Measuring Method for Strand Current of Stator Bars Based on Search Coils.

It is very important to uniform the strand current in stator bars’ design of a large generator. As the stator bars are made of several parallel strands that are closely adjacent to one another, the strand current cannot be measured by straight-through current transformer. In order to measure the strand current without changing the structure of the stator bar, a measuring method for strand current of stator bars based on the superposition magnetic field measurement surround the strand by using search coils is proposed in this paper. The optimal position assembly is determined by the structure and the magnetic field of the stator bar in end region. The leakage magnetic field surrounding the measuring position is measured by search coils, and the strand current is solved by the algorithm of least square error function. The correctness of this method is verified by comparing with the result of current transformers. This measuring method not only provides an evaluation basis for the transposition design of stator windings in large generators but also provides a technical support for the current measuring of adjacent transmission lines and large capacity parallel cables. [ABSTRACT FROM AUTHOR]