SIMPLE FINITE ELEMENT SOLUTIONS FOR EDDY CURRENT LOSSES IN PIPE-TYPE CABLES

摘要

This paper outlines a simple finite element approach for computing eddy current losses in pipe-type cables Essentially, what is solved for is the eddy current loss in a metallic shell that encompasses one or more power frequency currents, flowing parallel to the longitudinal axis of the shell. The traditional cross sectional model for this type of problem involves an open boundary, which can present difficulties for conventional finite element methods, although some success has recently been reported with asymptotic boundary conditions [1]. For many practical cases, the simplest way to bypass this obstacle is to impose an approximate boundary condition, H= 0, at the outer surface of the metal shell It is demonstrated in this paper that this approximate boundary condition is quite accurate if the shell is, as a rule of thumb, at least three skin depths thick. [Vol. 10, No. 2 (1995), pp 102- 109]