Principle for current injection into shielded cables

Applying a current to cables under test always poses a major challenge in high-voltage technology, especially when long cable runs are involved. This is due to the coupling of the power required for testing, while taking into account the necessary insulation from the excitation circuit. Furthermore, for DC applications, it is also advisable to test with DC current, which is still very complex with current methods.

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Jessica Retzlaff

Jessica Retzlaff

Innovationsmanagerin

Details

►Testing of long cable lengths possible ►Cost-effective solution ►Compact design

We have developed a method in which the cable under test simultaneously functions as a coreless coaxial transformer, transferring the required power from the grounded shield to the inner conductor to be energized. Due to the high frequency, no core is required, which would saturate under DC current. The coaxial arrangement creates very low stray fields, allowing even very long cables to be tested. The actual energization occurs by decoupling, transforming, and rectifying the voltage in the inner conductor. This method can be used for all cable tests on shielded cables and also for testing gas-insulated cables.

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