George J. Cokkinides

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(PSERC) is a multi-university Center conducting research on challenges facing the electric power industry and educating the next generation of power engineers. More information about PSERC can be found at the Center's website: Notice Concerning Copyright Material PSERC members are given permission to copy without fee all or part of this publication for(More)
This paper presents the application of the virtual test bed for visualization and animation of protective relaying problems. The development of protective relaying animation and visualization objects as well as the interfacing with the virtual test bed is described. Two examples of protective relaying animation are presented: (a) modified mho relays and (b)(More)
GPS-synchronized equipment (PMUs) is in general higher precision equipment as compared to typical SCADA systems. Conceptually, PMU data are time tagged with accuracy of better than 1 microsecond and magnitude accuracy that is better than 0.1%. This potential performance is not achieved in an actual field installation due to errors from instrumentation(More)
Present state estimator performance is not 100% reliable. Specifically, there is significant probability that the state estimators may not converge to an acceptable solution. On an industry wide basis, the probability of non convergence is about 5%. The reasons for this performance have been investigated and have been reported in earlier papers. In this(More)
In a deregulated environment, independent generators and utility generators may or may not participate in the load-frequency control of the system. For the purpose of evaluating the performance of such a system, a flexible method has been developed and implemented. The method assumes that load frequency control is performed by an ISO based on parameters(More)
The evolution of software engineering, multitasking environment, object oriented programming and symbolically assisted simulation methods have enable the creation of interactive simulation environments that come close to providing a virtual experience of the actual system. The initial attempts at utilizing this technology are impressive and yet the degree(More)
DRF data are useful for post mortem analysis of system disturbances. Central to this problem is the response of relays to disturbances. This paper presents an improved method for post-mortem analysis of relay response to disturbances from DFR data. Specifically, a visualization application for the operation of protective relays using digital fault recorder(More)
This paper presents the architecture as well as example applications of the Virtual Test Bed (VTB). The VTB is a simulation environment being developed as a virtual prototyping t ool for modern electric power distribution systems, with emphasis on power electronics. The VTB is built around an efficient and flexible network solver, an advanced visualization(More)