Abstract: A device (10) for measuring space charge in a high-voltage direct current electric cable includes a DC voltage source (12), a voltage step generator (14), a first electrode (16) connected to the DC voltage source (12) and to the voltage step generator (14), a second electrode (18) that is grounded, a piezoelectric sensor (20) connected to the second electrode (18), an electrical-signal amplifier (22) connected to the piezoelectric sensor (20), and at least one specimen (24) of the electric cable placed between the first and second electrodes (16, 18) and including a cut of the cable made to a predetermined depth in the electrical insulation system of the cable. The amplitude of the signal measured at the output of the amplifier (22) is related to the charge density in the specimen (24) and the delay related to the distance of the charges from the piezoelectric sensor (20) giving the position of the charges.

Abstract: A device (10) for heating and simultaneously applying a high voltage to an electric cable (12) includes the electric cable (12), an inductive transformer (14) connected to the electric cable (12), designed to heat the electric cable (12) to a first predetermined temperature, and a high-voltage transformer (16) connected between the electric cable (12) and ground, designed to apply a predetermined voltage of between 100 kV and 300 kV to the electric cable (12).

Abstract: A device (10) for applying and measuring a transient overvoltage in an electrical cable includes a test specimen representative of the electrical cable, a first DC voltage generator (DC1) designed to apply a predetermined DC voltage to the specimen, and a second DC voltage generator (DC2) designed to apply a predetermined overvoltage to the specimen. The device also has a high-voltage switch (12) that is connected to the second DC voltage generator (DC2) and is designed to convert the predetermined overvoltage into a square-wave voltage, a control resistor (R2) designed to monitor the voltage rise time of the specimen, and a decoupling capacitor (C1) designed to monitor the overvoltage fall time in the specimen.

Abstract: This power cable junction (10) has an end part of a power cable which has an electrically insulating material (122). The junction (10) has a predetermined region containing a module for measuring the space charge of the insulating material (122).

Abstract: An electrical cable (100, 101) includes at least one elongated electrical conductor (1), at least one protective element (4, 41, 42) surrounding the elongated electrical conductor (1), and at least one filling compound (5) surrounded by said protective element (4, 41, 42). The filling compound (5) has more than 20.0% by weight of a mineral oil, relative to the total weight of the filling compound, and at least one nanofiller.

Abstract: This power cable junction (10) has an end part of a power cable which has an electrically insulating material (122). The junction (10) has a predetermined region containing a module for measuring the space charge of the insulating material (122).