Investigating the effects of faulty induction machine in distribution systems

Abstract

In addition to its use as the workhorse in the industry, induction machines are fast gaining popularity in renewable energy applications, hence; the need for continual study on the performances of the machines. In this work, a phase frame analysis of a distribution system that feeds single-phase loads and a three-phase induction motor was implemented with the aim of investigating the effects on the distribution system, of an open-circuit fault that occurs in any of the phases of the stator winding of the motor. The IEEE 4-node test feeder was employed for the study and the phase impedance matrices for all the system components of the feeder determined. A programme based on MATLAB code was employed for the analysis that was done for both the healthy and the unhealthy operating conditions of the machine. Based on a specified voltage tolerance value of 0.00001 V, the simulation converged after five iterations giving relatable and reasonable result. The result showed that an open-circuit fault in any of the three phases of the induction machine resulted in high voltage imbalance that get worsened with increase in single-phase loads connected to the system. It is recommended that the machine be disconnected from the distribution network once such a fault is detected.

Keywords

• Induction machine
• phase frame analysis
• Phase impedance matrix
• Phase-open-circuit