Design method for coaxial bidirectional transmission direct-current high-temperature superconducting cable body

Abstract

The invention relates to a design method used for transmitting DC high-temperature superconducting cable body coaxially and bidirectionally, belonging to the field of power system transmission and transformation; the design method comprises the steps as follows: according to the mechanical characteristic and the radius of enwinding framework of the superconducting strips, parameters of the superconducting cable body such as the enwinding helix angle and the enwinding pitch are determined; the magnetic field distribution of all layers of superconducting cable body are determined according to the operation current, thus determining the critical current on all layers of the cable; according to the critical current and the operation redundancy, iterative calculation is carried out for operation current and the magnetic field, thus finally gaining the critical current, best operation current, enwinding layer number and number of the cables. The designed superconducting cable body increases no enwinding process difficulty and achieves bidirectional transmission of DC current; the utilization ratio of the superconducting strip critical current reaches more than 90%; the quantity and low-temperature heat loss of the superconducting cable low-temperature container are respectively reduced by half. The design method has the advantages of large transmission capability, no loss, compact structure, certain current limiting capability, stable mechanical structure, self-shielding, no electromagnetic interference and the like.

Description

technical field [0001] The invention belongs to the field of power transmission and transformation of power systems, and relates to a design method of a coaxial bidirectional transmission DC high-temperature superconducting cable body. Background technique [0002] Since the discovery of high-temperature superconductivity in the liquid nitrogen temperature region, the application of high-temperature superconducting materials in power systems has potential applications due to their zero-resistance characteristics under DC transmission conditions. Bi-based high-temperature superconducting materials have an unimpeded current transmission capability at liquid nitrogen temperature that is more than two orders of magnitude higher than that of ordinary copper conductors. Compared with traditional cables, high-temperature superconducting transmission cables have the advantages of small size, light weight, low loss, and no fire hazard. Therefore, high-temperature superconducting cab...

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Problems solved by technology

Although this design is effective for superconducting cables with fewer layers (less than 4 layers) and low current (less than 10kA), it is designed for superconducting cables with more layers, operating in the liquid nitrogen temperature zone, and currents greater than 10kA. No report

Because this design makes the engineering current density of each superconducting strip equal in principle, but the critical current of the superconducting strips on each layer is different, the critical current of the outermost layer is the smallest, and the critical current of the innermost layer is the largest. The difference between the transmission current and the critical current The ratio increases sequentially from the inner layer to the outer layer, resulting in very inefficient application of superconducting tape

This forward and reverse helix angle winding method is not optimal for high current superconducting cable designs

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