Fault Analysis of the Mid-point Grounding with Capacitors in Unipolar LVDC System

초록

Low voltage DC (LVDC) systems have been gaining increasing attention for improving energy efficiency and electrical safety. Compared to AC systems, using LVDC systems in residual households present many advantages, such as low energy conversion losses in home appliances operated with DC power. Thus, there have been many studies aimed at developing LVDC systems. Among them, the grounding system of LVDC system is a different research field because there are many differences from AC systems. In particular, the DC grounding system has different characteristics in terms of sensing, corrosion, etc. Therefore, this study presents an analysis of the fault characteristics in unipolar LVDC systems when a combination of capacitors and resistors were used as a mid-point grounding. Through fault tests according to the element configurations of mid-point grounding and the fault resistance, the change in the fault current characteristics caused by capacitor discharging could be confirmed. Through the analysis, it is considered that mid-point grounding with resistors and capacitors has many benefits, such as better human safety and system protection.

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