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In order to schedule the choice of maintaining or refurbishing MV equipment, an electrical utility may study ageing effects on different pieces of such equipment. In this paper, the analysis is based on record of outages (MV power cuts) during several years where causes of outages are noticed (and ages of pieces of equipment are also known). Failure rate versus age estimation results are given for...
This paper discusses a number of aspects of operational-risk assessment of transmission systems, operational-risk assessment uses techniques developed from reliability analysis to predict the performance of the transmission system during a short period of time (several hours) starting from a well-defined operational state. The influence of weather parameters on the momentary failure rate and the operational...
This paper provides an approach to the problem of power distribution network renewal planning where the challenge to the decision maker is to determine the most cost- effective multi-year development plan in terms of what feeders in the network to refurbish, by which renewal alternative and at what time in the planning horizon. The problem is subjected to several constraints of service requirements...
Most electric power utilities utilize probability methods in the planning and operation of generating capacity. Deterministic criteria, however, are usually used in the planning and operation of composite generation and transmission or bulk electric power systems. The most commonly applied deterministic criteria dictate that specific credible outages should not result in system failure. The traditional...
The main development trend of wind power generation system is large offshore wind farms with grid connection. Due to extraordinarily high investment, many technical issues yet to be solved and limited experience, the risk of building offshore wind power generation system is always very high. The study presented in this paper takes a view of the effect of offshore wind farm topology on its reliability...
Con Edison's distribution systems supply power to more than 3 million customers in New York City and Westchester County. About 85% of the load in the Con Edison service territory is supplied by underground low-voltage network systems. The reliability of underground low-voltage network systems is extremely high and Con Edison uses Network Reliability Index (NRI) programs - the Contingency program and...
This paper describes a method for predicting circuit breaker time-to-failures using a probabilistic operational model that incorporates generation capacity growth. Increases in generation capacity may cause fault current levels to approach or exceed circuit breaker ratings. This condition may increase the probability of a circuit breaker failure. Circuit breaker failures result in common-mode multiple...
Knowledge of the reliability of power transformers is of growing importance to the asset manager. A method is presented for determining the reliability of a power transformer based on the mechanical strength of winding insulation paper. In addition to the modelling technique, there is a validation method for the modelling technique presented. The validation method depends on a good data management...
The latest political initiatives on energy saving are forcing distributors to implement actions that increase the energy efficiency of their system. Among these actions distributors can drive the development of the distributed generation (DG) on their networks. The inclusion of the energy saving goal among the terms of the objective function makes the DG allocation problem more and more complicated,...
This paper describes the mid-continent area power pool (MAPP) transmission equipment outage data collection scheme and presents bulk transmission line average outage statistics for forced outage category for the 230 kV and above systems computed using the data for the ten-year operating period from 1991 to 2000. In addition, a causal and seasonal contribution to forced outages of bulk transmission...
Hidden failures in protection schemes, the traditional N - 1 security criterion and the introduction of the electricity market are usually major causes in the recent wide area blackouts. In the present work, we address the reliability analysis of power systems using the Generalized Stochastic Petri Nets (GSPN). The proposed modeling approach considers not only the most common failures of power system...
Heuristic methods have demonstrated the potential to and good feasible solutions, but not necessarily optimal. The success of such methods is related to their ability of avoiding local minima by exploring the basic structure of each particular problem. These methods can provide high quality solutions, within an acceptable CPU time, even for large-scale problems. This paper presents a new methodology...
In power system planning and operation, accurate assessment of reliability worth is essential for making informed decisions. One common simplification when modeling power system reliability is assuming constant failure rates and non time-varying restoration times. However, historical outages show differently; failure rates and restoration times for especially overhead lines are dependent upon time-varying...
The application of the telecontrolled switching elements in MV distribution networks is an effective tool for influencing the electricity supply continuity perceived by individual customers considerably. In this way, it is also a tool for reducing the possible costs resulting from breaching the customer's standards of electricity supply continuity. A method generally utilizable when making decisions...
In operation studies of distribution networks, the restoration problem is solved using optimization techniques. However, in planning studies, such as reliability evaluation, the restoration problem is solved considering engineering judgment. Therefore, there is a mismatch between the restoration modeling used in the operation of the network and in the planning studies. This paper presents a method...
This paper presents a new methodology for assessing both reliability and well-being indices for composite generation and transmission systems. Firstly, a transmission network reduction is applied to find an equivalent for assessing composite reliability for practical large power systems. After that, in order to classify the operating states, Artificial Neural Networks (ANNs) based on Group Method...
More and more wind power is being integrated into power grids in recent years. However, due to its intermittent characteristic, it is usually difficult to determine the appropriate penetration level to ensure a specified reliability requirement. For this purpose, the proper calculation of wind power capacity credit is of particular importance which is useful in both operations and planning stages...
The electric power market is restructuring to be price-based and auctions are considered a good pricing mechanism to be used. To assure that the market functions satisfactorily, strictness of guarantee of sellers' deliveries and buyers' receipts must be taken care properly by the central coordinator. This paper proposes market mechanisms for single-class auctions, which specifies the minimum strictness...
The ageing of power systems and their components are of great concern for the asset manager, especially in view of the coming replacement wave in the electrical infrastructure. The asset manager is in need for a prediction tool, to determine the long term effects on the statistical relevant parameters of a population of power systems components. In this paper we describe a method for forecasting the...
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