Testing of High Current Transformer by Non-uniform Equivalent Magnetomotive Force Method

Abstrac t In the testing of high current transformer performance under interference from external current, it is very difficult to reproduce the high current in adjacent bus-bar or eccentric primary bus-bar. To overcome the testing difficulty, this manuscript presents an effective and simple method named as Non-uniform Equivalent Magnetomotive Force (NEMMF) Method, which uses a single non-uniformly distributed testing winding to reproduce the magnetic field from adjacent and concentric primary bus-bars simultaneously. The principle of the NEMMF method is demonstrated and proved by magnetic circuit method, and some key formulas determining the parameters of testing winding have been derived. The NEMMF method is then verified by numerical simulation using Finite Element Method (FEM).