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Early detection of faults in stator winding is crucial for reliable and economical operation of induction motors in industries. Whereas major winding faults can be easily identified from supply current magnitude, minor faults involving less than 5% of turns are not readily discernible. The present work documents experimental results for monitoring of minor short circuit faults in stator windings of...
Along with the large-scale implementation of distributed generators, the current distribution networks have changed gradually from passive to active operation. State estimation plays a vital role to facilitate this transition. In this paper, a suitable state estimation method for the active network design is proposed. The method takes advantages of the multi-agent system technology to compute iteratively...
Due to the energy challenges in the world, new types of generation technologies, such as renewable energy based generators, attract great attention and are being quickly developed, which results in the dramatic developments and changes in modern power systems, the communication technologies play a increasingly important role in guaranteeing the power system's stability, reliability, and security....
A methodology based on data mining techniques to support the analysis of zonal prices in real transmission networks is proposed in this paper. The mentioned methodology uses clustering algorithms to group the buses in typical classes that include a set of buses with similar LMP values. Two different clustering algorithms have been used to determine the LMP clusters: the two-step and K-means algorithms...
Database generation for training is a critical aspect of the performance of data mining based power system reliability studies. Traditionally, Monte Carlo sampling of operational parameters are done to form various base cases and contingency analysis is performed to obtain the training database. This paper proposes an efficient sampling strategy that maximizes information content while minimizing...
Distribution Systems traditionally have a tree-like structure with several branches. They supply loads that vary through the day and as a result, some branches are loaded more than others are. By reconfiguring the system, loads from the overloaded branches may be moved to under-loaded branches. Consequently, loads in the branches can be balanced so that the real power losses are reduced and the voltage...
This paper presents an efficient security assessment system for validating power system operation planning, which has been used in Henan provincial power grid in China. Daily operation planning is to schedule unit commitment and to dispatch generator output economically considering next day generators and transmission components' maintenance planning. The security assessment for validating the daily...
This paper presents a new algorithm, Function Optimisation by Reinforcement Learning (FORL), to solve large-scale and complex function optimisation problems, in particular for those in a high-dimensional space. FORL undertakes the dimensional search in sequence, in contrast to evolutionary algorithms (EAs) which are based on the population-based search, and has the ability of memory of history incorporated...
With the advancement of sensor, communication and information technologies, Wide Area Monitoring, Protection and Control (WAMPAC) systems have been identified as the new generation of solutions to improve power system planning, operation, and maintenance. With huge amount of real-time data collected through distributed sensors deployed in a wide area, effective information presentation has become...
This paper presents an early warning and preventive control system for dynamic security, which has been used in several provincial power grids in China. The framework and the main modules of the proposed system are introduced. The system architecture is based on a Multi-agent system which is developed by our team. The modules like on-line contingency assessment, total transfer capacity evaluation,...
This paper presents the implementation of distributed energy resource management in smart grid operation. The approach utilizes the advantages of using multi agent systems for profitable operation of a smart grid in the energy market. The trading strategy adopted for the continuous double auction is a profit-maximizing adaptive bidding strategy based on risk and competitive equilibrium price prediction...
Dynamic voltage stability analysis demands a large amount of computing power because of the higher degree of model details and the longer simulated time span. In order to perform voltage stability analysis during operation - so called on-line dynamic voltage stability assessment - and to help the operator with the results to make the right decision, these analyses have to be performed rapidly within...
A smart grid is capable of integrating a broad array of generation resources and enables the participation of demand side resources in reliable system operation. To cost effectively realize this flexibility, the associated devices and systems need to connect and interact simply and reliably. Interoperability is the important ingredient to make this happen. Because the electric system transcends organizational...
Modern power grids with their physical current-carrying components and the embedded computer, communication and control networks are fast emerging as one of the largest and most complex cyber-physical systems. The addition of more sensing, communication, variable power sources and storage under the renewable energy thrust and smart grid initiative will add even higher orders of dimensionality and...
This paper presents the practical experience of the Brazilian System Operator with the online dynamic security assessment. More specifically, it describes the adopted models, analytical methods and functions, performance, EMS integration, user interface and implementation issues. Examples of situations in which the online security assessment was very useful are also shown.
Partial discharges (PDs) of power transformers can be measured via ultra high frequency (UHF) technique. Under the integrated condition monitoring and diagnostics framework of HOMIS (Optimal Maintenance Information System for Hydro power stations), an UHF PD monitoring system was developed for power transformers. The system is composed of internal UHF sensor installed in the oil tank, an amplifier...
In this paper, an Artificial Neural Network (ANN) based method is developed for quickly estimating the long-term voltage stability margin. The investigation presented in the paper showed that node voltage magnitudes and the phase angles are the best predictors of voltage stability margin. Further, the paper shows that the proposed ANN based method can successfully estimate the voltage stability margin...
The complex system architecture required to support smart grid technology introduces an undetermined level of risk in power systems. Many current techniques to evaluate cyber specific risk fail to scale to such a large environment. While attack graphs and trees are frequently used to model system security, both approaches require the ability to predict potential attack vectors. Access graphs have...
Utilities world over use decision support tools based on in-premise software with standalone architecture and suffer vulnerability when needing to extend their application to meet new business requirements. Accessibility of these applications are limited to specific operating environments resulting in restricted information being available at the right place and time to support decision making. Unlike...
This paper presents a practical approach in which smart meters with communication ports for third party integration in a high rise building that could be supplied with distributed energy sources, and can share the data to both local building management system and the utilities at the same time. Some examples will be used to demonstrate the capability of the approach.
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