Study of the Detection Method of Series AC Arc Faults Based on High-frequency Zero-sequence Current Coupling Signal

Arc fault is one of the main causes of electrical fire hazards. Most research is mainly based on current signals to detect arc faults. However, load type and other factors easily affect the current signal, which easily causes missed judgment and misjudgment of switches. To solve this issue, this paper proposes a detection method based on the high-frequency zero-sequence current coupling signal for low-voltage series AC arc faults. First, an experimental platform was built for low-voltage series AC arc fault according to the IEC 62606 standard, and the high-frequency zero-sequence current coupling signal of ten typical loads under different line conditions was collected. Then, the characteristics of zero-sequence current under different loads and line conditions were analyzed, and the arc fault detection algorithm was developed according to the different characteristics of the line’s normal and arc-fault states. Finally, the effectiveness, stability, and applicability of the arc fault detection method were verified by various experimental conditions with a prototype. The result shows that the detection accuracy of the presented method is about 98%, which has a certain guiding significance for the development of arc fault detection devices.

I. Introduction

The arc fault is the main cause of electrical fire hazards. The temperature of the arc column center is above 4000℃ [1], which easily ignites ambient combustible material and causes fire hazards. According to the data from China National Fire and Rescue Administration, the number of nationwide fire hazards in residential premises was 1324 thousand from 2012 to 2021, and the proportion of fire hazards caused by electrical faults is 42.7% [2]. According to the position of occurring arc faults in the distribution network, arc faults can be divided into series and parallel arc faults. The loop current will increase when a parallel arc fault occurs in the line. Therefore, traditional protection switches, such as miniature circuit breakers, can timely break the faulty branch. However, the arc current is lower than the normal loop current when a series arc fault occurs in the line, so the traditional protection switches can not timely detect the series arc fault [3] - [5]. The concealment of series arc faults makes it the prime culprit of many electrical fire hazards.