Transient Voltage Unit Protection Based on Fault Information Fusion

Transient protection has the advantage of ultra-fast operation. However, traditional transient protection is susceptible to the influences of transitional resistance and the initial fault angle, resulting in issues with sensitivity and reliability under weak fault conditions. To address these issues, a new method of transient voltage protection is proposed by mining the equipment configuration information of the bus and line, as well as the frequency characteristics of the line boundary. To solve the problem that single-terminal transient line protection cannot distinguish between line fault and bus fault and the fault of adjacent line head end, a new fault feature is constructed by introducing a difference of instantaneous amplitude of the high-frequency signals between line voltage and bus voltage. To solve the problem that transient protection is susceptible to the influence of fault condition attributes, the fusion of fault characteristics with fault condition attributes results in synthetic fault characteristics, which contain fault attribute information. This approach overcame the adverse effects of fault attributes on transient protection and enhances protection reliability. Transient voltage high-frequency instantaneous amplitudes are obtained and integrated using the Variational Mode Decomposition Hilbert Transform (VMD-HT) to increase the stability of high-frequency fault signal detection. This algorithm solved the original problem of 42.2% cross-data, 41.6% false operations, and 8.9% refusal to operate. It protects both the full length of a transmission line and a busbar at the same time, with twice protection zone comparing with traditional protection. It is simpler, more reliable and more economical. Extensive ATP-Draw simulation experiments have validated the accuracy and reliability of the proposed algorithm.