Academic Positions

  • Present 2019

    Associate Professor

    K.N. Toosi University of Technology, Department of Electrical Engineering

  • 2019 2013

    Assistant Professor

    K.N. Toosi University of Technology, Department of Electrical Engineering

Education & Training

  • Ph.D. 2013

    Ph.D. in Electrical engineering-Power System

    Sharif University of Technology, Tehran, Iran

  • M.Sc.2009

    M.Sc. in Electrical engineering-Power System

    Tehran University, Tehran, Iran

  • B.Sc.2007

    B.Sc. in Electrical engineering

    K.N. Toosi University of Technology, Tehran, Iran

Honors, Awards and Grants

  • 2007-2009
    Ranked 1st
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    Ranked 1st among all M.Sc. students of Power System and Power Market, Tehran University.
    2014
    Elite
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    A memeber of National Elite Foundation.

Laboratory Personel

M. Arian_nik

M.Sc. Student (alumnus:2014-2016)

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M. Abdollah

M.Sc. Student (alumnus:2014-2016)

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A.Rajabi-Nejad

M.Sc. Student(alumnus:2017-2019)

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M. Rostami

M.Sc. Student(alumnus:2015-2017)

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M. Hajian

M.Sc. Student (alumnus:2015-2017)

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M. Shariat

M.Sc. Student(alumnus:2015-2017)

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S. Rad

M.Sc. Student

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S. Ghvami

M.Sc. Student

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A. Pourebrahim

M.Sc. Student

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M. Heydary

M.Sc. Student

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M. Fallah

M.Sc. Student

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M. Jamali

M.Sc. Student

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H. Hamidi

Ph.D. Student

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M. Ahmadvand

Ph.D. Student

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F. Malekipour

M.Sc. Student

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Z. Malekipour

M.Sc. Student

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A. Allahyari

M.Sc. Student

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Great lab Personel!

Hard working,  Hope and   Success

Research Projects

  • image

    Ranking Iranian Researcher Outputs

    Tehran University

    2008-2009

  • image

    Optimal RTU Placement in Power Distribution Systems

    Great Tehran Electrical Distribution Co.

    2010-2013

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    Critical Component Identification in Reliability Cantered Asset Management of Distribution Power Systems

    Sharif University of Technology

    2012

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    Circuit Breakers on-line Monitoring Device

    K.N.Toosi University, Tehran Universiy

    2012-Present

    The Supervisory Team: Dr.Niayesh (Tehran University) and Dr. Razi-Kazemi (K.N.Toosi University).

    Students, who are interested in this issue, can contact with me.

  • image

    Investigation of Transient Phenomena in GIS Substations

    Sharif University of Technology

    2012

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Intelligent Failure Diagnosis for Gas Circuit Breakers Based on Dynamic Resistance Measurements

M. abdollah,A. A. Razi-Kazemi
Journal Paper IEEE Transactions on Power Delivery, vol.00, no. 00, 2019,Pages 1-1

Abstract

Moving and fixed main and arc contacts used in circuit breakers (CBs) are prone to erosion with time and usage. Static resistance measurement and dynamic resistance measurement (DRM) are well-known noninvasive methods for the condition assessment of the contacts. Practically, the implementation of various failures on contacts of the CB is so difficult due to their placement in a high-pressure interruption chamber. This paper investigates the impacts of common failure modes such as erosion, disconnection, and misalignment of contacts on DRM profile through 3-D multiphysical simulation of the interruption chamber in the finite-element analysis software COMSOL. The model has been verified against experiments conducted on a 24-kV, SF? CB with a high-resolution scope. The measured profiles indicate that DRM exhibits specific behavior with respect to each failure, e.g., the arc contact erosion leads to a change in the commutation point in DRM. The results have been organized into an intelligent failure diagnosis algorithm based on a set of DRM-based features. In the end, the performance of the proposed algorithm which could be suitable for smart grids is evaluated in the case of an experiment.

A Probabilistic Model-aided Failure Prediction Approach for Spring-Type Operating Mechanism of High Voltage Circuit Breakers

A. A. Razi-Kazemi, K. Niayesh, R. Nilchi
Journal Paper IEEE Transactions on Power Delivery, vol.00, no. 00, 2019,Pages 1-1

Abstract

o avoid failures in circuit breakers (CBs) and to extend the lifetime of these critical components, condition-based-maintenance has been increasingly requested by utilities to enable them to efficiently manage their assets. The origin of the most failures in CBs is the operating mechanism. Travel curve (TC) could effectively reveal the condition of the operating mechanism. However, the measurement of a TC profile is not simple in all CBs. This paper presents the impacts of common failure modes of CBs on TC profiles, and proposes a new model-aided approach to simulate the behavior of the operating mechanism with coupling the model-based and rule-based approaches. The simulation results along with experiments conducted on 72.5 kV SF6 CBs are organized into a fuzzy-probabilistic approach through maximum likelihood and interacting multiple models (IMM) to precisely predict the condition of CB and to detect intelligently the cause of the failure.The CB condition has been categorized into three modes based on its operating speed: normal, faulty-1 and faulty-2. The mode variations of the CB have been estimated via IMM in each operation. The proposed approach in prediction of the failures and cause(s) prior to their occurrence has been verified against experime

Probabilistic Assessment of Ground Potential Rise Using Finite Integration Technique

A. A. Razi-Kazemi, M. Hajian
Journal Paper IEEE Transactions on Power Delivery, vol.33, no. 5, 2018,Pages 2452-2461

Abstract

The behavior of grounding systems against waves with high-frequency content such as lightning or very fast transient over voltages is completely different from the steady state. This paper presents more flexible model of grounding system with respect to frequency dependency of electrical parameters of soil and moisture variations using finite integration technique (FIT). The applicability and accuracy of the FIT have been verified against experiments as well as conventional methods such as method of moments (MoM), finite-difference time-domain (FDTD) method, and partial element equivalent circuit (PEEC). In addition, the impacts of moisture variations of soil on resistivity and permeability have been quantified through Weibull distributions. The obtained probabilistic parameters of soil resulting from moisture uncertainty have been involved in the model to provide more realistic model. The probabilistic ground potential rise (GPR) indicated that the grounding system can be optimized up to 50 percent by accepting low-rate of risk depending on the soil moisture level. The provided insight into is a beneficial approach especially for gas insulation substation (GIS) where the available space is limited for grounding system.

Novel high-frequency-based diagnostic approach for main contact assessment of high-voltage circuit breakers

A. A. Razi-Kazemi, M. Abdollah
Journal Paper IET Generation, Transmission & Distribution , vol. 12, no. 5, 2018,Pages 1121-1126

Abstract

Maintenance and repair of circuit breakers (CBs) due to their protective role in the power systems is the centre of attention and assessing their condition is tremendously important. The interruption chamber of the CBs including main contacts is highly subjected to erosion over time due to friction, and excessive heat produced by an arc during the interruption of the currents. This study presents a new high-frequency (HF) non-intrusive diagnostic technique for the deterioration of contacts used in high-voltage CBs. The most striking result to emerge from the investigations is that the resonance frequency highly relies on the condition of contacts. The proposed approach is implemented in Computer Simulation Technology Studio Suite software and compared with the measured data obtained through the static resistance measurement. In addition, a HF model based on the transmission line theory has been developed for the interruption chamber of CBs. The comparison of the obtained results via a novel HF-based approach with the experimental data validates the feasibility and accuracy of this approach in analysing the ablation of contacts used in the interruption chamber of CBs.

Effect of cumulative moisture content on degradation of transformer paper insulation

M. Arian-nik,A. A. Razi-Kazemi, M. Lehtonen
Journal Paper IEEE Transactions on Dielectrics and Electrical Insulation, vol. 24, no. 1, Feb. 2017,Pages 611-618

Abstract

Nowadays, reliability of power system is of great importance. Therefore, the condition of transformers as the expensive and critical components of a power system should be monitored and assessed. The dominant factor that causes limitation in transformers lifetime is the paper insulation. This paper aims to investigate the conspicuous influence of moisture content, especially in low oxygen and temperature on lifetime estimation under constant conditions, based on the results of previous experiments. Degree of polymerization (DP) is employed to quantify the effects of detrimental parameters with respect to their time-varying nature. This paper proposes a novel lifetime estimation-approach considering a yearly moisture growth for transformers. The results indicate different trend of DP profiles, which lead to an accurate lifetime estimation in comparison with DP obtained through ideal conditions. Furthermore, oscillations in the hot-spot temperature of transformers are demonstrated to have a negative effect on the lifetime.

Aging failure model of circuit breakers equipped with condition monitoring systems

A. A. Razi-Kazemi, M. Lehtonen
Journal Paper International Transactions on Electrical Energy Systems, vol. 27, no. 2, Oct. 2017,Pages 1-20

Abstract

Lifetime management of circuit breakers (CBs) compared with the other components in power system is dependent not only on the natural age but also on the number of operation, applications, and maintenance scheduling. In addition, condition?monitoring systems (CMSs) are widely used to extend lifetime and improve the quality of maintenance. However, the employing CMSs for CBs are faced with economical and technical challenges. This paper presents a new probabilistic aging failure model for CBs equipped with CMS. The proposed model improves the conventional approach for the assessment of efficiency of maintenance strategies using available filed data and coupling some weighting factors. The model is based on the state diagram along with Monte Carlo simulations to provide more flexibility in quantification of practical concerns. The model helps us to compare all maintenance strategies within 1 framework to select the best policy with respect to working situation of CBs. The approach has been compared and verified with the conventional aging model. Moreover, it is numerically applied to 2 common types of CBs, that is, SF6 and minimum oil based on the field data to reveal the results of considering the real aging and dynamic behavior of CBs on cost/benefits of maintenance policies. The results of applying the proposed approach to CBs indicate that ignoring the realistic situation of CBs results in a significant underestimation or overestimation of reliability and consequently making a wrong decision on installation of CMS or even in selection of the optimum inspection time.

Online Condition Assessment of Interruption Chamber of Gas Circuit Breakers Using Arc Voltage Measurement

A. Bagherpour, S. Rahimi,A. A. Razi-Kazemi, K. Niayesh
Journal Paper IEEE Transaction on Power Delivery, vol. 32, no. 4, Aug. 2017,Pages 1776-1783

Abstract

Circuit breaker (CB) as the key element in power system requires regular maintenance. Nowadays, online condition assessment has been requested increasingly in smart environment. The interruption chamber as the most critical part of the CBs plays an important role in the proper operation of the CBs. Online assessment of this part is difficult from technical point of view due to high noise level and presence of transient recovery voltage. This paper proposes a set up for online measurement of arc voltage of the CBs during trip/close operations. In addition, a method has been proposed to evaluate the remaining useful lifetime (RUL) of interruption chamber based on the measured arc voltage and current. The setup and the proposed approach are verified through the experimental results.

Circuit Breaker Condition Assessment through a Fuzzy-Probabilistic Analysis of Actuating Coil Current

A. A. Razi-Kazemi
Journal Paper IET Generation, Transmission & Distribution, vol. 10, Jan. 2016,Pages 48-56

Abstract

Circuit breaker (CB) is a component providing significant electrical protection for power transmission and distribution systems. Hence, an effective condition monitoring system for the CBs is of imminent importance. This paper presents a fuzzy probabilistic based condition assessment algorithm to assess the CB operation performance by monitoring its trip/close coil current (C.C.), and suggests a simple yet effective condition assessment tool. The C.C. patterns are acquired by measurements carried out on sixty CBs (72.5 kV, SF6) under faulty and normal conditions. To intelligently assess the CBís operating state (i.e.; normal, alarm, emergency), in terms of its reliability, the optimum C.C. features with minimum interdependence were obtained. Furthermore, a fuzzy-probabilistic method is proposed based on the results of the statistical analyses of the features. The feasibility and applicability of the proposed method in CB condition assessment is verified against the experimental measured data.

Applicability of Auxiliary Contacts in Circuit Breaker Online Condition Assessment

A. A. Razi-Kazemi
Journal Paper Electric Power Systems Research, vol. 128, Nov. 2015,Pages 53-59

Abstract

Circuit breaker (CB) due to its important roles in protection of power system has been recognized as a critical component. In order to assess the condition of CBs, a prevalent and conventional diagnosis method is time measurement of the mechanical operations (called timing test) through the travel curve (T.C.). However, it is an inappropriate technique for the online assessment. The major objective of this paper is to reveal the correlation between the T.C. and auxiliary contacts (A.Cs) of CB. On the basis the results, timing of A.Cs is proposed as easy-to-access, easy-to-measure, and non-invasive diagnosis parameters in online condition assessment of mechanism of CBs. The investigations are established upon measurements carried out on sixty CBs (72.5 kV, SF6) under healthy and faulty conditions. The new approach is conducted through an adaptive neuro-fuzzy inference system (ANFIS). The feasibility and applicability of the proposed method in CB condition assessment is verified against the experimental measured data.

Circuit Breaker Automated Failure Tracking based on Coil Current Signature

A. A. Razi-Kazemi,M. Vakilian, K. Niayesh, and M. Lehtonen
Journal Paper IEEE Transaction on Power Delivery, vol. 29, no. 1, July. 2014,Pages 283-290

Abstract

The The online condition assessment of circuit breakers (CBs) has been increasingly requested by power utilities in recent years. Trip and close coil current (CC) signature is an effective and noninvasive parameter in CB online condition monitoring. This paper gives an insight into the impacts of the various failures on the coil current waveform, as well as on the CB operation time. The failures and their causes are categorized based on the outcome of these investigations. Finally, a new algorithm using trip/close CC is proposed to detect the mode and cause of CB incipient failures. In this study, the CC patterns are acquired by measurements carried out on (healthy and faulty) CBs of 72.5-kV and 24-kV rating voltages, having SF6 insulation medium, and are equipped with a spring-drive mechanism.

Priority Assessment of Online Monitoring Investment for Power System CBs Part I: Qualitative-Quantitative Approach

A. A. Razi-Kazemi,M. Vakilian, K. Niayesh, and M. Lehtonen
Journal Paper IEEE Transaction on Power Delivery, vol. 28, no. 2, Apr. 2013,Pages 928-938

Abstract

Recognition of the circuit-breaker's (CB) vital role in reliable operation and protection of power systems (i.e., during energization, disconnecting loads, and clearing faults), helps to understand the requirement and importance of its maintenance management as well as maintenance scheduling. Condition-based maintenance (CBM), employing online monitoring (OLM) of CBs, has been long reported as the most practical maintenance policy on the power system CBs. There are a large number of CBs in a power system to be monitored; however, to address the financial limitations for OLM implementation (in utilities), a method will be proposed to find the most critical breakers for enforcing effectively the CBs CBM planning in this power system. This paper employs some qualitative and quantitative criteria to develop this method. While, the former criterion is deals with through assessing the condition of CBs through fuzzy sets theory. And the latter criterion is dealt with through the evaluation of CBs' influence on the overall system reliability (through introduced indices). This method is applied on a sample transmission substation with a breaker-and-a-half configuration. Numerical analysis of this simulation results demonstrates how this method can be employed to prioritize the CBs for OLM.

Priority Assessment of Online Monitoring Investment for Power System CBs Part II: Determination of Optimum Number

A. A. Razi-Kazemi,M. Vakilian, K. Niayesh, and M. Lehtonen
Journal Paper IEEE Transaction on Power Delivery, vol. 28, no. 3, July. 2013,Pages 1440-1446

Abstract

The proper and reliable operation of circuit breakers (CBs) directly affects the reliability and continuity of electricity services in a power systems. Condition-based maintenance (CBM) is the best economic CB maintenance strategy through its online monitoring (OLM) possibilities. Since there is a large number of CBs in a power system, to equip all CBs with OLM systems is not economically justifiable however. This paper, as the second part of a two-part paper, presents an effective optimization framework to find the optimal number of CBs to be monitored online as the kernel of CBM process. To prove its feasibility, the proposed approach is applied to the IEEE Roy Billinton Test System, which includes 32 CBs. The impacts of interest rate and load interruption cost variations as well as nonoptimum selection of CBs for monitoring on the results are also discussed in this paper. The results of numerical analyses of the case study presented in this paper demonstrate how the proposed method can be employed for maintenance management of power system CBs.

Impact of Spark Gap Breakdown Phenomena on The Output Voltage of Compact Marx Generators

A. A. Razi-Kazemi,K. Niayesh
Journal Paper IEEE Transactions on Dielectrics and Electrical Insulation, vol.18, no.4, August 2011.,Pages 1022-1028

Abstract

The Compact Marx Generators (CMG) are widely used as portable pulse generators in different applications. They are of great importance anywhere that pulses with rise times on the order of tens of nanoseconds are needed such as nanosecond-pulse breakdown. Considering the fact that the breakdown of a spark gap is a statistical process, the delay times of the closing switches are also statistical and voltage dependent parameters. In this paper, a generalized state space-based model for compact Marx generators is proposed. It can be useful in investigating the impacts of statistical behavior of the breakdown process in spark gaps and closing switch time delays on nanosecond-pulse breakdown rod-plate gaps in nitrogen. Moreover, to increase the transferred current and energy to load, CMGs are used in parallel. The simulation results indicate that in this case, it is more important to have output voltages pulses with temporal low jitter. Discharges were modeled by a nonlinear load using a Rompe-Weizel model to calculate the time-dependent resistances of the spark gaps. The stray capacitances were calculated using electrostatic simulations.

Statistical Characteristics of the Output Voltage in Compact Marx Generators

A. A. Razi-Kazemi,K. Niayesh
Journal Paper ACTA PHYSICA POLONICA A, vol. 115, no. 6, Jun 2009.,Pages 1158-1159

Abstract

Compact Marx generators are widely used as portable pulse generator in different industrial applications, where high power pulses with rise times of order of some tens of nanoseconds are needed. For those applications, closing switches with very short delay and jitter times have to be used. Considering the fact that the breakdown of spark gap is a statistical process, the delay times of the closing switches are statistical voltage dependent parameters. As a result, the characteristics of the output voltage of the Marx generator, i.e. its amplitude and rise time, are also statistical parameters. In this paper, taking the statistical behaviour of the breakdown process in spark gaps into consideration, the statistical characteristics of the output voltage have been studied in detail.

A Practical Approach on Optimal RTU Placement in Power Distribution Systems Incorporating Fuzzy Sets Theory

A. A. Razi-Kazemi,P. Dehghanian
Journal Paper International Journal of Electrical Power and Energy Systems, vol. 37, May 2012.,Pages 31-42

Abstract

Supervisory control and data acquisition (SCADA) infrastructures have so far been brought into the huge amount of focus since the need for a more reliable power system accosting with the catastrophic events of interruptions has been raised. Hence, Benefiting from an automation technology which can remotely monitor and coordinate commands to enable immediate response and switching are obviously inevitable. This paper outlines an implementable method in response to the goal of placement of remote terminal units (RTUs) which are in charge for data acquisition and control in a power distribution system. In this light, a new practical methodology based on the robust decision making (DM) method, analytical hierarchical process (AHP), is proposed to simply and at the same time profoundly exploit some practical aspects which have not been considered before in the cases of placements. The proposed method investigates both qualitative and quantitative aspects interrelated with the placement problem. Fuzzy sets are then involved to overcome the existent uncertainty and judgment vagueness. The optimum number of RTUs to be located in the previous-step obtained candidates is determined through reliability cost/worth analysis. Having the belief practically implemented on a real distribution test feeder of Iranís power grid, the efficacy and accuracy of the proposed methodology are satisfactorily confirmed. .

Critical Component Identification in Reliability Centered Asset Management of Distribution Power Systems via Fuzzy AHP

P. Dehghanian, M. Fotuhi-Firuzabad, S. Bagheri-Shouraki,A. A. Razi-Kazemi
Journal Paper IEEE Systems Journal, vol. 6, December 2012,Pages 593 - 602

Abstract

Confronted with the power system restructuring trend reforming the past-regulated power systems, the need for a narrower insight on the costly maintenance strategies seems imperative. It falls within the realm of reliability centered maintenance to enhance the cost effectiveness of power distribution maintenance policies. From a practical point of view, this paper devises a novel approach on the basis of the analytical hierarchical process (AHP) accompanied by fuzzy sets theory to determine the most critical component types of distribution power systems to be prioritized in maintenance scheduling. In the presence of many qualitative and quantitative attributes, fuzzy sets can effectively help to deal with the existent uncertainty and judgment vagueness. As demonstrated in a practical case study, the proposed fuzzy AHP method introduces its applicability and efficiency in the asset management procedure.

Non-invasive Evaluation of Internal Pressure in Vacuum Circuit Breakers

M. RostamiA. A. Razi-Kazemi
Conference Papers IEEE Proc: 26th Iranian Conference on Electrical Engineering (ICEE), 2018.

Protection of Wind Electrical Power Energy Systems Against Indirect Lightning Strike Surge

A. A. Razi-Kazemi, et. al.
Conference Papers IEEE Proc: 24th Iranian Conference on Electrical Engineering (ICEE), 2016.

Noninvasive Condition Assessment of Circuit Breaker Contact Based on Voltage Measurement

A. A. Razi-Kazemi, et. al.
Conference Papers IEEE Proc: The 10th Power Systems Protection and Control (PSPC) conference 19-20 Jan., 2016.

Proposing a Comprehensive Model for CMG

A. A. Razi-Kazemi, et. al.
Conference Papers 30th International Power System Conference (PSC), 2015(In Persian)

Condition Assessment of High Voltage Circuit breaker using DRM

A. A. Razi-Kazemi, et. al.
Conference Papers 30th International Power System Conference (PSC), 2015(In Persian)

Investigation of Very Fast Transient over Voltages in Gas Insulated Substations

A. A. Razi-Kazemi, et. al.
Conference Papers IEEE Proc: 2nd International Conference Knowledge-based Engineering and Innovation (KBEI), 5-6 Nov. 2015.

Wind Turbine Protection against direct lightning strikes

A. A. Razi-Kazemi, et. al.
Conference Papers 30th International Power System Conference (PSC), 2015(In Persian)

Prioritization of High Voltage Circuit Breakers via FAHP

A. A. Razi-Kazemi
Conference Papers 29th International Power System Conference (PSC), 2014(In Persian)

Condition assessment of Transformers based on the Proposed Fuzzy-Probabilistic Approach

A. A. Razi-Kazemi, et. al.
Conference Papers International transformer conference and exhibition, 2014(In Persian)

A New Approach in Determination of Critical Circuit Breakers in Power Network

A. A. Razi-Kazemi, M. Vakilian, and K. Niayesh
Conference Papers 27th International Power System Conference (PSC), 2012(In Persian)

Incorporating Experts Knowledge in RTU Placement Procedure Using Fuzzy Sets Theory- A practical Approach

A. A. Razi-Kazemi, P. Dehghanian and Gh. Karami
Conference Papers The 33th IEEE International Telecommunications Energy Conference, INTELEC, Oct. 2011, Amsterdam, Netherlands

Abstract

So far, the need for power systems to be control automated has been approached. Moreover, the advent of smart technological infrastructures calls for a more systematic and well-designed schemes for data acquisition process. Hence, Remote Terminal Units (RTUs) are going to be considered as a crucial part of smart grid puzzle in power distribution systems. This paper aims to present a novel practical approach to have the RTU placement dilemma unraveled in power distribution systems. Practically approaching in this paper, some pragmatic factors of major importance in this respect are introduced. A framework with which the utility's experts' knowledge could be efficiently exploited is presented and handled through a robust decision making (DM) method referred to as Analytical Hierarchical Process (AHP). To overcome the existing inaccuracies associated with the experts knowledge and to effectively deal with the existent uncertainties and imprecision in the conventional AHP approach, fuzzy sets theory is incorporated to reach the most reliable and optimal substations as the RTU placement candidates. The efforts are focused on the pragmatic aspects interrelated with the procedure. Being applied to a real distribution power system of Iran's power grid, the applicability and practicality of the proposed fuzzy AHP (FAHP) method is well approved.

A Probabilistic Approach for Remote Terminal Unit Placement in Power Distribution Systems

A. A. Razi-Kazemi, P. Dehghanian and Gh. Karami
Conference Papers The 33th IEEE International Telecommunications Energy Conference, INTELEC, Oct. 2011, Amsterdam, Netherlands

Abstract

This paper investigates a reliability-centered approach for the placement procedure of remote terminal units (RTUs) in power distribution systems. Entire attempt is contributed to incorporate the practical aspects interrelated with the problem, e.g. the accessibility to the candidate substations, the load point criticality, as well as the load probabilistic behavior and consequently the inevitable variation in the electricity price. The placement process is done through an optimization problem wherein the common reliability indices, as the decisive factors in the placement process, are going to be minimized. The approach is successfully applied to a real power distribution feeder of Iran's power grid and well demonstrates its applicability accompanied by its accuracy in dealing with the practical planning concerns.

Optimal RTU Placement in Power Distribution Systems Using a Novel Method Based on Analytical Hierarchical Process (AHP)

P. Dehghanian, M. Fotuhi-Firuzabad, and A. A. Razi-Kazemi
Conference Papers The 10th International IEEE Conference on Environmental and Electrical Engineering, EEEIC, May 2011, Rome, Italy

Abstract

This In a practical power system, automating all the substations is neither affordable nor economically justifiable. On the other hand, the trend for electric power subsidies elimination in some regions, such as Iran, aggravates this situation. To enhance the cost effectiveness of distribution automation system, this paper proposes a novel applicable qualitative-quantitative method using analytical hierarchical process (AHP) to find the optimum placement of remote terminal units (RTU). Entire attempt is to contribute all the crucial technical and practical parameters related to this problem in order to find the most reliable solution. Optimum number of RTUs is determined using the concepts of reliability cost/worth taking into account the total cost of customer interruption and investment cost of RTUs. The effectiveness of the proposed technique is validated on a real distribution feeder of Iran's power grid.

Effects of Statistical Characteristics of the Output Voltage in Compact Marx Generator on Insulation Test Results

A. A. Razi-Kazemi, and K. Niayesh
Conference Papers 10th IEEE International Conference on Solid Dielectrics, ICSD2010, July, 2010

Abstract

Lightning strikes or flashovers of insulation can result in impulse voltages with very short front times of some tens of ns. Power apparatuses are exposed to these voltages. Steep-front square impulse voltage with high accuracy can be generated by applying advanced pulsed power technology. Nowadays, compact Marx generator (CMG) is used for achieving exact results in tests. Considering the fact that the breakdown of spark gap is a statistical process, the delay times of the closing switches are statistical and voltage-dependent parameters. In this paper, taking the statistical behaviour of the breakdown process in spark gaps into consideration, the statistical characteristics of the output voltage have been studied in detail and its effect on accuracy of insulation tests are described.

Reliability Analysis and Its Crucial Role on Critical Component Identification in Power Distribution Systems

A. A. Razi-Kazemi, P. Dehghanian, M. Moeini-Aghtaie, and M. Fotuhi-Firuzabad
Conference Papers The 1st Integrated Maintenance Conference, Feb. 2011, Tehran, Iran(In Persian)

Abstract

A Method on Optimal RTU Placement on the Basis of AHP

A. A. Razi-Kazemi, P. Dehghanian, Gh. Karami, and H. Mozaffari
Conference Papers The 25th International Power System Conference, PSC, Sep. 2010, Tehran, Iran. (In Persian)

Abstract

Statistical Characteristics of the Output Voltage in parallel Compact Marx Generators

A. A. Razi-Kazemi, and K. Niayesh
Conference Papers 17th Iranian Conference On Electrical Engineering (ICEE), April, 2009 (In Persian)

Abstract

Investigation of the Effects of Compact Fluorescent Lamps in Power Distribution Systems

M. Ghafuri,A. A. Razi-Kazemi,P. Dehghanian, and M. Vakilian
Conference Papers The 10th International IEEE Conference on Environmental and Electrical Engineering, EEEIC, May 2011, Rome, Italy

Abstract

The desire to decrease electrical loading by using energy efficient lighting has resulted in a high level of attention to replacing conventional incandescent lamps with compact fluorescent lamps (CFL). In Iran from energy management point of view, people are encouraged by ministry of power to use CFLs. Also after elimination of subsidies, the substantial increase in electric energy price resulted in a high level of penetration of CFLs in electricity grid. CFL is a nonlinear load, therefore it injects harmonic to the network. In past, due to lower application of CFL, these harmonics were ignored, however today by the widespread application of CFLs; these small sources are combined and have high effect on power distribution networks. This paper presents the results of an investigation on the effect of widespread application of CFLs on a real power distribution system of Iran. CFL has some disadvantages that should rectify gradually. However at present great use of this component may cause adverse effects especially on the distribution network. Most of the CFL disadvantages are related to its high level of harmonics. In this paper the interference of the harmonics generated by CFLs to a real distribution network of Iran power grid will be simulated and studied. Since the CFL employed in these network have a relatively poor quality, in this study three samples of the brands which are in wider use in Iran market are selected. The characteristic current of these samples are experimentally determined. After that, CFLs are modeled with considering the attenuation effect. For harmonic mitigation, optimize capacitor placement is done and at the end, Simulation results are discussed.

AHP Implementation on Finding the Important Indices of Power Distribution System Equipments

P. Dehghanian, A. A. Razi-Kazemi,M. Moeini-Aghtaie, and M. Fotuhi-Firuzabad
Conference Papers The 1st Integrated Maintenance Conference, Feb. 2011, Tehran, Iran(In Persian)

Abstract

Dynamical Behavior of DFIG with Different Powers during a Three Phase Voltage Drop

H. Ebrahimi, A. A. Razi-Kazemi,H. Lesani, and M. Nabavi
Conference Papers 17th Iranian Conference On Electrical Engineering (ICEE), April, 2009(In Persian)

Abstract

A New Look on the Automation of Medium Voltage Substations in Power Distribution Systems

M. Shojaie, V. Rastegar-Moghaddam, A. A. Razi-Kazemi,P. Dehghanian, and Gh. Karami
Conference Papers 17th Conference on Electric Power Distribution Networks, EPDC, May 2012, Tehran, Iran(In Persian)

Abstract

With the expansion of electricity networks, increasing operational complexities, improved knowledge of the system operators, all with the subsidies elimination in some countries such as Iran and experiencing the real price of electricity by then, it necessitates a more reliable power to be delivered to the system customers. Power system automation is regarded as an efficient solution and the effective key to this problem. However, the great number of substations in power distribution systems has led to the fact that it is neither feasible nor economic to automate all of them. This calls for a comprehensive scheme on the placement of the distribution substations to be automated. In this paper, a practical glance is followed on the calculation of outage times which follows a practical approach for the substations placement. Some reliability-oriented indices are also proposed with which, together with their suitable fuzzy membership functions, the optimal location of substations for automation would be identified. The presented approach is finally applied to a real part of a distribution system in Tehran, Iran. And the results, as expected, show the applicability and effectiveness of the proposed algorithm.

An Approach for Critical Component Identification in Reliability-Centered Maintenance of Power Distribution Systems Based on Analytical Hierarchical Process

P. Dehghanian, M. Fotuhi-Firuzabad,and A. A. Razi-Kazemi
Conference Papers The 21th International Conference and Exhibition on Electricity distribution, CIRED, June 2011, Frankfurt, Germany

Abstract

In a distribution power system, vividly in a deregulated market and restructured environment, blind time based maintenance of all the distribution equipments is neither affordable nor economically justifiable. Moreover, an acceptable level of system reliability is an indispensable criterion for the successful operation of a power distribution system. To enhance the cost effectiveness o distribution maintenance policy and particularly from the asset management point of view, this paper proposes a new applicable qualitative-quantitative approach based on analytical hierarchical process (AHP) to determine the most critical equipments to be prioritized in maintenance scheduling. Entire attempt is to contribute all the major technical and practical parameters related to this problem to find the most optimized solution. The proposed method i applied to a practical distribution feeder of Iran's power grid to illustrate the applicability and effectiveness of the method.

Engineering Mathematics

A.A. Razi-Kazemi
Book Nasir Scientific Institute|October, 2010 | ISBN-09: 789648290
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Electric Machinery

A. A. Razi-Kazemi, P. Dehghanian
Book Nasir Scientific Institute| October 28, 2010 | ISBN-09: 78-600-233-048-2
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Coming Soon!

A. A. Razi-Kazemi
Book Chapter John Wiley & Sons | September ?, ? | ISBN-?: ?
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Currrent Teaching

  • Present 2016

    Electrical Circuits II

    Room 206, Saturday 10:30-12:30

  • Present 2014

    Advances in High Voltage, Design and Theory of Circuit Breakers

    High voltage lab, Saturday-Monday 1:30-3:00.

  • Present 2013

    High voltage laboratory

    High Voltage Lab, Tuesday 10:30-12:00.

Teaching History

  • 2009 2011

    Electrical Fundamental-II

    Undergraduate course at Sharif University of Technology,Tehran, Iran.

  • 2012 2013

    Electromagtenic,Power distribution network, and Mathematics

    Undergraduate course

  • 2012 2013

    Analysis of Electric Machinery and Drive Systems

    Graduate course

  • 2013 2014

    Electrical Circuits-II

    Undergraduate course at KN Toosi University of Technology,Tehran, Iran.

  • 2013 2014

    Technology of Generation of Electricity Power

    Undergraduate course at KN Toosi University of Technology,Tehran, Iran.

  • 2014 2016

    Electrical Fundamental-I, High Voltage Technology

    Undergraduate course at KN Toosi University of Technology,Tehran, Iran.

At My Office

       You can find me at my office located at K. N. Toosi University, Electrical Engineering department, fourth floor, Room 413.

       I am at my office every day from 9:00 am until 5:00 pm, but you may consider a call or an email to fix an appointment.

At My Work

       You can find me at my Work located at K. N. Toosi University, Electrical Engineering department, High voltage Lab.

At My Lab

       You can find me at my Work located at K. N. Toosi University, Electrical Engineering department, High voltage Lab.

       I am at my office every day from 8:00 until 5:00 pm, but you may consider a call to fix an appointment.