High-Temperature Superconducting Cable Fault Location Method Based on Improved Time-Frequency Domain Reflection Method and EEMD Noise Reduction

Aiming at the operation and maintenance requirements of the fault location of high-temperature superconducting cables, a fault location method of high-temperature superconducting cables based on the improved time-frequency domain reflection method and EEMD noise reduction is proposed. Considering the cross-term interference problem in the traditional time-frequency domain reflection method, this paper introduces the affine transformation to project the time-frequency distribution of the self-term and the cross term and further highlights the characteristic differences between the two through coordinate transformation, and the particle swarm algorithm is employed to solve the optimal stagger angle of the affine transformation. The unscented particle filter is adopted to separate the cross term, and EEMD noise reduction is introduced to solve the signal noise problem. Finally, two software programs, PSCAD and MATLAB, are employed for joint simulation to build a model of high-temperature superconducting cable. The simulation example shows that the proposed method in this paper can eliminate the cross-term interference of the traditional time-frequency domain reflection method, effectively locate the fault of the high-temperature superconducting cable, and improve the positioning accuracy.

Application of distributed optical control technology in ship power systems

The article considers the point sensor technology for onshore power systems, which has a significant potential in providing new and effective solutions for monitoring and protecting marine electrical systems. These technologies can reduce the risk levels associated with marine electrical systems by providing comprehensive monitoring and protection functions that benefit from the distributed nature of the metering system. There has been described a system that consists of a data collecting device with optical fiber to collect multiple readings from a distributed passive array of sensors connected along a fiber length up to 100 km (applicable for any marine systems). There have been illustrated the variants of distributed monitoring and protection system in marine electrical systems. It has been stated that in the advanced marine systems there are used all-electric propulsion systems that distribute electricity between the ship's propulsion plants and other consumers. The power distribution has been proved necessary to rise efficiency, controllability, flexibility and cost of the system. Application of the new DC systems with zoned architecture, the emergence of batteries and other forms of power storage, and studying the superconducting cables and machines add to the importance of having knowledge of system operability and timely and safe response to failures and damages of the system.