Evaluation of Seismic Behaviour of High Voltage Switchgear Panel by Shake Table Testing

Switchgear and controlgear plays a vital role in electrical power distribution system. Switchgear and controlgear are designed for electrical performance requirements including short circuit, temperature and humidity environmental conditions. But design aspects due to a seismic event are usually not taken into consideration. Earthquake shock waves causes vigorous ground shaking which are three dimensional in nature. Past-earthquake records have revealed that electrical equipment are vulnerable to seismic event, this lead to an increased focus on the earthquake performance evaluation of electrical equipment. Dynamic loading due to earthquake should be considered at the design stage in addition to other performance parameters. Designing switchgear for earthquake loading and validating design by testing can ensure uninterrupted and safe power supply during crucial time of post-earthquake rescue operations. In case of metal enclosed switchgear, functioning of equipment during and after seismic event is the major concern. Malfunctioning due to breaking or loosening or deformation of components, loss of output due to open circuit or short circuit and spurious operation of protective relays are observed during past seismic events. Central Power Research Institute (CPRI) is equipped with stateof- the-art tri-axial shake table facility for simulating true earthquake vibration. Seismic performance evaluation of high voltage switchgear by shake table method is presented in this paper.