Quench detection of HTS power cable based on wavelet analysis

With the increasing demand of the electric power capacity, the existing power transmission lines cannot satisfy with the growing demand, especially in city of crowded population. As the development of high temperature superconducting (HTS) power technology, HTS power cable provides a new solution for increasing the capacity of power transmission. However, the quench of the HTS power cable will seriously affect its safety operation. If there are no measures which detect and protect the HTS cable, the cable will be destroyed. Thus, it is significant for the detection of the HTS power cable quench. Presently, detecting the temperature, pressure and flux of HTS cable system are the main methods for quench detection. These parameters respond slowly and can not offer sufficient safety. A quench detection method based on wavelet analysis is proposed for HTS power cable in this paper. Once the voltages and currents of the HTS power cable are extracted by the oscilloscope, the signal and noise can be separated by the wavelet analysis. In this method, the harmonic interference is eliminated, which leads to the precise calculation of the phase difference. In addition, the detecting method can also improve the quench sensitivity of HTS power cable.