| Popis: |
Transformers are one of the most essential electrical equipment in a substation, assessing their seismic withstand capacity is of great significance to sustain the normal function of substation. To evaluate the earthquake resistance performance of a 500 kV transformer, a finite element model of a whole transformer system composed of tank, turrets and bushings was first established. And dynamic properties and time history analysis were carried out to find its most vulnerable points. Then seismic vulnerability analysis can be conducted using the incremental dynamic analysis (IDA) method. Results show that the dynamic amplification of the tank and turret to the bushing is much larger than the threshold of 2.0 specified in the relevant codes, and the root section of the high voltage (HV) bushing is the most vulnerable and it is not likely to be acceptable for the ground motions with a peak ground acceleration (PGA) of 0.3 g, which is even less than the local fortification intensity. Therefore, the influence of transformer tank and turrets can not be ignored when evaluating the seismic performance of a transformer bushing, and some retrofitting measures should be taken to enhance their seismic withstand capacity. |
