Induction distribution of five-phase induction machines under open-phase fault

Area of Science:

• Electrical Engineering
• Electromagnetics
• Machine Design

Background:

• Five-phase induction machines offer advantages but are susceptible to unbalanced operation.
• Open-phase faults can significantly alter machine performance and lead to potential damage.

Purpose of the Study:

• To determine the airgap and iron part induction distribution in five-phase induction machines under unbalanced steady-state conditions, specifically with two opened stator phases.
• To develop and validate an analytical model for predicting these induction distributions.

Main Methods:

• Development of an analytical model based on symmetric components, incorporating third harmonic airgap induction.
• Validation of the model using two-dimensional Finite Element Analysis (FEA) and experimental data from a 5.5 kW prototype machine.

Main Results:

• The analytical model accurately predicts induction distribution in airgap and iron parts (cores, teeth) under two-phase open fault conditions.
• Significant changes in induction distribution, particularly in stator and rotor teeth, were observed due to additional harmonic components.
• FEA and experimental results closely matched the model's predictions, confirming its accuracy.

Conclusions:

• The proposed model accurately assesses induction distribution under fault conditions in five-phase induction machines.
• Altered field distribution in teeth can increase magnetic losses and create hot spots, impacting machine capacity.
• The model provides a basis for evaluating magnetic losses and load capacity during unbalanced operation.