Substructured dynamic testing of substation disconnect switches

The paper demonstrates the substructuring concept in seismic qualification testing of 550 kV electrical substation disconnect switches. In this study, the full and substructured (i.e., without support structure) switches are tested on a six degrees of freedom (DOFs) shaking table. Different combinations of translational and rotational excitations are obtained from full switch tests and used in the substructured ones. The behavior of the post insulators of the switches are compared to demonstrate validity and identify limitations of the substructuring concept applied to electrical substation equipment. From this comparison, critical DOFs for the response of post insulators in switches supported on flexible structures are identified. It is concluded that the in-plane and out-of-plane behavior of the investigated post insulators are uncoupled. The substructured tests driven by combined translational and rotational signals showed the best match with the full switch tests because the out-of-plane rotations contribute significantly to the response of the post insulators.