when power systems are expanded and connected together with weak tie lines, the low-frequency oscillations are increased and the stability margin of the power system decreases. therefore, when designing the transmission system to be used, it is necessary to maintain the dynamic stability of the power system, and to make sure to have the most possible stability margin. sssc is a facts device con...

flexible ac transmission systems (facts) controllers with its ability to directly control the power flow can offer great opportunities in modern power system, allowing better and safer operation of transmission network. in this paper, in order to find type, size and location of facts devices in a power system a dedicated improved particle swarm optimization (dipso) algorithm is developed for de...

analysis of non-laminar flows in coarse alluvial beds has a wide range of applications in various civil engineering, oil and gas, and geology problems. darcy equation is not valid to analyze transient and turbulent flows, so non-linear equations should be applied. non-linear equations are classified into power and binomial equations. binomial equation is more accurate in a wide range of velocit...

The confidentiality of information in a system can be breached through unrestricted information flow. The formal properties of non-deducibility and non-inference are often used to assess information flow in purely cyber environments. However, in a “cyber-physical system” (CPS), i.e., a system with significant cyber and physical components, physical actions may allow confidential information to ...

Conventionally, the correctness of functional and non-functional properties of hardware components is ensured during design process by simulation. Moreover, different description languages are needed during development phases. Thus, by adopting the Action Systems, we are able to use the same formalism from specification down to implementation. Recently, we have been exploiting possibilities to ...

In a power system, a contingency refers to an outage of power system components such as transformers, generators, lines, etc. due to faults or failure. A contingency could lead to voltage and power flow problems. This paper describes practical contingency studies based on a real power system provided by a utility. The aim of this study is to find out contingencies that cause undervoltage, overv...

this paper proposes an optimal power flow (opf) algorithm by direct load control (dlc) programs to optimize the operational cost of smart grids considering various scenarios based on different constraints. the cost function includes active power production cost of available power sources and a novel flexible load curtailment cost associated with dlc programs. the load curtailment cost is based ...

In this paper, a new open-source library of fluid power models is introduced. The intent of the library is to formally collect knowledge about fluid power components and systems, and to share and communicate this knowledge openly among the members of the fluid power community. The library takes advantage of the object-oriented features of the Modelica language to formulate the models in a forma...

The hybrid AC-DC microgrid (HMG) architecture has the merits of both DC and AC coupled structures. Microgrids are subject to intermittence when the renewable sources are used. In the HMG, since power fluctuations occur on both subgrids due to varying load and unpredictable power generation from renewable sources, proper voltage and frequency regulation is the critical issue. This article propos...