Decision Making Process for Selecting Reliable and Efficient Substations for Industrial Customers

This paper presents a methodology for modeling, analyzing, and selecting substations for industrial customers based on different criteria, such as initial investment, interest rate, life cycle, reliability, costs of interruption, maintainability or a combination of these criteria expressed as life cycle cost (present value). The methodology is implemented by utilizing specialized tools for calculating substation reliability, estimating economical efficiency and ranking substation alternatives. Depending of the industrial customer\´s preferences, different substation configurations, based on different technologies, can be modeled and analyzed. At the end, the proposed substation alternatives can be subjectively ranked by the customer using a ranking tool. A systematic procedure utilizing multi-objective value hierarchy is applied to make the final decision. A combination of "hard" attributes (usually presented in dollars) and "soft" attributes (subjective and difficult to express in numbers) are used for this purpose. The proposed methodology is applied for typical industrial substations. The results show the impact of combined criteria like the life cycle cost together with the customer\´s preferences on selecting reliable and economically efficient industrial substations. The paper illustrates the importance of reliability and cost of interruption in the final decision making process.