利用改进的相量图判定三相变压器的联结组别

Connection Group Identification of Three-Phase Transformers with Improved Phasor Diagram

在电力系统中,当变压器的容量不足时,通常会采用两台或两台以上的变压器并联运行。变压器并联运行必须满足的一个严格条件就是,并联的变压器联结组别必须一致,否则会出现严重的环流,因此准确判断变压器的联结组别至关重要。变压器联结组别判定是电类专业学生必须学习的知识,同时也是中级工、高级工、技师和高级技师认定考试的重点内容。判定联结组别时,文献资料上有的采用电压相量、有的采用电势相量,首末端的符号和相量图的画法也不尽相同,增大了学习难度。文章将改进的相量图下标与变压器的绕组实际联结关系一一对应,由浅入深,叙述判定过程,降低了难度,取得理想的教学效果。

In the power system,two or more transformers tend to be used to operate in parallel when the capacity of a transformer is insufficient.A crucial requirement for parallel operation of transformers is that the connection groups of parallel transformers must be consistent,otherwise serious circulation will occur.Therefore,it is very important to accurately identify the connection groups of transformers.Transformer connection group identification is what the students majoring in electricity must learn,and also the key content of the certification examination for intermediate workers,senior workers,technicians and senior technicians.When deciding the connection group,voltage phasor and potential phasor can be found in the literature.The symbols and phasor diagram of the head and the end are also different,which increases the difficulty for learning.In teaching and training,the author corresponds the improved phasor diagram to the actual winding connection of the transformer,starting with the easy part of the identification process and then going deeper,which achieves satisfactory results.