Interfacing Techniques for Transient Stability and Electromagnetic Transient Programs IEEE Task Force on Interfacing Techniques for Simulation Tools

Aristidou

2014 Power Systems Computation Conference

et al. 2014

Abstract-This paper deals with a new scheme for coupling phasor-mode and electromagnetic transients simulations. In each simulation, an iteratively updated linear equivalent is used to represent the effect of the subsystem treated by the other simulation. Time interpolation and phasor extraction methods adapted to this scheme are presented and compared to existing methods. Finally, simulation results obtained with a 74-bus test system are reported.

Section: Introductionmentioning

confidence: 99%

A relaxation scheme to combine phasor-mode and electromagnetic transients simulations

Aristidou

2014 Power Systems Computation Conference

et al. 2014

“…Significant advances have been made in hybrid PM-EMT simulation as testified by the state-of-the-art report in [2]. However, there is still room for improvements to reach the targeted speed-accuracy compromise.…”

Section: Introductionmentioning

confidence: 99%

On the convergence of relaxation schemes to couple phasor-mode and electromagnetic transients simulations

2014 IEEE PES General Meeting | Conference &Amp; Exposition

Cutsem

2014

Abstract-Hybrid simulations combining phasor-mode and electromagnetic transients models aim at taking advantage of computational speed of the former and accuracy of the latter. For simulation accuracy, a relaxation process is used, which consists of iterating between both models. The convergence properties of this relaxation process are investigated. The speed of convergence is assessed when the variables exchanged at the interface between both models are respectively pure voltage/current sources, Norton/Thévenin equivalents, or a combination of them. Iteratively updated Norton/Thévenin equivalents are shown to drastically reduce the number of relaxation iterations.

“…1.b, consists of a current source to represent the EMT sub-system, while a Frequency Dependent Network Equivalent (FDNE) admittance in parallel with an ideal current source is used to replace the PM subsystem. This representation is more accurate and valid over a wider frequency range, thus allowing to move the PM-EMT boundary closer to the disturbance location without degrading accuracy [8]. A variant of the latter is shown in Fig.…”

Section: A Short Review Of Boundary Conditionsmentioning

confidence: 99%

“…[6], [7]). A comprehensive literature review can be found in [8]. A drawback of many proposed methods is the relatively small size of the EMT sub-system considered, mainly for performance reasons.…”

Section: Introductionmentioning

confidence: 99%

Co-Simulation of Electromagnetic Transients and Phasor Models: A Relaxation Approach

Aristidou

IEEE Trans. Power Delivery

et al. 2016

Abstract-Co-simulation opens new opportunities to combine mature ElectroMagnetic Transients (EMT) and Phasor-Mode (PM) solvers, and take advantage of their respective high accuracy and execution speed. In this paper, a relaxation approach is presented, iterating between an EMT and a PM solver. This entails interpolating over time the phasors of the PM simulation, extracting phasors from the time evolutions of the EMT simulation, and representing each sub-system by a proper multiport equivalent when simulating the other sub-system. Various equivalents are reviewed and compared in terms of convergence of the PM-EMT iterations. The paper also considers the update with frequency of the Thévenin impedances involved in the EMT simulation, the possibility to compute the EMT solution only once per time step, and the acceleration of convergence through a prediction over time of the boundary variables. Results are presented on a 74-bus, 23-machine test system, split into one EMT and one PM sub-system with several interface buses.