Online Voltage Security Assessment in the Hellenic Interconnected System (original) (raw)
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Application of Real-Time Voltage Security Assessment to the Hellenic Interconnected System
This paper describes the on-line Voltage Security Assessment methods implemented at the national control center of the Hellenic Interconnected System, within the framework of the OMASES project funded by the European Union. The heart of all computations is a fast time-domain method. Security is analysed with respect to power transfers in critical corridors or power consumption in load areas. Results take on the form of either pre-contingency secure operation limits, or post-contingency loadability limits, together with various diagnosis tips. Contingency filtering is performed to meet the real-time requirement. Typical results obtained during the test phase of the project are reported.
2006
Abstract:[en] Voltage instability is widely recognized as a significant threat of power system blackout. As far as real-time operation is concerned, there is a need for appropriate tools to identify dangerous contingencies and assess security margins. The Hellenic Interconnected System presents a structural geographical imbalance between the main generation site and the main load center. This imbalance leads to bulk power transfers over long distances leading to voltage stability problems in areas of the southern system during heavy load ...
Investigation of parameters affecting voltage security of the Hellenic interconnected system
2005
Abstract:[en] The Hellenic Interconnected System pre-sents a structural geographical imbalance between generation sites and load centers. This imbalance leads to bulk power transfers on long electrical distances leading to voltage stability problems. In order to improve the opera-tional practices aiming at improving the voltage security, an on-line Voltage Security Assessment tool has been installed at the National Control Center of the Hellenic Transmission System Operator that operates and controls the interconnected ...
Contingency evaluation for voltage security assessment of power systems
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The demand for electricity is expected to continue to increase given the recent world population projection of about 30% increase in the next three decades. Consequently power systems are equally expected to be more heavily loaded than before. Unfortunately the environmental and economic constraints restrict the expansion of the existing power system facilities. This scenario requires a constant attention since it could result to voltage collapse which could in turn lead to a total blackout. This paper presents the procedure required to carry out a contingency assessment and ranking of the load buses and lines of power systems for voltage security. This would ensure that power systems are operated above a desired voltage stability margin to forestall voltage collapse. The impact of single line outage contingency on the static voltage stability margin, as well as the available transfer capability across the areas of the test system, are examined in the paper.
An advanced tool for preventive voltage security assessment
2000
Summary. This paper deals with methods for the preventive assessment of voltage security with respect to contingencies. We describe a computing tool for the determination of secure operation limits, together with methods for contingency filtering. Examples from two very different real-life systems are provided. We outline extensions in the field of preventive control. ... Keywords. Voltage security assessment, contingency analysis, contingency filtering, preventive control ... In the recent past, a significant number of incidents throughout the world have resulted in ...
Linear and nonlinear methods for contingency analysis in on-line voltage security assessments
2009 IEEE Power & Energy Society General Meeting, 2009
The strategy of using an effective scheme to screen out a large number of stable contingencies and to apply detailed simulation programs only to potentially unstable contingencies is well recognized. This strategy is implemented in on-line voltage security assessment (VSA). This paper presents a hybrid of linear, quadratic and nonlinear methods for on-line VSA. Linear methods are fast but may not be sufficiently accurate while nonlinear methods are accurate but may not be sufficiently fast. To meet the demands of speed and accuracy for online application, the hybrid of three methods for performing screening, ranking and detailed analysis is thus developed and applied to the CAISO system with promising results.
Security assessment of power systems
1975
A review of the state of the art in assessing the security of power system operations is provided. Emphasis is placed on the overall philosophy of preventive system operation, and the computational and data acquisition systems required for on-line monitoring and analysis of system security. Critical comparison of various approaches is provided. Recommendations for effective security assessment for a single company, es well as, an interconnection are provided. Furthermore, industry practices and guidelines in the area of system security are presented and commented upon. * The decomposition here is not unique since some utilities would use "Security Monitoring" to mean both of these primary functions. However, we are adopting tivse definitions to be consistent with DyLiacco.0')
On multi-area security assessment of large interconnected power systems
Proceedings of the Second Carnegie Mellon Conference in Electric Power Systems: Monitoring, Sensing, Software and its Valuation for the Changing electric Power Industry, 2006
The paper introduces a framework for information exchange and coordination of security assessment suitable for distributed multi-area control in large interconnections operated by a team of transmission system operators. The basic idea of the proposed framework consists of exchanging just enough information so that each operator can evaluate the impact in his control area of contingencies both internal and external to his area. The framework has been thought out with the European perspective in mind where it is presently not possible to set up a transnational security coordinator that would have authority to handle security control over the whole or part of the European interconnection. Nevertheless, it can also be considered as an approach to handle security control in North-American Mega-RTOs, where it could help to circumvent problems of scalability of algorithms and maintainability of data by distributing them over the TSOs under the authority of the RTO.
On-Line Stability and Dynamic Security Assessment of Electric Power Systems
IFAC Proceedings Volumes, 1985
/) ('/111111111' 111 "/ F il'lll';ut! { lIgi lll'n;lIg. [ •II;"I' nil." 11/ U i'g('. SlIrl• '!'iilllllll 1i28. Ii. / I}{){) 1.;I'gl'. 1i('lgilllll Abs tract. Security func ti ons des i gned for on-line use in modern control centers are f ir st considered and steady-state functions ar e scanned. Missing dynamic functions are then identified and related methods recently proposed reported. Particular attention is focused on t ransient stability issues : practical direct criteria are reviewed , and stability indices for on-li ne analysis and control ar e ass essed. Finally , a list of promising new theoretical approaches is tentatively g iven .
International Transactions on Electrical Energy Systems, 2019
In power systems operation and control rooms, the operator must not only supervise the system but also issue commands in order to ensure that the system meets certain security criteria. However, they are generally blind about the influence of several control variables on the system response. This paper presents an efficient probabilistic security region construction tool for this situational awareness problem, meeting the time constraints of an online application by using parallel computing. Besides, a tabu list algorithm has been introduced into the Monte Carlo simulation so that only nonvisited operating points are actually evaluated. Results for the Brazilian Interconnected Power Systems on different load conditions will be presented and compared with the ones obtained with the conventional voltage security assessment tool to illustrate the feasibility of this tool in the online environment. By visualizing the probabilistic voltage security assessment nomogram, the operator can take adequate corrective actions according to the level of risk the system is running into or even take no action at all if the operating procedures allow it.