A description is presented of an electrical distribution system for use in teaching power system reliability evaluation. It includes all the main elements found in practical systems. However, it is sufficiently small that students can analyze it using hand calculations and hence fully understand reliability models and evaluations techniques. All the data needed to perform basic reliability analyses are included in this work. It also contains the basic results for a range of case studies and alternative design/operating configurations. >

A reliability test system for educational purposes-basic distribution system data and results

Renewable energy sources, especially wind turbine generators, are considered as important generation alternatives in electric power systems due to their nonexhausted nature and benign environmental effects. The fact that wind power penetration continues to increase has motivated a need to develop more widely applicable methodologies for evaluating the actual benefits of adding wind turbines to conventional generating systems. Reliability evaluation of generating systems with wind energy sources is a complex process. It requires an accurate wind speed forecasting technique for the wind farm site. The method requires historical wind speed data collected over many years for the wind farm location to determine the necessary parameters of the wind speed models for the particular site. The evaluation process should also accurately model the intermittent nature of power output from the wind farm. A sequential Monte Carlo simulation or a multistate wind farm representation approach is often used. This paper presents a simplified method for reliability evaluation of power systems with wind power. The development of a common wind speed model applicable to multiple wind farm locations is presented and illustrated with an example. The method is further simplified by determining the minimum multistate representation for a wind farm generation model in reliability evaluation. The paper presents a six-step common wind speed model applicable to multiple geographic locations and adequate for reliability evaluation of power systems containing significant wind penetration. Case studies on a test system are presented using wind data from Canadian geographic locations.

A simplified wind power generation model for reliability evaluation

This paper presents the concept of overall power system reliability evaluation using an educational test system. The paper extends an existing test system by developing the necessary distribution and subtransmission networks. The extended test system has all the main facilities, such as generation, switching stations, transmission, sub-transmission and radial distribution networks found in a practical system. The test system, is however, sufficiently small that students can analyze it using hand calculations or by developing small computer programs to fully understand the reliability models and evaluation techniques. Overall power system reliability evaluation is concerned with providing acceptable customer service. This is an important concern in today's electric utility environment. This should therefore be an essential element in teaching power system reliability evaluation at either the graduate or undergraduate level, The extended test system presented in this paper and the concepts presented assist in satisfying this requirement.

A test system for teaching overall power system reliability assessment

Electrical power systems have been traditionally designed to be reliable during normal conditions and abnormal but foreseeable contingencies. However, withstanding unexpected and less frequent severe situations still remains a significant challenge. As a critical infrastructure and in the face of climate change, power systems are more and more expected to be resilient to high-impact low-probability events determined by extreme weather phenomena. However, resilience is an emerging concept, and, as such, it has not yet been adequately explored in spite of its growing interest. On these bases, this paper provides a conceptual framework for gaining insights into the resilience of power systems, with focus on the impact of severe weather events. As quantifying the effect of weather requires a stochastic approach for capturing its random nature and impact on the different system components, a novel sequential Monte-Carlo-based time-series simulation model is introduced to assess power system resilience. The concept of fragility curves is used for applying weather- and time-dependent failure probabilities to system's components. The resilience of the critical power infrastructure is modeled and assessed within a context of system-of-systems that also include human response as a key dimension. This is illustrated using the IEEE 6-bus test system.

Modeling and Evaluating the Resilience of Critical Electrical Power Infrastructure to Extreme Weather Events

The wind is a highly variable energy source and behaves far differently than conventional energy sources. This paper presents a methodology for capacity adequacy evaluation of power systems including wind energy. The results and discussions on two representative systems containing both conventional generation units and wind energy conversion systems (WECS) are presented. A Monte Carlo simulation approach is used to conduct the analysis. The hourly wind speeds are simulated using an autoregressive moving average time-series model. A wide range of studies were conducted on two different sized reliability test systems. The studies show that the contribution of a WECS to the reliability performance of a generation system can be quantified and is highly dependent on the wind site conditions. A WECS can make a significant reliability contribution given a reasonably high wind speed. Wind energy independence also has a significant positive impact on the reliability contribution of multiple WECS.

Generating capacity adequacy associated with wind energy

The IEEE Subcommittee on the Application of Probability Methods (APM) published the IEEE Reliability Test System (RTS) [1] in 1979. This system provides a consistent and generally acceptable set of data that can be used both in generation capacity and in composite system reliability evaluation [2,3]. The test system provides a basis for the comparison of results obtained by different people using different methods. Prior to its publication, there was no general agreement on either the system or the data that should be used to demonstrate or test various techniques developed to conduct reliability studies. Development of reliability assessment techniques and programs are very dependent on the intent behind the development as the experience of one power utility with their system may be quite different from that of another utility. The development and the utilization of a reliability program are, therefore, greatly influenced by the experience of a utlity and the intent of the system manager, planner and designer conducting the reliability studies. The IEEE-RTS has proved to be extremely valuable in highlighting and comparing the capabilities (or incapabilities) of programs used in reliability studies, the differences in the perception of various power utilities and the differences in the solution techniques. The IEEE-RTS contains a reasonably large power network which can be difficult to use for initial studies in an educational environment.

A reliability test system for educational purposes-basic data

The IEEE Reliability Test System (RTS) developed by the Application of Probability Method Subcommittee has been used to compare and test a wide range of generating capacity and composite system evaluation techniques and subsequent digital computer programs. A basic reliability test system is presented which has evolved from the reliability education and research programs conducted by the Power System Research Group at the University of Saskatchewan. The basic system data necessary for adequacy evaluation at the generation and composite generation and transmission system levels are presented together with the fundamental data required to conduct reliability-cost/reliability-worth evaluation

A Reliability test system for educational purposes-basic data

A set of basic reliability indices at the generation and composite generation and transmission levels for a small reliability test system are presented The test system and the results presented have evolved from reliability research and teaching programs The indices presented are for fundamental reliability applications which should be covered in a power system reliability teaching program The RBTS test system and the basic indices provide a valuable reference for faculty and students engaged in reliability teaching and research

A Reliability test system for educational purposes-basic results

A set of basic reliability indices at the generation and composite generation and transmission levels for a small reliability test system are presented. The test system and the results presented have evolved from reliability research and teaching programs. The indices presented are for fundamental reliability applications which should be covered in a power system reliability teaching program. The RBTS test system and the basic indices provide a valuable reference for faculty and students engaged in reliability teaching and research. >

A reliability test system for educational purposes-basic results

The authors describe the methodology and results of statistical analyses of data collected to estimate the losses incurred by the farm sector as a result of electric power system interruptions. The project was sponsored by the Canadian Electrical Association and employed a postal survey to estimate the costs to electric customers resulting from electric power outages. The survey included interruption cost estimation questions based on three principles: direct estimate of losses, an economic principle of substitution, and a willingness-to-accept method. The results of these questions together with the others included in the questionnaire were subjected to rigorous statistical analysis. The analysis presented unexpected challenges due to the peculiarities of the data. The difficulties associated with data analysis, the methodology used, and the results are discussed. >

P. Kos

Papers

A reliability test system for educational purposes-basic data

A Reliability test system for educational purposes-basic data

A Reliability test system for educational purposes-basic results

A reliability test system for educational purposes-basic results

Cost of electric power interruptions in the agricultural sector-statistical analysis