IP Library › Granted Patent US 12,531,400
Granted Patent B2
US 12,531,400 · App. 17/973,363 · Granted Jan 20, 2026

Optical profilometry on hv cable ends and on samples extracted form hv cables

Inventor: Espen Doedens (Halden, NO)
Assignee: NEXANS
H02G1/14H02G1/12
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,531,400
App. No.
17/973,363
Granted
Jan 20, 2026
Kind
B2
Abstract

A method is provided for preparing an uncovered insulation layer surface of an end section of a cable using optical profilometry, the uncovered insulation layer surface having an advantageous low roughness, a method for jointing two cables. A method is also provided for preparing a termination assembly on a cable, a cable end, a joint and a termination assembly.

Claims (24)

1 . A method for preparing a cable end of a cable for transition, wherein the cable has an electric conductor and an insulation system surrounding the electric conductor, the insulation system comprising an inner semiconducting layer, an insulating layer and an outer semiconducting layer, the method comprising:

removing the outer semiconducting layer from an end section of the cable, thereby providing an uncovered insulation layer surface on the end section of the cable; and

measuring a surface roughness of the uncovered insulation layer surface by optical profilometry and deriving a measured value of a roughness parameter for the uncovered insulation layer surface;

comparing the measured value to a preselected reference value of the same roughness parameter;

determining that the measured value is higher than the preselected reference value for the roughness parameter and that the uncovered insulation layer surface does not have an acceptable surface quality;

preparing a new uncovered insulation layer surface by one of:

cutting the end section of the cable to provide a new cable end and removing the outer semiconducting layer from the new end section of the cable, thereby providing the new uncovered insulation layer surface on the new end section of the cable; or

removing part of the insulation layer from the end section of the cable, thereby providing the new uncovered insulation layer surface;

measuring the surface roughness of the new uncovered insulation layer surface by optical profilometry and deriving a measured value of the roughness parameter for the new uncovered insulation layer surface;

comparing the measured value to a preselected reference value of the same roughness parameter; and

determining that the measured value is lower than the preselected reference value for the roughness parameter and that the new uncovered insulation layer surface has an acceptable surface quality for transition.

2 . The method according to claim 1 , wherein the surface roughness of the obtained uncovered insulation layer surface is measured in situ by use of a portable optical profilometry apparatus.

3 . The method according to claim 1 , wherein the roughness parameter is the average roughness, Sa, expressed as:

Sa=∫∫ a |Z ( x,y )| dxdy

where Z(x,y) represents a matrix of 3D coordinates on the surface, with Z expressing the local distance from the mean plane in m.

4 . The method according to claim 3 , wherein the preselected reference value for the roughness parameter Sa ref is one of: 800 nm, 600 nm, 400 nm, or 200 nm.

5 . The method according to claim 1 , wherein the roughness parameter is the unitless RMS surface slop, Sdq, expressed as:

Sdq =√{square root over (1/ A∫ 0 Lx ∫ 0 Ly (∂ Z ( x,y )/∂ x ) 2 +(∂ Z ( x,y )/∂ y ) 2 dxfy )}

where A is the area of the measurement domain in m 2 , Lx and Ly are respectively the x and y length of the investigated domain in m.

6 . The method according to claim 5 , wherein the preselected reference value for the roughness parameter Sdg ref is one of: 0.8, 0.6, 0.4, or 0.2.

7 . The method of claim 1 comprising:

jointing the end sections of the cable to an end section of a second cable having an electric conductor and an insulation system surrounding the electric conductor, the insulation system comprising an inner semiconducting layer, an insulating layer and an outer semiconducting layer.

8 . The method of claim 7 wherein an uncovered insulation layer surface is prepared at an end section of the second cables.

9 . The method of claim 8 , wherein the jointing step is realized using a pre-molded joint.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 10, 2025
From: DOEDENS, ESPEN
To: NEXANS
Reel/Frame 073177/0708 →
Priority Claims (1)
EP 21306532 · Oct 29, 2021 · regional
Continuity (1)
Related Publication 20230132865A1 · May 4, 2023
References Cited (16)
US 11404800B2 · Johansson · 2022 [cited by examiner]
US 12198326B2 · Francis · 2025 [cited by examiner]
US 20170229797A1 · Wurm · 2017 [cited by examiner]
US 20190013559A1 · Suenaga · 2019 [cited by examiner]
US 20190013560A1 · Suenaga · 2019 [cited by examiner]
JP H06178422 · 1994 [cited by applicant]
JP 2000152453A · 2000 [cited by examiner]
JP 2007124837A · 2007 [cited by examiner]
JP 2020117754A · 2020 [cited by examiner]
WO WO2012167821A1 · 2012 [cited by examiner]
WO WO2020132502A1 · 2020 [cited by examiner]
Translation of JP-2007124837-A (Year: 2007). [cited by examiner]
Translation of JP-2000152453-A (Year: 2000). [cited by examiner]
Translation of JP-2020117754-A (Year: 2020). [cited by examiner]
Doedens Espen et al: “Space Charge Accumulation at Material Interfaces in HVDC Cable Insulation Part I—Experimental Study and Charge Injection Hypothesis”, Energies, vol. 13, No. 8, Apr. 17, 2020. [cited by applicant]
European Search Report dated Apr. 7, 2022. [cited by applicant]