Stochastic Approach For Modeling Arcing Faults In Cables From Experimental Data

o This paper discusses stochastic arcing fault models developed based on examination of test data conducted at shipboard system voltage levels by the US Navy at KEMA-Power Test, Inc. The arc model resistance had a typical mean value based upon physical parameters of the particular class of test and a random variation around this mean value. Models were developed for arcing faults on both on AC and DC systems. The models were developed using ACSL (Advanced Continuous Simulation Language) and veried with the test data results so the arcing fault models could be included in simulations of shipboard power systems for conducting fault studies to set protective devices and rate apparatus. The main objective of the model development was to match the ratio of arc voltage to fault current between the test data and the simulation results. randomly variation around this value. This model was used develop simulation cases to match the results of experimental tests on several classes of ac and dc cables proposed for use in shipboard power systems. The project sponsors will insert the resulting arcing fault models into simulation models that include detailed representatiions of the shipboard power system and conduct fault studies. The results of these stud- ies will be used to determine magnitudes of fault currents and resulting voltages on system components to rate circuit breakers, rate insulation and overvoltage devices, and to set protective devices. The Advanced Continuous Simulation Lan- guage (ACSL) (6) was used for the detailed shipboard power system model, so the arcing fault models are developed in ACSL as well. The models have also been implemented in using FORTRAN statements in the control system modeling language in an emtp-type program as well. Section II of the paper provides background on the high voltage hardware testing. Section III describes other methods for modeling arcing faults. Section IV introduces the stochastic model. Sections V and VI describe the power system repre- sentation in the simulation model and show simulation results for several cases. Section VII describes the model verication.