam’s Market Economy

Abstract

A decent choice of conductor size for overhead power transmission lines can provide economic advantages throughout the project’s lifetime. One of the crucial criteria for sizing conductors is economic current density. In Vietnam, the electricity industry has extensively utilized the 1950s-era economic current density that ignores the value of cash flow at diverse points in time and applies the assumption of the constant electricity tariff and wire cost. These costs, nonetheless, are likely to greatly impact the figures of economic current density; as a result, these figures must be modified. This paper puts forward novel figures of economic current density that are systematically determined on the basis of lifetime cost (LTC) analysis in the presence of Vietnam’s market economy. The LTC is made up of the initial capital expenditure (ICE) and the overall operating cost (OPC), which includes the expense incurred for maintenance and electricity energy loss. An analytical formulation of ICE related to conductor size and system voltage is established based on information from recently built overhead transmission lines and a regression-based method. The electricity energy loss is computed based on equivalent hours of maximum power loss contingent upon equivalent hours of maximum power usage throughout an analytical expression obtained on the basis of the regression technique from load consumption patterns in the past. Finally, the feasibility and efficacy of the proposed economic current density values are validated by practical case studies of overhead transmission lines in Vietnam. The deployment of the suggested strategy demonstrates a decrease in lifetime cost ranging from approximately 5% to around 20% in comparison to the methodology prescribed by the existing Vietnam standard.