Innovative seismic design aspects of the Intermountain Power Project Converter Stations

Seismic designer requirements for the Intermountain Power Project Converter Station at Adelanto, California, were among the most stringent ever imposed. The project design criteria for critical HVDC components called for the use of a 0.5 g design ground acceleration. A report is presented on the seismic design of two such components: the thyristor valves and the large bushings. Innovative seismic design aspects include suspension of the thyristor valves from the roof of the valve hall and installation of a gimbal device to connect the bushings to their structural supports. Both schemes seismically isolated the equipment from the severest parts of the 0.5 g seismic design spectrum