Conceptual design of current lead for large scale high temperature superconducting rotating machine

Abstract

High-temperature superconducting (HTS) rotating machines always require an electric current of from several hundreds to several thousand amperes to be led from outside into cold region of the field coil. Heat losses through the current leads then assume tremendous importance. Consequently, it is necessary to acquire optimal design for the leads which would achieve minimum heat loss during operation of machines for a given electrical current. In this paper, conduction cooled current lead type of 10 MW-Class HTS rotating machine will be chosen, a conceptual design will be discussed and performed relied on the least heat lost estimation between conventional metal lead and partially HTS lead. In addition, steady-state thermal characteristic of each one also is considered and illustrated.

A compactly integrated cooling system of a combination dual 1.5-MW HTS motors for electric propulsion

“…To reduce the conduction heat loss (Q c ), for a conduction cooled metal lead operating between room-temperature and cold end temperature (27 K), they are designed based on varying to different diameters. An approximate differential equation for the steady state thermal transfer per unit lead has been derived as follows [9]. Where T and A are the temperature and the cross-section at z = l, respectively, while k(T) and ρ(T) are the thermal conductivity and electrical resistivity of material at T temperature, and I is the system operating current.…”

Thermal Design of a Cryogenics Cooling System for a 10 MW-Class High-Temperature Superconducting Rotating Machine

“…For a conduction-cooled metal lead operating between room temperature and cold-end temperature, the steady state lead power differential equation over a unit lead length according to variable diameter has been derived an approximate equation [9] …”

Transient characteristics of current lead losses for the large scale high-temperature superconducting rotating machine

“…Fig. 1 shows a conceptual design of the lead have already announced [2]. It includes a metal part which has the optimal design based on numerical analysis in terms of diameter, material, and it operates from 80 and 300 K. Another a HTS part is under operation in 30 and 80 K range.…”