Electromagnetic interference with electronic apparatus by switching surges in GIS-cable system

Thyristor malignitions and protector relay failures caused by gas circuit breakers closing in the gas insulated switchgear (GIS) of a power cable system could not be controlled by reducing the ground impedance or adding surge absorbing capacitors. As a result, a study was carried out on this problem with a 66 kV mock-up apparatus installed in a factory. It was found that malignitions and failures such as those mentioned above could be controlled by preventing 10 MHz ultra high-frequency surges emitted by the GIS from leaking out into the grounding system.<
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