Papers by Ebadollah Kamyab
Computational Intelligence in Electrical Engineering, Mar 15, 2015
2023 12th International Conference on Renewable Energy Research and Applications (ICRERA)
Archives of Electrical Engineering
Circuit Breakers (CBs) play an important role in ensuring the safe operation of protection system... more Circuit Breakers (CBs) play an important role in ensuring the safe operation of protection systems. Condition Monitoring (CM) devices are widely implemented to extend lifetime, and to improve the maintenance quality. The present paper proposes a cost-based prioritization approach for CBs in a network equipped with CM devices. To this end, a mathematical formulation is developed for the categorization and modeling of equipment failures based on their severity. This formulation quantifies the effect of the CM devices on the outage rate of the equipment. The reliability parameters of the substations 400/132/20 KV, including the failure rate, λ, average repair time, r, average outage time, U, substations, in two status of without CM and with CM of the CBs are calculated. These parameters are calculated implementing a minimal cut-set method. The outage rate of equipment with and without the CM devices is used to determine the effect of the CM devices on the reliability of the network. Finally, the prioritization of substations to install the CM devices on the CBs has been investigated in terms of the Expected Energy Not Supplied (EENS) and costs of CM. To verify the effectiveness and applicability of the method, the proposed approach is applied to the CBs in the power transmission network in the Khorasan Regional Electricity Company (KREC) in Iran.
By creating electricity markets, regional electrical companies are working to reduce their curren... more By creating electricity markets, regional electrical companies are working to reduce their current costs for greater profit and maintain Competitiveness strength. In this way, the reduction of maintenance costs, which is a significant part of the cost of operating the transmission network, has a much importance. On the other hand, electricity network equipment such as transformer, transmission lines and circuit breakers that have been exploited over the last few decades, naturally, With longer lifetime, have been aging. Consequently, regional electrical companies are now faced with a major challenge, such as aging equipment that to maintain the reliability of the system to an acceptable level and to escape the heavy costs associated with outages, they require a coherent planning for maintenance on the network. In the new competitive environment, regional electrical companies prefer to continue to use aging equipment as much as possible instead of replacing them with high costs by pe...
Over the recent years, a number of new maintenances methods for high voltage substations have bee... more Over the recent years, a number of new maintenances methods for high voltage substations have been introduced to reduce the number of substation events. The primary purpose of the present study is to presents a Cost-benefit analysis for Circuit-Breakers (CBS) in a substation equipped with Condition Monitoring (CM) devices. To this end, a mathematical formulation to categorize and model equipment failures based on their severity is developed. By CM, some of severity failures, named major failures, can be detected early, and corrected as the minor failure. This formulation quantifies the effect of CM devices on the outage rate and Predictive Maintenance (PDM) rate of the equipment. The PDM rate is used to modify the Markov maintenance model for the equipment. The proposed modified Markov model quantifies the effect of CM on the maintenance costs and lifetime of CB. The New Markov model is compared with the Preventive Maintenance (PM) model. Expected Energy Not Supply (EENS) and reliab...
In a widespread blackout, system restoration must begin from pre-selected generating units with t... more In a widespread blackout, system restoration must begin from pre-selected generating units with the ability to start themselves. Units, which participate in this ancillary service, must have the ability to provide at least three sequential black starts, within two hours, to allow for possible tripping of the transmission or distribution system during the re-instatement. Unwanted tripping of the black-start generators caused by inrush current during energization of the transformers, can misspend these sequential black-starts. This paper suggests a new start-up method to reduce such unwanted tripping. Almost all generators are equipped with under voltage relays, which operate when the voltage reaches under 95 percent of nominal value. It is shown in this paper, if the generator is connected to the transformer with %95 of its nominal voltage, inrush current will be reduced considerably. Simulations done by MATLAB software, confirm the capability and usefulness of the proposed method.
iranian journal of electrical and electronic engineering, 2020
The Circuit Breaker (CB) is one of the most important equipment in power systems. CB must operate... more The Circuit Breaker (CB) is one of the most important equipment in power systems. CB must operate reliably to protect power systems as well as to perform tasks such as load disconnection, normal interruption, and fault current interruption. Therefore, the reliable operation of CB can affect the security and stability of power network. In this paper, effects of Condition Monitoring (CM) of CB on the maintenance process and related costs are analyzed. For this, A mathematical formulation to categorize and model equipment failures based on their severity is developed. By CM, some of the high severity failures, named major failures, can be early detected and be corrected as a minor failure. This formulation quantifies the effect of CM on the outage rate and Predictive Maintenance (PDM) rate of equipment. Also, by combining the predictive maintenance to preventive maintenance, the Integrated Preventive and Predictive Maintenance Markov model is presented to analyze the effect of CM on th...
iranian journal of electrical and electronic engineering, 2012
Islanded operation of distributed generators is a problem that can happen when they are connected... more Islanded operation of distributed generators is a problem that can happen when they are connected to a distribution system. In this paper an islanding detection method is presented for inverter based Distributed Generation (DG) using under/over voltage relay. The method is an adaptive one and is based on the change of DG active power reference (Pref) in inverter control interface. The active power reference has a fixed value in normal condition, if the Point of Common Coupling (PCC) voltage changes, Pref , is determined as a linear function of voltage. The slope of Pref depends on the load active power (Pload) and it should be changed if Pload changes. The Non-Detection Zone (NDZ) of the proposed method is zero. If changing of the PCC voltage is sensed, islanding will be detected when it occurs. Also, it does not have any negative effects on the distribution system under normal conditions. The proposed method is evaluated according to the requirements of the IEEE 1547 and UL 1741 st...
IEEE Transactions on Power Delivery, 2019
Network parameters error may seriously affect the accuracy of fault location results, even making... more Network parameters error may seriously affect the accuracy of fault location results, even making them unacceptable in extreme cases. This paper proposes a new method which incorporates these errors in wide area fault location problem using phasor measurement units(PMU) to estimate inaccurate network parameters employing robust state estimation. Our proposed method is composed of two stages. The first stage or the primary stage provides an initial point for the second stage which is the main contribution of this paper. Additionally, the set of measurements contaminated with bad data could be obtained from the first stage and its intersection with leverage measurements are then eliminated from the measurement set before feeding it into the second stage. Finally, fault point and faulted line parameters are estimated by the main(second) stage of the method. The proposed method has been applied to two test systems, namely Institute of Electrical and Electronics Engineers (IEEE) 14-Bus and IEEE 57-Bus systems to evaluate its accuracy. Simulation results indicate high accuracy and consistency of the proposed method.
Abstract—Distance relay is the main protection of power transmission lines and make an important ... more Abstract—Distance relay is the main protection of power transmission lines and make an important role in power system stabilization if it operates selective and instantaneous. In this paper, the trajectory of the fault impedance is determined. It is shown that in the end of the first zone or in the middle of the second zone, distance relay could not make a correct decision for operating if the fault occurs with arc. So to overcome this problem, in this paper a novel technique using total harmonic distortion (THD) is proposed. The proposed method makes the distance relay more selective and instantaneous. Keywords- Distance protection; Arcing faults; Total harmonic distortion; Fast Fourier analysis; I.
Journal of Iranian Association of Electrical and Electronics Engineers, 2008
iranian journal of electrical and electronic engineering, 2012
Islanded operation of distributed generators is a problem that can happen when they are connected... more Islanded operation of distributed generators is a problem that can happen when they are connected to a distribution system. In this paper an islanding detection method is presented for inverter based Distributed Generation (DG) using under/over voltage relay. The method is an adaptive one and is based on the change of DG active power reference (Pref) in inverter control interface. The active power reference has a fixed value in normal condition, if the Point of Common Coupling (PCC) voltage changes, Pref , is determined as a linear function of voltage. The slope of Pref depends on the load active power (Pload) and it should be changed if Pload changes. The Non-Detection Zone (NDZ) of the proposed method is zero. If changing of the PCC voltage is sensed, islanding will be detected when it occurs. Also, it does not have any negative effects on the distribution system under normal conditions. The proposed method is evaluated according to the requirements of the IEEE 1547 and UL 1741 st...
IEEE Transactions on Power Delivery, 2019
Network parameters error may seriously affect the accuracy of fault location results, even making... more Network parameters error may seriously affect the accuracy of fault location results, even making them unacceptable in extreme cases. This paper proposes a new method which incorporates these errors in wide area fault location problem using phasor measurement units(PMU) to estimate inaccurate network parameters employing robust state estimation. Our proposed method is composed of two stages. The first stage or the primary stage provides an initial point for the second stage which is the main contribution of this paper. Additionally, the set of measurements contaminated with bad data could be obtained from the first stage and its intersection with leverage measurements are then eliminated from the measurement set before feeding it into the second stage. Finally, fault point and faulted line parameters are estimated by the main(second) stage of the method. The proposed method has been applied to two test systems, namely Institute of Electrical and Electronics Engineers (IEEE) 14-Bus and IEEE 57-Bus systems to evaluate its accuracy. Simulation results indicate high accuracy and consistency of the proposed method.
Conventional power distribution system is radial in nature, characterized by a single source feed... more Conventional power distribution system is radial in nature, characterized by a single source feeding a network of downstream feeders. Protection scheme for distribution system, primarily consisting of fuses and reclosures and, in some cases, relays, has traditionally been designed assuming the system to be radial. In last year extra attention applied in use of distributed generator units in distribution networks. The integration of distributed sources into existing networks brings up several technical, economical and regulatory questions. The connection of distributed generators (DG) to distribution networks also influences the performance of the networks and the impact depends on the number, location and size of injected DG. The presence of distributed generators in the distribution network can cause the mis-coordination of the protection system. In order to overcome this problem, one can change the relay setting based on the number and location of DGs in the network. In this paper, another approach is selected in which, the capacity of DG at each node is determined in such a way, that the mis-coordination does not happen. The proposed method is explained in two cases. In the first case, just one DG at each node is considered, but in the second case existence of two or more DGs in separate nodes is taken into account. The simulation result are presented and discussed in a typical distribution network.
2012 11th International Conference on Environment and Electrical Engineering, 2012
This paper presents a new method for determining the fault location on two-terminal transmission ... more This paper presents a new method for determining the fault location on two-terminal transmission lines using genetic algorithm. Distributed time-domain model of the transmission line is used to derive the fault location equations; therefore, impact of shunt capacitance of the line is fully considered. Synchronous post-fault voltage and current measurements from both sides of the line and the line parameters are used as the initial data for this method, while no assumption on the source impedance and fault type is made. Using the modal transformation, the presented method is applicable to both transposed and un-transposed lines and is independent of the fault type. By the use of time-domain model, the algorithm does not require filtering high frequency components and DC offset since these components are taken into account in the model. Evaluation studies based on EMTP/ATP simulation data demonstrate that the accuracy of the proposed algorithm is very high in different fault locations and fault resistances.
International Transactions on Electrical Energy Systems
IEEE Transactions on Power Delivery
Iet Generation Transmission Distribution, Feb 12, 2013
ABSTRACT
Conventional fault location methods using one-terminal voltages and currents are not applicable t... more Conventional fault location methods using one-terminal voltages and currents are not applicable to multi-terminal transmission lines. However, for determination of fault location in three-terminal lines at least voltages and currents of two terminals are necessary. There have been some techniques presented to solve fault location problem for multi-terminal transmission lines. In these methods lumped or distributed frequency domain models are used for transmission lines. In multi-terminal lines, faulty section should be detected before fault location estimation. In this paper, two methods based on time domain transmission line model are presented to identify the faulty section and to determine the location of faults for three terminal transmission lines. In the first method, samples of voltages and currents from all terminals are used while in the second method only the data of two terminals is used for calculating the location of the fault. The proposed algorithms are independent of fault resistance, insensitive to load current and fault inception angle. Furthermore they do not require any knowledge of source impedance and also fault type classification is not necessary. Filtering of dc and high frequency component of waves are not required. The results of computer simulation using EMTP/ATP software confirm the accuracy and precision of the proposed methods.
IET Generation, Transmission & Distribution, 2015
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Papers by Ebadollah Kamyab