On-line monitoring of electrical power quality for assessment of induction motor performance

The performance of three-phase induction motors can be severely affected by poor power quality supply, decreasing their efficiency and their life expectancy. Voltage unbalance, voltage magnitude deviation and voltage distortion are the electrical power quality disturbances that most affect the performance of these motors. This paper presents a low-cost virtual measurement instrument for on-line monitoring of the quality of voltage supply in a three-phase low-voltage distribution system. Voltage unbalance factor, voltage deviation magnitude, harmonic voltage factor and subharmonic voltage components are continuously monitored for assessment of three-phase induction motor performance.