Because of the great harm caused by fault arc, as early as in the 1930s, foreign countries, especially Europe and The United States and other developed countries have carried out in-depth theoretical research on the characteristics of fault arc by establishing mathematical models of arc.In the 1990 s, some scientists through near fault arc often accompanied by sound, light, heat, electromagnetic radiation, and physical phenomena such as pressure, temperature, sound, light and pressure sensors, such as making the arc fault detection system, but the system is mainly used for preventing arc fault in low-voltage switchgear, for arc fault in power distribution lines,Due to its low current, weak physical phenomenon, and difficult to predict the location of arc ignition, these characteristics greatly increase the difficulty of fault arc detection in low-voltage distribution lines.
With the deepening of the research, relevant experts found that the current and voltage waveform in the line will change correspondingly when the fault arc occurs in the distribution system, so they began to turn to the research on the detection technology of arc current and voltage.After more than ten years of development, great breakthroughs have been made in the development of Arc detection devices, especially since the United States was the first to issue the UL1699 standard used to regulate AFCI products (Arc Fault Circuit breaker,Arc Fault Circuit Interrupt) in 1999.It greatly promotes the development of arc fault detection technology.
In China, the 2014 domestic standard GB14287.4 electrical Fire Monitoring System part 4:Fault arc detector and JB/T11681 General Requirements for Arc Fault Detection Device (AFDD) have been released successively, which greatly promote the research and development of fault arc monitoring device in China, accelerate the market development of this kind of products, and improve the monitoring deployment in the field of electrical fire prevention in China.
General application of fault arc detectors
According to GB14287.4, fault arc detector is suitable for industrial and civil electrical lines of 10kW and below.
Gb50116-2013 “Automatic Fire Alarm System Design Code” in 9.2.4 provisions: “with the function of detecting line fault arc electrical fire monitoring detector, its protection line length should not be more than 100 meters.Gb50116-2013 explains in article 9.2.4: “The line length between the electric fire monitoring detector and the protected object that detects the fault arc function of the line determines whether the detector can reliably detect the fault arc, so this article is stipulated.”
Gb50116-2013 “Automatic Fire Alarm System Design Specification” in 12.4.6 provisions: “electrical lines should be set up electrical fire monitoring detector, lighting line should be set up with fault arc detection function of electrical fire monitoring detector.Part of the explanation of article 12.4.6 in gb50116-2013:”Lighting line fault caused by fire accounted for about 10% of the electric fire, this kind of building is higher, the top of a fire is not easy to find, can’t set other detectors, on which the only set which has the function of detection of arc fault electrical fire monitoring detector, to ensure effective fire detection caused by illumination line fault”.
According to the provisions and requirements of the above national standards, the current fault arc detector is generally used in lighting lines with a length of less than 100 meters.However, with the continuous practice and development of fault arc detection technology, its application will continue to expand, including all kinds of power lines, household distribution lines, power supply lines of public facilities, etc., are the future application objects.
Future development direction of fault arc detector
In general, foreign arc-electric fire detection technology has become increasingly mature, and related products have been on the market for many years, but the false alarm rate of detection devices still restricts the promotion and popularization of products.The domestic research on arc electric fire detection technology is not very mature, and the related products launched by some companies have yet to be tested in the market, so there is still a lot of space for the development of arc electric fire detection technology.
The research of arc electric fire detection technology aims to reduce the occurrence of electric fire by developing a detection device that can effectively prevent arc electric fire.Then the accuracy, reliability and real-time detection are very important, and future products should be further studied and improved in these three aspects.
