Stochastic modeling of the output power of photovoltaic generators in various weather conditions
- Authors: Batool, Munira , Islam, Syed , Shahnia, Farhad
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 Australasian Universities Power Engineering Conference, AUPEC 2016; Brisbane, Australia; 25th-28th September 2016 p. 1-5
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- Description: The intermittency of solar-powered energy sources prompt the uncertainty of load management. The influence of shading (whatever the reason may be) directly diminishes the feasible output power of the photovoltaic (PV) generators. The major causes of shading are the weather condition changes like the clouds, storms, and rains. Thereby, the dispatchable power for a distinct weather condition at an explicit time frame needs to be quantified. The stochastic modeling of a practical PV system has been performed in this paper. A step-by-step MATLAB-based algorithm is developed for tracking of dispatchable power limit using the Monte Carlo Principle. The proposed algorithm describes the weather condition as a function of cloud presence. The prescribed characteristics consist of the solar irradiance and the ambient temperature. The impact of weather changes on the output power of a PV system is evaluated by this algorithm. The results of this research are concluded by realistic data analysis taken from the Australian bureau of meteorology.
Understanding online frequency response signatures for transformer winding deformation: Axial displacement simulation
- Authors: Zhao, Zhongyong , Islam, Syed , Hashemnia, Naser , Hu, Di , Yao, Chenguo
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 International Conference on Condition Monitoring and Diagnosis, CMD 2016; Xi'an, China; 25th-28th September 2016 p. 404-407
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- Description: The power transformer is considered as the most critical and expensive device in substation, however, the irreversible transformer winding mechanical deformation can eventually develop into catastrophic failure if no further steps are taken in a proper way, which would cause the outage of transformer and the significant economic losses. Online frequency response analysis (FRA) has been proven to be a promising tool for condition monitoring and diagnosing of winding deformation. Online FRA relies on graphic comparison of signatures, but up to now, there is no standard and practical interpretation code for signatures classification and quantification. This paper particularly studies the characteristic of online FRA signatures under the winding axial displacement mode, in which the 3D finite element electromagnetic analysis and online transformer equivalent high frequency electrical model are established as auxiliary tools to precisely emulate winding axial displacement. Results of this simulation will provide guidance on understanding online frequency response signatures.
Voltage profile modification in harmonically affected power networks
- Authors: Yengejeh, Hadi , Islam, Syed , Galvani, Sadjad
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 17th International Conference on Harmonics and Quality of Power, ICHQP 2016; Minas Gerais, Brazil; 16th-19th October 2016 Vol. 2016, p. 652-656
- Full Text: false
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- Description: Considering importance of power quality in power systems especially in distribution systems and daily increasing application of electronic devices which are more sensitivity to quality of supplied power, improvement of quality of power is a must. Hence, in this paper voltage profile in distribution systems has been paid attention and improvement of voltage profile by various type of capacitor placement has been investigated. The effects of applying these methods on networks voltage profile have been scrutinized. These methods have been compared to each other and the best method has been selected for this affair. To achieve precise result, harmonic load flow is performed on case study that is IEEE 37 node test feeder.
Who are convincing? An experience based opinion formation dynamics in online social networks
- Authors: Das, Rajkumar , Kamruzzaman, Joarder , Karmakar, Gour
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 30th European Simulation and Modelling Conference, ESM 2016; Las Palmas, Spain; 26th-28th October 2016 p. 167-173
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- Description: Online social network (OSN) is one of the major platforms where our opinions are formed now-a-days and increasing so. Opinion formation dynamics captures the ways public opinions are formed, mainly from two different sources, (i) neighbours' opinions, (ii) external opinions from sources other than the neighbours. In this paper, we formulate an opinion formation model by considering two very important factors, that were ignored or a very little explored in the literature. First, we model the convincing power of the opinions encountered from the two sources. Second, we incorporate the experience of users' previous interactions with the two opinion sources. The problem is formulated as an agent based model where each member of an OSN is represented with an agent and their relationships with a graph. Finally through simulation, we create various scenarios, and apply our model to observe the steady state outcomes of the dynamics. This helps us to study the nature of the public opinions under various influences of our model parameters.
- Description: European Simulation and Modelling Conference 2016, ESM 2016
A novel depth motion vector coding exploiting spatial and inter-component clustering tendency
- Authors: Shahriyar, Shampa , Murshed, Manzur , Ali, Mortuza , Paul, Manoranjan
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: Visual Communications and Image Processing, VCIP 2015; Singapore; 13th-16th December 2015 p. 1-4
- Relation: http://purl.org/au-research/grants/arc/DP130103670
- Full Text: false
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- Description: Motion vectors of depth-maps in multiview and free-viewpoint videos exhibit strong spatial as well as inter-component clustering tendency. This paper presents a novel coding technique that first compresses the multidimensional bitmaps of macroblock mode and then encodes only the non-zero components of motion vectors. The bitmaps are partitioned into disjoint cuboids using binary tree based decomposition so that the 0's and 1's are either highly polarized or further sub-partitioning is unlikely to achieve any compression. Each cuboid is entropy-coded as a unit using binary arithmetic coding. This technique is capable of exploiting the spatial and inter-component correlations efficiently without the restriction of scanning the bitmap in any specific linear order as needed by run-length coding. As encoding of non-zero component values no longer requires denoting the zero value, further compression efficiency is achieved. Experimental results on standard multiview test video sequences have comprehensively demonstrated the superiority of the proposed technique, achieving overall coding gain against the state-of-the-art in the range [22%, 54%] and on average 38%. © 2015 IEEE.
- Description: 2015 Visual Communications and Image Processing, VCIP 2015
Analysis of end-to-end delay characteristics for various packets in IEC 61850 substation communications system
- Authors: Das, Narottam , Ma, Wu , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 25th Australasian Universities Power Engineering Conference, AUPEC 2015, Wollongong, Australia; 27th-30th September 2015 p. 1-5
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- Description: Substation plays an important role in power system communications for safe and reliable operation of entire power networks. Substation communication networks are connected with various substation intelligent electronic devices (IEDs), which is substation systems lifeblood and the system availability is decided by its real-Time performance. International Electro-Technical Commission (IEC) has been developed the standards based on object-oriented technologies for substation automation. IEC 61850 protocol has been applied widely in substation communication applications. It presents new challenges to realtime performance simulation and testing of protective relays. In this paper, an optimized network engineering tool (OPNET) or Riverbed modeler simulation tool/ software has been used for the modeling of IED in substation level network. Based on the simulation results, different types of data stream have been discussed, such as, periodic data stream, random data stream and burst data steam. The typical studies using these models, to construct substation automation system (SAS) network on the OPNET modeler or Riverbed modeler was made to reveal the impact of each affecting parameter or factor to the real-Time performance of substation communications system, which is also incorporated in this report.
- Description: 2015 Australasian Universities Power Engineering Conference: Challenges for Future Grids, AUPEC 2015
Disconnection time and sequence of rooftop PVs under short-circuit faults in low voltage networks
- Authors: Yengejeh, Hadi , Shahnia, Farhad , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: North American Power Symposium, NAPS 2015; Charlotte, United States; 4th-6th October 2015 p. 1-6
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- Description: This paper presents an analysis on the disconnection time of single-phase rooftop PVs, located in a three-phase four-wire low voltage distribution feeder after a line-to-ground short-circuit fault on the low voltage feeder. The paper aims to evaluate and discuss the disconnection time and sequence of PVs in a network with 100% PV penetration level. The impact of different parameters such as the location of the fault, impedance of the fault and the ratio of PVs generation capacity to the load demand are considered. Furthermore, the effect of the system earthing in the form of multiple earthed neutral and non-effectively grounded systems are evaluated on the PVs disconnection time. The analyses intend to figure out the conditions under which the PVs in the feeder may fail to disconnect after a line-to-ground fault and keep feeding the fault. The analyses are carried out in PSCAD/EMTDC software.
Fast intermode selection for HEVC video coding using phase correlation
- Authors: Podder, Pallab , Paul, Manoranjan , Murshed, Manzur , Chakraborty, Subrata
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 2014 International Conference on Digital Image Computing: Techniques and Applications, DICTA 2014; Wollongong, Australia; 25th-27th November 2014 p. 1-8
- Relation: http://purl.org/au-research/grants/arc/DP130103670
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- Description: The recent High Efficiency Video Coding (HEVC) Standard demonstrates higher rate-distortion (RD) performance compared to its predecessor H.264/AVC using different new tools especially larger and asymmetric inter-mode variable size motion estimation and compensation. This requires more than 4 times computational time compared to H.264/AVC. As a result it has always been a big concern for the researchers to reduce the amount of time while maintaining the standard quality of the video. The reduction of computational time by smart selection of the appropriate modes in HEVC is our motivation. To accomplish this task in this paper, we use phase correlation to approximate the motion information between current and reference blocks by comparing with a number of different binary pattern templates and then select a subset of motion estimation modes without exhaustively exploring all possible modes. The experimental results exhibit that the proposed HEVC-PC (HEVC with Phase Correlation) scheme outperforms the standard HEVC scheme in terms of computational time while preserving-the same quality of the video sequences. More specifically, around 40% encoding time is reduced compared to the exhaustive mode selection in HEVC. © 2014 IEEE.
- Description: 2014 International Conference on Digital Image Computing: Techniques and Applications, DICTA 2014
Forecasting plug-in electric vehicles load profile using artificial neural networks
- Authors: Panahi, Delshad , Deilami, Sara , Masoum, Mohammad , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 25th Australasian Universities Power Engineering Conference, AUPEC 2015; Wollongong, Australia; 27th-30th September 2015 p. 1-6
- Full Text: false
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- Description: Plug-in electric vehicles (PEVs) are becoming very popular these days and consequently, their load management will be a challenging issue for the network operators in the future. This paper proposes an artificial intelligence approach based on neural networks to forecast daily load profile of individual and fleets of randomly plugged-in PEVs, as well as the upstream distribution transformer loading. An artificial neural network (ANN) model will be developed to forecast daily arrival time (Ta) and daily travel distance (Dtr) of individual PEV using historical data collected for each vehicle in the past two years. The predicted parameters are then will be used to forecast transformer loading with PEV charging activities. The results of this paper will be very beneficial to coordination and charge/discharge management of PEVs as well as demand load management, network planning and operation proposes. Detailed simulations are presented to investigate the feasibility and accuracy of the proposed forecasting strategy.
High performance communication redundancy in a digital substation based on IEC 62439-3 with a station bus configuration
- Authors: Kumar, Shantanu , Das, Narottam , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 25th Australasian Universities Power Engineering Conference, AUPEC 2015; Wollongong, Australia; 27th-30th September 2015 p. 1-5
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- Description: High speed communication is critical in a digital substation from protection, control and automation perspectives. Although International Electro-Technical Commission (IEC) 61850 standard has proven to be a reliable guide for the substation automation and communication systems, yet it has few shortcomings in offering redundancies in the protection architecture, which has been addressed better in IEC 62439-3 standard encompassing Parallel Redundancy Protocol (PRP) and High-Availability Seamless Redundancy (HSR). Due to single port failure, data losses and interoperability issues related to multi-vendor equipment, IEC working committee had to look beyond IEC 61850 standard. The enhanced features in a Doubly Attached Node components based on IEC 62439-3 provides redundancy in protection having two active frames circulating data packets in the ring. These frames send out copies in the ring and should one of the frame is lost, the other copy manages to reach the destination node via an alternate path, ensuring flawless data transfer at a significant faster speed using multi-vendor equipment and fault resilient circuits. The PRP and HSR topologies provides higher performance in a digitally protected substation and promise better future over the IEC 61850 standard due to its faster processing capabilities, increased availability and minimum delay in data packet transfer and wireless communication in the network. This paper exhibits the performance of PRP and HSR topologies focusing on the redundancy achievement within the network and at the end nodes of a station bus ring architecture, based on IEC 62439-3.
Impact of insulating oil degradation on the power transformer frequency response analysis
- Authors: Aljohani, Omar , Abu-Siada, Ahmed , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 11th IEEE International Conference on the Properties and Applications of Dielectric Materials, ICPADM 2015; Sydney, Australia; 19th-22nd July 2015 Vol. OCT, p. 396-399
- Full Text: false
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- Description: Frequency Response Analysis (FRA) has become a reliable tool to detect mechanical deformation within power transformers. Many researchers have investigated the impact of various mechanical winding and core deformations on transformer FRA signature using either simulation analysis or practical testing to establish a standard code for FRA signature interpretation. None of them however, have given attention to the impact of power transformer insulating oil degradation on the transformer FRA signature. This paper investigates the effect of insulating mineral oil degradation on power transformer FRA signature. In this regard, the physical geometrical dimension of a single-phase transformer filled with insulating mineral oil is simulated using three dimensional finite element analysis to emulate the real transformer operation. Transformer FRA signature is measured and analysed with various health conditions of the insulating oil. Results show that, insulating oil degradation has a significant impact on the transformer FRA signature.
LeSiNN : Detecting anomalies by identifying least similar nearest neighbours
- Authors: Pang, Guansong , Ting, Kaiming , Albrecht, David
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 15th IEEE International Conference on Data Mining Workshop, ICDMW 2015; Atlantic City, New Jersey; 14th-17th November 2015; published in Proceedings - 15th IEEE International Conference on Data Mining Workshop, ICDMW 2015
- Full Text: false
- Description: We introduce the concept of Least Similar Nearest Neighbours (LeSiNN) and use LeSiNN to detect anomalies directly. Although there is an existing method which is a special case of LeSiNN, this paper is the first to clearly articulate the underlying concept, as far as we know. LeSiNN is the first ensemble method which works well with models trained using samples of one instance. LeSiNN has linear time complexity with respect to data size and the number of dimensions, and it is one of the few anomaly detectors which can apply directly to both numeric and categorical data sets. Our extensive empirical evaluation shows that LeSiNN is either competitive to or better than six state-of-the-art anomaly detectors in terms of detection accuracy and runtime. © 2015 IEEE.
- Description: Proceedings - 15th IEEE International Conference on Data Mining Workshop, ICDMW 2015
Optimal scheduling of LTC and switched shunt capacitors in smart grid concerningovernight charging of Plug-in Electric Vehicles
- Authors: Deilami, Sara , Masoum, Amir , Masoum, Mohammad , Abu-Siada, Ahmed , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: AASRI International Conference on Applied Engineering Science, ICAES 2014; Los Angeles, United States; 23rd-24th July 2014 p. 71-76
- Full Text: false
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- Description: It is well-known that load variation and nonlinearity have detrimental impacts on the operation and performance of the conventional power systems and future smart grids (SGs) including their voltage profiles, power quality, losses and efficiency particularly during the peak load hours. This paper will perform optimal scheduling of transformer load tap changer (LTC) and switched shunt capacitors (SSCs) in smart grid with nonlinear loads and plug-in electric vehicle (PEV) charging activities to improve voltage profile, reduce grid losses and control the total harmonic distortion (THD). An established genetic algorithm (GA) for the dispatch of LTC/SSC and a recently implemented algorithm based on maximum sensitivity selections (MSS) optimization for coordination of PEVs are used to perform detailed simulations and analyses.
Overnight coordinated charging of plug-in electric vehicles based on maximum sensitivities selections
- Authors: Masoum, Amir , Deilami, Sara , Masoum, Mohammad , Abu-Siada, Ahmed , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: AASRI International Conference on Applied Engineering Science, ICAES 2014; Los Angeles, United States; 23rd-24th July 2014 p. 65-70
- Full Text: false
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- Description: The future smart grid (SG) will be populated with high penetrations of plug-in electric vehicles (PEVs) that may deteriorate the quality of electric power. The consumers will also be seeking economical options to charge their vehicles. This paper proposes an overnight maximum sensitivities selection based coordination algorithm (ON-MSSCA) for inexpensive overnight PEV charging in SG. The approach is based on a recently implemented online algorithm (OL-MSSCA) that charges the vehicles as soon as they are randomly plugged-in while considering SG generation, demand and voltage constraints. In contrast to the online approach, ON-MSSCA relies on inexpensive off-peak load hours charging to reduce the cost of generating energy such that SG constraints are not violated and all vehicles are fully charged overnight. Performances of the online and overnight algorithms are compared for the modified IEEE 23kV distribution system with low voltage residential feeders populated with PEVs.
The effect of simplification based on words and their role in approving or rejecting articles
- Authors: Mirzaei, Bahareh , Jafarabad, Mohammad , Karimi, Hossein , Khastavaneh, Mohammad , Parveh, Abdolkarim , Dehno, Shahin , Khandelwal, Manoj , Safari, Amirali
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 3rd IEEE International Conference on Progress in Informatics and Computing, PIC 2015; Nanjing, China; 18th-20th December 2015; Published in Proceedings of 2015 IEEE Interntational Conference on Progress in Informatics and Computing, PIC 2015 p. 71-76
- Full Text: false
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- Description: One of the main reasons of text complexity is usage of uncommon vocabulary. We can overcome this issue by suggesting simpler words as replacements. This paper analyzed texts from Simple English Wikipedia, Wikipedia and IEEE articles. After running the tests, the results indicated that removing Complex words and replacing them with simpler phrases is the fastest practical algorithm to simplify a scientific complex text. Result of our data analysis tests and checking inputs against a database of 2000 words show that IEEE articles use about 15% uncommon words. © 2015 IEEE.
- Description: Proceedings of 2015 IEEE International Conference on Progress in Informatics and Computing, PIC 2015
Travelling wave fault location in rural radial distribution networks to reduce wild fire risk
- Authors: Jahromi, Ali , Wolfs, Peter , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 25th Australasian Universities Power Engineering Conference, AUPEC 2015; Wollongong, Australia; 27th-30th September 2015 p. 1-6
- Full Text: false
- Reviewed:
- Description: This paper introduces a new fault location algorithm for radial MV distribution networks employing distributed travelling wave observers. Incipient fault location may reduce the risk of wild or bush fire ignition by faulty MV overhead lines. Some faults can develop over time and may exist for an extended period before the right weather conditions result in a fire. Developing faults will produce travelling voltage waves. The distributed observers are synchronized by global positioning system and use the arrival time differences to locate faults. Modal and wavelet transformation is used to detect and time stamp the travelling wave arrival time by observers. The paper first provides a brief review of fault location technology then describes the Floyd-Warshell algorithm to calculate point to point distance matrix. A travelling wave detection methods and finally the fault location algorithm will be described. Simulation model is developed in EMTP-RV software to illustrate the performance of proposed algorithm based on real network data.
A new control approach to improve the overall performance of DFIG-based WECS
- Authors: Khamaira, Mahmoud , Abu-Siada, Ahmed , Islam, Syed , Masoum, Mohammad
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-5
- Full Text: false
- Reviewed:
- Description: Doubly Fed Induction Generators (DFIGs) are currently extensively used in variable speed wind power plants due to their superior advantages that include reduced converter rating, low cost, reduced losses, easy implementation of power factor correction schemes, variable speed operation and four quadrants active and reactive power control capabilities. On the other hand, DFIG sensitivity to grid disturbances, especially for voltage sags represents the main disadvantage of the equipment. In this paper, a coil is proposed to be integrated within the DFIG converters to improve the overall performance of a DFIG-based wind energy conversion system (WECS). A proportional integral (PI) controller to control the charging and discharging of the coil is introduced. Simulation results reveal the effectiveness of the proposed topology in improving the overall performance of the WECS under study.
Alleviating post-contingency congestion risk of wind integrated systems with dynamic line ratings
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-6
- Full Text: false
- Reviewed:
- Description: One of the factors hindering the large scale integration of wind power is the post contingency congestion of a network due to limited availability of network capacity and auxiliary constraints. Under such conditions, the network operators can potentially request a curtailment of wind farm output if the remedial strategies fail. The paper investigates this problem in detail and proposes a mathematical framework to capture the post contingency spare capacity of network assets that is required to limit the wind curtailment. The proposed approach incorporates stochastic variation in asset thermal rating; models network congestion, and quantifies the risk of congestion using an extended version of conic-quadratic programming based optimization. The uniqueness of the proposed mathematical model is that it converts conventional thermal constraints to dynamic constraints by using a discretized stochastic penalty function with quadratic approximation of constraint relaxation penalty. The results suggest that the wind utilization can be maximized if the networks are operated 30-50% less than the nominal rating of the assets.
Analysis of power system communication architectures between substations using IEC 61850
- Authors: Das, Narottam , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 5th Brunei International Conference on Engineering and Technology, BICET 2014; Bandar Seri Begawan, Brunei Darussalam; 1st-3rd November 2014 Vol. 2014, p. 1-6
- Full Text: false
- Reviewed:
- Description: Interoperability among multi-vendor substations automation devices, is now achievable due to the introduction of IEC 61850 standard, which allows power system communication between substations. This standard does not mandatorily demands for redundancy in any type of substation neither does it mentions a specific type of substation design application. Ethernet based communication protocols for substation automation systems (SASs) are specified in IEC 61850 standard. The standards include Ethernet based process-level connections between switchyards and control rooms. However, their in-service performance is not well known. Moreover, IEC 61850 demands for a communication topology which is zero point failure proof and provides worthy data transmission rates, without pursuing any delays. In order to achieve these norms, Ethernet architectures must be modelled and analysed in detail. The performance of individual architecture must be analysed in terms of their reliability, availability and efficiency of data transfer. This paper presents the reliability and availability using the reliability block diagrams, along with OPNET network real-time simulations, which shows the efficiency of individual architecture along with comparing and synthesizing the most effective communication topology for the SASs.
Application of digital image processing to diagnose transformer winding deformation using FRA polar plot
- Authors: Aljohani, Omar , Abu-Siada, Ahmed , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 2014 International Conference on Condition Monitoring and Diagnosis, CMD 2014; Jeju, Korea; 21st September 2014
- Full Text: false
- Reviewed:
- Description: Digital image processing (DIP) technique has been growing rapidly as an essential tool to interpret various image features for many applications of science and engineering. Condition monitoring and diagnosis are considered the main areas that relay on DIP. Frequency response analysis (FRA) technique has become a popular and reliable diagnostic tool in detecting various winding deformations within power transformers. However, interpretation of FRA signatures still requires high expertise because of its reliance on graphical analysis. This paper presents a new technique for the interpretation of transformers FRA signatures. The proposed technique relies on incorporating both magnitude and angle of the FRA signature in one polar plot, which is manipulated to extract some unique features using DIP techniques. The proposed technique can assess in identifying and quantifying various winding deformation within power transformers. The proposed technique is easy to implement in any frequency response analyser.