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The objective of the paper is to assess the feasibility of the neural network (NN) approach in power plant process evaluations. A “feed-forward” technique with a back propagation algorithm was applied to a gas turbine equipped with waste heat boiler and water heater. Data from physical or empirical simulators of plant components were used to train such a NN model. Results obtained using a conventional computing technique are compared with those of the direct method based on a NN approach. The NN simulator was able to perform calculations in a really short computing time with a high degree of accuracy, predicting various steady-state operating conditions on the basis of inputs that can be easily obtained with existing plant instrumentation. The optimization of NN parameters like number of hidden neurons, training sample size, and learning rate is discussed in the paper.

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The reliability of bidirectional dc-dc converters is a critical issue in many applications where the power flows from or to energy storage systems regularly, such as automotive applications and standalone power systems. This paper addresses dual active bridge converters faulty operation and proposes a fault detection method. © 2012 IEEE

Abstract. A continuously energy production is the most difficult and important feature to be guaranteed when designing a standalone power system for telecommunications. This paper focuses on a standalone power system for telecommunications already proposed in the literature, combining the most mature generators and technologies related to renewable energies and environment friendliness. It is important to know the operational problems, the best way to solve them and how to apply efficient maintenance. Reliability studies based on existent applications of renewable generators (some of them used in standalone power systems) help to know what to expect from their operational behaviour and to reduce time and costs in maintenance tasks. Notwithstanding their undoubted importance, they are not much recognised in literature, yet. The paper presents a brief review based on the few reliability reports about wind and photovoltaic systems available in the literature. Contributions and important aspects are discussed having in mind all the obstacles to achieve an uninterruptible power supply.

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Measurements have been carried out on a four-cylinder spark-ignition engine to estimate the amount of heat recoverable in particular when the engine runs at low loads. Such heat is sucient to feed an absorption cooling system for car air conditioning when the speed is over a threshold value. Data for the design of a heat recovery system are reported and discussed.