Effect of Voltage Dip on the Operation of Synchronous Reluctance Motor Coupled to a Constant Torque Load

Synchronous reluctance motors (SynRM) are increasingly being considered for various application due to their rugged structure and maintenance-free operation. Considering that remote locations in India are fed by a weak power grid, it is necessary to know the consequences faced by an SynRM coupled to a constant torque load, if a sustained voltage dip (beyond the tolerable limits of the motor)occurs at the terminals of the motor. This work presents a novel analysis of the behavior of the motor when a sustained voltage dip, beyond the tolerable voltage dip margin, occurs at the motor terminals. The changes in speed, torque, current and other operating quantities after a large voltage dip occurrence, are also investigated thoroughly. This analysis is supported by simulations in MATLAB/Simulink as well as experimental results. This paper paves the way for engineers working on drives to understand and tackle the problem related to sustained voltage dips at the motor terminals, while it is driving a constant torque load.