High-Resistance Connection Detection in Induction Motor Drives Using Signal Injection

Two new methods for high-resistance connection (HRC) diagnosis in induction motor (IM) drives are presented in this effort. These automatic offline methods are based on a signal injection strategy applied to the IM at standstill. By measuring the voltage in the machine neutral point and phase currents, it is possible to detect and isolate connection problems. Experimental results showing a good sensitivity to HRCs and immunity to symmetrical stator resistance variations were obtained in a laboratory setup.