Single Phasing Effects on the Behavior of Three-Phase Induction Motor

Abstract

The output of three-phase induction motors (3IM) is adversely affected by voltage imbalance. This work analyzes and estimates the output of a 3PIM operating on a balanced supply while contrasting it with a "single phasing" case. Simulation additionally makes use of MATLAB /SIMULINK. The effects of single phasing on a 3PIM's performance for system rerating are suggested. An example was given using a 4 kW 3PIM. It is not a big problem; however, it should be considered if a three-phase motor is purposely connected to a single-phase source or whenever a three-phase source loses one of its phases due to a fault. When a three-phase motor operates in a single-phase, the motor will continue to try to run the load until it is destroyed or the protective components remove the motor from the line. The outcome of single phasing is an increase in phase currents, which causes overheating and damage to the motor. A downline on the distribution grid or a blown pole upper fuse might cause a phase loss on a three-phase line. A single-phase overload condition that causes one fuse to blow or a device breakdown inside the end-user facility may also result in a single-phase loss.

Keywords

• IMs, Single phasing, Voltage unbalance, Torque, Negative sequence, Positive sequence