Recent technical development of site-assembly transformer

The costs of transporting large-capacity transformers have steeply increased due to transportation limitations, which are becoming more severe every year as a result of site-acquisition difficulties. The transportation limitation is one of the most important factors of designing a transformer. In case of strictly transportation limitation, the disassembled transportation system of the first generation was applied to transformers in 1950s, furthermore special three phase subdivided type was applied after 1960s. After 1990s, Toshiba has developed the disassembled transportation system of the second generation, the epoch-making ASA (Advanced Site Assembly) transformer to reduce such problem related to transportation restrictions. The core, windings, and tank of ASA transformer can be separated into transportable units conveyable by an ordinary low-bed trailer. Therefore, the core erecting process was eliminated at site and shortening of local assembly time was realized. The paper introduces the composition of the ASA transformer, the actual manufacturing experience and the application effect and a future view.