Method and a device for space-charge measurement in cables using a pulsed electroacoustic method

摘要

A method for space-charge measurement in a coaxial cable comprising an inner conductor (2), a cable screen (3) and an electric insulation (4) between the inner conductor and the cable screen, wherein the cable screen is removed on both sides of a measurement region, an electric voltage pulse is generated by an electric pulse generator (10) and is applied over part of the insulation (4) of the cable within the measurement range, an acoustic signal, in the presence of space charges in the cable insulation, is generated by the voltage pulse in cooperation with the space charges and a possible acoustic signal is recorded by a sound-recording device (8). A grounded annular outer electrode (7) is applied around the measurement region, the sound-recording device is arranged in direct contact with the annular outer electrode, the voltage pulse is applied to the cable screen on both sides of the measurement region and is connected, via the impedance of the cable, to the inner conductor of the cable.