4514 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 58, NO. 10, OCTOBER 2011 Smart Operation of Wind Turbines and Diesel Generators According to Economic Criteria Carlo Cecati, Fellow, IEEE, Costantino Citro, Antonio Piccolo, Member, IEEE, and Pierluigi Siano, Member, IEEE Abstract—This paper proposes an innovative system for Smart Grid (SG) management aiming at minimizing the total costs sup- ported for carrying out the delivery of energy to consumers. These costs include the production costs of distributed generators, the cost of the power provided by the primary substation, and the cost associated with grid power losses. After a brief overview on the main SG aspects, this paper describes the proposed approach that makes use of an optimal power ﬂow algorithm and the active management schemes. The efﬁciency of the method is veriﬁed on a distribution system comprising wind turbines and diesel gen- erators, considering the time-varying characteristics of the load demand and wind power generation. Index Terms—Active management, diesel generators, economic criteria, optimal power ﬂow (OPF), Smart Grid (SG), wind tur- bines (WTs). I. I NTRODUCTION T HE TERM Smart Grid (SG) refers to a generic power network that is able to “smartly” integrate the actions of all the elements connected to it (distributed generators (DGs), loads, energy storage systems, protection, and control systems) through a coordinate process that ensures the optimal electrical energy generation, transmission, and distribution in an efﬁcient, safe, and economical way [1]. The SG concept is somehow related to the existing necessity of meeting different requirements: 1) to restrain the environmental pollution levels; 2) to satisfy the growing electrical energy demand; 3) to renew the current power system; 4) to obtain the optimal integration of distributed generation based on renewable or conventional sources. A great convergence of scientiﬁc, political, and industrial interests is born for bringing innovations in every stage of the energetic cycle (generation, transmission, distribution, and con- sumption) in order to achieve the aforementioned objectives. The SG will be more similar to a communication system than to a simple electrical power system: its goal will not be anymore Manuscript received May 26, 2010; revised September 23, 2010; accepted November 4, 2010. Date of publication January 13, 2011; date of current version August 30, 2011. C. Cecati is with the Department of Electrical and Information Engineering, University of L’Aquila, 67100 L’Aquila, Italy (e-mail: carlo.cecati@univaq.it). C. Citro, A. Piccolo, and P. Siano are with the Department of Industrial Engineering, University of Salerno, 84084 Fisciano, Italy (e-mail: costantino- citro@gmail.com; piccolo@unisa.it; psiano@unisa.it). Color versions of one or more of the ﬁgures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identiﬁer 10.1109/TIE.2011.2106100 the simple energy delivery to the end users connected to the grid, but it will offer a ﬂexible and dynamical connection for all of the actors involved in the process of energy production and consumption. The usual distinction between the producers and consumers of energy will be replaced by the ﬁgure of the prosumers, i.e., users who can act both as producers and consumers in each moment of the day [2]. Most of the scientiﬁc literature dealing with the SG theme depicts hypothetical unborn sceneries characterized by a strate- gic management of the power system that is very different from the actual one, which is able to exploit the new advancing technologies in order to address the changing requirements of the utilities and customers. The SG is often described as a cap- illary network carrying information, control data, and electrical energy through a series of powerful cooperating intelligent devices, highly distributed along the system. As emphasized in [3]–[6], one of the key components of the future SG will be an advanced metering infrastructure. The future SG will, in fact, be equipped with a complex informa- tion and communication infrastructure to which every operator will be interfaced by a system that is able to give real-time information about the electrical energy availability and price. According to this approach, every user will assume an active role in the optimal management of the power consumption, choosing the moment of the day in which the consumption of electricity is more convenient and postponing his activities according to the energy price and availability. By using advanced smart meters, the consumption and gener- ation proﬁles will be available for both consumers and grid op- erators. This mechanism will give the former greater awareness of how they consume their energy, bringing about changes in their behaviors toward eco-friendly lifestyles. It will also make grid operators able to achieve a more dynamic management of the whole power system. Consequently, the SG also represents an opportunity for the entrance in the energy market of new services based on ﬂexible tariffs and for the realization of the so-called demand side management [7], [8]. Demand side management includes the set of mechanisms and strategies executed by the grid operators in order to inﬂu- ence and modify the users’ energy consumptions. It represents a very useful and economic solution for grid operators, energy suppliers, and consumers. By mitigating the problems related to the imbalance between energy supply and consumption, it allows a better exploitation of renewable energy sources and avoids the high peak demand that should force energy suppliers to make heavy investments in the production system. Conversely, in order to achieve their best integration into the electrical network, DGs must play an active role in the 0278-0046/$26.00 © 2011 IEEE