When using traveling wave technology to achieve fault location, why does the main center-server still need to participate in logical calculations and rely entirely on traveling wave terminals to complete the application of fault location

1、 The particularity of the distribution network determines that it is very difficult to rely solely on terminals to achieve The current situation of the distribution network has a wide coverage, varying lengths of lines, many branches, mixed coexistence of overhead and buried cables, and constantly changing operating conditions. These conditions result in relying entirely on terminals to complete fault location in such complex and changing situations, and relying solely on traveling wave terminals to make incorrect judgment results. These external complex situations seriously affect the correctness of the judgment. 2、 The variability of operating modes has affected the correct diagnosis of faults The dynamic operation mode changes of the distribution network interconnection switch switching, load transfer, and line maintenance, resulting in real-time changes in the topology structure and parameters. It relies entirely on various on-site terminals and cannot perceive the changes in the operation mode of the entire network in real time. It is necessary to rely on the SCADA system in the main center-server to update the topology model and operation parameters in real time, and dynamically adjust the calculation strategy during traveling wave analysis. With the help of the main center-server system, it is more convenient to perform correlation calculations on the traveling wave terminals involved in the fault, which simplifies the calculation and improves the accuracy of fault location. 3、 Various resources of traveling wave terminals are limited, and some complex algorithms are difficult to implement The traveling wave terminal itself is limited by size, power consumption, cost, computing power, and storage resources, and cannot complete complex traveling wave signal analysis algorithms (such as wavelet transform, spectrum analysis, and traveling wave head recognition). The traveling wave terminal only needs to complete the acquisition of traveling wave signals, simple calculations, and upload to the main center-server, reducing the hardware cost and operation difficulty of the terminal. The main center-server system has high-performance computing resources and can run complex logical algorithms. It can perform various complex calculations on the collected traveling wave waveform data, including precise identification of wave heads, accurate calculation of time differences, and storage of historical fault data for subsequent analysis and algorithm optimization. 4、 Combining traveling wave data with grid topology structure to improve the accuracy of traveling wave positioning The special situation of the distribution network directly leads to the occurrence of faults. During the transmission of traveling wave signals, multiple traveling wave terminals will collect traveling wave signals and reflected waves. The traveling wave at the fault point propagates along the line to both ends, and may be reflected or refracted by branch lines, transformers, and other equipment, resulting in multiple terminals (such as FTUs and traveling wave acquisition terminals) collecting multiple sets of traveling wave signals. These signals may have various problems such as asynchronous timestamps, amplitude attenuation differences, and confusion between reflected waves and initial waves. Traveling wave terminals can only collect signals from their own measurement points and cannot determine the source and correlation of the signals. The main center-server can collect the traveling wave data from all network terminals, and perform signal screening, redundancy elimination, and authenticity identification through logical calculations to distinguish between fault initial traveling waves, reflected traveling waves, and interference waves, avoiding misjudgment by individual terminals. 5、 Integrate multiple devices and data information to complete logical verification of fault location The logic verification of fault location and cross system linkage distribution network fault location are not independent links, and need to be linked with fault recording, protection action, and SCADA system verification. The main center-server can integrate multi-source data such as traveling wave positioning results, protection action information, and switch status changes, and perform cross validation through logical calculations. Whether the fault point of traveling wave positioning is within the range of protection action, and whether the switch tripping time matches the arrival time of the traveling wave, thereby improving the reliability of the positioning results. In addition, the main center-server can directly send the positioning results to the operation and maintenance system to guide on-site repairs and achieve closed-loop management of "fault location operation and maintenance dispatch"; If relying solely on terminals, it is impossible to achieve cross system data linkage and business closure.