Studying Induction Motor Load Asymmetry Influence Through MCSA Method

Fault detection is very important in all types of systems. Systems’ operation monitoring allows maintenance planning and thereby reducing costs and losses. Because electrical motors are important parts of systems it is very useful to know and detect all types of failures. The paper presents the importance of electrical motor fault detection; and different technics used for its detection. These faults can appear during induction motor running and influence the whole system function and vibration. The normal functioning of the electrical motor can be influenced by several noises, which can be internal and/or external. In case of any fault the power consumption increases, the absorbed current spectrum is deformed, more heat is generated and vibrations are growing. There are several faults detection techniques, motor current signature analysis, vibration analysis, current and voltage harmonics analysis, etc. MCSA is a non-invasive method, which does not use sensors, but it monitors and analyses the stator current. Different faults lead to the appearance of different harmonics in the stator current spectrum. The paper presents how the faults distort the motor current spectrum and what faults can be detected. A measuring system is presented for monitoring the condition of the induction motor and to detect load torque asymmetry. The motor stator current spectrum is analysed in case of load torque asymmetry.