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Your search keyword '"Razavi, Seyed-Ehsan"' showing total 22 results
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22 results on '"Razavi, Seyed-Ehsan"'

14. Dual Enhancement of Power System Monitoring: Improved Probabilistic Multi-Stage PMU Placement with an Increased Search Space &amp

Author

Ali, Ziad M., Razavi, Seyed-Ehsan, Javadi, Mohammad Sadegh, Gandoman, Foad H., and Aleem, Shady H.E. Abdel

Subjects
Phasor Measurement Unit (PMU), zero-injection bus (ZIB), probability of observability, channel limitation, increased search space, linear expansion, probabilistic multi-stage PMU placement
Abstract

This paper presents a mathematical linear expansion model for the probabilistic Multistage Phasor Measurement Unit (PMU) Placement (MPP) in which zero-injection buses (ZIBs), as well as communication channel limitations, are taken into consideration. From the linearization perspective, presenting a model formulizing the probabilistic concept of observability while modelling the ZIB is of great significance, and has been done in this paper for the first time. More importantly, the proposed probabilistic MPP utilizes a technique disregarding the prevalent subsidiary optimizations for each planning stage. Although this technique, in turn, increases the problem complexity with manifold variables, it guarantees the global optimal solution in a wider and thorough search space, while in the prevalent methods, some parts of the search space might be missed. Furthermore, the proposed model indicates more realistic aspects of the MPP where system operators are allowed to follow their intention about the importance of buses such as strategic ones based on monitoring the priority principles. In addition, the model is capable of considering the network topology changes due to long-term expansions over the planning horizon. Finally, in order to demonstrate the effectiveness of the proposed formulation, the model is conducted on the IEEE 57-bus standard test system and the large scale 2383-bus Polish power system.

Published
2018
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22. Mixed‐integer nonlinear programming framework for combined heat and power units with nonconvex feasible operating region: Feasibility, optimality, and flexibility evaluation.

Author

Razavi, Seyed‐Ehsan, Javadi, Mohammad Sadegh, and Esmaeel Nezhad, Ali

Subjects
*NONCONVEX programming, *INTERIOR-point methods, *NONLINEAR programming, *HEAT
Abstract

This paper presents an optimization framework to determine the optimal operating points of combined heat and power (CHP) units with nonlinear, nonconvex feasible operating region (FOR). The mentioned problem is the economic dispatch (ED) of heat‐only units, thermal units, and CHP units. Also, the electric units are of thermal technology while their valve‐point impact is taken into consideration. Also, the heat power curve of heat‐only units is nonlinear. It is noted that the FOR of CHP units has been defined both as convex and nonconvex regions. For those with nonconvex characteristic, a method is proposed to convert it into a convex characteristic. Accordingly, a separate binary variable must be defined to determine the optimal operating point in each convex region. Thus, the presented problem in this paper is of mixed‐integer nonlinear programming (MINLP) type modeled in General Algebraic Modeling System (GAMS) software. In this respect, different case studies have been presented to assess the optimality, feasibility, and the flexibility of the model. It is noteworthy that the valve‐point effect of thermal units and different FORs of CHP units as well as the electrical power losses have been considered. [ABSTRACT FROM AUTHOR]

Published
2019
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