Numerical simulations of electromagnetic behavior in CORC cable based on a modified <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mrow> <mml:mi>H</mml:mi> </mml:mrow> </mml:mrow> <mml:mo>−</mml:mo> <mml:mi>ϕ</mml:mi> </mml:math> formulation
Shouhong Shan, Sijian Wang, Huadong Yong, Youhe Zhou
Abstract
Abstract Alternating current (AC) losses have an important effect on the stable operation of high-temperature superconductors (HTSs). Researchers have proposed many formulations to estimate AC losses based on finite element methods, such as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="bold">T</mml:mi> </mml:mrow> </mml:mrow> <mml:mo>−</mml:mo> <mml:mrow> <mml:mrow> <mml:mi mathvariant="bold">A</mml:mi> </mml:mrow> </mml:mrow> </mml:math> formulation, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="bold">H</mml:mi> </mml:mrow> </mml:mrow> </mml:math> formulation and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="bold">H</mml:mi> </mml:mrow> </mml:mrow> <mml:mo>−</mml:mo> <mml:mi>ϕ</mml:mi> </mml:math> formulation. In this paper, in order to simulate complicated multi-layer conductor on round core (CORC) cable with transport current, a modified <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="bold">H</mml:mi> </mml:mrow> </mml:mrow> <mml:mo>−</mml:mo> <mml:mi>ϕ</mml:mi> </mml:math> formulation is proposed to calculate AC losses in complicated HTS structures. The formulation, which is easy to implement and has fast computation speed, is verified by comparing the calculation results with the existing formulations and experiments. The electromagnetic behavior of CORC cables and a helical coil wound by a three-layer CORC cable is investigated with a modified <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="bold">H</mml:mi> </mml:mrow> </mml:mrow> <mml:mo>−</mml:mo> <mml:mi>ϕ</mml:mi> </mml:math> formulation. The numerical results show the non-uniformity of the losses and currents in the different layers of the CORC cable. Furthermore, the effects of the external magnetic field on the distribution of the transport current are also discussed.