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Increasing uncertainties in power system operation require novel approaches for utilizing operational flexibility to enable a both secure and efficient power supply. This paper presents a real-time coordination approach for adaptive redispatch of generation and load in case of overloads in the electrical transmission network. For this, a previously developed multi-agent system for coordinating power...
In order to enhance the system operator's awareness of the remaining margins towards critical system states in the transmission system the P/V-Analysis is a suitable tool for the on-line security assessment. This paper presents a method to reduce the computational effort needed to meet the stringent time constraints of the control room environment. It is shown how the information from the P/V-Analysis...
In many power systems, fluctuating in-feed contributes a big share of total energy produced. This means new challenges to operate the system securely. In this paper, a risk-based method for security assessment of power systems is presented. The method takes the probability and severity of contingencies into account. The method proposed considers also the forecast errors of fluctuating in-feed and...
In both restructured and vertically integrated power systems, it is desirable to transmit power to remote locations without causing any congestion and consequently avoiding inefficiency in generation dispatch. In this paper, in order to relieve network congestion, transmission switching is employed as a powerful tool to change network topology which consequently yields lower energy prices and higher...
Considering aging power system infrastructures in conjunction with increased electricity trading activities, there is a strong need for future investments in electricity grids. Technological progress has made available a number of different investment alternatives, ranging e.g. from “standard” reinforcements of existing transmission capacities to the installation of Flexible AC Transmission Systems...
In the literature many methods for overload relieving have been reported for determining a secure operating point. Most of these methods use conventional optimization techniques, which are generally time - consuming from a computation point of view, especially for large systems. Further the conventional optimization technique updates all the controllers for most of the operating conditions. Under...
This paper presents an optimal power flow (OPF) model which maximizes system security. Loading factor has been chosen as objective function of OPF problem to enhance system security. It is demonstrated that available transfer capability (ATC) is a suitable criterion for evaluation of system security. In addition, this concept is consistent to ISO requirements for system operation. On the other hand,...
This paper proposes a composite security index for the on-line critical contingency selection and ranking in terms of both the line flow and bus voltage limit violations. In order to evaluate the vector valued security index, a scalar index is derived based on the concept of hyper-ellipse inscribed within a hyper-box. The proposed index, which provides an efficient method for filtering and ranking...
Power grids have traditionally been planned and operated to withstand without resulting in cascading events transmission outage contingencies of the N-1 or N-2 kind. However, in actual operation, power grids are potentially vulnerable to cascading outages. Reliable operations therefore require a risk-based approach to monitoring and managing the probability and impact of potential cascading outages...
Deregulation of electric power industry has affected its overall operation, which in turn has altered the pricing strategy. In this paper, we present a suitable pricing system for this emerging environment. The proposed multi-objective OPF gives optimum pricing while incorporating voltage stability, security and reliability constraints. Voltage stability constraint is included to ensure the stability...
This paper presents principles and results of dynamic testing of an SRAM-based FPGA using time- resolved fault injection with a pulsed laser. The synchronization setup and experimental procedure are detailed. Fault injection results obtained with a DES crypto-core application implemented on a Xilinx Virtex II are discussed.
Cryptographic devices are recently implemented with different countermeasures against side channel attacks and fault analysis. Moreover, some usual testing techniques, such as scan chains, are not allowed or restricted for security requirements. In this paper, we analyze the impact that error detecting schemes have on the testability of an implementation of the advanced encryption standard, in particular...
This paper addresses the congestion management problem avoiding offline transmission capacity limits related to stability. These limits on line power flows are replaced by optimal power flow-related constraints that ensure an appropriate level of security, mainly targeting voltage instabilities, which are the most common source of stability problems. Results from an illustrative case study based on...
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