Views: 160 Author: Site Editor Publish Time: 2021-02-02 Origin: Site
In distribution lines, power cables, switch cabinets, and overhead lines, grounding faults and short circuit faults often occur. In order to facilitate maintenance personnel to find fault points, we need to install automated short circuit fault indicators in the cable.
In the ring network distribution system, especially in the system where a large number of load switches are used, the upper-level power supply system must diagnose within the specified time to prevent major accidents if the short-circuit fault or ground fault occurs in the lower level distribution network system. The advanced earthing and short-circuiting device can mark the fault part and the maintenance personnel can find the fault section quickly according to the alarm signal to disconnect the fault section, so as to restore the power supply of the fault-free section in time. It has to be admitted that this method can save a lot of working time and reduce blackout time and scope.
The accurate short circuit fault indicator consists of sensors and displays. The sensor is responsible for detecting the current passing through the cable and the display part is responsible for judging the current information transmitted by the sensor and making fault indication action. After the digital short circuit fault indicator is installed on the cable, all the indicator lights on the corresponding line will flash because of the fault current in the line from the fault point to the feed point. Follow the line where the reliable short circuit fault indicator is flashing and the last flashing point is the fault point. It is an effective way to improve the operation level and accident handling efficiency of the distribution network.
l Digital earthing and short-circuiting devices originated in Germany in the 1980s, which is used to indicate the path of short-circuit current flowing through a power line to help people find fault points.
l Since the 1990s, China began to introduce and learn foreign research and development technology of advanced short circuit fault indicators.
l In the 20th century, people began to pay attention to the signal remote transmission of short circuit indicator. The realization of remote signal transmission breaks through the sight obstacle of overhead lines and cable equipment and extends observation distance, thus evolving into the distribution cable fault location system gradually.
l Until the 21st century, the main domestic manufacturers began to study the problem of a single-phase ground fault detection on the cable and launched some trial products successively, such as reliable earth fault passage indicators and accurate earthing short-circuiting device.
l With the rapid development of chip manufacturing technology and communication technology, digital fault indicator has appeared. This kind of indicator mainly changes the analog circuit into a single-chip microcomputer, but the signal acquisition, fault criterion, and communication technology have little change in practice. In addition to the functions of fault detection, indication, and signal remote transmission, the automated earthing and short-circuiting device can also realize signal quantization, remote control, and parameter adjustment.