Reliability Planning Research Articles

Value-based reliability transmission planning

This paper presents a new value-based reliability planning (VBRP) process proposed for planning Duke Power Company's (DPC) regional transmission system. All transmission served customers are fed from DPC's regional transmission system which consists of a 44 kV predominately radial system and a 100 kV predominately nonradial system. In the past, any single contingency that could occur during system peak conditions and cause a thermal overload required the overloaded facility to be upgraded, regardless of the costs or the likelihood of the overload occurring. The new VBRP process is based on transmission system reliability evaluation and includes the following important elements: (1) a ten-year historical database describing the probabilities of forced outages for lines and transformers; (2) a five-year average load duration curve describing the probability of an overload should a contingency occur; (3) a customer outage cost data base; and (4) probabilistic techniques. The new process attempts to balance the costs of improving service reliability with the benefits or value that these improvements bring to these customers. The objective is to provide customers with their required level of reliability while minimizing the total cost of their electric service.

Reliability and quality in design

Designers are not immune to improvements even though they treasure independence and autonomy. The author argues that it is important that: there be both a strategic and annual reliability and quality improvement plan for the way designing is done; there should be both a strategic and annual reliability and quality improvement plan for designs; a systematic approach should be used in the improvement effort; and measures of design process improvement can and should be made on the inputs to activities and output of design processes. Many organizations have shown substantial improvement in the design effort. >

95/01600 Using customer outage costs in electricity reliability planning

95/01600 Using customer outage costs in electricity reliability planning

Using customer outage costs in electricity reliability planning

We propose an economic electricity reliability planning model which includes customer outage costs (COCs). The objective is to select transmission and distribution (T&D) planning projects which minimize the total costs of providing service in the T&D system. Total costs include both traditional labor and material costs of a T&D project and customer outage costs. We apply this model to evaluate two distribution projects using outage cost data recently collected by Niagara Mohawk Power Corporation (NMPC). We compare the projects selected in this approach to the projects that would have been chosen if outage costs were not used in the analysis.

Value-based distribution reliability assessment and planning

This paper presents a reliability assessment method for radial distribution systems. It combines, the radial network reliability and the customer interruption costs to form the Value-Based Distribution Reliability Assessment (VBDRA) methodology, which is a valuable tool for distribution system planning incorporating customer interruption costs. The proposed method is implemented in a Lotus 1-2-3 macro program with a specially designed data structure for the radial network. The analysis of the proposed computational method shows that the method is valid and fast in practical applications. Various applications of VBDRA planning at the Scarborough Public Utilities are reported in the paper. >

Using customer outage costs to plan generation reliability

There is a general consensus that the 1990s will be a decade characterized by generation capacity shortages, at least in portions of the U.S. This poses the question “should the utility industry be committed to maintain its reserve margin at the historical level?” To answer this question, we develop and discuss a simple model of reliability planning, which incorporates customer value of service (VOS) information. Next, we describe a more sophisticated approach that was recently implemented.

Power system reliability planning practices in North America

The authors present selected results from a recently completed research project for the Electric Power Research Institute. One component of the project was intended to develop and test methodologies for gathering data on how utility customers value service reliability, as measured by either the cost of outages or the willingness to pay for reliability. Another component of this project involved a survey of current and emerging reliability planning practices in the North American utility industry, especially regarding interest in value-based reliability planning. The results of the survey, including the survey design and methodology, are given. The authors briefly discuss potential applications of interruption costs in generation and composite system reliability planning. >

Economics of energy reliability

The types of reliability considerations and the deterministic criteria currently used by most utilities for electric transmission reliability planning are outlined. The complex process of weighing outage costs against prevention costs in this approach is discussed. A probabilistic approach increasingly being adopted by electric utilities is described that allows costs and benefits of reliability to be compared directly.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Cost/benefit approach to establish optimum adequacy level for generating system planning

There is an increasing worldwide interest in economic optimisation approaches for power system expansion and reliability planning. The reliability-cost/worth approach for assessing an optimal level of customer service reliability is based on calculating the costs associated with different system configurations and evaluating the corresponding reliability worth at the customer level. This optimality condition simply intends that the marginal dollar spent to improve service reliability should yield the same benefits to consumers. The application of basic adequacy assessment concepts to generating capacity evaluation is relatively straightforward and the basic concepts are well known. The application of the optimality condition to evaluate simultaneously optimal generation investments and reliability levels is complicated by the difficulty of estimating the functional dependence of consumer interruption costs upon alternate generation and reliability levels. This difficulty has resulted in a number of studies directed towards estimating customer interruption costs. This paper utilises the economic criterion for system optimisation which extends the traditional approach by treating the reliability level as a variable to be optimised. The method is illustrated using the IEEE Reliability Test System (IEEERTS).

Implications of R&amp;M 2000 on Software

This paper presents the implications on software of the US Air Force Reliability and Maintainability Action Plan: R&M 2000, whose objective is to improve defense system reliability and maintainability. These implications are very important, even though R&M 2000 does not explicitly mention software. However, Air Force Regulation 800-18, which implements R&M 2000, does state that ``system ... comprises both hardware and software elements'' and includes the requirement to ``integrate the development of reliable software into the overall system development and acquisition program.'' Further, the US Department of Defense (DoD) Software Initiatives, new DoD Directives, and other Air Force Regulations on software, together with industry/academic initiatives, are intended to result in policies, standards, and specifications which lead to defense system software with requisite reliability and maintainability. This difficult goal can be achieved provided that: •The DoD Software Initiatives successfully create new software technology and transfer it to industry. •Industry associations (eg, Electronic Industries Association [EIA], National Industrial Security Association INSIA]) and professional societies (eg, Institute of Electrical and Electronics Engineers [IEEE], American Institute of Aeronautics and Astronautics [AIAA]) create and improve software reliability and maintainability standards through effective committee work. •Industry/Academe upgrade software development procedures to be consistent with software engineering principles based on Ada® technology.

A New Reliability Tool for Designers

This article presents some discussion on the role of design engineers in achieving specified reliability requirements. Highly reliable products can only be manufactured through effective quality control, reliability planning, and design reviews rights from the initial design stage. To be able to estimate reliability of electronic equipment, a new database in the form of a Handbook has been compiled by British Telecom. The purpose of the Handbook (HRD4) is to provide a common basis for system/products reliability predictions in civil applications, especially telecommunications. This article also describes the application of two prediction models and explains how the data was collected and analysed.

Quality Control and Reliability Management—The Role of Production Engineers

This article presents some discussions on the role of production engineers in quality and reliability planning and control in the context of the manufacturing sector in Singapore. Superior productive efficiency in manufacturing can only be achieved through effective quality control and reliability planning. To be able to compete with other and more advanced countries, Singapore has to emphasise modern manufacturing methods, like automated, computer‐integrated and flexible manufacturing systems. Therefore, concerted efforts are now being taken to train adequately skilled and professional manpower to operate and manage such manufacturing systems. The role of production engineers in operating and managing the modern manufacturing systems has thus become more important and demanding.

The specification and achievement of reliability in military equipment

This paper reviews developments in the Army's approach to the specification and achievement of equipment reliability. It outlines the findings of a wide-ranging review of the state of reliability achievement on past equipment projects and argues the case for increased emphasis to be devoted to the management control of reliability during development. The paper indicates the minimum essential requirements for reliability progress reporting and for the contents of a reliability plan.

Optimal electricity supply: Reliability, pricing and system planning

This paper provides a state-of-the-art summary of recent developments in electricity supply reliability, pricing and system planning, with emphasis on the close interrelationships among these aspects. Economic theory indicates that net social benefits would be maximized if price was set equal to marginal cost while the marginal system costs of improving reliability were equal to the averted marginal outage costs. Attention is focused on the measurement of outage costs and a reliability optimizing model is used to develop an operational criterion for system planning in which the sum of system costs and outage costs is minimized. This approach subsumes the traditional criterion of minimizing only the system costs at an arbitrary target level of reliability. The results of a case study to test the new methodology are summarized and the use of reliability indices and techniques of estimating outage costs are also discussed.

Reliability planning for solar electric power generation

Planning for electric power system reliability requires strategic changes when large-scale use of solar electric generation technologies is contemplated. Bulk storage will be required in any long-term evolution of power systems that are dominated by baseload central station plants. The basic relations among loads, conversion technologies, storage, and reliability are characterized. The responses of systems to exogenous uncertainties are studied. Solar electric technologies produce a more diffuse risk profile than systems dominated by central station plants. This makes solar electric power generation more resilient to unplanned disturbances.

Effective reliability planning and implementation : William W. Provett Jr. and Richard S. Ullman. Proc. A. Reliability and Maintainability Symposium. Nevada. U.S.A. p. 257 (20–22 Jan. 1976)

Effective reliability planning and implementation : William W. Provett Jr. and Richard S. Ullman. Proc. A. Reliability and Maintainability Symposium. Nevada. U.S.A. p. 257 (20–22 Jan. 1976)

Time Dependent Static Strength and Reliability for Composites

An experimental investigation was conducted to study the fracture properties of laminated composites under uni-axial tension. It was found that the distribution of breaking strength of a composite ma terial under a constant stress rate or variable stress history can be described accurately by the Weibull distribution. The shape param eter of the distribution was shown to remain nearly constant under varying loading conditions, temperatures and strength degradations. A relation between the shape parameter and breaking strength- lifetime curve was established. Using these data, a reliability plan was developed, taking into consideration order statistics, sample size and time dependence. A proof test experiment was performed which showed that, for this particular material at least, proof testing is an effective method of removing weak members from a population. It is concluded that composite materials can be designed to yield structure with a higher degree of reliability per unit weight than its equivalent metallic structure.