Tuesday, March 1, 2011

ABSTRACT - Expert System Fault Transmission Overhead Line Protection System

   1.   Guo, W.X., Wen, F.S., Liao, Z.W., Wei, L.H., Xin, J.B., 2010. An Analytic Model-Based Approach for Power System Alarm Processing Employing Temporal Constraint Network. Ieee Transactions on Power Delivery 25, 2435-2447.

Abstract: The alarm-processing problem is to interpret a large number of alarms under stress conditions, such as faults or disturbances, by providing summarized and synthesized information instead of a flood of raw alarm data. Alarm timestamps represent the temporal relationship among event occurrences and consist of rich and useful information for alarm processing. However, the temporal information has not been well utilized in existing alarm-processing methods. The temporal constraint network (TCN) is a type of directed acyclic graph suitable for representing temporal logics. Based on TCN, a new analytic model is developed for alarm processing with temporal information taken into account. Three major modules are included in the developed approach or alarm processor (i.e., alarm selection, event analysis, and result evaluation). In the alarm selection module, reported alarms are divided into related groups. The function of the event analysis module is to find out what events cause the reported alarms and to estimate when these events happen. The result evaluation module is used to identify abnormal or missing alarms. Finally, two alarm-processing scenarios of an actual power system are served for demonstrating the feasibility and efficiency of the developed approach
   2.   Bhowmik, P.S., Purkait, P., Bhattacharya, K., 2009. A novel wavelet transform aided neural network based transmission line fault analysis method. International Journal of Electrical Power & Energy Systems 31, 213-219.

Abstract: In the present scenario of market driven business, power supply has become more like a commodity. Reliable and quality power need to be ensured to meet customer requirements. In such a situation, it is extremely important that transmission line faults be identified accurately, reliably and in quick time. Advanced signal processing tools such as discrete wavelet transform (DWT) can be used very effectively for parameterisation and characterization of the fault signals. On the other hand, properly configured neural network (NN) can be utilized for classification of the faults based on the DWT signal, The present contribution uses electromagnetic transient program (EMTP) for modeling of a real transmission system and MATLAB for DWT and NN. Various types of faults have been simulated at different locations along the transmission line and an attempt has been made to correctly identify and locate the fault. (C) 2009 Elsevier Ltd. All rights reserved
   3.   Reddy, M.J.B., Mohanta, D.K., 2008. Performance Evaluation of an Adaptive-Network-Based Fuzzy Inference System Approach for Location of Faults on Transmission Lines Using Monte Carlo Simulation. Ieee Transactions on Fuzzy Systems 16, 909-9

Abstract: This paper employs a wavelet multiresolution analysis (MRA) along with the adaptive-network-based fuzzy inference system to overcome the difficulties associated with conventional voltage- and current-based measurements for transmission-line fault location algorithms, due to the effect of factors such as fault inception angle, fault impedance, and fault distance. This proposed approach is different from conventional algorithms that are based on deterministic computations on a well-defined model to be protected, employing wavelet transform together with intelligent computational techniques, such as the fuzzy inference system 9 adaptive neurofuzzy inference system (ANFIS), and artificial neural network (ANN) in order to incorporate expert evaluation so as to extract important features from wavelet MRA coefficients for obtaining coherent conclusions regarding fault location. A comparative study establishes that the ANFIS approach has superiority over ANN- and FIS-based approaches for the location of line faults. In addition, the efficacy of the ANFIS is validated through the Monte Carlo simulation for incorporating the stochastic nature of fault occurrence in practical systems. Thus, this ANFIS-based digital relay can be used as an effective tool for real-time digital relaying purposes
   4.   Liu, Y., Li, Y., Cao, Y.J., Guo, C.X., 2008. Forward and backward models for fault diagnosis based on parallel genetic algorithms. Journal of Zhejiang University-Science A 9, 1420-1425.
Abstract: In this paper, a mathematical model consisting of forward and backward models is built on parallel genetic algorithms (PGAs) for fault diagnosis in a transmission power system. A new method to reduce the scale of fault sections is developed in the forward model and the message passing interface (MPI) approach is chosen to parallel the genetic algorithms by global single-population master-slave method (GPGAs). The proposed approach is applied to a sample system consisting of 28 sections, 84 protective relays and 40 circuit breakers. Simulation results show that the new model based on GPGAs can achieve very fast computation in online applications of large-scale power systems
   5.   Samantaray, S.R., Dash, P.K., Panda, G., 2008. A combined S-transform and fuzzy expert system for phase selection in digital relaying. European Transactions on Electrical Power 18, 448-460.

Abstract: This paper presents a new approach for faulty phase selection in transmission line based on combined S-transform and Fuzzy Expert System (FES). The S-transform with complex window is used to generate S-contours (time-frequency contours), Which 'time-localizes the fault. Features Such as standard deviation (sd) and change in energy (ce) of the S-contours for half cycle post fault Current Samples are calculated and fuzzified with simple triangular membership function. The fuzzified inputs are fed to the FES and the corresponding fuzzy rule is fired to provide the Output as "1" for faulty phase and ground involved and "0" for no-fault. The proposed integrated approach is tested for all 11 types of shunt faults with a wide rant,e of operating conditions of the power system network. For testing the robustness of the proposed technique. the same is applied for the faults created on experimental set LIP with different operating conditions and provides accurate results. The Output front the FES shows the fastness of the proposed technique and thus Suitable for online application. Copyright (c) 2007 John Wiley & Sons, Ltd
   6.   Reddy, M.J., Mohanta, D.K., 2007. A wavelet-fuzzy combined approach for classification and location of transmission line faults. International Journal of Electrical Power & Energy Systems 29,  669-678.
Abstract: This paper presents a real-time wavelet-Fuzzy combined approach for digital relaying. The algorithm for fault classification employs wavelet multi resolution analysis (MRA) to overcome the difficulties associated with conventional voltage and current based measurements due to effect of factors such as fault inception angle, fault impedance and fault distance. The proposed algorithm for fault location, different from conventional algorithms that are based on deterministic computations on a well-defined model to be protected, employs wavelet transform together with fuzzy logic. The wavelet transform captures the dynamic characteristics of the non-stationary transient fault signals using wavelet MRA coefficients. The fuzzy logic is employed to incorporate expert evaluation through fuzzy inference system (FIS) so as to extract important features from wavelet MRA coefficients for obtaining coherent conclusions regarding fault location. Computer simulations using MATLAB have been conducted for a 300 Km 400 KV line. Simulation results indicate that both the classification and localization algorithms are immune from effects of faults inception angle, impedance and distance. The most significant contribution of this paper is that the proposed location algorithm has a maximum error of 6.5% with a computational time of about one cycle. Thus both classification and location algorithms can be used as effective tools for real-time digital relaying purpose. (C) 2007 Elsevier Ltd. All rights reserved
   7.   Namdari, F., Jamali, S., Crossley, P.A., 2007. Power differential based wide area protection. Electric Power Systems Research 77, 1541-1551.

Abstract: Current differential based wide area protection (WAP) has recently been proposed as a technique to increase the reliability of protection systems. It increases system stability and can prevent large contingencies such as cascading outages and blackouts. This paper describes how power differential protection (PDP) can be used within a WAP and shows that the algorithm operates correctly for all types of system faults whilst preventing unwanted tripping, even if the data has been distorted by CT saturation or by data mismatches caused by delays in the WAP data collection system. The PDP algorithm has been simulated and tested on an Iranian 400kV transmission line under different fault and system operating conditions. The proposed operating logic and the PDP algorithm have also been evaluated using simulation studies based on the Northern Ireland Electricity (NIE) 275 kV network. The results presented illustrate the validity of the proposed protection. (C) 2006 Elsevier B.V. All rights reserved
   8.   Reddy, M.J., Mohanta, D.K., 2007. A wavelet-neuro-fuzzy combined approach for digital relaying of transmission line faults. Electric Power Components and Systems 35, 1385-1407.

Abstract: The proposed algorithm for fault location, different from conventional algorithms that are based on deterministic computations on a well-defined model to be protected, employs wavelet transform together with fuzzy inference system (FIS) and the adaptive neuro-fuzzy inference system (ANFIS) to incorporate expert evaluation so as to extract important features from wavelet multi-resolution analysis (MRA) coefficients for obtaining coherent conclusions regarding fault location. Simulation results indicate that both the classification and localization algorithms are immune to the effects of fault inception angle, impedance and distance. The most significant contribution of this article is that the proposed ANFIS approach has superiority over FIS for location of transmission line faults and thus can be used as an effective tool for real-time digital relaying purposes
   9.   Zhu, Y.L., Huo, L.M., Lu, J.L., 2006. Bayesian networks-based approach for power systems fault diagnosis. Ieee Transactions on Power Delivery 21, 634-639.

Abstract: In this paper, three element-oriented models based on simplified Bayesian networks with Noisy-Or and Noisy-And nodes are proposed to estimate the faulty section of a transmission power system. The three models are used to test if any transmission line, transformer, or busbar within a blackout area is faulty. They can deal with uncertain or incomplete data and knowledge relating to power system diagnosis, so they are flexible. The structures and initial parameters of the Bayesian networks depend on the prior knowledge of the domain experts. The parameters can be revised by using an error back propagation algorithm similar to the back-propagation algorithm for artificial neural networks. The fault diagnosis models do not vary with the change of the network structure, so they can be applied to any transmission power system. Furthermore, they have clear semantics, rapid reasoning, powerful error tolerance ability, and no convergence problem during the diagnosing procedure. Experimental tests show that the approach is feasible and efficient, so the prototype program based on the approach is promising to be used in a large transmission power system for online fault diagnosis
10.   El-Arroudi, K., Joos, G., McGillis, D.T., Brearley, R., 2005. Comprehensive transmission distance protection settings using an intelligent-based analysis of events and consequences. Ieee Transactions on Power Delivery 20, 1817-1824.

Abstract: This paper introduces a new methodology for settings of transmission system distance protection based on an intelligent analysis of events and their consequences. The output of the proposed methodology is comprehensive distance relay settings which include not only the zone reaches and zone time delays, as in the existing approaches, but also the optimal impedance operating characteristics, the fault detection settings, and the required relay sensitivities in terms of voltage and current. The need for this methodology is the result of the increased complexity of interconnected power systems protected with a large number of relays with different relay technologies, such as electromechanical, static, and numerical as well as diversity in their operating algorithms. The relay settings are automatically updated after every major change in the state of the network topology. Since it is not possible to include all design details of the proposed system, sample design events and rules are given to illustrate the proposed methodology
11.   Ding, Y.H., Yu, D.T., 2005. Estimation of failure probability of oil and gas transmission pipelines by fuzzy fault tree analysis. Journal of Loss Prevention in the Process Industries 18, 83-88.
Abstract: Failure of oil and gas transmission pipelines was analyzed by fault tree analysis in this paper. According to failure modes of pipeline: leakage and rupture, a fault tree of the pipeline was constructed. Fifty-five minimal cut sets of the fault tree had been achieved by qualitative analysis, while the failure probability of top event and the important analyses of basic events were evaluated by quantitative analysis. In conventional fault tree analysis, probabilities of the basic events were treated as precise values, which could not reflect real situation of system because of ambiguity and imprecision of some basic events. In order to overcome this disadvantage, a new method was proposed which combined expert elicitation with fuzzy set theories to evaluate probability of the events. As an example, failure probability of pipeline installation was assessed by using the proposed method, achieving its fuzzy failure probability of 6.4603 x 10(-3). The method given in this article is effective to treat fuzzy events of FTA. (c) 2005 Elsevier Ltd. All rights reserved
12.   Das, B., Reddy, J.V., 2005. Fuzzy-logic-based fault classification scheme for digital distance protection. Ieee Transactions on Power Delivery 20, 609-616.
Abstract: In this paper, a fuzzy-logic-based algorithm to identify the type of faults for digital distance protection system has been developed. The proposed technique is able to accurately identify the phase(s) involved in all ten types of shunt faults that may occur in a transmission line under different fault resistances, inception angle, and loading levels. The proposed method needs only three line-current measurements available at the relay location and can perform the fault classification task in about a half-cycle period. Thus, the proposed technique is well suited for implementation in a digital distance protection scheme
13.   Youssef, O.A.S., 2004. Combined fuzzy-logic wavelet-based fault classification technique for power system relaying. Ieee Transactions on Power Delivery 19, 582-589.

Abstract: This paper presents a new approach to real-time fault classification in power transmission systems using fuzzy-logic-based multicriteria approach. Only the three line currents are utilized to detect fault types such as LG, LL, and LLG, and then to define the faulty line. An online wavelet-based preprocessor stage,[1]-[4] is used with data window of ten samples (based on 4.5-kHz sampling rate and 50-Hz power frequency). The multicriteria algorithm is developed based on fuzzy sets for the decision-making part of the scheme. Computer simulation has been conducted using EMTP programs. Results are shown and they indicate that this approach can be used as an effective tool for high-speed digital relaying, as the correct detection is achieved in less than half a cycle and that computational burden is much simpler than the recently postulated fault classification techniques
14.   Youssef, O.A.S., 2004. A novel fuzzy-logic-based phase selection technique for power system relaying. Electric Power Systems Research 68, 175-184.

Abstract: Fast tripping and consequent single-pole auto-reclosure of the faulted phase for single-phase earth faults is extensively used in long line applications. Traditional phase selection techniques can suffer some drawbacks due to their dependency on varying system and fault conditions. However, with the advent of fuzzy-logic techniques, and their ability to map complex and non-linear power system configurations provide a very attractive solution to accurate and fast phase selection procedure. This paper presents a new approach to real-time phase selection in power transmission systems using fuzzy-logic-based multi-criteria approach. Only the three line currents are utilised to detect the faulted phase. An online wavelet-based pre-processor stage [IEEE Trans. Power Delivery, 18 (4) (2003) 1158; IEEE Trans. Power delivery 17(4) (2002) 908; IEEE Trans. Power Delivery, 18 (1) (2003) 170; Paper # 01TD069, IEEE T&D Conference, 28 October-2 November 2001, Atlanta, GA] is used with 10 samples data window (based on 4.5 kHz sampling rate and 50 Hz power frequency). The paper demonstrates the multi-criteria algorithm that is based on fuzzy sets for the decision making part of the scheme. Computer simulation have been conducted using EMTP programs. Results proved that the correct detection is achieved in less than half a cycle and that computational burden is simpler than the recently postulated phase selection techniques, and this approach can be used as an effective tool for high speed digital relaying. (C) 2003 Elsevier B.V. All rights reserved
15.   Bansal, R.C., 2003. Literature survey on expert systems applications to power systems (1990-2001). Engineering Intelligent Systems for Electrical Engineering and Communications 11, 103-112.

Abstract: Application of expert system (ES) to power systems is an area of growing interest. For the past twenty years, a great deal of ES applications has been developed to help in the planning, analyzing, managing, control and operation of various aspects of power generation, transmission and distributions systems. This paper presents an extended bibliography of expert system applications in power system. Brief discussion on applications of expert system to various power systems problems have also been presented in this paper
16.   Zhu, Y.L., Malik, O.P., 2003. Intelligent automatic generation of graphical one-line substation arrangement diagrams. Ieee Transactions on Power Delivery 18, 729-735

Abstract: The conventional graph editing of one-line substation diagrams for a graphical user interface is time-consuming and needs considerable effort. A method for automatic generation of the substation diagrams is described in this paper. In this method, artificial intelligence (AI) frames are adopted for the representation of substations and their network, some expert rules on the layout and drawing-of substation buses are accumulated and summarized, and AI rule-based inference techniques are used for branch analysis on different types of buses and drawing of the buses and their branches. A vertical coordinates conversion relationship is obtained to narrow the testing of substation diagram components' vertical layout. The method has been programmed and applied to two power system analysis programs, one of which is undergoing field test in a transmission system for real time fault diagnosis in northern China
17.   Babnik, T., Gubina, F., 2002. Two approaches to power transformer fault classification based on protection signals. International Journal of Electrical Power & Energy Systems 24, 459-468.

Abstract: A large amount of data is generated when a fault triggers transformer protection. However, no precise information is obtained regarding where and what type of fault has occurred. Consequently, the operator must wait, sometimes for days, before he can switch on the transformer, which may not have been affected by the fault at all. As a result, the network suffers reduced security and transmission capacity. This paper presents two methods that enable the identification of faults affecting power transformer protection based on its signals. These methods should assist the operator in deciding whether the transformer should be left off or switched back into the system immediately after the event. The statistical data on faults and protection operation enable fault classification based on the B ayes' theorem. The probability could be used as a measure of the event occurrence likelihood regarding a set of alternative events. A second method is further proposed, which uses the norm in the Banach space as a measure for the most probable event. Tests of both methods showed that they yield a fast and successful identification of power transformer faults. (C) 2002 Elsevier Science Ltd. All rights reserved
18.   Garza, L.E., Cantu, F., Acevedo, S., 2000. A methodology for multiple-fault diagnosis based on the independent choice logic. Advances in Artificial Intelligence 1952, 417-426.
Abstract: We propose a methodology to diagnose multiple faults in complex systems. The approach is based on the Independent Choice Logic (ICL) and comprises two phases. In phase 1 we generate the explanations of the observed symptoms and handle the combinatorial explosion with a heuristic. In phase 2 we observe process signals to detect abnormal behavior that can lead us to identify the real faulted components. A proposal is made to automate this task with Dynamic Bayesian Networks (DBNs) embedded in the ICL formalism. The overall scheme is intended to give a definite diagnosis. ICL is a framework, which comprises a theory and a development environment. We show that ICL can be scaled-up to real-world, industrial-strength problems by using it in diagnosing faults in an electrical power transmission network
19.   Tan, J.C., Crossley, P.A., McLaren, P.G., Hall, I., Farrell, J., Gale, P., 2002. Sequential tripping strategy for a transmission network back-up protection expert system. Ieee Transactions on Power Delivery 17, 68-74.

Abstract: This paper describes a Sequential Tripping Strategy used in a wide area back-up protection expert system (BPES) to combat situations in which protection relays have maloperated or information is Missing. The BPES: is an innovative back-up protection scheme designed to prevent the occurrence of widespread blackouts. The BPES evaluates the certainty that transmission lines are likely to be affected by the. fault and uses a Sequential Tripping Strategy to isolate the fault if a firm decision is not available due to maloperated relays and/or missing information. The mode of analysis and the Sequential Tripping Strategy ensures that the BPES will clear a fault at minimum risk to the network. An example is included to demonstrate how the Certainty Factor based Sequential nipping Strategy is employed by the BPES to clear a fault which occurred on the South Western part of the UK National Grid System
20.   Hadjicostis, C.N., Verghese, G.C., 2000. Power system monitoring using Petri net embeddings. Iee Proceedings-Generation Transmission and Distribution 147, 299-303.

Abstract: A failure in a power transmission line causes a number of circuit breakers to activate in an effort to isolate the failure and prevent it from corrupting the rest of the power system. Based on information from these physically distributed protective devices, a central controller needs to quickly locate and identify the failure. The task becomes challenging due to the complexity of modern power transmission networks and due to the possibility of sensor failures or incorrect operation of protective devices. A solution to this problem is investigated using Petri net models. Our approach allows concurrent/incremental processing of the information that arrives at the controller and only requires simple calculations (linear checks) during execution time. Most reasoning is implicitly performed at design time, which gives our method an important edge for real-time monitoring. These same techniques can potentially handle multiple failures or perform hierarchical and/or distributed monitoring
21.   Tan, J.C., Crossley, P.A., Kirschen, D., Goody, J., Downes, J.A., 2000. An expert system for the back-up protection of a transmission network. Ieee Transactions on Power Delivery 15, 508-514.

Abstract: A back-up protection scheme for a transmission network is described in the paper. The Back-up Protection uses an action factor based Expert decision System (referred to as the BPES) to provide optimal fault clearance for faults located anywhere on the protected network, To achieve an optimal response the BPES needs to know the topology of the network and the operating response of existing protection relays. Based on this information, the expert decision system will try to identify the feeder that contains the fault and which circuit breakers need to be tripped to clear the fault
22.   Lee, H.J., Park, D.Y., Ahn, B.S., Park, Y.M., Park, J.K., Venkata, S.S., 2000. A fuzzy expert system for the integrated fault diagnosis. Ieee Transactions on Power Delivery 15, 833-838.

Abstract: An integrated fuzzy expert system is presented to diagnose various faults that may occur in a regional transmission network and substations. Fuzzy reasoning method is applied, and it is discussed in detail; Discrimination of false operations or nonoperations of protective devices as well as the fault identification scheme are also analyzed, together with the fuzzy inference process. The proposed system is designed to improve efficiency, generality, and reliability of the solution. The system will replace a fault diagnosis system that had been tested as a part of an intelligent support system on a local control center in Korea
23.   Chang, C.S., Chen, J.M., Srinivasan, D., Wen, F.S., Liew, A.C., 1997. Fuzzy logic approach in power system fault section identification. Iee Proceedings-Generation Transmission and Distribution 144, 406-414.

Abstract: Great emphasis has been put on applying expert systems for transmission system fault diagnosis. However, very few papers deal with the unavoidable uncertainties that occur during operation involving the fault location and other available information. The paper proposes a method using fuzzy sets to cope with such uncertainties. A fuzzy expert system is developed, which requires much less memory to store an active database than that used by conventional rule-based expert systems. The fuzzy expert system identifies two basic network section sets, S-healthy for the healthy subnetwork and S-island for the fault islands, using the postfault status of circuit breakers and relays. It then conducts inference to determine the most likely fault sections and the associated fault sequences. Two case studies are provided to demonstrate salient features of the proposed approach, and to compare results both with a conventional rule-based expert system and a refined genetic algorithm. The proposed fuzzy expert system can be operated either in a stand-alone manner, or as part of the overall architecture of a diagnosis system for parallel decision making
24.   Rayudu, R.K., Samarasinghe, S., Kulasiri, D., Ypsilantis, J., 1997. Model-based learning for fault diagnosis in power transmission networks. Engineering Intelligent Systems for Electrical Engineering and Communications 5, 63-74.

Abstract: This paper presents a hybrid algorithm for fault diagnosis in power transmission networks. The prime objective of a power transmission network is to supply power to the customers and to meet the lend demands. When a fault occurs in a transmission network, it must be identified and eliminated as soon as possible. Since control centres are flooded with hundreds of alarm messages during a fault, fault diagnosis, which involves the analysis of alarm messages, is a time consuming task. Faults in a power network are caused by various environmental conditions which change with time and their diagnosis involves real time decision making which cannot be modelled by using traditional mathematical modelling techniques. Earlier research suggested that decision-support systems can aid system controllers during emergency situations. Artificial intelligence techniques such as expert systems, neural networks and model based reasoning have been used in the past but these techniques lack efficiency when applied to large systems such as power networks. As part of our an going research towards the development of an intelligent architecture for fault diagnosis, we attempt to develop an efficient model by combining two reasoning techniques (model-based and heuristic) and incorporating a machine learning algorithm called Explanation Eased Generalisation (EBG) for automated knowledge acquisition. The machine learning algorithm learns shallow knowledge from the reasoning process of the combined (or hybrid) model and stores it for future problem solving. In this paper, the developed hybrid fault diagnosis system is discussed and its performance is compared with the traditional model based reasoning approach
25.   Chang, C.S., Chen, J.M., Liew, A.C., Srinivasan, D., Wen, F.S., 1997. Fuzzy expert system for fault diagnosis in power systems. Engineering Intelligent Systems for Electrical Engineering and Communications 5, 75-81.

Abstract: Fault diagnosis of power system plays a crucial role in power system monitoring and control that ensures a stable supply of electrical power to consumers. In the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires judgment of complex conditions of various levels, especially considering the unavoidable uncertainties that occur during operation involving the fault location and other information available. This paper presents a methodology for fault diagnosis far complex electrical power systems, which is based on fuzzy logic and expert system to deal with the uncertainties. Expert knowledge concerning normal and faulted operation is acquired via knowledge acquisition techniques. A fuzzy logic expert system for fault diagnosis of power system is developed which uses as input status change of the operated circuit breakers and relays. The fuzzy expert system requires much less memory space to stare active databases than those used by conventional expert systems. The fuzzy expert system first identifies a short list of possible fault sections and deals with one possible fault section at a time. It then conducts inference to determine the most likely fault sections and the associated fault section sequences. Several study cases are given in this paper to demonstrate salient features of the proposed method
26.   Nakatani, M., Yamaoka, T., Hosono, Y., Nishida, S., 1997. Proposal of decision support system for cooperation in hierarchical structures. Electronics and Communications in Japan Part Iii-Fundamental Electronic Science 80, 78-91.

Abstract: In most previous research on group decision making systems, all participants are assumed to be working on the same decision. But, in electric power systems and the like, in-service fault handling must deal with a variety of externally caused problems in real time. The system described here assumes a hierarchical organization in which the upper levels issue broad strategic directives and the lower levels take specific actions based on them. Even in the making of seemingly diverse decisions, this decision process is actually cooperative. It requires a correct comprehension of system states and of the intentions of others (goals and strategies). A representation that superimposed goals, strategies, and states of the system is capable of revealing inconsistencies between intentions and circumstances. The proposed system has undergone expert evaluation in applications to two malfunctions in an electric power system. The representation method promotes a focus on errors in strategy and in the transmission of strategy from upper to lower levels and facilitates the revision of strategy in case of error
27.   Huang, Y.C., Yang, H.T., Huang, C.L., 1997. A new intelligent Hierarchical Fault Diagnosis System. Ieee Transactions on Power Systems 12, 349-356.

Abstract: As a part of a substation-level decision support system, a new intelligent Hierarchical Fault Diagnosis System for on-line fault diagnosis is presented in this paper. The proposed diagnosis system divides the fault diagnosis process into two phases. Using time-stamped information of relays and breakers, phase I identifies the possible fault sections through the Group Method of Data Handling (GMDH) networks, and phase II recognizes the types and detailed situations of the faults identified in phase I by using a fast bit-operation logical inference mechanism. The diagnosis system has been practically verified by testing on a typical Taiwan power secondary transmission system. Test results show that rapid and accurate diagnosis can be obtained with flexibility and portability for fault diagnosis purpose of diverse substations
28.   Miao, H., Sforna, M., Liu, C.C., 1996. A new logic-based alarm analyzer for on-line operational environment. Ieee Transactions on Power Systems 11, 1600-1606.

Abstract: Existing fault diagnostic techniques for power systems are based on the operation of breakers using on-line alarm messages available from the Energy Management Systems (EMSs). Some utility systems also acquire, on-line, the information on relay operations in order to increase the precision of fault diagnosis. This paper proposes a new on-line fault diagnosis system called Intelligent Alarm Analyzer (IAA). This paper identifies the information from sequence-of-events recorders (SERs) at the substations that can be used in the EMS environment. The breaker operations together with the selected SER information provide sufficient data to help pinpoint the fault location(s) and malfunctioning device(s) online. The proposed IAA is capable of handling transmission line, busbar and transformer faults as well as relay and breaker malfunctions. The other unique feature of IAA is its logic-based algorithms implemented in an object-oriented software structure. Based on our testing with the actual data from ENEL, the Italian power system, the proposed implementation is highly efficient and promising for the on-line environment
29.   Saengsuwan, T., Crossley, P.A., Fernandez, C., 1996. Expert system applied to the back-up protection of a transmission network. Engineering Intelligent Systems for Electrical Engineering and Communications 4, 43-48.

Abstract: The paper will describe a new type of protection, designed to provide back-up protection for a region of a transmission network. The protection uses an expert system, based on the shell GoldWorks III. This determines the optimum response to the fault, based on the knowledge of the network configuration and the operating response of the main protection. The back-up protection clears the fault, if one of the main protection relays and its associated circuit breaker failed to operate. The paper will include results showing the response of the back-up protection when rested using a power system simulator
30.   Kawahara, K., Sasaki, H., Kubokawa, J., Kitagawa, M., Sugihara, H., 1995. Expert-System for Designing Transmission-Line Protection System. International Journal of Electrical Power & Energy Systems 17, 69-78.

Abstract: This paper presents a powerful expert system (ES) which makes a basic design of an adequate protective relaying system based on the knowledge of skilled protection engineers. Following the basic design, the ES carries out the relay setting and its validation by means of the integrated power flow and fault calculation programs. Furthermore, the ES has a capability of securing coordination among separately set relays. It is very flexible in that it is able to reset the relays according to power system changes. The effectiveness has been demonstrated by using a part of the Chugoku Electric Power Company System
31.   Yang, H.T., Chang, W.Y., Huang, C.L., 1995. Power-System Distributed Online Fault Section Estimation Using Decision Tree-Based Neural Nets Approach. Ieee Transactions on Power Delivery 10, 540-546.

Abstract: This paper proposes a distributed neural nets decision approach to on-line estimation of the fault section of a transmission and distribution (T & D) system. The distributed processing alleviates the burden of communication between the control center and local substations, and increases the reliability and flexibility of the diagnosis system. Besides, by using the algorithms of data-driven decision tree induction and direct mapping from the decision tree into neural net, the proposed diagnosis system features parallel processing and easy implementation, overcoming the limitations of overly large and complex system. The approach has been practically tested on a typical Taiwan Power (Taipower) T & D system. The feasibility of such a diagnosis system is presented
32.   Yang, H.T., Chang, W.Y., Huang, C.L., 1994. A New Neural Networks Approach to Online Fault Section Estimation Using Information of Protective Relays and Circuit-Breakers. Ieee Transactions on Power Delivery 9, 220-229.

Abstract: This paper proposes a new Neural Networks Diagnostic System for on-line fault section estimation using information of relays and circuit breakers. This system has similar profile of an expert system, but can be constructed much more easily from elemental samples. These samples associate fault section with its primary, local and/or remote protective relays and breakers. The diagnostic system can be applicable to the power system control center for single or multiple fault sections estimation, even in the cases of failure operation of relay and breaker, or error-existent data transmission. The proposed approach has been practically verified by testing on a model power system. The test results, although preliminary, suggest our system can be implemented by various electric utilities with relatively low customization effort
33.   Zhu, Y.L., Yang, Y.H., Hogg, B.W., Zhang, W.Q., Gao, S., 1994. An Expert-System for Power-Systems Fault Analysis. Ieee Transactions on Power Systems 9, 503-509.

Abstract: This paper describes an expert system for fault analysis which has been put into field test in the dispatch centre of the North East China Electric Network. Previous expert systems for fault analysis on transmission power systems are mainly based on information about the operation of protective relays, whereas this new expert system mainly uses information on tripped circuit breakers, which is more readily available. For some complicated faults, a small number of relay signals are needed. Data concerning the distribution and characteristics of protective relays are concealed in the fault models in the knowledge base of the expert system, and consequently the large database normally required for these data is unnecessary. This also enables the expert system to be more easily transplanted to other networks. Furthermore, because it can distinguish the operational performances of different relays, it analyses faults more accurately
34.   Kezunovic, M., Spasojevic, P., Fromen, C.W., Sevcik, D.R., 1993. An Expert-System for Transmission Substation Event Analysis. Ieee Transactions on Power Delivery 8, 1942-1949.

Abstract: Digital fault recorders (DFRs) are used in substations to capture recordings of various disturbances and fault events. Protection engineers use these recordings to identify reasons for particular operation of protection relays and circuit breakers. In performing this task protection engineers use their expertise related to specific power system conditions, equipment and operations. This paper describes implementation of an expert system which performs fault detection and diagnosis automatically and can aid operators in their task of analyzing disturbances and fault events
35.   Mcdonald, J.R., Burt, G.M., Young, D.J., 1992. Alarm Processing and Fault-Diagnosis Using Knowledge Based Systems for Transmission and Distribution Network Control. Ieee Transactions on Power Systems 7, 1292-1298.

Abstract: This paper presents two expert system developments which are each concerned with utilizing, to the best effect, the increasing volume of SCADA (Supervisory Control And Data Acquisition) system data available to power system control staff. The systems presented, APEX and RESPONDD, are aimed at the two related fields of alarm processing, and fault diagnosis respectively. The areas of commonality between these systems are discussed as well as details specific to each separate system, including a case study of practical operation of each
36.   Ma, T.K., Liu, C.C., Tsai, M.S., Rogers, R., Muchlinski, S.L., Dodge, J., 1992. Operational Experience and Maintenance of An Online Expert System for Customer Restoration and Fault Testing. Ieee Transactions on Power Systems 7, 835-842.

Abstract: CRAFT (Customer Restoration And Fault Testing) is a rule-based expert system capable of locating the faulted section of a transmission line based on the status of breakers and automatic switches. CRAFT has been operating on-line in the Puget Sound Power and Light control center since July 1988. In this paper, the on-line operational experience is reported. Many of the developed expert systems will be maintained or modified by utility engineers. This study proposes a methodology for maintaining rule-based expert systems. The following capabilities are incorporated: (1) Detecting the relations of conflict, redundancy, etc., to maintain consistency of the rule base, (2) Tracing the reasoning process to understand the problem solving approach, (3) Reducing the size of test cases after changes are made to the rules. The proposed method has been implemented for CRAFT
37.   Maduri, O., 1991. Transmission Controller Troubleshooting - An Expert Systems-Approach. Computers in Industry 17, 375-384.

Abstract: This paper describes an expert system (EXPATEC) developed for troubleshooting the automatic transmission controller used on heavy-payload mining and earth-moving equipments to improve the usablity of fault location, troubleshooting and diagnostics. The controller used on the transmission model CLBT 6062 with a self-diagnostic feature (displays a fault location code) called Allison Transmission Electronic Control (ATEC) installed on a 50 ton rear dumper is considered for applying the rule-based expert system. The expert system (EXPATEC) developed at M/s Bharat Earth Movers Ltd. for this application has been implemented in its equipment assembly and service departments. The experience gained in developing has given scope and strength for further development of expert systems for several other applications in and outside the domain of this industry
38.   Wang, Y.F., Ula, A.H.M.S., 1991. A High-Speed Power-System Transmission-Line Protection Scheme Using A 32-Bit Microprocessor. Electric Power Systems Research 21, 195-202.
Abstract: The availability of cheap and powerful microprocessors in recent years has led to their increasing use in all aspects of power engineering. In future years they are expected to play an even greater role in power system protection schemes because of their ability to: (1) compare on-line data and come to a logical or quick decision; (2) store information from past events and make an expert decision; (3) combine various complicated tasks, etc. Thus, the application of microprocessors in power system protection is much more attractive than in many other fields. As an example, this paper develops a high speed digital protection scheme for a power transmission line. A signal processing technique is used to analyze the power spectrum of the transient fault currents, which makes it possible to develop a desired digital filtering algorithm using computer-aided design (CAD) techniques and minimize the potential for false tripping due to the steady-state system harmonics. This design was implemented on a 32-bit MVME133 monoboard microcomputer to demonstrate the protection of a model power transmission line
39.   Marathe, H.Y., Rogers, R.G., 1991. An Online Operational Expert System with Data Validation Capabilities. Ieee Transactions on Power Systems 6, 882-889.

Abstract: This paper discusses implementation and operation of an expert system in a control center environment. CRAFT (Customer Restoration And Fault Testing) is an existing rule based expert system which is capable of locating the faulted section of a transmission line equipped with automatic switches and circuit breakers. In this study, the capabilities of CRAFT are extended by adding two new knowledge bases with rules to determine the status of unsupervised automatic switches and to detect the presence and location of a manual switch with an incorrect status, following a fault. In this research, an approach of appending a separate expert system computer to the existing SCADA system is developed. Software and hardware interfaces are designed and implemented. The completed implementation is operating online. The implementation represents a step towards practical application of expert systems for real-time operation of power system

1 comment:

  1. Increasingly, transmission lines with overhead line materials are routed through areas of poor ground conditions, often for reasons of amenity. This results in the need for the use of special, generally larger, foundations.