Realization of long-term investment strategies for medium voltage cables

Abstract

As a result of the liberalization of the electrical energy market, asset managers have to solve conflicting tasks: Reduction of the life cycle costs while ensuring high system availability. In general the decision-making process of asset management can be divided into four steps which start with the evaluation of the long term strategy and stop with a concrete maintenance activity of a certain equipment. This paper describes the first step of the overall asset management process to derive the optimal strategy for the equipment. There are different management tools to improve operation efficiency. One possibility is to measure the impact of the technical and financial boundary conditions to determine the entire costs for a group of equipment in consideration of the unavailability at system nodes. Consequently, the different effects concerning investment and maintenance strategy, for example the useful lifetime, the extension of the service cycle, the evaluation of life cycle costs of pieces of equipment and the yearly budget, can be investigated. The principal task of this analysis is to develop a long-term concept for the maintenance and investment strategy, comprising the capital expenditures (CAPEX) as well as the operational expenditures (OPEX). To complete this task suitable equipment models are required. These models should be able to simulate the equipment behavior for a simulation horizon of for example 30 to 70 years, according to the service life time of the different components. Beside the determination of the financial requirements caused by the current maintenance and renewal strategy, the essential advantage of a dynamic asset simulation is to evaluate the influence of different strategies on the final result. Such influences could be the modification of a maintenance strategy or the postpone of a renewal measure. This information will be of notable interest during the discussion with appropriate national authorities concerning the investment strategy and the resultant financial expenditures. The paper describes the fundamental proceeding in the case of dynamic asset simulations and their importance during the decision making process based on replacement strategies for medium voltage cables. For this, an ageing model is required which provides the asset manager with information about the age distribution of medium voltage cables after a certain simulation time as well as about the cost assessment comprising CAPEX and OPEX. (4 pages)