An Improved Method for Diagnosis of Induction Motor Load Mechanical Unbalance Fault Using Current Signal Analysis

Most induction motor problems are due to load instabilities. Load problems mainly influence on system mechanical properties. Therefore, it is preferred to detect these problems using mechanical sensors (e.g. accelerometer, velocity sensor, etc.). However, all motors and loads are not accessible, and remote monitoring of systems can be helpful. Motor current signature analysis (MCSA) is a remote monitoring method that has developed recent years. The aim of the current paper is to evaluate the ability of MCSA to detect centrifugal fan faults. It tries to show how to distinguish between unbalanced load and other types of induction motor unbalances based on MCSA method. In the current study, condition monitoring methods are improved by reformulating the current equations. These results come from a large research with the objective population of 60 induction motors in the alloy steel industry and here three case studies are used to check the theoretical results.