海外水电工程主变压器相序调整实例与分析

随着我国承担的海外水电站等机电工程项目越来越多,因标准、设计和制造习惯方面存在的差异,如变压器相序和组别的不同规定,往往会导致出现已制造完成的变压器的相序、组别与当地规定不符的情况。在这种情况下,变压器能否投入系统,组别会如何变化、产生何种影响,以及如何对成品变压器的相序或组别进行变更等,都成为较大的现实问题。结合工程实际,对大型变压器相序(变更)与组别的关系、调整相序的方案比较以及方法原理等方面进行了深入的分析和探讨。分析结果表明,所采纳的改接变压器低压绕组端子联接的方式成本较高,但调整最为彻底,对工程和系统的影响也最小。

Case study of phase sequence adjustment for main transformer of oversea hydropower projects

With more and more construction of oversea hydropower stations undertaken by China, and due to the differences in standards, design and manufacture habits, the phase sequence and groups of Chinese made transformers are not complied with local requirement. To this case, it is urgent to solve the problems including whether the transformer can be put into system and what is the change of the connection and its corresponding effects, and how to change the transformer phase sequence of the manufactured product, etc. Combined with practical engineering, the relationship between phase sequence (change) and groups for large transformer, the comparison of sequence adjustment scheme, the method and principle are analyzed and discussed. The results show that the cost of the change of the terminal connecting of LV winding side is higher, but it can solve the problem completely and minimize the influence on the project and system.