VOLTAGE DIPS RIDE THROUGH TECHNIQUES FOR SYNCHRONOUS MOTORS

Although synchronous motors are widely used in large industries, the reliability of its mains supply or excitation control supply is not always guaranteed. Moderate variations in voltage will cause those motors to trip, consequently, causing huge losses to the end users that are possible to ride through and mitigate. Voltage dips are often caused by the electrical utility supply company. Voltage dips then propagate in the electrical grid to the end user and negatively affect the performance of such motors making those vulnerable. Based on practical developments, this paper will identify and review necessary techniques for synchronous motors to ride through voltage dips of different magnitudes and durations. Techniques will include increasing motor's shaft kinetic energy, optimal utilization of the excitation system capabilities, sound management of the motor protection scheme besides under voltage settings and supplying critical components from an Uninterruptible Power Supply ( UPS) system ... etc. The paper indicates that the performance of synchronous motors during severe voltage dips will also improve significantly. Robust operation can be achieved consistently with international standards, specifications and design. Based on technological advances in the construction of synchronous motors and manufacturing of semiconductor components, directions of further enhancement researches and ride through capabilities are suggested.