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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...
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...
Markov models are a well established technique widely used for modeling deterioration processes of the electric power equipment and in reliability analysis. Recently, several papers using Markov and semi-Markov models have been published addressing the issue of the calculation of the remaining life, future failure rates and the probability of failure of power equipment. This paper focuses on one such...
Spinning contingency reserve is idle capacity connected to the system to ensure reliable system operations in the case of equipment outages. The reserve has an economic value since it reduces the outage costs. In several electricity markets, reserve demand functions have been implemented to take into account the value of reserve in the market clearing process. These often take the form of a step-down...
In this study hourly wind speed time series data of Eskisehir region, Turkey have been used for stochastic generation of wind speed data using the transition matrix approach of the Markov chain process. Previous work on synthetic data generation did not focus on the effects of different choices of wind states. In this work, it was observed that increasing the number of states has a significant benefit...
Better modelling and forecasting of very short-term power fluctuations at large offshore wind farms may significantly enhance control and management strategies of their power output. The paper introduces a new methodology for modelling and forecasting such very short-term fluctuations. The proposed methodology is based on a Markov-switching autoregressive model with time-varying coefficients. An advantage...
Electric utilities schedule power transformers in high voltage load stations (customer delivery or regional supply systems) for planned outages such as unit refurbishment, unit replacement, etc. that may last for a few weeks. During the planned outage time, companion units may fail causing a complete loss of supply to customers. Mobile unit transformers (MUT's) could be used in these emergency situations...
Detailed maintenance modeling is indispensable for utilities to determine optimum maintenance policy. Traditional reliability studies assume that transition rates or probabilities in Markov models are accurate. However, in reality, reliability data is either insufficient or mixed with uncertainty. This paper intends to utilize fuzzy set theory to represent parameters for Markov and semi-Markov processes...
This paper presents a reliability assessment of the HVDC converter transformer system (CTS) comparing different component models and configurations. The CTS model is based on the Markov modelling approach, which is shown to be well suited for these relatively small systems. The failure rate data in the models is based on statistical surveys by OGRE. A number of scenarios are calculated in order to...
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