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In this paper, the operation of electrical, heat and gas networks with flexible energy hubs is presented, where hubs is contributed in energy market that is based on market clearing price. This scheme maximizes the difference between energy hubs profit and operation cost of generation units subjected to operation model of sources, storages and responsible load in hub format, flexibility limits of hubs, and optimal power flow model of energy networks. This formulation is based on market clearing price model, so that it obtain value of energy price according to balancing between the generation and demand in different buses if energy networks. Penalty function method in this paper uses to calculate of primal variables and some dual variables (energy prices). In the following, the stochastic optimization uses to model the uncertainties of load and renewable power. Finally, the obtained numerical results show the capabilities of the proposed scheme in the improving flexibility and economic situations of hubs. Also, optimal operation of hubs is able to improve the economic and operation induces of energy networks in comparison to load flow study, and it improves the social welfare based on reducing of energy price. So that 100% flexibility condition obtains for Hubs. In this condition, the operation cost, energy loss, voltage drop and temperature drop are reduced about to 19.8%, 7.1%, 19.5% and 16.7%, respectively, with respect to load flow analysis, but the pressure drop increases about to 4.9%. [ABSTRACT FROM AUTHOR]

Due to renewable generation increment in power systems and the complexity of control and protection of them, the evaluation of transient stability is necessary. This paper aims at analyzing the impact of wind power generation on the transient stability of power systems. To this end, doubly fed induction generator (DFIG) converters were first investigated in a closed-loop control mode. More detailed controls were used for the rotor side converter. Controls of the DC link converter on the network side were assumed to be ideal. Then, through using Gershgorin's theory, a new approach to adjust converter control parameters was presented. The simulation results in different operating modes confirmed the capability of this method in adjusting the converter's control parameters. Also, by using performed simulations, the effect of increasing wind power production penetration and the changes of reactive power compensation by DFIG on the transient stability of power system were investigated. Finally, the effect of power system strength and DFIG parameters change, in the presence of DFIGbased wind power generation, on transient stability was analyzed. The simulation results showed that an increase in wind power generation initially led to an improvement and finally to the weakening of the transient stability of the system. In fact, this paper provides a professional and valuable perspective towards the investors and operators of the power systems with wind power generation from the viewpoint of transient stability. [ABSTRACT FROM AUTHOR]

In this paper an off-grid microgrid, based on 100% renewable energy, integrated with an electric vehicle charging station, an electric vehicle parking station, and a demand-response program was modeled. The electric vehicle charging station operated based on a battery swapping model in order to charge the electric vehicles in the shortest time possible. The electric vehicle parking station was used to park vehicles during various hours of the 24-hour period. The vehicles inside the parking had to be fully charged by the microgrid when leaving the parking station. Since these vehicles were parked for several hours, their charging time was not limited, and they are charged by direct chargers rather than battery swapping. The loads of the microgrid were under a demand-response program, and they were curtailable, non-curtailable, shiftable, and interruptible loads. The only energy source of microgrid was solar PV systems; the solar-energy related issues such as zero energy during night, output power variations, and the possibility of losing the whole or a part of energy due to shade should be dealt with. In the proposed method, an optimal programming was applied to the chargingdischarging of the swapping batteries in charging station, to the charging-discharging of electric vehicles in the parking station, and to the energy management of loads (i.e., curtailable, non-curtailable, shiftable, and interruptible loads). The mismatch of energy and the lack of solar energy were compensated by the discharging power from charging and parking stations as well as by the management of the power of loads. Simulation results demonstrated that the unavailability of solar energy during the night resulted in paying 50% of the daily revenue as penalty cost. During hours such as 7 to 19, when the solar energy was available, the plan used the solar power as much as possible and limited the extracted energy from other energy resources. The energy of shiftable loads was supplied mostly from 13 to 15 hours, when solar energy was at the maximum level. [ABSTRACT FROM AUTHOR]

Copyright of TECHNE: Journal of Technology for Architecture & Environment is the property of Firenze University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of TECHNE: Journal of Technology for Architecture & Environment is the property of Firenze University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of TECHNE: Journal of Technology for Architecture & Environment is the property of Firenze University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energy Engineering & Management is the property of University of Kashan Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Economic & Regional Studies/Studia Ekonomiczne i Regionalne is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)