A DC Arc Model for Series Faults in Low Voltage Microgrids

Abstract

Abstract-This paper presents a dc arc fault model to simplify the study of a critical issue in dc microgrids: series faults. The model is derived from a hyperbolic approximation of observed arc voltage and current patterns, which permit analyzing the arc in terms of its resistance, power, energy, and quenching condition. Recent faults staged by the authors on a dc microgrid yielded enough fault data to develop an arc model. These faults were of three types: constant-gap speed, fixed-gap distance, and accelerated gap. The results in this paper compare experimental and simulation results for the three fault types. It is concluded that because the instantaneous voltage, current, power, and energy waveforms produced by the model agree well with experimental results, the model is suitable for transient simulations.

Development of Fault Detector for Series Arc Fault in Low Voltage DC Distribution System using Wavelet Singular Value Decomposition and State Diagram

“…Some researchers have been developed arc model from a hyperbolic approximation of the arc's dynamic component of voltage and current. This arc model can be considered as a right model because the instantaneous current behavior of the arc model is consistent with experimental results and we can see this in [18]. For example, there is a consistent decrease in the gap current while the exact magnitude and position of the individual spikes appear to be random.…”

“…As we can see in Fig. 4 and 5, simulation results of implemented model correspond well with those of reference [18] and it is clear that modeling for the series arc fault using EMTP/MODELS is effective and appropriate.…”

“…EMTP/ MODELS is very useful when generating user-defined signals with specific logic. We consider two fault cases; 'fixed gap distance fault' which represents fault where the electrodes remain stationary after reaching a predetermined distance and 'constant gap speed fault' which represents conductors tearing longitudinally at a constant speed [18]. For each fault cases, variable q, representing arc random characteristic, is controlled differently according to the logic indicated in the pseudo code.…”

“…3, the random() is a function which returns a random value between 0 and 1. [18]. Variables used in modeling are equal to those in [18] to verify the performance of the series arc fault modeling using EMTP.…”

“…[18]. Variables used in modeling are equal to those in [18] to verify the performance of the series arc fault modeling using EMTP. We present only system current waveform because system current signal can be used only due to arbitrary location of the series arc fault.…”