f. aminifar

Microgrids as the local area power systems are changing the power system landscape due to their potential of offering a viable solution for integrating renewable energy resources into the main grid. From the operational point of view, microgrids should have the appropriate power electronic interfaces, control schemes, as well as monitoring and automation infrastructures to provide the required flexibility and meet the related IEEE 1547 standard requirements. This paper describes some of the efforts made in the smart microgrid educational laboratory to provide these facilities and create a real-world conditions needed to conduct researches and teach the related courses. Laboratory works not only increase the practical skills of the students but also can motivate them to pursue theoretical courses with more passion. The introduced facilities are somehow unique for the integration of both electric and communication infrastructures which overcome the shortcomings of not considering data transfer challenges in the studies. Complete hardware design of power plant components, and incorporation of solar photovoltaic (PV) and two types of wind turbine generations are some of the efforts made to bring the real-world conditions in the laboratory. In the load-related side, dynamic behaviors of the various types of motors are modeled.

This paper focuses on a dynamic equilibrium considering the flexible ramp market and demand response resources. With ever-swelling installation of variable renewable energies, demand response programs can play an important role in mitigating the system ramping deficiency. Hence in this paper, the ramping capability of demand response resources in procuring system ramp requirement is considered. The strategic behavior of different players is modeled through a multi-leader-common-follower game, in which suppliers and demand response aggregators are laid as the leaders and market operator is considered as the single follower of the game. In addition, a dynamic forward rolling process to find equilibria at the real-time market is proposed. The effect of considering demand response resources and flexible ramp penalty price on the strategic behavior of players in equilibrium is evaluated. Finally, the effectiveness of the proposed approach is verified on a three-firm system. While revealing demand response resources roles in mitigating ramping deficiency, the results show that how penalty price on flexible ramp violation can lead uplift payments to be formed.

This paper presents a response-based generating rejection scheme (GRS) based on an angular stability prediction logic to initiate the outage of accelerated generating units while saving the rest of generating units from the loss of synchronism. First trigonometric, polynomial, and hybrid models of rotor angle trajectory based on the reasonable assumptions are proofed. Then, by taking these models in the prediction step, through the maximum use of measured data based on defining the forecast horizon (FH) and data window with incremental length, the stability/instability of generating units is separately predicted. Next, the status of tripping signal based on a combinational logic of the output results of the angular stability prediction method is specified. In the developed logic, if at least two models of the three designated models yield the same response about the unit stability status, the trip signal is accordingly fired or blocked. The proposed method is examined on the one machine infinite bus and the WSCC standard test bed under different operation and fault scenarios. The obtained results demonstrate that beside simplicity, low computational burden, and very short processing time, the proposed combinatorial method outperforms the existing ones working with individual prediction models.

Heat exchangers facilitate the transfer of heat between fluids with different temperatures. Compared with solids, most fluids have lower heat transfer coefficients and as a result, the use of high heat transfer coefficient solid particles as additives can increase the convective heat transfer coefficient of the fluid. In this study, the effect of the addition of nanoparticles to the base fluid (deionized water), application of triangular-cut twisted tapes as well as corrugation of shell and tube type heat exchangers pipes, is investigated on heat transfer values, friction coefficient variations as well as variations in performance evaluation criterion. The effects of addition of 0.7 and 1% magnesium-oxide nanoparticles on heat transfer coefficient improvements is investigated and the results of simultaneous application of magnesium-oxide water nanoparticles, corrugated pipes, and twisted tapes are compared. Comparisons against the basic conditions (deionized water without nanofluid, corrugated pipes or triangular-cut twisted tapes) indicate a 48% increase in thermal performance, a minuscule increase of 6.3% in friction coefficient and a 46% increase in the performance evaluation criterion as a result of the application of %0.7 magnesium-oxide water nanoparticles, use of corrugated pipes and triangular cut twisted tapes on the inner surface of shell and tube heat exchanger piping. Also, the application of 1% magnesium-oxide water nanofluid, and simultaneous use of corrugated pipes and triangular-cut twisted tapes on shell and tube heat exchanger piping inner surface results in a 72% increase in thermal performance, a minuscule increase of 6.9% in friction coefficient and a 70% increase in the performance evaluation criterion.