Uniform current distribution conductor of HTS power cable with variable tape-winding pitches

Mukoyama, S.; Miyoshi, K.; Tsubouti, H.; Yoshida, Taichi; Mimura, M.; Uno, Naoki; Ikeda, M.; Ishii, Hideo; Honjo, S.; Iwata, Y.

doi:10.1109/77.783532

Cited by 50 publications

(8 citation statements)

References 5 publications

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“…The main method to obtain a uniform current distribution is to alternate the inductive impedances of layers by adjusting the structural parameters of the cable conductors. The validity of this method has been verified by the experimental results of current distribution [4], [5].…”

Section: Introductionmentioning

confidence: 75%

“…The schematic view of the simulated cable is given in Fig.1. The modeling of a warm dielectric type HTS cable by an equivalent circuit as shown in Fig.2, which takes into account the resistive behaviors of the superconductor, has been presented in an earlier paper [4]. Here r i and L i are the resistance and self-inductance of the i-th layer, respectively, and M ij is the mutual inductance between the i-th and j-th layers.…”

Section: A Warm Dielectric Type Hts Cablementioning

confidence: 99%

“…Without quenching, the objective function of optimization for the warm dielectric type HTS cable is derived to find a solution for a uniform current distribution in a HTS cable conductor layer. (4) where I ix (X) and I iy (X) are the real and imaginary components of current İ i (X) in the i-th layer. İ i (X) as a function of the parameter vector X can be derived from (3).…”

Section: A Objective Functionmentioning

confidence: 99%

“…For the large current transmission, a HTS cable has a multilayer structure which consists of parallel connected tapes, twisted in each layer. Due to different inductance among layers, the currents flowing in the layers are not the same, as demonstrated by a number of experiments performed on the cable conductors [3], [4]. Hence, the control of the current distribution among layers is an important issue for design and optimization of a HTS cable conductor because it is related to current transmission capacity and power losses.…”

Section: Introductionmentioning

confidence: 99%

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Robust Optimization of Multilayer Conductors of HTS AC Cable Using PSO and Perturbation Analysis

Wang

Qiu

Zhao

et al. 2006

Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting

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For a High Temperature Superconducting (HTS) cable, a non-uniform AC current distribution among the multilayer conductors gives rise to increased AC losses. To get a uniform current distribution among the multilayer conductors, a constrained optimization model is constructed with continuous and discrete variables, such as the winding angle, radius and the winding direction of each layer. Under the constraints of the mechanical properties and critical current of the tape, the Particle Swarm Optimization (PSO) algorithm is employed for structural parameter optimization in both warm and cold dielectric type HTS cables. A uniform current distribution among layers is realized by optimizing the structural parameters. The perturbation analysis is employed to evaluate the parameters after optimization. It is found that the robust stabilizations are different among the various optimal results. The PSO is proved to be a more powerful tool than the Genetic Algorithm (GA) for structural parameter optimization. Keywords-Current distribution, high temperature superconducting (HTS) cable, particle swarm optimization (PSO), perturbation analysis.I.

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Section: Introductionmentioning

confidence: 75%

Section: A Warm Dielectric Type Hts Cablementioning

confidence: 99%

Section: A Objective Functionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Robust Optimization of Multilayer Conductors of HTS AC Cable Using PSO and Perturbation Analysis

Wang

Qiu

Zhao

et al. 2006

Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting

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“…However, one can see from Fig. 2(a) that much of the relative improvement of an optimized concentric shell conductor over a solid conductor occurs for structures with only a handful of elements, where even a brute force approach of individually matching the impedance of each shell to achieve the optimal current distribution could be implemented (similar impedance matching considerations arise in multi-layer high-T c superconducting power cables 12,13 , albeit at much lower frequencies). As shown in Fig.…”

mentioning

confidence: 99%

Optimized design of a low-resistance electrical conductor for the multimegahertz range

Kurs

Kesler

Johnson

2011

Applied Physics Letters

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We propose a design for a conductive wire composed of several mutually insulated coaxial conducting shells. With the help of numerical optimization, it is possible to obtain electrical resistances significantly lower than those of a heavy-gauge copper wire or litz wire in the 2-20 MHz range. Moreover, much of the reduction in resistance can be achieved for just a few shells; in contrast, litz wire would need to contain ∼ 10 4 strands to perform comparably in this frequency range.In this letter, we show that a structure of concentric cylindrical conducting shells can be designed to have much lower electrical resistance for ∼ 10 MHz frequencies than heavy gauge wire or available litz wires. At such frequencies, resistance is dominated by skin-depth effects, which prevent the current from being uniformly distributed over the cross section; this is typically combatted by breaking the wire into a braid of many thin insulated wires (litz wire 1 ), but the ∼ 10 µm skin depth at these frequencies makes traditional litz wire impractical (∼ 10 4 µm-scale strands). In contrast, we show that as few as 10 coaxial shells can improve resistance by more than a factor of 3 compared to solid wire, and thin concentric shells can be fabricated by a variety of processes (such as electroplating, electrodeposition, or even a fiber-drawing process 2-4 ). Good conductors at these frequencies are increasingly important, e.g. to make low-loss resonators for wireless power transfer 5,6 , or for other applications (e.g. RFID) operating at ISM (Industrial, Scientific, and Medical 7 ) frequencies (e.g. 6.78 and 13.56 MHz). We derive an analytical expression for the impedance matrix of both litz wire and nested cylindrical conductors starting from the quasistatic Maxwell equations; in particular, a key factor turns out to be the proximity losses 8 induced by one conductor in another conductor via magnetic fields. Using this result combined with numerical optimization, we are able to quickly optimize all of the shell thicknesses to minimize the resistance with a given frequency and number of shells.For a cylindrically symmetrical system of nested conductors oriented along the z direction, we first see below that Maxwell's equations reduce to a Helmholtz equation in each annular layer. In the quasistatic limit of low frequency, we show that this further simplifies into a scalar Helmholtz equation for E z alone, which can be solved in terms of Bessel functions, the coefficients of which are determined by the boundary conditions at each interface: continuity of E z and of H φ ∼ ∂E z /∂r. Once the solution for E z , and thus the current density σE z (for conductivity σ) and the magnetic fields (from Ampere's law), are obtained, the impedance matrix can be derived from energy considerations. Of course, a real wire is not perfectly cylindrical because of bending and other perturbations, but these effects can typically be neglected (e.g., if the bending radius is much larger than the wire radius).We start by analytically solving Maxwell's equations in...

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Case Study of Superconductivity Applications in Power System-HTS Cable

Wang

2013

Fundamental Elements of Applied Superconductivity in Electrical Engineering

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Uniform current distribution conductor of HTS power cable with variable tape-winding pitches

Cited by 50 publications

References 5 publications

Robust Optimization of Multilayer Conductors of HTS AC Cable Using PSO and Perturbation Analysis

Robust Optimization of Multilayer Conductors of HTS AC Cable Using PSO and Perturbation Analysis

Optimized design of a low-resistance electrical conductor for the multimegahertz range

Case Study of Superconductivity Applications in Power System-HTS Cable

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