A Thermal Model for Three-Core Armored Submarine Cables Based on Distributed Temperature Sensing

Abstract

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Experimental validation of ultra-shortened 3D finite element electromagnetic modeling of three-core armored cables at power frequency

“…This results in a simulation time below 1 minute without loss in accuracy compared to larger 3D-FEM models [34]. Consequently, finer meshes and more complex models can be simulated without greatly increasing the computational requirements [35]. Moreover, ( 1) and ( 2) are applicable for any value of N, including the cases when some of the steel wires are removed (N ′ < N) or replaced by polyethylene (PE) separators (N ′ ≈ N/2, named here as half-armored cables).…”

“…Having all this in mind, this paper develops the experimental validation of the USM presented in [32][33][34][35]. To this aim, a faithful replication of previously published experimental studies on a set 10 actual TCACs, representing a wide variety of voltages, cross sections and conductor materials, has been performed.…”

“…In this sense, the use of rotated periodicity as an additional boundary condition was proposed in [29] for reducing the length of the 3D geometry to be simulated, being shorter than 2 m in most situations. Subsequent studies [30,31] proposed further improvements, reducing the length of the 3D-FEM model to the maximum in [32][33][34][35], with values as short as 2-3 cm. This ultra-shortened 3D-FEM model (USM) reduces simulation time below 1 minute without loss in accuracy compared to larger 3D-FEM models [34].…”

Induction Motor Field-Oriented Sensorless Control with Filter and Long Cable

“…The inverter and the filter are located on the oil platform while the motor and the pump are on the subsea oil exploitation, and they are connected through a 19.74 km cable. This system, analogous to what has been argued in [4], presents a series of challenges for the control system; first of all, the difficulty in carrying out measurements such as motor speed, stator current, and stator voltage. For this type of application, the state of the art involves the use of scalar control algorithms, as shown in [5], in order to avoid the use of motor realtime feedback.…”

Experimental Validation of Ultra-Shortened 3D Finite Element Models for Frequency-Domain Analyses of Three-Core Armored Cables

“…To overcome this problem, [23] proposed a shortened 3D-FEM model by including rotated periodicity as an additional boundary condition. This model was further simplified (without loss of accuracy) in [24]- [27], reducing the simulation time below 1 minute. This ultrashortened 3D-FEM model (USM) has been exhaustively faced to experimental measurements for evaluating its performance regarding relevant aspects of TCACs at power frequency, such as the series resistance, inductive reactance, induced sheath current, and zero sequence impedance [28].…”