【正文】 Most oil leaking could be attributable to bushing damage. Therefore, it is crucial to improveBushing’s aseismatic performance.SwitchgearThere were several types of damage to switchgears caused by the earthquake, such as break and collapse, body deformation, leaking of gas, mechanical failure and so on. Damage statistics on switchgears are shown in Table 2. It can be seen from the table that the main type of damage to switchgears was breaking and collapse.Table 2 Statistics on number of switchgeardamage by typeType of damageGIS252 kVCircuit252 kVBreaker126 kVDisconnector252 kV126 kVBreaking and collapse15222942Body deformation2255Leaking of gas51Mechanical failure166Others224total423314051Damage to disconnecting switches happened mostly in epicentre area with high seismic intensity. There were fewer disconnecting switches damaged in circumjacent areas.In respect of the damage to circuit breakers, it seemed to vary with types of products. There was one set of 252kV gas insulated switchgear (GIS) involved in this investigation. The earthquake just caused a bushing incline between two cubicles and the equipment was restored soon.For traditional circuit breakers, the degree of damage related closely to their structures. At the voltage level of 252 kV, the post porcelain insulators of oldtype doublebreak SF6 circuit breakers were broken widely because of heavy top (see Fig. 4). The new type of singlebreak SF6 circuit breakers were in better conditions thanks to light top, especially for some imported porcelain products (see Fig. 5). At the voltage level of 126 kV, most of the circuit breakers were damaged slightly except the oldtype ones in epicenter area where the intensity was very high. According to the investigation, most of the switchgears at various voltage levels were made of porcelain and were of openair type, so they had bad aseismatic performance. In parison, GIS and tank circuit breakers had better aseismatic performance. Therefore they can be considered as a choice in future equipment selection for earthquake areas. Bus bars and post insulatorsThere were two kinds of bus bar in the substations, that is, hard and flexible. The hard one was made of aluminum tube and aluminum conductor, and the flexible one was made of aluminum conductor. They were damaged in different ways by the earthquake. The damage relating hard bus bars was mainly breaking of solidcore post insulators (normally made of porcelain)。 for flexible bus bars, the damage was generally breaking of porcelain insulators suspending flexible bus bars. Analysis of reasons for damageSeismic fortifying criteriaOne of the main reasons for damage to transmission and substation facilities in Wenchuan earthquake was that the actual earthquake intensity exceeded the fortifying limitation set for the facilities. Also, the main earthquake lasted for a paratively longer period of time. The maximum intensity of this earthquake attained XI, but the seismic fortifying intensity set for electric facilities in this area is just VII.Generally, buildings and structures in a substation are designed and built according to a given seismic fortifying intensity, so their earthquake resisting ability is limited. In case seismic acceleration overruns the bearing capability of buildings/structures, they may be damaged.SuggestionsIn order to reduce damage to transmission and substation facilities in future earthquakes and shorten repair time, some suggestions are presented according to the investigation results.1) More detailed damage investigations and countermeasure studies should be furthered for electric facilities. Builders should record the overall details of equipment damage in all substations before reconstruction.2) All substations located on seismic belt should be evaluated for their aseismatic performance. As recorded in seismic information concerning earthquakes having happened worldwide, super earthquakes used to occur on seismic belt with a seismic intensity much higher than了fortifying limitation and extremely tremendous execution. Consequently, it is necessary to make evaluations for substation facilities in these zones.3) The earthquake reduction and isolation technology should be applied to substation project construction. By way of isolating important equipment and buildings/ structures from steadier and groundwork, their earthquake resisting ability could be greatly enhanced.4) Considering the destructibility of highvoltage porcelain equipment in earthquakes, researches should be carried out aiming at replacing porcelain with new type of high strength silicon porcelain or other fictile insulation material.5) For largescale electric equipment such as transformer and switchgear, inspection of their bushing quality should be given more attention and the equipment should be made sure to have connected firmly with the base.6) Studies on earthquake reduction and isolation technology for substation facilities should be carriedout in depth. Meanwhile, the aseismatic performance of highvoltage substation equipment should be traversed, especially for the devices with porcelain bushings or post insulators for which certain requirements should be demanded of manufacturers.7) It is remended to spotcheck porcelain devices for their earthquake resisting capability. Certain proportion of porcelain devices should be chosen as random sample on earthquake simulation platform to ensure designed aseismatic performance.8) The earthquake fortifying design criteria of key substations and line towers on seismic belt should be raised, with appropriate spare devices and spare parts being prepared.9) Emergency response mechanism should be improved for earthquake and other unexpected phone can be considered to provide for some key substations.袁節(jié)膅薂羄肅蒃薁蚃芀荿薀螆肅芅蕿袈羋膁蚈羀肁蒀蚇蝕襖莆蚇螂肀莂蚆羅