Measuring Method for Strand Current in Formed-Parallel Coil of Flat-Wire Motor Based on Hall Sensors

Formed-parallel coil is a new stator coil type of flat-wire motor. It is designed to reduce the eddy current loss in the stator coil and decrease the difficulty of coil production. In the experiments, it can only detect the total current of each stator coil instead of the current distribution of each strand. Aiming to solve the problem, this paper proposes a strand current measuring method based on Hall sensors without destroying the coil structure. The end leakage magnetic field (ELMF) and strand current are analyzed by finite element solution (FEM). The relationship between the strand currents, ELMF and Hall output signal is derived. The coil strand current test platform is built and the experimental verification is carried out by a 15 kW flat-wire motor. The result shows that the current measuring method can measure the current distribution in the strands accurately. It provides an experimental evaluation basis for analyzing the reasonableness of the strand current distribution and the design of the formed-parallel coil.