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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 work presents a procedure to validate sags monitoring results based on a stochastic assessment of voltage sag indices. The main practical use of this methodology is to analyze the accuracy of sag indices obtained from very short monitoring periods. Probabilistic models of several factors can be taken into account: lines and busbars fault rate, pre-fault voltage, fault type distribution, fault...
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...
Due to the regulatory requirements related to power quality, the problem of fault location in electrical power systems has been consider as very important, specially in power distribution utilities. In this paper, a statistical classification algorithm based on fuzzy probability functions used to locate single phase faults in distribution systems is presented. The proposed algorithm is tested in a...
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...
This paper introduces the infeed modeling requirements for investigations on energy storage in power systems with complex spatial dependence structures between stochastic infeeds. It is shown that synthesizing multivariate time series, including correct modeling of persistence and spatial dependence, is crucial for obtaining statistically relevant results. A suited new multivariate time series model...
It is recognized today that short-term (up to 2-3 days ahead) probabilistic forecasts of wind power provide forecast users with a paramount information on the uncertainty of expected wind generation. When considering different areas covering a region, they are produced independently, and thus neglect the interdependence structure of prediction errors, induced by movement of meteorological fronts,...
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...
This paper presents an Bayesian approach for the estimation of sojourn time distribution parameters. Expert opinion and condition monitoring data can be used as source of information for the estimation. It is shown how expert opinion and data can be combined and how estimates for the parameters can be calculated by means of numerical methods. It is also discussed how expert uncertainty and systematic...
A Markovian approach already developed in a previous paper by some of the authors to evaluate the energy production and power availability of a wind turbine is utilized to size a hybrid wind-diesel stand alone system. The wind turbine power time variability is taken into account by means of a discrete reduced number of contiguous power classes, each corresponding to an opportune range of values, starting...
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...
There is an increasing trend towards using the concept of risk assessment as an important tool in distribution system asset management. In an ongoing R&D project (RISK DSAM), the main objective is to investigate how information about risk exposure can improve maintenance and reinvestment decisions in an electrical distribution company. As the popularity of Bayesian networks (BN) is increasing,...
This paper reports new results in adopting entropy concepts to the training of mappers such as neural networks to perform wind power prediction as a function of wind characteristics (mainly speed and direction) in wind parks connected to a power grid. Renyi's Entropy is combined with a Parzen Windows estimation of the error pdf to form the basis of three criteria (MEE, MCC and MEEF) under which neural...
This paper illustrates the challenges associated with risk assessment for reinvestments decisions. A holistic framework for risk assessment in electricity distribution systems will be described first and then used to structure the analysis and decision making in a case study concerning cable reinvestment. These decisions are generally multi criteria decisions, including risks related to e.g.; economy,...
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...
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