DESIGN AND OPTIMIZATION OF VARIABLE FREQUENCY DRIVE SYSTEMS FOR OVERHEAD CRANES:

Abstract

This thesis examines the configuration and optimization of a variable frequency drive (VFD) system for an overhead crane to enhance its operational efficiency and reliability. The overhead crane is operated via a Telecrane remote control system and powered by a squirrel cage motor. It is equipped with two hooks: a 20-tonne hook and a 5-tonne hook. However, the 5-tonne hook was not functioning properly, resulting in downtime for the workshop operations. To address these issues, a variable frequency drive was installed, along with an AC magnetic contactor, an electromechanical relay, and two intermediate power relays. Furthermore, a brake resistor was integrated to improve deceleration, with additional cabling for the control circuit and power line to interconnect the motor and hoist, ensuring signal integrity and electromagnetic compatibility. The implementation of the VFD offers several advantages, including precise speed control, reduced mechanical stress, smoother movement, and improved energy efficiency. This study systematically documents the Variable Frequency Drive (VFD) configuration process, highlighting the integration of adaptive programming for predictive protection, dynamic braking, and intelligent load-handling strategies. The analysis evaluates performance gains, addresses implementation challenges, and outlines system-level improvements. The findings contribute to best practices for industrial VFD retrofits in crane systems, demonstrating their potential to enhance operational reliability, reduce mechanical wear, and improve energy efficiency in continuous-use workshop environments.