Online Detection of High-Resistance Connections in Multiphase Induction Machines

High-resistance connections in electrical machines cause unbalances in the stator resistances, reduce the efficiency, and increase the fire hazard. In this paper, the problem of detection of high-resistance connections is investigated for multiphase induction machines with an odd number of phases. The main contribution of this paper is a control scheme that can determine the stator resistance unbalance of all phases, under transient and steady-state operating conditions. The theoretical analysis and the feasibility of the control scheme are confirmed by experimental tests.