The Experts below are selected from a list of 593940 Experts worldwide ranked by ideXlab platform
Xiaodong Liang - One of the best experts on this subject based on the ideXlab platform.
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Composite Load Model and Transfer Function Based Load Model for High Motor Composition Load
2019 IEEE Electrical Power and Energy Conference (EPEC), 2019Co-Authors: Hla U May Marma, Xiaodong LiangAbstract:There are two common forms of dynamic Load Models suitable for power system dynamic studies: a composite Load Model and a transfer function based Load Model. The composite Load Model typically refers to a combination of an induction motor and a static Load in the form of ZIP (constant impedance, constant current, and constant power) Load. In this paper, the two types of Load Models are derived for a high motor composition Load, and their performance is compared and analyzed through several case studies considering both voltage and frequency dependency of the Load Models.
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IAS - Comparative Study of Transfer Function Based Load Model and Composite Load Model
2019 IEEE Industry Applications Society Annual Meeting, 2019Co-Authors: Hla U May Marma, Xiaodong Liang, Huaguang ZhangAbstract:The composite Load Model consisting of an induction motor and a static Load has been adopted by some utility companies in practical power system dynamic studies. Another form of dynamic Load Model is the transfer function based Load Model. Although both types of dynamic Load Models are well accepted, there is no comparison done regarding their performance, and no evaluation on the influence of voltage and frequency dependency terms on the overall Model accuracy for transfer function based Load Models. In this paper, a transfer function based Load Model is developed analytically using a composite Load Model. Dynamic responses of the developed transfer function based Load Model and the original composite Load Model are compared subjected to various voltage and frequency disturbances. The transfer function based Load Model is a function of both voltage and frequency, three levels of simplifications are made to the full Model in order to evaluate the corresponding accuracy. It is found the reduced Model with both the 1storder voltage $\Delta \mathrm{V}$ term and 1storder frequency Δf term has the smallest error among the three reduced Models.
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Dynamic Load Modeling for industrial facilities using template and PSS/E composite Load Model structure CLOD
2017 IEEE IAS 53rd Industrial and Commercial Power Systems Technical Conference (I&CPS), 2017Co-Authors: Xiaodong LiangAbstract:Industrial facility Loads have significant impact on power system stability. Due to their large power demand and complicated impact on system dynamic performance, it is critical to Model them properly. Because the knowledge of industry-specific Load composition data are limited, Load Model accuracy of the current utility practice is greatly compromised. In this paper, a new dynamic Load Modeling method is proposed by combining a template of a specific type of industrial facilities and the composite Load Model structure (CLOD) in the commercial software PSS/E. This method is relatively easier to implement in PSS/E and can still achieve reasonable accuracy. The proposed method consists of three steps: 1) create a template by conducting an in-depth Load survey for a specific type of industrial facilities; 2) determine Load composition of the facility that is required by PSS/E CLOD Load Model structure using the template; 3) create a PSS/E CLOD Load Model of the facility using the Load composition data. To validate the proposed method, a case study and a sensitivity study are conducted using a real 110-megawatt (MW) Kraft paper mill facility. The case study verifies the accuracy of the proposed Model by comparing simulation results with actual field measurements of the 110 MW Kraft paper mill facility; the sensitivity study shows the robustness of the proposed Modeling method when subjected to Load parameters variation. The proposed method can serve as a generic method for dynamic Load Modeling of any type of industrial facilities.
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A new composite Load Model structure for industrial facilities
2016 IEEE IAS 52nd Industrial and Commercial Power Systems Technical Conference (I&CPS), 2016Co-Authors: Xiaodong LiangAbstract:In this paper, a new generic composite Load Model structure for industrial facilities is proposed, which consists of four main Loads, an induction motor, a synchronous motor, a motor drive system, and a static Load. This structure can be applied to existing or future industry facilities. Major factors to be considered when developing this new composite Load Model are demonstrated. To achieve the final composite Load Model for an industrial facility of interest, a two-step procedure is recommended in this paper. Step 1 is to create a power system full Model for existing or future industrial facilities. In this step, the full Model for existing facilities can be created with the known system configurations and electrical single-line diagrams; while the full Model for future industrial facilities with unknown system configurations can be created using the template-based Load Modeling technique. Step 2 is to perform effective Load aggregation in order to obtain a simplified equivalent Load Model in the format of the proposed composite Load Model structure for industrial facilities.
Ragu Balanathan - One of the best experts on this subject based on the ideXlab platform.
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Modelling induction motor Loads for voltage stability analysis
International Journal of Electrical Power & Energy Systems, 2002Co-Authors: Ragu Balanathan, Nalin C Pahalawaththa, Udaya AnnakkageAbstract:This paper deals with Modelling induction motor Loads for voltage stability analysis. A simple first order induction motor Load Model and a detailed third order induction motor Load Model suitable for this purpose are derived in terms of real power, reactive power and slip. It is shown analytically that the generic dynamic Load Models (GDLM) proposed in the literature, in their present form, are incapable of capturing induction motor characteristics. The generic dynamic Load Model is modified to capture the dynamics represented by the proposed induction motor Load Models. The appropriateness of the proposed dynamic Load Models in analysing the transient and steady state stabilities of induction motor Loads are evaluated. It is shown that the first or third order induction motor Models can be used for studying the power system voltage stability, with different degrees of accuracy.
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Influence of induction motor Modelling for undervoltage Load shedding studies
IEEE PES Transmission and Distribution Conference and Exhibition, 2002Co-Authors: Ragu BalanathanAbstract:This paper explores the influence of Modelling induction motor Loads for undervoltage Load shedding studies. A first order and a third order dynamic Load Model in terms of real power, reactive power and voltage are defined using the 'slip' and 'slip flux' induction motor Models, respectively. In a voltage unstable situation it is shown that the real power and reactive power responses of the Load Models differ, owing to the dynamic characteristics of the respective Load Model. Consequently, the amount of Load to shed at a given voltage is significantly influenced by the dynamic Load Model. The objective is to reveal how different Load Models influence the analysis and the calculation, for undervoltage Load shedding to be successful. It is also shown that the use of generic dynamic Load Models (GDLMs) to capture induction motor Loads lead to over shedding.
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Undervoltage Load shedding to avoid voltage instability
IEE Proceedings - Generation Transmission and Distribution, 1998Co-Authors: Ragu Balanathan, Nalin C Pahalawaththa, Udaya Annakkage, P. W. SharpAbstract:The paper presents a technique for undervoltage Load shedding (UVLS) in power systems. The undervoltage Load shedding criterion has been developed using a dynamic Load Model. The parameters of the dynamic Load Model are estimated online using a nonlinear least squares technique, namely the Gauss-Newton method. The amount of Load to be shed is calculated using the parameters of the dynamic Load Model. In the event of a voltage unstable situation, the proposed undervoltage Load shedding criterion can be used to calculate the minimum amount of Load to be shed at any point in time to avoid a voltage collapse. The criterion is general and can be applied to any power system.
David J. Hill - One of the best experts on this subject based on the ideXlab platform.
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Clustering of Uncertain Load Model Parameters with K-medoids Algorithm
2018 IEEE Power & Energy Society General Meeting (PESGM), 2018Co-Authors: Xinran Zhang, David J. HillAbstract:Load Model is difficult to build due to the uncertain property of power Load. Using ambient signal based Load Model parameter identification method, Load Model parameter identification can be performed very frequently and then many different identification results at different time points can be obtained. To deal with these uncertain Load Model parameters, a Load Model parameter clustering method is proposed to pick up the representative Load Model parameters from the identification results. The distances of Models used for clustering are based on the post-fault response curves to get better clustering results. K-medios clustering algorithm is applied and the cluster number is decided by the radius of the clusters. The simulation results have shown the effectiveness of the proposed Load Model parameter clustering method.
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reducing identified parameters of measurement based composite Load Model
IEEE Transactions on Power Systems, 2008Co-Authors: Dong Han, Zhao Yang Dong, David J. HillAbstract:A Load Model is one of the most important elements in power system simulation and control. Recently, the constant impedance, constant current, and constant power Load in combination with the induction motor Load have been widely used as the composite Load Model, whose parameters are all identified from the field measurements in measurement-based Load Modeling practices so far. However, there is virtually no research conducted on whether all these parameters could really be identified. This paper investigates the possibility on reducing the number of composite Load Model parameters to be identified from field measurements. This paper first shows that direct application of the IEEE Load motor parameters in the composite Load Model may be inadequate on describing the Load dynamics over different operating status. Then the perturbation method is used to derive the trajectory sensitivities of the equivalent motor parameters, based on which the reduction on the identified parameters of the composite Load Model is presented. Two cases of measurement-based Load Modeling in North China and Northeast China are studied to illustrate the validity of the reduction method. It is shown that the reduction does not lose the Model's capability on describing the Load dynamics. The reduction on the number of identified parameters not only provides a possible way to solve the multi-valued Load Model problem based on the current practices on measurement-based Load Modeling, but it also facilitates building of the Load Model with more components included in it. Meanwhile, reducing the identified parameters reduces the identification time; thus, the proposed strategy significantly enhances the efficiency of the Load Modeling work.
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Composite Load Modeling via measurement approach
2006 IEEE Power Engineering Society General Meeting, 2006Co-Authors: David J. HillAbstract:Summary form only given. The accuracy of the Load Model has great effects on power system stability analysis and control. Based on our practice in China on Modeling Load from field measurements, this paper systematically develops a measurement-based composite Load Model. Principles guiding the Load Modeling practice are discussed based on detailed analysis on stochastic characteristics of Modeling procedure. The structure of the measurement-based composite Load Model is presented. A multi-curve identification technique is described to derive parameters. The generalization capability of thus built Load Model is also investigated in the paper. Two cases are studied to illustrate the accuracy of the developed Load Model on describing the Load dynamic characteristics in the actual power system.
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Composite Load Modeling via measurement approach
IEEE Transactions on Power Systems, 2006Co-Authors: H. Renmu, Ma Jin, David J. HillAbstract:The accuracy of the Load Model has great effects on power system stability analysis and control. Based on our practice in China on Modeling Load from field measurements, this paper systematically develops a measurement-based composite Load Model. Principles guiding the Load Modeling practice are discussed based on detailed analysis on stochastic characteristics of the Modeling procedure. The structure of the measurement-based composite Load Model is presented. A multicurve identification technique is described to derive parameters. The generalization capability of this built Load Model is also investigated in this paper. Two cases are studied to illustrate the accuracy of the developed Load Model on describing the Load dynamic characteristics in the actual power system.
Yue Yuan - One of the best experts on this subject based on the ideXlab platform.
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Load Model for prediction of electric vehicle charging demand
Power System Technology (POWERCON), 2010 International Conference on, 2010Co-Authors: Qian Kejun, Malcolm Allan, Zhou Chengke, Chengke Zhou, Kejun Qian, Yuan Yue, Yue YuanAbstract:Increasing environmental concerns, the decarbonisation of future auto industry, the consequent regulatory requirements and the depletion of oil have made the fuel independent battery electric vehicle (EV), with zero emission increasingly more attractive as practical and economical alternative to the gasoline fuelled car. The expected increasing number of EV connected to power systems for charging will have significant impact on power systems, such as generation capacity, transformer Loading level, line congestion level and Load profile, among which, the impact of EV charging Load on the system Load profile claims most attention. This paper develops a methodology to determine the EV battery charging Load on the power system Load profile. Three scenarios were simulated, comprising uncontrolled charging, controlled off-peak charging and smart charging. The proposed method in this paper takes into account the initial state of charge and start time of EV battery charging. Results show that uncontrolled charging will impose a new peak to the system and may cause congestion issues to local network. Controlled off-peak charging can shift EVs charging Load to an off-peak time, however, EV can also introduce a new peak or near peak in early off-peak time. Smart charging method which optimises the start time of EVs charging is the most beneficial charging method to both distribution network operator and EV users.
Xiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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simulating low velocity impact induced delamination in composites by a quasi static Load Model with surface based cohesive contact
Composite Structures, 2015Co-Authors: Jikui Zhang, Xiang ZhangAbstract:Abstract In this paper, a computationally efficient finite element Model is presented for predicting low-velocity impact damage in laminated composites using a quasi-static Load Model with surface-based cohesive contact. The effect of compressive through-thickness stress on delamination is taken into account by introducing contact friction force in the shear force direction. Damage onset and propagation in a cross-ply plate [90 3 /0 3 ] S is simulated and the numerical results agree well with the experimental observation in terms of damage location, shape and size. Through-thickness stress analysis shows that resistance to the upper interface delamination propagation is mainly contributed by the friction force due to the high compressive through-thickness stress, whereas, for the lower interface, it is the cohesive behaviour that controls the delamination initiation and propagation. Predicted delamination area is not sensitive to the interlaminar friction coefficient when it is greater than 0.6. The range of friction coefficient of the interlaminar contact is recommended to be between 0.6 and 0.9.
