Khorasan Regional Electrical Company

Mashhad, Iran

Khorasan Regional Electrical Company

Mashhad, Iran
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Niazy I.,Ferdowsi University of Mashhad | Mortazavi H.,Khorasan Regional Electrical Company | Ebadi J.,Ferdowsi University of Mashhad | Sabzevari S.,Ferdowsi University of Mashhad | Niazy A.,Ferdowsi University of Mashhad
International Review of Electrical Engineering | Year: 2010

As one of the most important ancillary services, reactive power production plays a crucial rule in power system operation, reliability and security. Because of the opportunity costs in providing reactive power, producers are under great pressure to provide VAr support. This paper presents a new challenge on the reactive capability curves (RCC) of the synchronous generator taking in account the normal limits of operation without exceeding thermal limitations. The importance of re-evaluation of RCC in the real world is because of the RCC is changed over time and aging of the generators. In this paper it is discusses about some reasons, which lead to the variations, and the importance of re-evaluation of RCC. © 2010 Praise Worthy Prize S.r.l. - All rights reserved.


Jafarian H.,Ferdowsi University of Mashhad | Mashhadi M.R.,Khorasan Regional Electrical Co | Javidi M.H.,Ferdowsi University of Mashhad
2011 19th Iranian Conference on Electrical Engineering, ICEE 2011 | Year: 2011

Power system restoration is an important task for system operators. Due to the importance of the problem, the ways which will be used for solving it are significant as well. One of the best methods for restoring a power system is recognition and access to the network reconfiguration. If the main skeleton-network is recognized appropriately, other parts of the network can be restored at the shortest possible time. Restructuring in power industry add new complicated constraints to the problem of power system restoration. While this issue has been investigated by many researchers, little attention has been paid to this task in a market based environment. In most solving methods an index is defined to rank the network nodes. But none of the suggested indices have the comprehensiveness and also none of them considered the issues which have been dictated by the power market. This article represents a new combined index and market based method for ranking the network buses, which by applying it to different power systems; the best reconfigured network can be distinguished. Restoring other parts of the network from this skeleton network will lessen the restoration time. By using this index we can also decrease the cost of blackout and the cost of the power system restoration. This index in compare to similar indices has a better function and performs a better bus ranking for complicated power networks in market environment. Genetic algorithm is used to solve this problem. The suggested method is used to rank the buses of the IEEE 30-bus network. Results show that this method in compare with similar methods has a better performance © 2011 AmirKabir Univ of Tech.


Bashir M.,Ferdowsi University of Mashhad | Sadeh J.,Ferdowsi University of Mashhad | Kamyab E.,Khorasan Regional Electrical Company | Yaghobi H.,Semnan University
2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012 - Conference Proceedings | Year: 2012

In substations, protective equipments such as arresters and neutral transformer are being connected to substation ground grid to protect them against transient overvoltage, firing and other damages. But unfortunately, lack of grounding connection of electrical equipments or high resistance of grounding grid is one of the main reasons which cause risk for staffs and electrical equipments. In this paper, effect of increasing in grounding grid resistance on transient overvoltage which is caused by short circuit, switching and lightning on the interior equipments and safety in a grounding grid at substation is investigated. Effect of transient overvoltage with different short circuits is another subject that is considered. In this paper, indices for ground grid safety are expressed and grounding grid analysis will be done with CYMGrd software. Transient analysis simulations are carried out using DigSilent software and the results of investigation on a real system are presented © 2012 IEEE.


Yaghobi H.,Semnan University | Mortazavi H.,Khorasan Regional Electrical Company | Ansari K.,Ferdowsi University of Mashhad | Mashhadi H.R.,Ferdowsi University of Mashhad | And 2 more authors.
International Transactions on Electrical Energy Systems | Year: 2013

This contribution deals with the analysis of synchronous generator loss of excitation (LOE) protection. This paper presents a new method for detecting LOE in synchronous generator based on the variation of the magnetic flux linkage in the air gap. To show the effectiveness of the proposed protection, comparisons are made with the conventional LOE protection methods by considering different generator sizes. The simulation results show that the proposed method is useful and effective to detect LOE conditions. The main advantage of this method is its speed and sensitivity. Copyright © 2012 John Wiley and Sons, Ltd.


Mashhadi M.R.,Ferdowsi University of Mashhad | Mashhadi M.R.,Khorasan Regional Electrical Company | Ghazizadeh M.S.,Power and Water University of Technology, Tehran | Javidi M.H.,Ferdowsi University of Mashhad
Iranian Journal of Science and Technology, Transaction B: Engineering | Year: 2011

Primary frequency regulation, as an ancillary service, is usually supported by generation reserves. Modern generating units have special technical features; e.g. their governor operation mode can be selected, their ramp rate can be selected to be either normal or fast, etc. On the other hand, there are some technical constraints; e.g. some generating units cannot participate in primary frequency control at their capacity limits. In this paper, operational technical features and constraints of generating units are incorporated in a"simultaneous scheduling of energy and primary reserve" problem. To obtain the optimal scheduling, a heuristic iterative method based on genetic algorithm is proposed. The role of fast ramp rate and other capabilities and constraints on scheduling are investigated through simulation studies. Simulation results show that taking fast ramp rate of generating units into account not only reduces the total operation cost, but will also end up with a feasible solution, even in cases where previously proposed methods fail. Also, simulation results indicate that using fast ramp rate, results in the reduction of both the price of electricity and its volatility. © Shiraz University.


Jafarian H.R.,Ferdowsi University of Mashhad | Rajabi Mashhadi M.,Khorasan Regional Electrical Company | Javidi M.H.,Ferdowsi University of Mashhad
International Review of Electrical Engineering | Year: 2011

Power system restoration is an important task for system operators. Therefore, much research has been carried out to optimize restoration process, among which, recognition and access to the network skeleton during restoration has been considered as a dominant approach. If the main skeleton-network is recognized appropriately, then reconfiguration and restoring major parts of the network can be performed at the shortest possible time. Restructuring in power industry has introduced new challenges to power system. While, restructuring has affected power system operation seriously, little attention has been paid to restoration process as an extra ordinary mode of system operation in a market based environment. One approach for restoration problem is based on performance indices introduced to rank nodes of the network. In this paper, a new method based on a comprehensive ranking index for electrification of network buses during restoration process is proposed which results in reduction of both the interruption cost and restoration cost. In our ranking approach, both the network configuration and the value of lost load at different buses of the network have been considered in a market based operated system. In the method, the dominant network skeleton for restoration is distinguished such that the restoration time for the rest of network from this skeleton network will be reduced. Our simulation results confirm the validity and efficacy of our proposed approach in different situations, especially in a market-based environment. We have used the Genetic Algorithm (GA) to solve the optimization problem. The method has been tested on IEEE 30-bus network. Results show that this method in compare with similar methods has a better performance. © 2011 Praise Worthy Prize S.r.l. All rights reserved.


Rajabi Mashhadi M.,Ferdowsi University of Mashhad | Rajabi Mashhadi M.,Khorasan Regional Electrical Company | Javidi D. B. M.H.,Ferdowsi University of Mashhad | Ghazizadeh M.S.,Power and Water University of Technology, Tehran
Electrical Engineering | Year: 2011

Frequency control, as an ancillary service, is usually provided by generation reserves. Modern generating units have special technical capabilities; e.g., their governor operation mode can be selected to be either active or passive, their ramp rate can be selected to be either normal or fast, etc. On the other hand, generating units have some technical constraints; e.g. some generating units cannot participate in primary frequency control at their capacity limits. In this paper, operational capabilities and constraints of generating units are incorporated in a "simultaneous scheduling of energy and primary reserve" problem. Furthermore, a heuristic iterative method (based on genetic algorithm) is proposed to obtain the optimal scheduling. The impacts of capabilities and constraints on scheduling are investigated through simulation studies. Simulation results depicts that taking these capabilities and constraints of generating units into account, not only reduces the total operational cost of generating units, but also will end up with a feasible solution for the system, even in cases where the previously proposed methods fail. © 2011 Springer-Verlag.


Hojjat M.,Islamic Azad University at Shahrood | Javidi M.H.,Ferdowsi University of Mashhad | Yazdanpanah D.,Khorasan Regional Electrical Company
Turkish Journal of Electrical Engineering and Computer Sciences | Year: 2016

Considering system uncertainties in developing power systems, algorithms such as congestion management (CM) are vital in power system analysis and studies. This paper proposes a new model for power system CM by considering power system uncertainties based on chance-constrained programming (CCP). In the proposed approach, transmission constraints are taken into account by stochastic, instead of deterministic, models. The proposed approach considers network uncertainties with a specific level of probability in the optimization process, and then an analytical approach is used to solve the new model of stochastic congestion management. In this approach, the stochastic optimization problem is transformed into an equivalent deterministic problem. Moreover, an efficient numerical approach based on a real-coded genetic algorithm and Monte Carlo technique is proposed to solve the CCP-based congestion management problem in order to make a comparison to the analytical approach. The effectiveness of the proposed approach is evaluated by applying the method to the IEEE 30-bus test system. The results show that the proposed CCP model and the analytical solving approach outperform the existing models. © Tubitak.


Niazy I.,Ferdowsi University of Mashhad | Ebadi J.,Ferdowsi University of Mashhad | Sabzevari S.,Ferdowsi University of Mashhad | Niazy A.,Ferdowsi University of Mashhad | And 2 more authors.
2010 9th International Power and Energy Conference, IPEC 2010 | Year: 2010

As one of the most important ancillary services, reactive power production plays a crucial rule in power system operation, reliability and security. Because of the opportunity costs in providing reactive power, producers are under great pressure to provide VAr support. In this paper, a new challenge on the reactive capability curves (RCC) of the synchronous generator is discussed. The RCC is a graphical representation of the reactive and active power produced by the generators under various operating conditions, as specified by the cold gas pressure and temperature inside the generators as well as the power factor. These curves define the normal limits of operation without exceeding thermal limitations. The generator manufactures provide the determined RCC, However, in the real world RCC is changed over time and aging of the generators. This paper discusses about some reasons, which lead to the variations, and the importance of re-evaluation of RCC. ©2010 IEEE.

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