Power System Research

Presented at the 2011 IEEE 33rd International Telecommunications Energy Conference (INTELEC) October 2011:

Open Series Fault Comparison in AC & DC Micro-Grid Architecture

Image of an open series arc fault in a 217 V rms ac system

The paper, “Open series fault comparison in ac & dc micro-grid architectures,” coauthored by Hunter Estes, Alexis Kwasinski, Robert Hebner, Fabian Uriarte, and Angelo Gattozzi and presented at the 2011 IEEE 33rd International Telecommunications Energy Conference (INTELEC) in Amsterdam, The Netherlands in October 2011 explores empirical observations of open series fault (arc fault) testing during current interruptions. Emphasis is on dc systems, but arc behavior is also compared to that of ac systems under “quasi-equivalent” circuit parameters. Specific parameters that are considered regarding arc behavior include gap voltage, current, dissipated power, voltage and current transient characteristics, reignition, bus disturbances, and contact position during dc arc collapse. Based on these results, comparisons between ac and dc systems seem to indicate that different arc-related challenges exist for both dc and ac architectures. Please contact Robert Hebner, for more information.

Presented at the 2012 IEEE PES Innovative Smart Grid Technologies Conference in Washington, DC January 2012:

Analytical Description of a Series Fault on a dc Bus

Comparison of theoretical results with test data for the case of a gap opening at a uniform velocity of 0.1”/s

In the paper, “Analytical description of a series fault on a dc bus,” coauthored by Angelo Gattozzi, John Herbst, Fabian Uriarte, and Robert Hebner and presented at the 2012 IEEE PES Innovative Smart Grid Technologies Conference in Washington, DC in January 2012, the solution of the equations of a dc circuit containing an arc is given and compared with experimental data. The arc is modeled according to its classical equivalent circuit and the adequacy of this model is discussed. The analytical solution for the circuit with an opening gap is given for the case of a constant gap and the results are extended to the cases of a gap opening with uniform velocity and a gap opening with constant acceleration, under the assumption of a quasi-static approximation for which the limits of applicability are estimated. Voltage and current evolutions in time are derived, including an estimate of the arc duration and quenching time. The results are compared to experimental data. Also provided is a generalized view of the transient behavior of an arc in a circuit that extends the description commonly used, in terms of only a voltage-current relationship, by also including inductive effects. Please contact Angelo Gattozzi, for more information.

Development of a Series Fault Model for DC Microgrids

Image of an open series arc fault in a 217 V rms ac system

Series faults are self-sustained arcs produced in series with the normal path of supply power. The electromagnetic transients produced by these series faults are of interest during the design and analysis of existing and forthcoming dc microgrids. The paper, “Development of a series fault model for dc microgrids,” coauthored by Fabian Uriarte, Hunter Estes, Tom Hotz, Angelo Gattozzi, John Herbst, Alexis. Kwasinski, and Robert Hebner and presented at the 2012 IEEE PES Innovative Smart Grid Technologies Conference in Washington, DC in January 2012, presents a preliminary series fault simulation model to predict the electromagnetic transients introduced by series faults. Experimental results are compared with simulation results. The simulation results show the random nature of the arc, quenching attempts, arc energy consumption, and the influence of inductive loads. Please contact Fabian Uriarte, for more information.