Calculation of Frequency-Dependent Parameters of Pipe-Type Cables: Comparison of Methods

In this paper the results of four analytical methods for the calculation of frequency-dependent parameters of pipe-type cables are compared. Method 1 is Ametani´s method, which neglects proximity effects among conductors and assumes that the pipe has infinite thickness. Method 2 is a proposed method that takes proximity effects into account and assumes that the pipe has infinite thickness. Method 3 is also a proposed method, but neglects proximity effects among conductors and assumes that the pipe has finite thickness. Method 4 is Kane´s method, which takes proximity effects into consideration and assumes that the pipe has finite thickness. With respect to Kane´s method, the results obtained from the three first methods yield relative errors as high as 95 %, particularly at low frequencies