تعیین مقدار هزینه قطع برق برای تجزیه و تحلیل سود هزینه سیستم اتوماسیون توزیع

Deregulation of electric power industry has motivated electricity customers to pay more attention in evaluating both the direct cost of electric service and the monetary value of reliable electric service. This movement has been recognized by the utilities and the value-based aspects are introduced into the planning and design of power systems to consider the outage costs. The value of service reliability that can portray and respond to actual utility and customer impacts as a result of power interruptions plays a major role on justifying whether a distribution automation (DA) system is beneficial or not. However, for the value of service reliability, there are a number of factors that can affect it. To exactly evaluate the service reliability value, two formulas for quantifying the customer interruption costs and utility reduced energy revenues associated with power failures are derived in this paper. The customer types, feeder loads, feeder failure rate, number of switch, restoration time, and repair time are taken into account. The proposed formulas can provide an exact estimate in outages costs of a feeder and their computation is simplified and straightforward. The estimated outage costs can then be used to calculate the reliability improvement benefit of DA systems for the system benefit–cost analysis. A practical DA system implemented by Taiwan Power Company is used to illustrate the proposed formulas and the benefit–cost analysis result is presented. Sensitivity analysis is also performed to reduce the effects of benefit–cost analysis parameters on the analysis result.

Today’s energy market that is moving toward an intense price competition has forced electric utilities to face many challenges. One of the major challenges is to increase the market value of services. To provide lower electricity rates for customers, utilities have provided adequate reliability, and reduced its costs of operation, maintenance, and construction. Since distribution networks provide the final link between the bulk transmission system and the customers, it is important to the total electrical supply system. It has been reported that over 80% of customer service interruptions are due to failures in distribution networks. To achieve significant and immediate improvement in the distribution supply reliability and concurrently to enhance the customers service quality, various types of distribution automation (DA) systems are implemented by the utilities worldwide. DA systems have been defined by IEEE as systems that enable an electric utility to monitor, coordinate, and operate distribution network components in real-time mode from remote control centers [1]. DA systems are usually modular and can be implemented in phases to include remote monitoring and control of substations, feeders, and consumer loads. DA systems are built to achieve the goals of operation and maintenance (O&M) cost reduction, capital investment deferment, supply reliability improvement, and operation efficiency enhancement [2] and [3]. The installation of a DA system requires a large capital investment; therefore, the benefit–cost or economic analysis of DA systems is critical to identify the DA functions that produce significant operational benefits. Many methods were proposed for the DA economic analysis [4], [5], [6], [7], [8], [9] and [10]. Ref. [4] proposed a set of general guidelines for evaluating the benefits of various DA functions. Ref. [5] developed a computer program to evaluate the benefits and costs of the DA functions using standard engineering economic methods. A comprehensive methodology and application guidelines were used in [6] to evaluate the DA functions and a master plan was developed to implement the DA system on a system-wide basis. Ref. [7] used a present worth method to determine the savings and costs of the DA functions under considerations and conducted the economic analysis for different combinations of the DA functions by using a cost–benefit analysis method. Reliability worth assessment is currently receiving considerable attention as it provides an opportunity to incorporate the costs or losses incurred by utility customers as results of power failure. A distribution reliability program was used in [8] to evaluate the reliability of supply to the customers. The reliability indices used in justifying capital expenditure were computed and the best option is selected from various available alternatives. Ref. [9] proposed an analytical approach to study the impact of DA on the distribution reliability and used historical outage and customer interruption cost (CIC) data to conduct the DA economic analysis. The unserved-energy costs and momentary-outage costs considering feeder loads and outage duration are determined in [10] to determine which DA functions are beneficial. The number of switch that is strongly relative to outage duration and outage cost is not considered in the existing outage cost assessment methods. To more exactly quantify the customer interruption costs and utility reduced energy revenues associated with power failures, two outage costs quantification formulas are derived in this paper. The customer types, feeder loads, feeder failure rate, number of switch, restoration time, and repair time are taken into account. The proposed formulas can provide an exact estimate in outages costs of a feeder and their computation is simplified and straightforward. The estimated outage costs can then be used to calculate the reliability improvement benefit of DA systems for the system benefit–cost analysis. Application of the proposed formulas to benefit–cost analysis of a practical DA system implemented by Taiwan Power Company (Taipower) is presented.

The outage costs quantification formulas for quantifying the customer and utility costs due to power failures are proposed in this paper. The customer types, feeder loads, feeder failure rate, feeder length, number of switch, repair time, and restoration time have been taken into account in the determination of the outage cost losses. The estimated outage costs are then used to determine the reliability improvement benefits of the DA systems. Application of the proposed formulas to the economic analysis of a practical DA system has been presented. The study results have shown that the proposed formulas could explicitly represent the relationships of the customer and utility outage cost, customer types, feeder topology, repair time and restoration time, and provide an accurate estimate in the outage costs for the economic analysis of DA system. The results also indicate that the implementation of DA system is suitable for the area with the high values of interruption costs, failure rate, and inflation rate, and can be justified when a small value of interest rate is considered. The proposed outage costs quantification formulas can assist the utility in assessing the reliability improvement benefits of the DA system. The study results can also serve as the base for the utility‘s future DA system implementation guideline.