System overview
The system is a distributed monitoring, centralized management and instant notification mode with long-distance transmission capability. The background fault location software cooperates with the on-site fault detection and indication device. When the system is working normally, the overhead intelligent fault indicator will send the line load, voltage, working power and other information to the data forwarding station through short-distance wireless transmission; when the line has fault, the overhead intelligent indicator will automatically identify and judge according to the collected waveform signal, and will The information is transmitted to the nearby overhead intelligent data forwarding station. After receiving the information, the overhead intelligent data forwarding station performs zero sequence synthesis and data storage, and transmits the data to the master station through the built-in wireless public network module. In a few minutes after the fault occurs, the location and time of the fault can be displayed accurately. At the same time, the fault location results can be forwarded to the designated person's mobile phone number to help the maintenance personnel rush to the site, eliminate the fault, restore the normal power supply, improve the reliability of power supply, at the same time, greatly reduce the fault line patrol personnel and improve the work efficiency.
system function
■ realize the fast search and location of faults, reduce the time of fault inspection and troubleshooting;
■ realize line load current monitoring, line waveform acquisition and automatic identification and judgment to meet the basic requirements of distribution network operation management.
System characteristics
■ the fault detection method is accurate and reliable: using full digital waveform level digital signal processing technology to identify short circuit and ground fault is more accurate and reliable than the method based on analog circuit for fault detection. The self-adaptive method is used for short-circuit fault diagnosis, which can automatically calculate and set fault current according to the load current. In case of ground fault, the device can collect the fault information and waveform locally, transmit the fault information and waveform to the master station for judgment, receive the fault data information sent by the master station, and indicate the fault locally in the form of flash.
■ improve the judgment of single-phase ground fault: when single-phase ground fault occurs, the acquisition unit can realize three-phase synchronous wave recording and send it to the collection unit to synthesize zero sequence current waveform for the judgment of ground fault. At the same time, combined with the big data analysis function of the main station, the analysis and comparison of the whole network can be realized, thus greatly improving the accuracy of single-phase ground fault detection and judgment.
■ wide range of application: it can not only detect the fault of the small current grounding system, but also the fault of the small resistance grounding system, making it more suitable for China's current distribution network with the constantly changing network, avoiding the waste of investment due to frequent changes in the connection mode of the power supply network.
Scope of application
■ automation construction mode of distribution network in small and medium-sized cities and counties;
■ transformation of overhead radiation line or line branch of urban distribution automation;
■ application area: Class A / B / C / D / power supply area