Calculation Of Transient Radiation Field From Enclosure Of Gas Insulated Substation

It is known that switching operation in gas insulated substation(GIS) is an important source of electromagnetic disturbances. Normal closing or opening switches can generate a very fast traveling transient wave which could damage electronic protection devices. The thin-line model and surface-patch model of the substation are created via the code of NEC and FEKO, respectively, and the transient radiation fields from the metallic enclosure of GIS due to switching operation are calculated. The vector fitting and recursive convolution are used to substitute FFT and IFFT in the progress of field calculation, which can overcome conventional problems of FFT successfully. An actual 125 kV GIS is computed and the results of calculated and measured agree well, which confirms the correctness of the method and the models. Among the comparison of computed results by thin-line model and by surface-patch model, and the measured results, it is seen that using the surface-patch model can obtain a more accurate results than the thin-line model.