Generation Reliability Evaluation Research Articles

The Effects of Forced Outages Rates and Load Uncertainty on The Generation Reliability Evaluation.(Dept.E)

In analysis of generation reliability assessment in power systems, the effect of both forced outages, and uncertainties in load forecasting must be taken into consideration. In this paper, the analysis has been evolved from loss-of-load and loss-of-energy probability techniques. The student-t-distribution method is used to calculate the uncertainty of the forecast peak demand at specified intervals of confidence. The effects of the numbers and the forced outage rates of the generating units have been studied.

Small Hydro Power Plants Energy Availability Modeling for Generation Reliability Evaluation

This paper presents a model for evaluating small hydro power plants (SHPP) generation availability that can be applied to generation systems reliability and to generation planning studies. The model considers the uncertainties of rivers inflows and generation units operation. The river inflow is modeled as a stationary stochastic process by a multiple states Markov chain and the generator unit by a two states Markov model. The large number of different inflow values is reduced by the application of the statistical clustering techniques K-means in two different approaches: inflow clustering and power clustering. The steady state probabilities of each power generation value of the SHPP are calculated by the solution of the stochastic system. The expected value of the annual power generation of the SHPP, the duration curve, and several reliability indices are then calculated in a more accurate way than conventional approaches, since the model considers both the river inflow variation and the generation unit operation. Results obtained with actual Brazilian rivers inflows used for SHPP generation are reported in the paper and demonstrate the accuracy and applicability of the presented method for reliability evaluation.

A frequency and duration approach for generation reliability evaluation using the method of stages

A frequency and duration approach for generation reliability evaluation using the method of stages is presented. Two separate expressions are provided, one for the loss of load expectation (LOLE) and the other for the loss of load frequency (LOLF). Explicit relationships for determining the parameters of these expressions from the generation system data are derived. Several studies to illustrate the accuracy and efficiency of the proposed approach are also reported. >

A Direct Method for Multi-Area Reliability Evaluation

This paper describes a model developed for multiarea generation reliability evaluation. It is based on an analytic characterization of the system failure modes, when the interconnected generation is represented by a network flow model. Reliability indices are obtained as functions of each failure mode probability and expected capacity, which are calculated directly by integrating the capacity distribution function over the set that characterizes the failure mode. The dependence of generating capacity on hydrological conditions is explicitly represented. Sensitivity indices of the expected unserved demand with respect to area generation and interconnection reinforcements are also obtained. A case study with a 5-area Brazilian is presented and discussed.

Comparison of two algorithms for power system reliability calculations

In this paper, two algorithms are proposed for the computation of the static generation reliability of a power system. The loss-of-load probability (LOLP), which is the reliability index usually employed in static generation reliability evaluation, is computed by using both the capacity outage table and effective load approaches. Numerical results obtained from the study of a sample power system consisting of 44 generating units are compared in terms of the required computational time and numerical accuracy. It is found that, with the generating capacities properly rounded off, the capacity outage table method can be employed as an effective means of computing power system reliability. The effect of generation expansion planning on generation reliability is also examined.

Modelling wind energy sources in generating reliability evaluation

Considerable interest exists in using wind sources to generate electrical energy and trial systems are already in operation. The main reason is that conventional fossil fuels are limited and expensive. Unfortunately, wind is not always available, and conventional sources must supply the demand in these quiescent periods. Standard techniques for evaluating generation reliability containing wind sources are inappropriate since they are capacity based. Instead, techniques based on energy are required. This paper describes techniques that assimilate wind energy sources in generation reliability evaluation. A typical generating system is also considered and the effect that wind energy sources have on the reliability of this system is demonstrated.