In recent years, energy efficiency and related solutions to enhance the efficiency of power plants have been the focus of attention. For this purpose, the combined heat and power (CHP) plants are increasingly used to generate the required electrical and thermal powers, simultaneously. On the other hand, the reliability of the power system has become one of the important studies of the power system, so that today the consumers expect the electricity provided them with least possible interruption. For this purpose, in this paper, the reliability of the power system including CHP plants from adequacy point of view is evaluated. To study the effect of the CHP units on the adequacy indices of the power system, a reliability model is developed for CHP units that considers both the failure of composed components and the effect of this unit from thermal power generation point of view. To consider the heat generation of the CHP units in the related reliability model, a four-state reliability model is developed for each unit based on the electrical and thermal power of the CHP plant. In this paper, the reliability modeling of different CHP technologies including the CHP units based on the gas turbine, reciprocating engine, micro-turbine, steam turbine, and fuel cell is studied. To investigate the effectiveness of the proposed model, the adequacy assessment of the Roy Billinton test system (RBTS) and IEEE reliability test system (IEEE-RTS) including the CHP units is performed and the impact of the CHP units on the reliability indices is evaluated پرونده مقاله

Produced power of wind, solar, run of the river, ocean thermal, tidal and wave power plants is respectively, dependent on wind velocity, sun radiation, river flow, temperature of ocean upstream, period & height of waves, tidal level or tidal stream velocity. Due to wide change in these quantities, produced power of these renewable resources changes a lot over time. As the penetration level of renewable resources in electric network is increased, reliability and other aspects of electric network may be affected that should be studied. Analytical method is not suitable to study uncertainties of output power of renewable resources in reliability analysis of electric network with these renewable power plants. Thus, the current research suggests Monte Carlo simulation method to study effect of renewable power plants on reliability indices. Renewable power plants studied in the research are wind turbines, solar farms, wave energy converters, run of the river power plants, both types of tidal units, and ocean thermal energy conversion systems. Numerical studies are performed on test electric networks, to study these renewable resources impact on reliability indices of electric networks with renewable power plants. It is concluded from numerical outcomes that these renewable power plants improve reliability performance of electric network. However, due to the variation of renewable resources, the impact of renewable power plants on reliability performance of the electric network is less than the conventional units with the same capacity. پرونده مقاله