Iranian Journal of Electrical and Electronic Engineering

This paper develops a new method of integral sliding mode control redesign for a class of perturbed nonlinear dissipative switched systems by modifying the dissipativity-based control law that was designed for the unperturbed systems. The nominal model is considered affine with matched and unmatched perturbations. The redesigned control law includes an integral sliding-based control signal such that the system always operates on the sliding mode and the dissipativity of the perturbed switched system is maintained from the initial time of the system operation for the norm bounded perturbations. The proposed techniques eliminates the restrictive design conditions on the derivative of storage functions offered in a recent work. In addition, the global dissipativity of the perturbed system is always maintained if the original unperturbed system is globally dissipative. Depending on the type of stability of the unperturbed system, the designed control law for the perturbed system guarantees robust exponential or asymptotic stability of the closed-loop system. The theoretical results are applied to nonlinear switched systems, and the convergence of the state vectors to the origin is verified by simulation in presence of nonlinear perturbations.

Multi agent systems (MAS) are popularly used in practice, however; a few studies have looked at MAS capabilities from the power engineering perspective. This paper presents the results of an investigation concerning the compatibility of MAS capabilities in different power engineering categories. Five MAS capabilities and seven power system categories are established. A framework for applying MAS in power engineering is developed. A fuzzy inference system is adopted to evaluate the paper proposed framework. Two approaches, namely simulation and real, are considered for different power categories. The paper shows that MAS capabilities are generally compatible with both approaches, although compatibility of MAS with real approach is more significant. The paper concludes that in the near future MAS is anticipated to be a key important tool in the development of intelligent systems and smart grids in power system. This paper contributes to thinking on perspective of MAS in power System.

Congestion and overloading for lines are the main problems in the exploitation of power grids. The consequences of these problems in deregulated systems can be mentioned as sudden jumps in prices in some parts of the power system, lead to an increase in market power and reduction of competition in it. FACTS devices are efficient, powerful and economical tools in controlling power flows through transmission lines that play a fundamental role in congestion management. However, after removing congestion, power systems due to targeting security restrictions may be managed with a lower voltage or transient stability rather than before removing. Thus, power system stability should be considered within the construction of congestion management. In this paper, a multi-objective structure is presented for congestion management that simultaneously optimizes goals such as total operating cost, voltage and transient security. In order to achieve the desired goals, locating and sizing of series FACTS devices are done with using components of nodal prices and the newly developed grey wolf optimizer (GWO) algorithm, respectively. In order to evaluate reliability of mentioned approaches, a simulation is done on the 39-bus New England network.