Ride through of the adjustable speed drive due to unsymmetrical voltage sags

Abstract

This project focuses on sensitivity of adjustable speed drive (ASD) towards voltage sags. From reading, the fact of voltage sags especially unsymmetrical can cause adjustable speed drive (ASD) performance degradation, primarily reduction of available motor torque and the occurrence of significant dc link voltage ripple. In the experimental, results and under-voltage protection limit settings related to different unsymmetrical voltage sag types. In order to determine the behaviors of adjustable speed drives (ASDs) under unsymmetrical voltage sags conditions, an experimental test-bench was set up. It consists of four major parts: a programmable power source with voltage sag generator, the ASD (AC drive) and motor as load. Final result from this project experimental has shown as positive manner. Hence, the objective of this project has been achieved and successfully obtained in the effect on motor as the load and was interpreted in the sensitive curves. The voltage sag event even of a small duration leads to the shutdown of the industrial drive and the process stops, leading to lost time, material and financial losses.