Influences of Transient Electromagnetic Fields on Control Cables in a Gas-Insulated Substation Due to Switching Operations

The transient electromagnetic fields during switching operation in gas-insulated substations (GIS) have rise times of nanoseconds. These fields leak into the external environment through the discontinuities of gas-insulated modules and affect on control cables and lead to induce transient voltage in cables which result in malfunctioning of equipment. Amplitudes of the electrical and magnetic fields could be a few tens of kilovolts per meter and a few hundreds of amperes per meter according to layout of gas-insulated substations, respectively.In this paper, the induced voltage in a control cable and induced current in its sheath in a gas-insulated substation with rated voltage of 245 kilovolts were calculated. Also, the effect of cable's length and type of cable sheath grounding on the induced current will be calculated.